@article{thorlund_inappropriate_2020,
	title = {Inappropriate opioid dispensing in patients with knee and hip osteoarthritis: a population-based cohort study},
	volume = {28},
	issn = {1522-9653},
	shorttitle = {Inappropriate opioid dispensing in patients with knee and hip osteoarthritis},
	url = {https://doi.org/10.1016/j.joca.2019.10.004},
	doi = {10.1016/j.joca.2019.10.004},
	abstract = {OBJECTIVE: To estimate inappropriate opioid dispensing in patients with knee or hip osteoarthritis (OA) defined as (1) dispensing of opioids within the first year of diagnosis or (2) long-term opioid use.
DESIGN: Data from Skåne Healthcare Register was linked with the Swedish Prescribed Drug Register. Incidence proportion of dispensed opioids within first year of incident knee or hip OA diagnosis was determined in knee (n = 399,670) and hip (413,216) OA cohorts without a history of OA. The 1-year period prevalence of long-term opioid dispensing was determined in a prevalence cohort (n = 48,574 with knee and/or hip OA and n = 457,587 without OA). The proportion of OA patients with excess opioid dispensing attributable to OA was estimated using inverse probability weighted regression adjustment.
RESULTS: In the incident cohorts, 5866 and 2359 developed knee and hip OA, respectively. Within the first year after OA diagnosis 14.7\% patients with knee OA and 20.7\% with hip OA had an opioid dispensed. The estimated inappropriate dispensing attributable to OA was 7.4\% (95\% CI 6.5-8.4) for knee OA and 12.8\% (95\% CI 11.1-14.4) for hip OA. Among persons with prevalent knee, hip or knee and hip OA inappropriate, long-term opioid use attributable to OA was 1.3\%, 2.0\% and 2.4\% of, respectively.
CONCLUSIONS: More than half the incident opioid dispensations to patients within their first year after knee or hip OA diagnosis are inappropriate according to current treatment guidelines. Furthermore, 2\% of patients with prevalent knee or hip OA have inappropriate long-term dispensing of opioids.},
	language = {eng},
	number = {2},
	journal = {Osteoarthritis and Cartilage},
	author = {Thorlund, J. B. and Turkiewicz, A. and Prieto-Alhambra, D. and Englund, M.},
	year = {2020},
	pmid = {31669311},
	keywords = {Analgesics, Epidemiology, Opioids, Osteoarthritis, Pain, Pharmacology},
	pages = {146--153},
}

OBJECTIVE: To estimate inappropriate opioid dispensing in patients with knee or hip osteoarthritis (OA) defined as (1) dispensing of opioids within the first year of diagnosis or (2) long-term opioid use. DESIGN: Data from Skåne Healthcare Register was linked with the Swedish Prescribed Drug Register. Incidence proportion of dispensed opioids within first year of incident knee or hip OA diagnosis was determined in knee (n = 399,670) and hip (413,216) OA cohorts without a history of OA. The 1-year period prevalence of long-term opioid dispensing was determined in a prevalence cohort (n = 48,574 with knee and/or hip OA and n = 457,587 without OA). The proportion of OA patients with excess opioid dispensing attributable to OA was estimated using inverse probability weighted regression adjustment. RESULTS: In the incident cohorts, 5866 and 2359 developed knee and hip OA, respectively. Within the first year after OA diagnosis 14.7% patients with knee OA and 20.7% with hip OA had an opioid dispensed. The estimated inappropriate dispensing attributable to OA was 7.4% (95% CI 6.5-8.4) for knee OA and 12.8% (95% CI 11.1-14.4) for hip OA. Among persons with prevalent knee, hip or knee and hip OA inappropriate, long-term opioid use attributable to OA was 1.3%, 2.0% and 2.4% of, respectively. CONCLUSIONS: More than half the incident opioid dispensations to patients within their first year after knee or hip OA diagnosis are inappropriate according to current treatment guidelines. Furthermore, 2% of patients with prevalent knee or hip OA have inappropriate long-term dispensing of opioids.

@article{struglics_molecular_2020,
	title = {Molecular and imaging biomarkers of local inflammation at 2 years after anterior cruciate ligament injury do not associate with patient reported outcomes at 5 years},
	volume = {28},
	issn = {1522-9653},
	url = {https://doi.org/10.1016/j.joca.2019.12.010},
	doi = {10.1016/j.joca.2019.12.010},
	abstract = {OBJECTIVE: To estimate the association between molecular or imaging inflammatory biomarkers at 2 years after anterior cruciate ligament (ACL) injury and patient-reported outcomes at 5 years.
METHODS: For 116 ACL-injured patients, molecular biomarkers of inflammation (synovial fluid and serum cytokines) and Hoffa- and effusion-synovitis as visualized on magnetic resonance imaging (MRI) were assessed 2 years post-injury. Knee injury and Osteoarthritis Outcome Score (KOOS) and SF-36 were assessed at 2 and 5 years. We used multiple imputation to handle biomarker values that were below the level of detection or missing, and linear regression for statistical analyses.
RESULTS: None of the synovial fluid cytokines or imaging biomarkers of inflammation at 2 years were associated with any of the patient-reported outcomes at 5 years. With each log10 unit higher of serum tumor necrosis factor concentration the knee-related quality of life of KOOS was increased (i.e., better outcome) by 35 (95\% confidence interval 7 to 63) points. No other serum biomarker measured at 2 years was associated with patient-reported outcome at 5 years.
CONCLUSION: Local joint inflammation assessed by biomarkers in synovial fluid and Hoffa- and effusion-synovitis on MRI at 2 years after an ACL injury did not associate with patient-reported outcomes at 5 years. Thus, chronic inflammation in the ACL-injured knee, as reflected by the biomarkers studied here, seems not to be a key determinant for the long-term patient-reported outcomes.},
	language = {eng},
	number = {3},
	journal = {Osteoarthritis and Cartilage},
	author = {Struglics, A. and Turkiewicz, A. and Larsson, S. and Lohmander, L. S. and Roemer, F. W. and Frobell, R. and Englund, M.},
	year = {2020},
	pmid = {31940458},
	keywords = {Anterior cruciate ligament injury, Biomarkers, Inflammation, Patient reported outcomes, Synovitis},
	pages = {356--362},
}

OBJECTIVE: To estimate the association between molecular or imaging inflammatory biomarkers at 2 years after anterior cruciate ligament (ACL) injury and patient-reported outcomes at 5 years. METHODS: For 116 ACL-injured patients, molecular biomarkers of inflammation (synovial fluid and serum cytokines) and Hoffa- and effusion-synovitis as visualized on magnetic resonance imaging (MRI) were assessed 2 years post-injury. Knee injury and Osteoarthritis Outcome Score (KOOS) and SF-36 were assessed at 2 and 5 years. We used multiple imputation to handle biomarker values that were below the level of detection or missing, and linear regression for statistical analyses. RESULTS: None of the synovial fluid cytokines or imaging biomarkers of inflammation at 2 years were associated with any of the patient-reported outcomes at 5 years. With each log10 unit higher of serum tumor necrosis factor concentration the knee-related quality of life of KOOS was increased (i.e., better outcome) by 35 (95% confidence interval 7 to 63) points. No other serum biomarker measured at 2 years was associated with patient-reported outcome at 5 years. CONCLUSION: Local joint inflammation assessed by biomarkers in synovial fluid and Hoffa- and effusion-synovitis on MRI at 2 years after an ACL injury did not associate with patient-reported outcomes at 5 years. Thus, chronic inflammation in the ACL-injured knee, as reflected by the biomarkers studied here, seems not to be a key determinant for the long-term patient-reported outcomes.

@article{wijn_arthroscopic_2020,
	title = {Arthroscopic meniscectomy versus non-surgical or sham treatment in patients with {MRI} confirmed degenerative meniscus lesions: a protocol for an individual participant data meta-analysis},
	volume = {10},
	issn = {2044-6055},
	shorttitle = {Arthroscopic meniscectomy versus non-surgical or sham treatment in patients with {MRI} confirmed degenerative meniscus lesions},
	url = {https://doi.org/10.1136/bmjopen-2019-031864},
	doi = {10.1136/bmjopen-2019-031864},
	abstract = {INTRODUCTION: Arthroscopic partial meniscectomy (APM) after degenerative meniscus tears is one of the most frequently performed surgeries in orthopaedics. Although several randomised controlled trials (RCTs) have been published that showed no clear benefit compared with sham treatment or non-surgical treatment, the incidence of APM remains high. The common perception by most orthopaedic surgeons is that there are subgroups of patients that do need APM to improve, and they argue that each study sample of the existing trials is not representative for the day-to-day patients in the clinic. Therefore, the objective of this individual participant data meta-analysis (IPDMA) is to assess whether there are subgroups of patients with degenerative meniscus lesions who benefit from APM in comparison with non-surgical or sham treatment.
METHODS AND ANALYSIS: An existing systematic review will be updated to identify all RCTs worldwide that evaluated APM compared with sham treatment or non-surgical treatment in patients with knee symptoms and degenerative meniscus tears. Time and effort will be spent in contacting principal investigators of the original trials and encourage them to collaborate in this project by sharing their trial data. All individual participant data will be validated for missing data, internal data consistency, randomisation integrity and censoring patterns. After validation, all datasets will be combined and analysed using a one-staged and two-staged approach. The RCTs' characteristics will be used for the assessment of clinical homogeneity and generalisability of the findings. The most important outcome will be the difference between APM and control groups in knee pain, function and quality of life 2 years after the intervention. Other outcomes of interest will include the difference in adverse events and mental health.
ETHICS AND DISSEMINATION: All trial data will be anonymised before it is shared with the authors. The data will be encrypted and stored on a secure server located in the Netherlands. No major ethical concerns remain. This IPDMA will provide the evidence base to update and tailor diagnostic and treatment protocols as well as (international) guidelines for patients for whom orthopaedic surgeons consider APM. The results will be submitted for publication in a peer-reviewed journal.
PROSPERO REGISTRATION NUMBER: CRD42017067240.},
	language = {eng},
	number = {3},
	journal = {BMJ open},
	author = {Wijn, Stan R. W. and Rovers, Maroeska M. and Rongen, Jan J. and Østerås, Håvard and Risberg, May A. and Roos, Ewa M. and Hare, Kristoffer B. and van de Graaf, Victor A. and Poolman, Rudolf W. and Englund, Martin and Hannink, Gerjon},
	year = {2020},
	pmid = {32152157},
	pmcid = {PMC7064080},
	keywords = {IPDMA, arthroscopic surgery, individual participant data meta-analysis, meniscectomy, osteoarthritis},
	pages = {e031864},
}

INTRODUCTION: Arthroscopic partial meniscectomy (APM) after degenerative meniscus tears is one of the most frequently performed surgeries in orthopaedics. Although several randomised controlled trials (RCTs) have been published that showed no clear benefit compared with sham treatment or non-surgical treatment, the incidence of APM remains high. The common perception by most orthopaedic surgeons is that there are subgroups of patients that do need APM to improve, and they argue that each study sample of the existing trials is not representative for the day-to-day patients in the clinic. Therefore, the objective of this individual participant data meta-analysis (IPDMA) is to assess whether there are subgroups of patients with degenerative meniscus lesions who benefit from APM in comparison with non-surgical or sham treatment. METHODS AND ANALYSIS: An existing systematic review will be updated to identify all RCTs worldwide that evaluated APM compared with sham treatment or non-surgical treatment in patients with knee symptoms and degenerative meniscus tears. Time and effort will be spent in contacting principal investigators of the original trials and encourage them to collaborate in this project by sharing their trial data. All individual participant data will be validated for missing data, internal data consistency, randomisation integrity and censoring patterns. After validation, all datasets will be combined and analysed using a one-staged and two-staged approach. The RCTs' characteristics will be used for the assessment of clinical homogeneity and generalisability of the findings. The most important outcome will be the difference between APM and control groups in knee pain, function and quality of life 2 years after the intervention. Other outcomes of interest will include the difference in adverse events and mental health. ETHICS AND DISSEMINATION: All trial data will be anonymised before it is shared with the authors. The data will be encrypted and stored on a secure server located in the Netherlands. No major ethical concerns remain. This IPDMA will provide the evidence base to update and tailor diagnostic and treatment protocols as well as (international) guidelines for patients for whom orthopaedic surgeons consider APM. The results will be submitted for publication in a peer-reviewed journal. PROSPERO REGISTRATION NUMBER: CRD42017067240.

@article{wolf_occupational_2020,
	title = {Occupational load as a risk factor for clinically relevant base of thumb osteoarthritis},
	volume = {77},
	issn = {1470-7926},
	url = {https://doi.org/10.1136/oemed-2019-106184},
	doi = {10.1136/oemed-2019-106184},
	abstract = {OBJECTIVE: It is postulated that increased load from pinch and grasp in occupational tasks increases the risk of thumb carpometacarpal (CMC1) osteoarthritis (OA). We sought to characterise the relationship between doctor-diagnosed CMC1 OA and occupation in a large working population.
METHODS: We performed a matched case-control study using a Swedish healthcare register. We identified residents aged 30-65 years in 2013 with physician-diagnosed CMC1 OA from 1998 to 2013. We matched four controls per person with CMC1 OA by age, sex, education and postcode. Swedish Standard Classification of Occupations was used to assign occupation. Occupation was categorised as light, light-moderate, moderate and heavy labour. We used conditional logistic regression to estimate ORs with 95\% CIs.
RESULTS: We identified 3462 patients with CMC1 OA and matched 13 211 controls. The mean age of the CMC1 OA group was 63 (SD 7) years, with 81\% women. The ORs for CMC1 OA in men were 1.31 (95\% CI 0.96 to 1.79) for light-moderate, 1.76 (95\% CI 1.29 to 2.40) for moderate and 2.00 (95\% CI 1.59 to 2.51) for heavy compared with light work. Women had ORs for CMC1 OA of 1.46 (95\% CI 1.32 to 1.61) for light-moderate, 1.27 (95\% CI 1.10 to 1.46) for moderate and 1.31 (95\% CI 1.07 to 1.59) for heavy compared with light work.
CONCLUSIONS: The association between increased manual load in occupation and risk of CMC1 OA is more pronounced in men than in women, likely due to higher workload in the heavy labour category.},
	language = {eng},
	number = {3},
	journal = {Occupational and Environmental Medicine},
	author = {Wolf, Jennifer Moriatis and Turkiewicz, Aleksandra and Atroshi, Isam and Englund, Martin},
	year = {2020},
	pmid = {31959639},
	keywords = {Aged, Carpometacarpal Joints, Case-Control Studies, Female, Hand Strength, Humans, Logistic Models, Male, Middle Aged, Occupational Diseases, Osteoarthritis, Physician's Role, Registries, Risk Factors, Sweden, Thumb, Workload, occupation, osteoarthritis, thumb carpometacarpal joint},
	pages = {168--171},
}

OBJECTIVE: It is postulated that increased load from pinch and grasp in occupational tasks increases the risk of thumb carpometacarpal (CMC1) osteoarthritis (OA). We sought to characterise the relationship between doctor-diagnosed CMC1 OA and occupation in a large working population. METHODS: We performed a matched case-control study using a Swedish healthcare register. We identified residents aged 30-65 years in 2013 with physician-diagnosed CMC1 OA from 1998 to 2013. We matched four controls per person with CMC1 OA by age, sex, education and postcode. Swedish Standard Classification of Occupations was used to assign occupation. Occupation was categorised as light, light-moderate, moderate and heavy labour. We used conditional logistic regression to estimate ORs with 95% CIs. RESULTS: We identified 3462 patients with CMC1 OA and matched 13 211 controls. The mean age of the CMC1 OA group was 63 (SD 7) years, with 81% women. The ORs for CMC1 OA in men were 1.31 (95% CI 0.96 to 1.79) for light-moderate, 1.76 (95% CI 1.29 to 2.40) for moderate and 2.00 (95% CI 1.59 to 2.51) for heavy compared with light work. Women had ORs for CMC1 OA of 1.46 (95% CI 1.32 to 1.61) for light-moderate, 1.27 (95% CI 1.10 to 1.46) for moderate and 1.31 (95% CI 1.07 to 1.59) for heavy compared with light work. CONCLUSIONS: The association between increased manual load in occupation and risk of CMC1 OA is more pronounced in men than in women, likely due to higher workload in the heavy labour category.

@article{berg_development_2020,
	title = {Development of osteoarthritis in patients with degenerative meniscal tears treated with exercise therapy or surgery: a randomized controlled trial},
	volume = {28},
	issn = {1522-9653},
	shorttitle = {Development of osteoarthritis in patients with degenerative meniscal tears treated with exercise therapy or surgery},
	url = {https://doi.org/10.1016/j.joca.2020.01.020},
	doi = {10.1016/j.joca.2020.01.020},
	abstract = {OBJECTIVE: To evaluate progression of individual radiographic features 5 years following exercise therapy or arthroscopic partial meniscectomy as treatment for degenerative meniscal tear.
DESIGN: Randomized controlled trial including 140 adults, aged 35-60 years, with a magnetic resonance image verified degenerative meniscal tear, and 96\% without definite radiographic knee osteoarthritis. Participants were randomized to either 12-weeks of supervised exercise therapy or arthroscopic partial meniscectomy. The primary outcome was between-group difference in progression of tibiofemoral joint space narrowing and marginal osteophytes at 5 years, assessed semi-quantitatively by the OARSI atlas. Secondary outcomes included incidence of radiographic knee osteoarthritis and symptomatic knee osteoarthritis, medial tibiofemoral fixed joint space width (quantitatively assessed), and patient-reported outcome measures. Statistical analyses were performed using a full analysis set. Per protocol and as treated analysis were also performed.
RESULTS: The risk ratios (95\% CI) for progression of semi-quantitatively assessed joint space narrowing and medial and lateral osteophytes for the surgery group were 0.89 (0.55-1.44), 1.15 (0.79-1.68) and 0.77 (0.42-1.42), respectively, compared to the exercise therapy group. In secondary outcomes (full-set analysis) no statistically significant between-group differences were found.
CONCLUSION: The study was inconclusive with respect to potential differences in progression of individual radiographic features after surgical and non-surgical treatment for degenerative meniscal tear. Further, we found no strong evidence in support of differences in development of incident radiographic knee osteoarthritis or patient-reported outcomes between exercise therapy and arthroscopic partial meniscectomy.
TRIAL REGISTRATION: www.clinicaltrials.gov (NCT01002794).},
	language = {eng},
	number = {7},
	journal = {Osteoarthritis and Cartilage},
	author = {Berg, B. and Roos, E. M. and Englund, M. and Kise, N. J. and Tiulpin, A. and Saarakkala, S. and Engebretsen, L. and Eftang, C. N. and Holm, I. and Risberg, M. A.},
	year = {2020},
	pmid = {32184135},
	keywords = {Degenerative meniscal tears, Exercise therapy, Knee arthroscopy, Knee osteoarthritis, Partial meniscectomy, Rehabilitation},
	pages = {897--906},
}

OBJECTIVE: To evaluate progression of individual radiographic features 5 years following exercise therapy or arthroscopic partial meniscectomy as treatment for degenerative meniscal tear. DESIGN: Randomized controlled trial including 140 adults, aged 35-60 years, with a magnetic resonance image verified degenerative meniscal tear, and 96% without definite radiographic knee osteoarthritis. Participants were randomized to either 12-weeks of supervised exercise therapy or arthroscopic partial meniscectomy. The primary outcome was between-group difference in progression of tibiofemoral joint space narrowing and marginal osteophytes at 5 years, assessed semi-quantitatively by the OARSI atlas. Secondary outcomes included incidence of radiographic knee osteoarthritis and symptomatic knee osteoarthritis, medial tibiofemoral fixed joint space width (quantitatively assessed), and patient-reported outcome measures. Statistical analyses were performed using a full analysis set. Per protocol and as treated analysis were also performed. RESULTS: The risk ratios (95% CI) for progression of semi-quantitatively assessed joint space narrowing and medial and lateral osteophytes for the surgery group were 0.89 (0.55-1.44), 1.15 (0.79-1.68) and 0.77 (0.42-1.42), respectively, compared to the exercise therapy group. In secondary outcomes (full-set analysis) no statistically significant between-group differences were found. CONCLUSION: The study was inconclusive with respect to potential differences in progression of individual radiographic features after surgical and non-surgical treatment for degenerative meniscal tear. Further, we found no strong evidence in support of differences in development of incident radiographic knee osteoarthritis or patient-reported outcomes between exercise therapy and arthroscopic partial meniscectomy. TRIAL REGISTRATION: www.clinicaltrials.gov (NCT01002794).

@article{folkesson_proteomic_2020,
	title = {Proteomic comparison of osteoarthritic and reference human menisci using data-independent acquisition mass spectrometry},
	volume = {28},
	issn = {1522-9653},
	url = {https://doi.org/10.1016/j.joca.2020.05.001},
	doi = {10.1016/j.joca.2020.05.001},
	abstract = {OBJECTIVE: Recent research in knee osteoarthritis (OA) highlights the role of the meniscus in OA pathology. Our aim was to compare the proteomes of medial and lateral menisci from end-stage medial compartment knee OA patients, with reference menisci from knee-healthy deceased donors, using mass spectrometry.
DESIGN: Tissue plugs of Ø3 mm were obtained from the posterior horns of the lateral and medial menisci from one knee of 10 knee-healthy deceased donors and 10 patients undergoing knee replacement. Proteins were extracted and prepared for mass spectrometric analysis. Statistical analysis was conducted on abundance data that was log2-transformed, using a linear mixed effects model and evaluated using pathway analysis.
RESULTS: We identified a total of 835 proteins in all samples, of which 331 were included in the statistical analysis. The largest differences could be seen between the medial menisci from OA patients and references, with most proteins showing higher intensities in the medial menisci from OA patients. Several matrix proteins, e.g., matrix metalloproteinase 3 (MMP3) (4.3 times higher values [95\%CI 1.8, 10.6]), TIMP1 (3.5 [1.4, 8.5]), asporin (4.1 [1.7, 10.0]) and versican (4.4 [1.8, 10.9]), all showed higher abundance in medial menisci from OA patients compared to medial reference menisci. OA medial menisci also showed increased activation of several pathways involved in inflammation.
CONCLUSION: An increase in protein abundance for proteins such as MMP and TIMP1 in the medial menisci from OA patients suggests simultaneous activation of both catabolic and anabolic processes that warrants further attention.},
	language = {eng},
	number = {8},
	journal = {Osteoarthritis and Cartilage},
	author = {Folkesson, E. and Turkiewicz, A. and Ali, N. and Rydén, M. and Hughes, H. V. and Tjörnstrand, J. and Önnerfjord, P. and Englund, M.},
	year = {2020},
	pmid = {32407894},
	pmcid = {PMC7397514},
	keywords = {Extracellular matrix, Mass spectrometry, Meniscus, Osteoarthritis},
	pages = {1092--1101},
}

OBJECTIVE: Recent research in knee osteoarthritis (OA) highlights the role of the meniscus in OA pathology. Our aim was to compare the proteomes of medial and lateral menisci from end-stage medial compartment knee OA patients, with reference menisci from knee-healthy deceased donors, using mass spectrometry. DESIGN: Tissue plugs of Ø3 mm were obtained from the posterior horns of the lateral and medial menisci from one knee of 10 knee-healthy deceased donors and 10 patients undergoing knee replacement. Proteins were extracted and prepared for mass spectrometric analysis. Statistical analysis was conducted on abundance data that was log2-transformed, using a linear mixed effects model and evaluated using pathway analysis. RESULTS: We identified a total of 835 proteins in all samples, of which 331 were included in the statistical analysis. The largest differences could be seen between the medial menisci from OA patients and references, with most proteins showing higher intensities in the medial menisci from OA patients. Several matrix proteins, e.g., matrix metalloproteinase 3 (MMP3) (4.3 times higher values [95%CI 1.8, 10.6]), TIMP1 (3.5 [1.4, 8.5]), asporin (4.1 [1.7, 10.0]) and versican (4.4 [1.8, 10.9]), all showed higher abundance in medial menisci from OA patients compared to medial reference menisci. OA medial menisci also showed increased activation of several pathways involved in inflammation. CONCLUSION: An increase in protein abundance for proteins such as MMP and TIMP1 in the medial menisci from OA patients suggests simultaneous activation of both catabolic and anabolic processes that warrants further attention.

@article{kiadaliri_mapping_2020,
	title = {Mapping {EQ}-{5D}-{3L} from the {Knee} {Injury} and {Osteoarthritis} {Outcome} {Score} ({KOOS})},
	volume = {29},
	issn = {1573-2649},
	url = {https://doi.org/10.1007/s11136-019-02303-9},
	doi = {10.1007/s11136-019-02303-9},
	abstract = {PURPOSE: To develop a mapping model to estimate EQ-5D-3L from the Knee Injury and Osteoarthritis Outcome Score (KOOS).
METHODS: The responses to EQ-5D-3L and KOOS questionnaires (n = 40,459 observations) were obtained from the Swedish National anterior cruciate ligament (ACL) Register for patients ≥ 18 years with the knee ACL injury. We used linear regression (LR) and beta-mixture (BM) for direct mapping and the generalized ordered probit model for response mapping (RM). We compared the distribution of the original data to the distributions of the data generated using the estimated models.
RESULTS: Models with individual KOOS subscales performed better than those with the average of KOOS subscale scores (KOOS5, KOOS4). LR had the poorest performance overall and across the range of disease severity particularly at the extremes of the distribution of severity. Compared with the RM, the BM performed better across the entire range of disease severity except the most severe range (KOOS5 {\textless} 25). Moving from the most to the least disease severity was associated with 0.785 gain in the observed EQ-5D-3L. The corresponding value was 0.743, 0.772 and 0.782 for LR, BM and RM, respectively. LR generated simulated EQ-5D-3L values outside the feasible range. The distribution of simulated data generated from the BM model was almost identical to the original data.
CONCLUSIONS: We developed mapping models to estimate EQ-5D-3L from KOOS facilitating application of KOOS in cost-utility analyses. The BM showed superior performance for estimating EQ-5D-3L from KOOS. Further validation of the estimated models in different independent samples is warranted.},
	language = {eng},
	number = {1},
	journal = {Quality of Life Research: An International Journal of Quality of Life Aspects of Treatment, Care and Rehabilitation},
	author = {Kiadaliri, Ali and Alava, Monica Hernández and Roos, Ewa M. and Englund, Martin},
	month = jan,
	year = {2020},
	pmid = {31541386},
	pmcid = {PMC6962127},
	keywords = {Adult, Algorithms, Beta-mixture, EQ-5D-3L, Female, Humans, KOOS, Knee Injuries, Linear regression, Male, Mapping, Osteoarthritis, Quality of Life, Response mapping, Surveys and Questionnaires},
	pages = {265--274},
}

PURPOSE: To develop a mapping model to estimate EQ-5D-3L from the Knee Injury and Osteoarthritis Outcome Score (KOOS). METHODS: The responses to EQ-5D-3L and KOOS questionnaires (n = 40,459 observations) were obtained from the Swedish National anterior cruciate ligament (ACL) Register for patients ≥ 18 years with the knee ACL injury. We used linear regression (LR) and beta-mixture (BM) for direct mapping and the generalized ordered probit model for response mapping (RM). We compared the distribution of the original data to the distributions of the data generated using the estimated models. RESULTS: Models with individual KOOS subscales performed better than those with the average of KOOS subscale scores (KOOS5, KOOS4). LR had the poorest performance overall and across the range of disease severity particularly at the extremes of the distribution of severity. Compared with the RM, the BM performed better across the entire range of disease severity except the most severe range (KOOS5 \textless 25). Moving from the most to the least disease severity was associated with 0.785 gain in the observed EQ-5D-3L. The corresponding value was 0.743, 0.772 and 0.782 for LR, BM and RM, respectively. LR generated simulated EQ-5D-3L values outside the feasible range. The distribution of simulated data generated from the BM model was almost identical to the original data. CONCLUSIONS: We developed mapping models to estimate EQ-5D-3L from KOOS facilitating application of KOOS in cost-utility analyses. The BM showed superior performance for estimating EQ-5D-3L from KOOS. Further validation of the estimated models in different independent samples is warranted.

@article{pihl_wild_2020,
	title = {Wild goose chase - no predictable patient subgroups benefit from meniscal surgery:  patient-reported outcomes of 641 patients 1 year after surgery.},
	volume = {54},
	copyright = {© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and  permissions. Published by BMJ.},
	issn = {1473-0480 0306-3674},
	url = {https://doi.org/10.1136/bjsports-2018-100321},
	doi = {10.1136/bjsports-2018-100321},
	abstract = {BACKGROUND: Despite absence of evidence of a clinical benefit of arthroscopic  partial meniscectomy (APM), many surgeons claim that subgroups of patients benefit  from APM. OBJECTIVE: We developed a prognostic model predicting change in  patient-reported outcome 1 year following arthroscopic meniscal surgery to identify  such subgroups. METHODS: We included 641 patients (age 48.7 years (SD 13), 56\% men)  undergoing arthroscopic meniscal surgery from the Knee Arthroscopy Cohort Southern  Denmark. 18 preoperative factors identified from literature and/or orthopaedic  surgeons (patient demographics, medical history, symptom onset and duration,  knee-related symptoms, etc) were combined in a multivariable linear regression  model. The outcome was change in Knee injury and Osteoarthritis Outcome Score  (KOOS(4)) (average score of 4 of 5 KOOS subscales excluding the activities of daily  living subscale) from presurgery to 52 weeks after surgery. A positive KOOS(4)  change score constitutes improvement. Prognostic performance was assessed using R(2)  statistics and calibration plots and was internally validated by adjusting for  optimism using 1000 bootstrap samples. RESULTS: Patients improved on average 18.6  (SD 19.7, range -38.0 to 87.8) in KOOS(4). The strongest prognostic factors for  improvement were (1) no previous meniscal surgery on index knee and (2) more severe  preoperative knee-related symptoms. The model's overall predictive performance was  low (apparent R(2)=0.162, optimism adjusted R(2)=0.080) and it showed poor  calibration (calibration-in-the-large=0.205, calibration slope=0.772). CONCLUSION:  Despite combining a large number of preoperative factors presumed clinically  relevant, change in patient-reported outcome 1 year following meniscal surgery was  not predictable. This essentially quashes the existence of 'subgroups' with certain  characteristics having a particularly favourable outcome after meniscal surgery.  TRIAL REGISTRATION NUMBER: NCT01871272.},
	language = {eng},
	number = {1},
	journal = {British journal of sports medicine},
	author = {Pihl, Kenneth and Ensor, Joie and Peat, George and Englund, Martin and Lohmander, Stefan and Jørgensen, Uffe and Nissen, Nis and Fristed, Jakob Vium and Thorlund, Jonas Bloch},
	month = jan,
	year = {2020},
	pmid = {31186258},
	note = {Place: England},
	keywords = {*Meniscectomy/adverse effects, *Patient Reported Outcome Measures, Adolescent, Adult, Aged, Denmark, Female, Follow-Up Studies, Humans, Logistic Models, Male, Meniscectomy, Middle Aged, Patient Reported Outcome Measures, Postoperative Complications, Prospective Studies, Tibial Meniscus Injuries, Tibial Meniscus Injuries/*surgery, Young Adult, arthroscopy, knee, meniscus, patient-reported outcomes, prognosis},
	pages = {13--22},
}

BACKGROUND: Despite absence of evidence of a clinical benefit of arthroscopic partial meniscectomy (APM), many surgeons claim that subgroups of patients benefit from APM. OBJECTIVE: We developed a prognostic model predicting change in patient-reported outcome 1 year following arthroscopic meniscal surgery to identify such subgroups. METHODS: We included 641 patients (age 48.7 years (SD 13), 56% men) undergoing arthroscopic meniscal surgery from the Knee Arthroscopy Cohort Southern Denmark. 18 preoperative factors identified from literature and/or orthopaedic surgeons (patient demographics, medical history, symptom onset and duration, knee-related symptoms, etc) were combined in a multivariable linear regression model. The outcome was change in Knee injury and Osteoarthritis Outcome Score (KOOS(4)) (average score of 4 of 5 KOOS subscales excluding the activities of daily living subscale) from presurgery to 52 weeks after surgery. A positive KOOS(4) change score constitutes improvement. Prognostic performance was assessed using R(2) statistics and calibration plots and was internally validated by adjusting for optimism using 1000 bootstrap samples. RESULTS: Patients improved on average 18.6 (SD 19.7, range -38.0 to 87.8) in KOOS(4). The strongest prognostic factors for improvement were (1) no previous meniscal surgery on index knee and (2) more severe preoperative knee-related symptoms. The model's overall predictive performance was low (apparent R(2)=0.162, optimism adjusted R(2)=0.080) and it showed poor calibration (calibration-in-the-large=0.205, calibration slope=0.772). CONCLUSION: Despite combining a large number of preoperative factors presumed clinically relevant, change in patient-reported outcome 1 year following meniscal surgery was not predictable. This essentially quashes the existence of 'subgroups' with certain characteristics having a particularly favourable outcome after meniscal surgery. TRIAL REGISTRATION NUMBER: NCT01871272.

@article{sihvonen_statistical_2020,
	title = {Statistical analysis plan for the 5-year and 10-year follow-up assessments of the {FIDELITY} trial},
	volume = {21},
	issn = {1745-6215},
	url = {https://doi.org/10.1186/s13063-019-3833-2},
	doi = {10.1186/s13063-019-3833-2},
	abstract = {BACKGROUND: The research objectives of the 5-year and 10-year assessments in the Finnish degenerative meniscal lesion study (FIDELITY) are twofold: (1) to assess the long-term efficacy of arthroscopic partial meniscectomy (APM) in adults (age 35 to 65 years) with a degenerative meniscus tear and (2) to determine the respective effects of APM and degenerative meniscus tear on the development of radiographic and clinical knee osteoarthritis (OA).
METHODS AND DESIGN: FIDELITY is an ongoing multi-center, randomized, participant and outcome assessor blinded, placebo-surgery-controlled trial in 146 patients. This statistical analysis plan (SAP) article describes the overall principles for analysis of long-term outcomes (5-year and 10-year follow up), including how participants will be included in each analysis, the primary and secondary outcomes and their respective analyses, adjustments for covariates, and the presentation of the results. In addition, we will present the planned sensitivity and subgroup analyses.
DISCUSSION: To assess the long-term efficacy of APM on knee symptoms and function we are carrying out a long-term (5-year and 10-year) follow up of our placebo-surgery-controlled FIDELITY trial according to statistical principles outlined in detail in this document. As our second primary objective, whether APM (resection of torn meniscus tear) accelerates or delays the development of knee osteoarthritis in patients with an arthroscopically verified degenerative tear of the medial meniscus, a pre-registered follow-up is also carried out.
TRIAL REGISTRATION: ClinicalTrials.gov, NCT00549172 (Arthroscopy in the Treatment of Degenerative Medial Meniscus Tear). Registered on 25 October 2007 (NCT00549172). ClinicalTrials.gov, NCT01052233 (Development of Knee Osteoarthritis After Arthroscopic Partial Resection of Degenerative Meniscus Tear). Registered on 20 January 2010.},
	language = {eng},
	number = {1},
	journal = {Trials},
	author = {Sihvonen, Raine and Kalske, Roope and Englund, Martin and Turkiewicz, Aleksandra and Toivonen, Pirjo and Taimela, Simo and Järvinen, Teppo L. N. and {Finnish Degenerative Meniscal Lesion Study (FIDELITY) Investigators}},
	month = jan,
	year = {2020},
	pmid = {31937344},
	pmcid = {PMC6961384},
	keywords = {Arthroscopic partial meniscectomy, Osteoarthritis, Randomized controlled trial, Statistical analysis plan},
	pages = {76},
}

BACKGROUND: The research objectives of the 5-year and 10-year assessments in the Finnish degenerative meniscal lesion study (FIDELITY) are twofold: (1) to assess the long-term efficacy of arthroscopic partial meniscectomy (APM) in adults (age 35 to 65 years) with a degenerative meniscus tear and (2) to determine the respective effects of APM and degenerative meniscus tear on the development of radiographic and clinical knee osteoarthritis (OA). METHODS AND DESIGN: FIDELITY is an ongoing multi-center, randomized, participant and outcome assessor blinded, placebo-surgery-controlled trial in 146 patients. This statistical analysis plan (SAP) article describes the overall principles for analysis of long-term outcomes (5-year and 10-year follow up), including how participants will be included in each analysis, the primary and secondary outcomes and their respective analyses, adjustments for covariates, and the presentation of the results. In addition, we will present the planned sensitivity and subgroup analyses. DISCUSSION: To assess the long-term efficacy of APM on knee symptoms and function we are carrying out a long-term (5-year and 10-year) follow up of our placebo-surgery-controlled FIDELITY trial according to statistical principles outlined in detail in this document. As our second primary objective, whether APM (resection of torn meniscus tear) accelerates or delays the development of knee osteoarthritis in patients with an arthroscopically verified degenerative tear of the medial meniscus, a pre-registered follow-up is also carried out. TRIAL REGISTRATION: ClinicalTrials.gov, NCT00549172 (Arthroscopy in the Treatment of Degenerative Medial Meniscus Tear). Registered on 25 October 2007 (NCT00549172). ClinicalTrials.gov, NCT01052233 (Development of Knee Osteoarthritis After Arthroscopic Partial Resection of Degenerative Meniscus Tear). Registered on 20 January 2010.

@article{lindeus_educational_2020,
	title = {Educational inequalities in fracture-related mortality using multiple cause of death data in the {Skåne} region, {Sweden}},
	volume = {48},
	issn = {1651-1905},
	url = {https://doi.org/10.1177/1403494818807831},
	doi = {10.1177/1403494818807831},
	abstract = {Aim: To assess the absolute and relative educational inequalities in mortality from hip and non-hip fractures in Skåne region, Sweden. Methods: We conducted a population-based open cohort study. People aged 30-99 years, resident in the region during 1998-2013 (n = 999, 148) were followed until death, their 100th birthday, relocation outside Skåne, or the end of 2014. We obtained individual-level data from the Statistics Sweden and the Swedish National Board of Health and Welfare's Cause of Death Register. Death certificates coded with any fracture diagnosis were defined as fracture-related deaths. Educational inequalities were assessed by slope and relative indices of inequality (SII and RII). Cox regression and additive hazard models were used to estimates these indices. Results: During a mean follow-up of 12.2 years, there were 5,121 fracture-related deaths, of which 3,110 were associated with hip fracture. Age-standardized, hip fracture-related mortality rates per 100,000 person-years were 31, 95\% confidence interval (CI) (30, 32) and 23 (20, 26) in people with low and high levels of education, respectively (rate ratio 1.4, 95\% CI (1.2, 1.5)). Corresponding mortality rates for non-hip-fracture related deaths were 20 (18, 21) and 16 (14, 19) (rate ratio 1.2, 95\% CI (1.0, 1.4)). SII and RII revealed educational inequalities in hip fracture-related mortality in favour of highly educated people. For non hip fracture-related mortality, there were statistically significant educational inequalities in people aged {\textless}70 years. Conclusions: We found higher fracture-related mortality with lower education suggesting preventative and therapeutic interventions for fractures should pay special attention to people with low-level education.},
	language = {eng},
	number = {1},
	journal = {Scandinavian Journal of Public Health},
	author = {Lindéus, Maria and Englund, Martin and Kiadaliri, Aliasghar A.},
	month = feb,
	year = {2020},
	pmid = {30345871},
	keywords = {Adult, Aged, Aged, 80 and over, Cause of Death, Cohort Studies, Educational Status, Educational inequality, Female, Fractures, Bone, Health Status Disparities, Hip Fractures, Humans, Male, Middle Aged, Sweden, fracture, mortality, multiple cause of death},
	pages = {72--79},
}

Aim: To assess the absolute and relative educational inequalities in mortality from hip and non-hip fractures in Skåne region, Sweden. Methods: We conducted a population-based open cohort study. People aged 30-99 years, resident in the region during 1998-2013 (n = 999, 148) were followed until death, their 100th birthday, relocation outside Skåne, or the end of 2014. We obtained individual-level data from the Statistics Sweden and the Swedish National Board of Health and Welfare's Cause of Death Register. Death certificates coded with any fracture diagnosis were defined as fracture-related deaths. Educational inequalities were assessed by slope and relative indices of inequality (SII and RII). Cox regression and additive hazard models were used to estimates these indices. Results: During a mean follow-up of 12.2 years, there were 5,121 fracture-related deaths, of which 3,110 were associated with hip fracture. Age-standardized, hip fracture-related mortality rates per 100,000 person-years were 31, 95% confidence interval (CI) (30, 32) and 23 (20, 26) in people with low and high levels of education, respectively (rate ratio 1.4, 95% CI (1.2, 1.5)). Corresponding mortality rates for non-hip-fracture related deaths were 20 (18, 21) and 16 (14, 19) (rate ratio 1.2, 95% CI (1.0, 1.4)). SII and RII revealed educational inequalities in hip fracture-related mortality in favour of highly educated people. For non hip fracture-related mortality, there were statistically significant educational inequalities in people aged \textless70 years. Conclusions: We found higher fracture-related mortality with lower education suggesting preventative and therapeutic interventions for fractures should pay special attention to people with low-level education.

@article{snoeker_does_2020,
	title = {Does early anterior cruciate ligament reconstruction prevent development of meniscal  damage? {Results} from a secondary analysis of a randomised controlled trial.},
	volume = {54},
	copyright = {© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and  permissions. Published by BMJ.},
	issn = {1473-0480 0306-3674},
	url = {https://doi.org/10.1136/bjsports-2019-101125},
	doi = {10.1136/bjsports-2019-101125},
	abstract = {OBJECTIVES: To determine development of new and worsening meniscal damage over 5  years after acute anterior cruciate ligament (ACL) injury comparing rehabilitation  plus early ACL reconstruction ('early-ACLR') versus rehabilitation with optional  delayed ACL reconstruction ('optional-delayed-ACLR'). METHODS: We used knee MRIs  from the only randomised controlled trial in the field including 121 young adults.  One musculoskeletal radiologist read baseline and 5-year follow-up images using the  Anterior Cruciate Ligament Osteoarthritis Score (ACLOAS). We defined development  (ie, new and worsening) of meniscal damage both dichotomously and as a sum score  representing severity (based on the reclassified ACLOAS meniscus grades). In the  full analysis set, we analysed development of meniscal damage (yes/no) with logistic  regression and severity with zero-inflated Poisson regression and adjusted for age,  sex and baseline meniscal damage. RESULTS: Over 5 years, new or worsening meniscal  damage developed in 45\% of subjects with early-ACLR and in 53\% of subjects with  optional-delayed-ACLR. The relative risk for development of meniscal damage on knee  level was 1.3 (95\% CI 0.9 to 1.9) in optional-delayed-ACLR versus early-ACLR. For  medial and lateral meniscal damage, respectively, the relative risks were 2.1 (95\%  CI 1.1 to 3.9) and 1.0 (95\% CI 0.6 to 1.5). The mean severity score was 1.5 higher  (more severe damage) on knee level in optional-delayed-ACLR versus early-ACLR (95\%  CI 1.1 to 1.9) among those with meniscal damage at 5 years. For medial and lateral  meniscal damage, respectively, the corresponding scores were 1.7 (95\% CI 1.2 to 2.5)  and 1.1 (95\% CI 0.8 to 1.4). CONCLUSION: A strategy of early-ACLR may reduce  development of medial meniscal damage following acute ACL injury. For the lateral  meniscus, ACLR seems neither to be protective nor to increase the risk of damage.  TRIAL REGISTRATION NUMBER: ISRCTN 84752559.},
	language = {eng},
	number = {10},
	journal = {British journal of sports medicine},
	author = {Snoeker, Barbara A. and Roemer, Frank W. and Turkiewicz, Aleksandra and Lohmander, Stefan and Frobell, Richard B. and Englund, Martin},
	month = may,
	year = {2020},
	pmid = {31653779},
	note = {Place: England},
	keywords = {*Time-to-Treatment, ACL, Adult, Anterior Cruciate Ligament Injuries, Anterior Cruciate Ligament Injuries/rehabilitation/*surgery, Anterior Cruciate Ligament Reconstruction, Anterior Cruciate Ligament Reconstruction/*methods, Female, Humans, Magnetic Resonance Imaging, Male, Postoperative Complications, Risk Factors, Tibial Meniscus Injuries, Tibial Meniscus Injuries/diagnostic imaging/*prevention \& control, Time-to-Treatment, Young Adult, knee, knee surgery, meniscus, randomised controlled trial},
	pages = {612--617},
}

OBJECTIVES: To determine development of new and worsening meniscal damage over 5 years after acute anterior cruciate ligament (ACL) injury comparing rehabilitation plus early ACL reconstruction ('early-ACLR') versus rehabilitation with optional delayed ACL reconstruction ('optional-delayed-ACLR'). METHODS: We used knee MRIs from the only randomised controlled trial in the field including 121 young adults. One musculoskeletal radiologist read baseline and 5-year follow-up images using the Anterior Cruciate Ligament Osteoarthritis Score (ACLOAS). We defined development (ie, new and worsening) of meniscal damage both dichotomously and as a sum score representing severity (based on the reclassified ACLOAS meniscus grades). In the full analysis set, we analysed development of meniscal damage (yes/no) with logistic regression and severity with zero-inflated Poisson regression and adjusted for age, sex and baseline meniscal damage. RESULTS: Over 5 years, new or worsening meniscal damage developed in 45% of subjects with early-ACLR and in 53% of subjects with optional-delayed-ACLR. The relative risk for development of meniscal damage on knee level was 1.3 (95% CI 0.9 to 1.9) in optional-delayed-ACLR versus early-ACLR. For medial and lateral meniscal damage, respectively, the relative risks were 2.1 (95% CI 1.1 to 3.9) and 1.0 (95% CI 0.6 to 1.5). The mean severity score was 1.5 higher (more severe damage) on knee level in optional-delayed-ACLR versus early-ACLR (95% CI 1.1 to 1.9) among those with meniscal damage at 5 years. For medial and lateral meniscal damage, respectively, the corresponding scores were 1.7 (95% CI 1.2 to 2.5) and 1.1 (95% CI 0.8 to 1.4). CONCLUSION: A strategy of early-ACLR may reduce development of medial meniscal damage following acute ACL injury. For the lateral meniscus, ACLR seems neither to be protective nor to increase the risk of damage. TRIAL REGISTRATION NUMBER: ISRCTN 84752559.

@article{stamatis_infections_2020,
	title = {Infections are associated with increased risk of giant cell arteritis - a population-based case-control study from {Southern} {Sweden}},
	issn = {0315-162X},
	url = {https://doi.org/10.3899/jrheum.200211},
	doi = {10.3899/jrheum.200211},
	abstract = {OBJECTIVE: To investigate the association of infections with the subsequent development of giant cell arteritis (GCA) in a large population-based cohort from a defined geographic area in Sweden.
METHODS: Patients diagnosed with biopsy-confirmed GCA between 2000 and 2016 were identified through the database of the Department of Pathology in Skåne, the southernmost region of Sweden. For each GCA case, 10 controls matched for age, sex, and area of residence were randomly selected from the general population. Using the Skåne Healthcare Register, we identified all infection events prior to the date of GCA diagnosis and index date of controls. With infection as exposure, a conditional logistic regression model was employed to estimate the odds ratio (OR) for developing GCA. The types of infections contracted nearest in time to the GCA diagnosis/index date were identified.
RESULTS: A total of 1005 patients with biopsy-confirmed GCA (71\% female) and 10 050 controls were included in the analysis. Infections were more common among patients subsequently diagnosed with GCA compared to controls [51\% vs. 41\%, OR 1.78; 95\% confidence interval (CI) 1.53-2.07]. Acute upper respiratory tract infection (OR 1.77; 95 \%. CI 1.47-2.14), influenza and pneumonia (OR 1.72; 95 \% CI 1.35-2.19), and unspecified infections (OR 5.35; 95 \% CI 3.46-8.28) were associated with GCA. Neither skin nor gastrointestinal infections showed a correlation.
CONCLUSION: Infections, especially those of the respiratory tract, were associated with subsequent development of biopsy-confirmed GCA. Our findings support the hypothesis that a range of infections may trigger GCA.},
	language = {eng},
	journal = {The Journal of Rheumatology},
	author = {Stamatis, Pavlos and Turkiewicz, Aleksandra and Englund, Martin and Jönsson, Göran and Nilsson, JanÅke and Turesson, Carl and Mohammad, Aladdin J.},
	month = may,
	year = {2020},
	pmid = {32414956},
}

OBJECTIVE: To investigate the association of infections with the subsequent development of giant cell arteritis (GCA) in a large population-based cohort from a defined geographic area in Sweden. METHODS: Patients diagnosed with biopsy-confirmed GCA between 2000 and 2016 were identified through the database of the Department of Pathology in Skåne, the southernmost region of Sweden. For each GCA case, 10 controls matched for age, sex, and area of residence were randomly selected from the general population. Using the Skåne Healthcare Register, we identified all infection events prior to the date of GCA diagnosis and index date of controls. With infection as exposure, a conditional logistic regression model was employed to estimate the odds ratio (OR) for developing GCA. The types of infections contracted nearest in time to the GCA diagnosis/index date were identified. RESULTS: A total of 1005 patients with biopsy-confirmed GCA (71% female) and 10 050 controls were included in the analysis. Infections were more common among patients subsequently diagnosed with GCA compared to controls [51% vs. 41%, OR 1.78; 95% confidence interval (CI) 1.53-2.07]. Acute upper respiratory tract infection (OR 1.77; 95 %. CI 1.47-2.14), influenza and pneumonia (OR 1.72; 95 % CI 1.35-2.19), and unspecified infections (OR 5.35; 95 % CI 3.46-8.28) were associated with GCA. Neither skin nor gastrointestinal infections showed a correlation. CONCLUSION: Infections, especially those of the respiratory tract, were associated with subsequent development of biopsy-confirmed GCA. Our findings support the hypothesis that a range of infections may trigger GCA.

@article{snoeker_risk_2020,
	title = {Risk of knee osteoarthritis after different types of knee injuries in young adults: a population-based cohort study},
	volume = {54},
	issn = {1473-0480},
	shorttitle = {Risk of knee osteoarthritis after different types of knee injuries in young adults},
	url = {https://doi.org/10.1136/bjsports-2019-100959},
	doi = {10.1136/bjsports-2019-100959},
	abstract = {OBJECTIVES: To estimate the risk of clinically diagnosed knee osteoarthritis (OA) after different types of knee injuries in young adults.
METHODS: In a longitudinal cohort study based on population-based healthcare data from Skåne, Sweden, we included all persons aged 25-34 years in 1998-2007 (n=149 288) with and without diagnoses of knee injuries according to International Classification of Diseases (ICD)-10. We estimated the HR of future diagnosed knee OA in injured and uninjured persons using Cox regression, adjusted for potential confounders. We also explored the impact of type of injury (contusion, fracture, dislocation, meniscal tear, cartilage tear/other injury, collateral ligament tear, cruciate ligament tear and injury to multiple structures) on diagnosed knee OA risk.
RESULTS: We identified 5247 persons (mean (SD) age 29.4 (2.9) years, 67\% men) with a knee injury and 142 825 persons (mean (SD) age 30.2 (3.0) years, 45\% men) without. We found an adjusted HR of 5.7 (95\% CI 5.0 to 6.6) for diagnosed knee OA in injured compared with uninjured persons during the first 11 years of follow-up and 3.4 (95\% CI 2.9 to 4.0) during the following 8 years. The corresponding risk difference (RD) after 19 years of follow-up was 8.1\% (95\% CI 6.7\% to 9.4\%). Cruciate ligament injury, meniscal tear and fracture of the tibia plateau/patella were associated with greatest increase in risk (RD of 19.6\% (95\% CI 13.2\% to 25.9\%), 10.5\% (95\% CI 6.4\% to 14.7\%) and 6.6\% (95\% CI 1.1\% to 12.2\%), respectively).
CONCLUSION: In young adults, knee injury increases the risk of future diagnosed knee OA about sixfold with highest risks found after cruciate ligament injury, meniscal tear and intra-articular fracture.},
	language = {eng},
	number = {12},
	journal = {British Journal of Sports Medicine},
	author = {Snoeker, Barbara and Turkiewicz, Aleksandra and Magnusson, Karin and Frobell, Richard and Yu, Dahai and Peat, George and Englund, Martin},
	month = jun,
	year = {2020},
	pmid = {31826861},
	keywords = {Adult, Anterior Cruciate Ligament Injuries, Anterior Cruciate Ligament Injuries/complications, Cartilage, Articular, Cartilage, Articular/injuries, Contusions, Contusions/complications, Female, Fracture Dislocation, Fracture Dislocation/complications, Humans, Knee Injuries, Knee Injuries/*complications, Longitudinal Studies, Male, Osteoarthritis, Knee, Osteoarthritis, Knee/*epidemiology/etiology, Risk Factors, Sweden, Sweden/epidemiology, Tibial Fractures, Tibial Fractures/complications, Tibial Meniscus Injuries, Tibial Meniscus Injuries/complications, Time Factors, Young Adult, fracture, knee ACL, knee injuries, meniscus, osteoarthritis},
	pages = {725--730},
}

OBJECTIVES: To estimate the risk of clinically diagnosed knee osteoarthritis (OA) after different types of knee injuries in young adults. METHODS: In a longitudinal cohort study based on population-based healthcare data from Skåne, Sweden, we included all persons aged 25-34 years in 1998-2007 (n=149 288) with and without diagnoses of knee injuries according to International Classification of Diseases (ICD)-10. We estimated the HR of future diagnosed knee OA in injured and uninjured persons using Cox regression, adjusted for potential confounders. We also explored the impact of type of injury (contusion, fracture, dislocation, meniscal tear, cartilage tear/other injury, collateral ligament tear, cruciate ligament tear and injury to multiple structures) on diagnosed knee OA risk. RESULTS: We identified 5247 persons (mean (SD) age 29.4 (2.9) years, 67% men) with a knee injury and 142 825 persons (mean (SD) age 30.2 (3.0) years, 45% men) without. We found an adjusted HR of 5.7 (95% CI 5.0 to 6.6) for diagnosed knee OA in injured compared with uninjured persons during the first 11 years of follow-up and 3.4 (95% CI 2.9 to 4.0) during the following 8 years. The corresponding risk difference (RD) after 19 years of follow-up was 8.1% (95% CI 6.7% to 9.4%). Cruciate ligament injury, meniscal tear and fracture of the tibia plateau/patella were associated with greatest increase in risk (RD of 19.6% (95% CI 13.2% to 25.9%), 10.5% (95% CI 6.4% to 14.7%) and 6.6% (95% CI 1.1% to 12.2%), respectively). CONCLUSION: In young adults, knee injury increases the risk of future diagnosed knee OA about sixfold with highest risks found after cruciate ligament injury, meniscal tear and intra-articular fracture.

@article{folkesson_proteomic_2020-1,
	title = {Proteomic characterization of the normal human medial meniscus body using data-independent acquisition mass spectrometry},
	volume = {38},
	issn = {1554-527X},
	url = {https://doi.org/10.1002/jor.24602},
	doi = {10.1002/jor.24602},
	abstract = {Recent research suggests an important role of the meniscus in the development of knee osteoarthritis. We, therefore, aimed to analyze the proteome of the normal human meniscus body, and specifically to gain new knowledge on global protein expression in the different radial zones. Medial menisci were retrieved from the right knees of 10 human cadaveric donors, from which we cut a 2 mm radial slice from the mid-portion of the meniscal body. This slice was further divided into three zones: inner, middle, and peripheral. Proteins were extracted and prepared for mass spectrometric analysis using data-independent acquisition. We performed subsequent data searches using Spectronaut Pulsar and used fixed-effect linear regression models for statistical analysis. We identified 638 proteins and after statistical analysis, we observed the greatest number of differentially expressed proteins between the inner and peripheral zones (163 proteins) and the peripheral and middle zones (136 proteins), with myocilin being the protein with the largest fold-change in both comparisons. Chondroadherin was one of eight proteins that differed between the inner and middle zones. Functional enrichment analyses showed that the peripheral one-third of the medial meniscus body differed substantially from the two more centrally located zones, which were more similar to each other. This is probably related to the higher content of cells and vascularization in the peripheral zone, whereas the middle and inner zones of the meniscal body appear to be more similar to hyaline cartilage, with high levels of extracellular matrix proteins such as aggrecan and collagen type II.},
	language = {eng},
	number = {8},
	journal = {Journal of Orthopaedic Research: Official Publication of the Orthopaedic Research Society},
	author = {Folkesson, Elin and Turkiewicz, Aleksandra and Rydén, Martin and Hughes, Harini Velocity and Ali, Neserin and Tjörnstrand, Jon and Önnerfjord, Patrik and Englund, Martin},
	month = aug,
	year = {2020},
	pmid = {31989678},
	keywords = {data-independent acquisition, meniscus, proteomics},
	pages = {1735--1745},
}

Recent research suggests an important role of the meniscus in the development of knee osteoarthritis. We, therefore, aimed to analyze the proteome of the normal human meniscus body, and specifically to gain new knowledge on global protein expression in the different radial zones. Medial menisci were retrieved from the right knees of 10 human cadaveric donors, from which we cut a 2 mm radial slice from the mid-portion of the meniscal body. This slice was further divided into three zones: inner, middle, and peripheral. Proteins were extracted and prepared for mass spectrometric analysis using data-independent acquisition. We performed subsequent data searches using Spectronaut Pulsar and used fixed-effect linear regression models for statistical analysis. We identified 638 proteins and after statistical analysis, we observed the greatest number of differentially expressed proteins between the inner and peripheral zones (163 proteins) and the peripheral and middle zones (136 proteins), with myocilin being the protein with the largest fold-change in both comparisons. Chondroadherin was one of eight proteins that differed between the inner and middle zones. Functional enrichment analyses showed that the peripheral one-third of the medial meniscus body differed substantially from the two more centrally located zones, which were more similar to each other. This is probably related to the higher content of cells and vascularization in the peripheral zone, whereas the middle and inner zones of the meniscal body appear to be more similar to hyaline cartilage, with high levels of extracellular matrix proteins such as aggrecan and collagen type II.

@article{wolski_early_2020,
	title = {Early tibial subchondral bone texture changes after arthroscopic partial meniscectomy in knees without radiographic {OA}: {A} prospective cohort study},
	volume = {38},
	issn = {1554-527X},
	shorttitle = {Early tibial subchondral bone texture changes after arthroscopic partial meniscectomy in knees without radiographic {OA}},
	url = {https://doi.org/10.1002/jor.24593},
	doi = {10.1002/jor.24593},
	abstract = {Arthroscopic partial meniscectomy (APM) may lead to changes in underlying trabecular bone (TB) structure potentially promoting the development of knee joint osteoarthritis. Our aim was to investigate if there are early changes occurring in tibial subchondral TB texture in the leg undergoing medial APM compared with the unoperated non-injured contra-lateral leg. The bone texture was measured as the medial-to-lateral ratio of fractal dimensions (FD) calculated for regions selected on weight-bearing anteroposterior tibiofemoral x-rays. Twenty-one subjects before and 12 months after APM were included from 374 patients scheduled for unilateral medial APM. The medial-to-lateral ratio was calculated for horizontal, vertical, and roughest FDs respectively. Higher FD means higher bone roughness. Each FD was calculated over a range of scales using a variance orientation transform method. Mean values of medial-to-lateral horizontal FD calculated for APM knees at follow-up were higher than those at baseline. For unoperated knees the values were lower. The difference in the horizontal FD change from baseline to follow-up between APM and contra-lateral legs was 0.028 (95\% CI, 0.004-0.052). The bone roughness changes may reflect the increase in peak knee adduction moment (KAM) and KAM impulse during walking reported for the same cohort in a previous study. They may also reflect early signs of osteoarthritis development and thus, we speculate that individuals with increased bone texture roughness ratio after APM might be at higher risk of knee osteoarthritis development.},
	language = {eng},
	number = {8},
	journal = {Journal of Orthopaedic Research: Official Publication of the Orthopaedic Research Society},
	author = {Wolski, Marcin and Thorlund, Jonas B. and Stachowiak, Gwidon W. and Holsgaard-Larsen, Anders and Creaby, Mark W. and Jørgensen, Gitte M. and Englund, Martin and Podsiadlo, Pawel},
	month = aug,
	year = {2020},
	pmid = {31965586},
	keywords = {fractal analysis, meniscectomy, osteoarthritis, tibiofemoral},
	pages = {1819--1825},
}

Arthroscopic partial meniscectomy (APM) may lead to changes in underlying trabecular bone (TB) structure potentially promoting the development of knee joint osteoarthritis. Our aim was to investigate if there are early changes occurring in tibial subchondral TB texture in the leg undergoing medial APM compared with the unoperated non-injured contra-lateral leg. The bone texture was measured as the medial-to-lateral ratio of fractal dimensions (FD) calculated for regions selected on weight-bearing anteroposterior tibiofemoral x-rays. Twenty-one subjects before and 12 months after APM were included from 374 patients scheduled for unilateral medial APM. The medial-to-lateral ratio was calculated for horizontal, vertical, and roughest FDs respectively. Higher FD means higher bone roughness. Each FD was calculated over a range of scales using a variance orientation transform method. Mean values of medial-to-lateral horizontal FD calculated for APM knees at follow-up were higher than those at baseline. For unoperated knees the values were lower. The difference in the horizontal FD change from baseline to follow-up between APM and contra-lateral legs was 0.028 (95% CI, 0.004-0.052). The bone roughness changes may reflect the increase in peak knee adduction moment (KAM) and KAM impulse during walking reported for the same cohort in a previous study. They may also reflect early signs of osteoarthritis development and thus, we speculate that individuals with increased bone texture roughness ratio after APM might be at higher risk of knee osteoarthritis development.

@article{magnusson_relationship_2020,
	title = {The relationship between {MRI} features and knee pain over 6 years in knees without radiographic osteoarthritis at baseline},
	issn = {2151-4658},
	url = {https://doi.org/10.1002/acr.24394},
	doi = {10.1002/acr.24394},
	abstract = {AIM: To explore whether MRI features suggestive of knee OA are associated with presence of knee pain in possible early-stage OA development.
METHODS: We included 294 participants from the Osteoarthritis Initiative (mean [SD] age 50 (3) years, 50\% women), with baseline Kellgren and Lawrence grade=0 in both knees, and who had all obtained knee MRIs from 4 different time points over 6 years (baseline, 24, 48 and 72 months). Using a linear mixed model (knees matched within individuals), we studied whether MRI features: meniscal body extrusion (millimeter), cartilage area loss (score 0 to 39), cartilage full thickness loss (0-16), osteophytes (0-29), meniscal integrity (0-10), bone marrow lesions (BML) including bone marrow cysts (0-20), Hoffa or effusion synovitis (absent/present) and popliteal cysts (absent/present) were associated with knee-specific pain as reported on the Knee injury and Osteoarthritis Outcomes Score (KOOS) questionnaire on 0-100 scale (worst-best).
RESULTS: The difference in KOOS knee pain for a knee with a one unit higher score on MRI feature was: for meniscal extrusion -1.52 (95\% CI -2.35,-0.69), cartilage area loss -0.23 (-0.48,0.02), cartilage full thickness loss: -1.04 (-1.58,-0.50), osteophytes -0.32 (-0.61,-0.03), meniscal integrity -0.28 (-0.58,0.02), BMLs including potential cysts -0.19 (-0.55,0.16), synovitis 0.23 (-1.14,1.60) and popliteal cysts 0.86 (-0.56,2.29).
CONCLUSION: Meniscal extrusion, full thickness cartilage loss and osteophytes are associated with having more knee pain. Although these features may be relevant targets for future trials, the clinical relevance of our findings is unclear because no feature was associated with a clinically important difference in knee pain.},
	language = {eng},
	journal = {Arthritis Care \& Research},
	author = {Magnusson, Karin and Turkiewicz, Aleksandra and Kumm, Jaanika and Zhang, Fan and Englund, Martin},
	month = aug,
	year = {2020},
	pmid = {32741084},
}

AIM: To explore whether MRI features suggestive of knee OA are associated with presence of knee pain in possible early-stage OA development. METHODS: We included 294 participants from the Osteoarthritis Initiative (mean [SD] age 50 (3) years, 50% women), with baseline Kellgren and Lawrence grade=0 in both knees, and who had all obtained knee MRIs from 4 different time points over 6 years (baseline, 24, 48 and 72 months). Using a linear mixed model (knees matched within individuals), we studied whether MRI features: meniscal body extrusion (millimeter), cartilage area loss (score 0 to 39), cartilage full thickness loss (0-16), osteophytes (0-29), meniscal integrity (0-10), bone marrow lesions (BML) including bone marrow cysts (0-20), Hoffa or effusion synovitis (absent/present) and popliteal cysts (absent/present) were associated with knee-specific pain as reported on the Knee injury and Osteoarthritis Outcomes Score (KOOS) questionnaire on 0-100 scale (worst-best). RESULTS: The difference in KOOS knee pain for a knee with a one unit higher score on MRI feature was: for meniscal extrusion -1.52 (95% CI -2.35,-0.69), cartilage area loss -0.23 (-0.48,0.02), cartilage full thickness loss: -1.04 (-1.58,-0.50), osteophytes -0.32 (-0.61,-0.03), meniscal integrity -0.28 (-0.58,0.02), BMLs including potential cysts -0.19 (-0.55,0.16), synovitis 0.23 (-1.14,1.60) and popliteal cysts 0.86 (-0.56,2.29). CONCLUSION: Meniscal extrusion, full thickness cartilage loss and osteophytes are associated with having more knee pain. Although these features may be relevant targets for future trials, the clinical relevance of our findings is unclear because no feature was associated with a clinically important difference in knee pain.

@article{sihvonen_arthroscopic_2020,
	title = {Arthroscopic partial meniscectomy for a degenerative meniscus tear: a 5 year follow-up of the placebo-surgery controlled {FIDELITY} ({Finnish} {Degenerative} {Meniscus} {Lesion} {Study}) trial},
	issn = {1473-0480},
	shorttitle = {Arthroscopic partial meniscectomy for a degenerative meniscus tear},
	url = {https://doi.org/10.1136/bjsports-2020-102813},
	doi = {10.1136/bjsports-2020-102813},
	abstract = {OBJECTIVES: To assess the long-term effects of arthroscopic partial meniscectomy (APM) on the development of radiographic knee osteoarthritis, and on knee symptoms and function, at 5 years follow-up.
DESIGN: Multicentre, randomised, participant- and outcome assessor-blinded, placebo-surgery controlled trial.
SETTING: Orthopaedic departments in five public hospitals in Finland.
PARTICIPANTS: 146 adults, mean age 52 years (range 35-65 years), with knee symptoms consistent with degenerative medial meniscus tear verified by MRI scan and arthroscopically, and no clinical signs of knee osteoarthritis were randomised.
INTERVENTIONS: APM or placebo surgery (diagnostic knee arthroscopy).
MAIN OUTCOME MEASURES: We used two indices of radiographic knee osteoarthritis (increase in Kellgren and Lawrence grade ≥1, and increase in Osteoarthritis Research Society International (OARSI) atlas radiographic joint space narrowing and osteophyte sum score, respectively), and three validated patient-relevant measures of knee symptoms and function (Western Ontario Meniscal Evaluation Tool (WOMET), Lysholm, and knee pain after exercise using a numerical rating scale).
RESULTS: There was a consistent, slightly greater risk for progression of radiographic knee osteoarthritis in the APM group as compared with the placebo surgery group (adjusted absolute risk difference in increase in Kellgren-Lawrence grade ≥1 of 13\%, 95\% CI -2\% to 28\%; adjusted absolute mean difference in OARSI sum score 0.7, 95\% CI 0.1 to 1.3). There were no relevant between-group differences in the three patient-reported outcomes: adjusted absolute mean differences (APM vs placebo surgery), -1.7 (95\% CI -7.7 to 4.3) in WOMET, -2.1 (95\% CI -6.8 to 2.6) in Lysholm knee score, and -0.04 (95\% CI -0.81 to 0.72) in knee pain after exercise, respectively. The corresponding adjusted absolute risk difference in the presence of mechanical symptoms was 18\% (95\% CI 5\% to 31\%); there were more symptoms reported in the APM group. All other secondary outcomes comparisons were similar.
CONCLUSIONS: APM was associated with a slightly increased risk of developing radiographic knee osteoarthritis and no concomitant benefit in patient-relevant outcomes, at 5 years after surgery.
TRIAL REGISTRATION: ClinicalTrials.gov (NCT01052233 and NCT00549172).},
	language = {eng},
	journal = {British Journal of Sports Medicine},
	author = {Sihvonen, Raine and Paavola, Mika and Malmivaara, Antti and Itälä, Ari and Joukainen, Antti and Kalske, Juha and Nurmi, Heikki and Kumm, Jaanika and Sillanpää, Niko and Kiekara, Tommi and Turkiewicz, Aleksandra and Toivonen, Pirjo and Englund, Martin and Taimela, Simo and Järvinen, Teppo and {FIDELITY (Finnish Degenerative Meniscus Lesion Study) Investigators}},
	month = aug,
	year = {2020},
	pmid = {32855201},
	keywords = {meniscus, osteoarthritis},
}

OBJECTIVES: To assess the long-term effects of arthroscopic partial meniscectomy (APM) on the development of radiographic knee osteoarthritis, and on knee symptoms and function, at 5 years follow-up. DESIGN: Multicentre, randomised, participant- and outcome assessor-blinded, placebo-surgery controlled trial. SETTING: Orthopaedic departments in five public hospitals in Finland. PARTICIPANTS: 146 adults, mean age 52 years (range 35-65 years), with knee symptoms consistent with degenerative medial meniscus tear verified by MRI scan and arthroscopically, and no clinical signs of knee osteoarthritis were randomised. INTERVENTIONS: APM or placebo surgery (diagnostic knee arthroscopy). MAIN OUTCOME MEASURES: We used two indices of radiographic knee osteoarthritis (increase in Kellgren and Lawrence grade ≥1, and increase in Osteoarthritis Research Society International (OARSI) atlas radiographic joint space narrowing and osteophyte sum score, respectively), and three validated patient-relevant measures of knee symptoms and function (Western Ontario Meniscal Evaluation Tool (WOMET), Lysholm, and knee pain after exercise using a numerical rating scale). RESULTS: There was a consistent, slightly greater risk for progression of radiographic knee osteoarthritis in the APM group as compared with the placebo surgery group (adjusted absolute risk difference in increase in Kellgren-Lawrence grade ≥1 of 13%, 95% CI -2% to 28%; adjusted absolute mean difference in OARSI sum score 0.7, 95% CI 0.1 to 1.3). There were no relevant between-group differences in the three patient-reported outcomes: adjusted absolute mean differences (APM vs placebo surgery), -1.7 (95% CI -7.7 to 4.3) in WOMET, -2.1 (95% CI -6.8 to 2.6) in Lysholm knee score, and -0.04 (95% CI -0.81 to 0.72) in knee pain after exercise, respectively. The corresponding adjusted absolute risk difference in the presence of mechanical symptoms was 18% (95% CI 5% to 31%); there were more symptoms reported in the APM group. All other secondary outcomes comparisons were similar. CONCLUSIONS: APM was associated with a slightly increased risk of developing radiographic knee osteoarthritis and no concomitant benefit in patient-relevant outcomes, at 5 years after surgery. TRIAL REGISTRATION: ClinicalTrials.gov (NCT01052233 and NCT00549172).

@article{kiadaliri_complex_2020,
	title = {Complex sociodemographic inequalities in consultations for low back pain: lessons from multilevel intersectional analysis},
	volume = {In Press},
	issn = {1872-6623},
	shorttitle = {Complex sociodemographic inequalities in consultations for low back pain},
	url = {https://doi.org/10.1097/j.pain.0000000000002081},
	doi = {10.1097/j.pain.0000000000002081},
	abstract = {Sociodemographic inequalities in the occurrence of low back pain (LBP) are well-studied. This study aimed to examine complex sociodemographic inequalities in the risk LBP consultation in the population from a socioeconomical intersectional perspective. Using register data, we identified 458,852 individuals aged 35-75 years residing in Skåne in 2013, with no previous LBP consultation since 2006. We created 108 strata using categories of age, sex, education, income, and nativity. With individuals nested within strata, we modelled the absolute risk (AR) of LBP consultation during 2014 in a series of multilevel logistic regression models. We quantified discriminatory accuracy (DA) of these variables by computing the variance partition coefficient (VPC) and area under the receiver operating characteristic curve (AUC). We identified 13,657 (3.0\%) people with a LBP consultation. The AR ranged from 2.1\% (95\% credible interval: 1.9\%, 2.3\%) among young native men with high education and high income to 4.8\% (4.3\%, 5.5\%) among young foreign-born women with medium education and low income (2.3-fold relative difference). DA of intersectional strata was very low (VPC 1.1\%, (0.7, 1.6); and AUC 0.56, (0.55, 0.56)). Sex (35.6\%) and nativity (19.2\%) had the largest contributions in explaining the initially small between-strata variation in risk of LBP. The low DA of the intersectional strata indicates the existence of limited intersectional inequalities in LBP consultation. Therefore, interventions to reduce LBP risk should be universal rather than targeted to specific socioeconomic groups with a higher average risk. Before planning targeted intervention, other risk factors with higher DA needs to be identified.},
	language = {eng},
	journal = {Pain},
	author = {Kiadaliri, Ali and Merlo, Juan and Englund, Martin},
	month = sep,
	year = {2020},
	pmid = {32947540},
}

Sociodemographic inequalities in the occurrence of low back pain (LBP) are well-studied. This study aimed to examine complex sociodemographic inequalities in the risk LBP consultation in the population from a socioeconomical intersectional perspective. Using register data, we identified 458,852 individuals aged 35-75 years residing in Skåne in 2013, with no previous LBP consultation since 2006. We created 108 strata using categories of age, sex, education, income, and nativity. With individuals nested within strata, we modelled the absolute risk (AR) of LBP consultation during 2014 in a series of multilevel logistic regression models. We quantified discriminatory accuracy (DA) of these variables by computing the variance partition coefficient (VPC) and area under the receiver operating characteristic curve (AUC). We identified 13,657 (3.0%) people with a LBP consultation. The AR ranged from 2.1% (95% credible interval: 1.9%, 2.3%) among young native men with high education and high income to 4.8% (4.3%, 5.5%) among young foreign-born women with medium education and low income (2.3-fold relative difference). DA of intersectional strata was very low (VPC 1.1%, (0.7, 1.6); and AUC 0.56, (0.55, 0.56)). Sex (35.6%) and nativity (19.2%) had the largest contributions in explaining the initially small between-strata variation in risk of LBP. The low DA of the intersectional strata indicates the existence of limited intersectional inequalities in LBP consultation. Therefore, interventions to reduce LBP risk should be universal rather than targeted to specific socioeconomic groups with a higher average risk. Before planning targeted intervention, other risk factors with higher DA needs to be identified.

@article{turkiewicz_probabilistic_2020,
	title = {Probabilistic {Quantification} of {Bias} to {Combine} the {Strengths} of {Population}-{Based} {Register} {Data} and {Clinical} {Cohorts}-{Studying} {Mortality} in {Osteoarthritis}},
	volume = {189},
	issn = {1476-6256},
	url = {https://doi.org/10.1093/aje/kwaa134},
	doi = {10.1093/aje/kwaa134},
	abstract = {We propose combining population-based register data with a nested clinical cohort to correct misclassification and unmeasured confounding through probabilistic quantification of bias. We have illustrated this approach by estimating the association between knee osteoarthritis and mortality. We used the Swedish Population Register to include all persons resident in the Skåne region in 2008 and assessed whether they had osteoarthritis using data from the Skåne Healthcare Register. We studied mortality through year 2017 by estimating hazard ratios. We used data from the Malmö Osteoarthritis Study (MOA), a small cohort study from Skåne, to derive bias parameters for probabilistic quantification of bias, to correct the hazard ratio estimate for differential misclassification of the knee osteoarthritis diagnosis and confounding from unmeasured obesity. We included 292,000 persons in the Skåne population and 1,419 from the MOA study. The adjusted association of knee osteoarthritis with all-cause mortality in the MOA sample had a hazard ratio of 1.10 (95\% confidence interval (CI): 0.80, 1.52) and was thus inconclusive. The naive association in the Skåne population had a hazard ratio of 0.95 (95\% CI: 0.93, 0.98), while the bias-corrected estimate was 1.02 (95\% CI: 0.59, 1.52), suggesting high uncertainty in bias correction. Combining population-based register data with clinical cohorts provides more information than using either data source separately.},
	language = {eng},
	number = {12},
	journal = {American Journal of Epidemiology},
	author = {Turkiewicz, Aleksandra and Nilsson, Peter M. and Kiadaliri, Ali},
	month = dec,
	year = {2020},
	pmid = {32639513},
	pmcid = {PMC7705601},
	keywords = {Aged, Aged, 80 and over, Bias, Female, Humans, Male, Middle Aged, Osteoarthritis, Knee, Registries, Sweden, mortality, osteoarthritis, probabilistic quantification of bias, register data},
	pages = {1590--1599},
}

We propose combining population-based register data with a nested clinical cohort to correct misclassification and unmeasured confounding through probabilistic quantification of bias. We have illustrated this approach by estimating the association between knee osteoarthritis and mortality. We used the Swedish Population Register to include all persons resident in the Skåne region in 2008 and assessed whether they had osteoarthritis using data from the Skåne Healthcare Register. We studied mortality through year 2017 by estimating hazard ratios. We used data from the Malmö Osteoarthritis Study (MOA), a small cohort study from Skåne, to derive bias parameters for probabilistic quantification of bias, to correct the hazard ratio estimate for differential misclassification of the knee osteoarthritis diagnosis and confounding from unmeasured obesity. We included 292,000 persons in the Skåne population and 1,419 from the MOA study. The adjusted association of knee osteoarthritis with all-cause mortality in the MOA sample had a hazard ratio of 1.10 (95% confidence interval (CI): 0.80, 1.52) and was thus inconclusive. The naive association in the Skåne population had a hazard ratio of 0.95 (95% CI: 0.93, 0.98), while the bias-corrected estimate was 1.02 (95% CI: 0.59, 1.52), suggesting high uncertainty in bias correction. Combining population-based register data with clinical cohorts provides more information than using either data source separately.

@article{magnusson_high_2020,
	title = {High genetic contribution to anterior cruciate ligament rupture: {Heritability} {\textasciitilde}69},
	volume = {In Press},
	issn = {1473-0480},
	shorttitle = {High genetic contribution to anterior cruciate ligament rupture},
	url = {https://doi.org/10.1136/bjsports-2020-102392},
	doi = {10.1136/bjsports-2020-102392},
	abstract = {OBJECTIVES: We aimed to determine the lifetime genetic risk for anterior cruciate ligament (ACL) rupture.
METHODS: We used a twin study approach, linking the Swedish Twin Register with national healthcare data to form a 30 year, population wide, longitudinal twin cohort. We studied ACL rupture in this cohort of 88 414 identical and fraternal twin pairs, aged ≥17 years, to determine the familial risk and heritability of ACL rupture.
RESULTS: The incidence rate of ACL rupture was 70 (95\% CI 66 to 74) per 100 000 person years. The familial risk, which is the excess risk ratio (RR) of the second twin having ACL rupture given that the first twin has had such a rupture, was higher in identical twin pairs (RR=8.6, 95\% CI 6.2 to 11.0) than in fraternal twin pairs (RR=1.9, 95\% CI 0.9 to 3.0). The overall heritability of ACL rupture was high, 69\% (95\% CI 47 to 91), increasing from 60\% at age 17 years to 80\% at age 60 years. Women and men had similar familial risk and heritability of ACL rupture.
CONCLUSION: The genetic contribution to ACL rupture of {\textasciitilde}69\% is high and suggests strong familial clustering. If clinicians recognise the high genetic risk of such injury, they may be better able to counsel athletes whose near relatives have had ACL rupture.},
	language = {eng},
	journal = {British Journal of Sports Medicine},
	author = {Magnusson, Karin and Turkiewicz, Aleksandra and Hughes, Velocity and Frobell, Richard and Englund, Martin},
	month = dec,
	year = {2020},
	pmid = {33288618},
	keywords = {ACL, contact sports, epidemiology, genetics, injury prevention},
}

OBJECTIVES: We aimed to determine the lifetime genetic risk for anterior cruciate ligament (ACL) rupture. METHODS: We used a twin study approach, linking the Swedish Twin Register with national healthcare data to form a 30 year, population wide, longitudinal twin cohort. We studied ACL rupture in this cohort of 88 414 identical and fraternal twin pairs, aged ≥17 years, to determine the familial risk and heritability of ACL rupture. RESULTS: The incidence rate of ACL rupture was 70 (95% CI 66 to 74) per 100 000 person years. The familial risk, which is the excess risk ratio (RR) of the second twin having ACL rupture given that the first twin has had such a rupture, was higher in identical twin pairs (RR=8.6, 95% CI 6.2 to 11.0) than in fraternal twin pairs (RR=1.9, 95% CI 0.9 to 3.0). The overall heritability of ACL rupture was high, 69% (95% CI 47 to 91), increasing from 60% at age 17 years to 80% at age 60 years. Women and men had similar familial risk and heritability of ACL rupture. CONCLUSION: The genetic contribution to ACL rupture of \textasciitilde69% is high and suggests strong familial clustering. If clinicians recognise the high genetic risk of such injury, they may be better able to counsel athletes whose near relatives have had ACL rupture.

@article{dellisola_willingness_2020,
	title = {Willingness to undergo joint surgery following a first-line intervention for osteoarthritis: data from the {BOA} register},
	volume = {In Press},
	issn = {2151-4658},
	shorttitle = {Willingness to undergo joint surgery following a first-line intervention for osteoarthritis},
	url = {https://doi.org/10.1002/acr.24486},
	doi = {10.1002/acr.24486},
	abstract = {OBJECTIVE: to assess the proportion of participants reconsidering their willingness to undergo surgery after three and 12 months. Secondary aims are to analyse and compare the characteristics of people willing and unwilling to undergo joint surgery for osteoarthritis (OA) before a first-line intervention; to study the association between pain intensity, walking difficulties, self-efficacy and fear of movement with the willingness to undergo surgery.
DESIGN: This is an observational study based on Swedish register data. We included 30,578 people with knee or hip OA who participated in a first-line intervention including education and exercise.
RESULTS: People willing to undergo surgery at baseline showed a higher proportion of men (40\% vs 27\%) and more severe symptoms and disability. Respectively, 45\% and 30\% of the people with knee and hip OA who were willing to undergo surgery at baseline became unwilling after the intervention. At the end of the study period (12 months), 35\% and 19\% of those with knee and hip OA, respectively, who were willing to undergo surgery at baseline became unwilling. High pain intensity, walking difficulties, and fear of movement were associated with higher odds of being willing to undergo surgery at both follow-ups while increased self-efficacy showed the opposite association.
CONCLUSIONS: A first-line intervention for OA is associated with reduced willingness to undergo surgery with a greater proportion among knee OA than hip OA people. Due to its temporal variability, willingness to undergo surgery should be used with care to deem surgery eligibility.},
	language = {eng},
	journal = {Arthritis Care \& Research},
	author = {Dell'Isola, Andrea and Jönsson, Thèrèse and Rolfson, Ola and Cronström, Anna and Englund, Martin and Dahlberg, Leif},
	month = oct,
	year = {2020},
	pmid = {33053273},
}

OBJECTIVE: to assess the proportion of participants reconsidering their willingness to undergo surgery after three and 12 months. Secondary aims are to analyse and compare the characteristics of people willing and unwilling to undergo joint surgery for osteoarthritis (OA) before a first-line intervention; to study the association between pain intensity, walking difficulties, self-efficacy and fear of movement with the willingness to undergo surgery. DESIGN: This is an observational study based on Swedish register data. We included 30,578 people with knee or hip OA who participated in a first-line intervention including education and exercise. RESULTS: People willing to undergo surgery at baseline showed a higher proportion of men (40% vs 27%) and more severe symptoms and disability. Respectively, 45% and 30% of the people with knee and hip OA who were willing to undergo surgery at baseline became unwilling after the intervention. At the end of the study period (12 months), 35% and 19% of those with knee and hip OA, respectively, who were willing to undergo surgery at baseline became unwilling. High pain intensity, walking difficulties, and fear of movement were associated with higher odds of being willing to undergo surgery at both follow-ups while increased self-efficacy showed the opposite association. CONCLUSIONS: A first-line intervention for OA is associated with reduced willingness to undergo surgery with a greater proportion among knee OA than hip OA people. Due to its temporal variability, willingness to undergo surgery should be used with care to deem surgery eligibility.

@article{kiadaliri_trajectory_2020,
	title = {Trajectory of excess healthcare consultations, medication use, and work disability in newly diagnosed knee osteoarthritis: a matched longitudinal register-based study},
	volume = {In Press},
	issn = {1522-9653},
	shorttitle = {Trajectory of excess healthcare consultations, medication use, and work disability in newly diagnosed knee osteoarthritis},
	url = {https://doi.org/10.1016/j.joca.2020.12.008},
	doi = {10.1016/j.joca.2020.12.008},
	abstract = {PURPOSE: To estimate the excess healthcare use and work disability attributable to knee osteoarthritis (OA) in the first 5 years following diagnosis.
METHODS: Among individual aged 40-80 years who resided in Skåne on 31st December 2008, we identified those with a main diagnosis of knee OA during 2009-2014 and no previous diagnosis of any OA from 1998 (n = 16,888). We created a comparison cohort matched (1:1) by sex, age, and municipality from individuals with no OA diagnosis (at any site) during 1998-2016. We compared healthcare use and net disability days for 60 months following diagnosis between the two groups. We applied a survival-adjusted regression technique controlling for sociodemographic characteristics as well as pre-diagnosis outcome and comorbidity.
RESULTS: The estimated 5-year incremental effects of knee OA per-patient were 16.8 (95\% CI: 15.8, 17.7) healthcare consultations, 0.7 (0.4, 1.1) inpatient days, 420 (372, 490) defined daily dose of prescribed medications, and 21.8 (15.2, 30.0) net disability days. Primary care consultations constituted about 73\% of the excess healthcare consultations. Most of these incremental effects occurred in the first year after diagnosis. Better survival in the knee OA group accounted for 0.7 (95\% CI: 0.5, 0.8) and 1.4 (0.7, 2.6) of the excess healthcare consultations and net disability days, respectively. Both estimated total and incremental resources use were generally greater for women than men with knee OA.
CONCLUSION: Knee OA was associated with considerable excess healthcare use and work disability independent of pre-diagnosis resources use, comorbidity, and sociodemographic characteristics.},
	language = {eng},
	journal = {Osteoarthritis and Cartilage},
	author = {Kiadaliri, A. and Englund, M.},
	month = dec,
	year = {2020},
	pmid = {33359251},
	keywords = {Healthcare consultation, Incremental analysis, Knee osteoarthritis, Sweden, Work disability},
}

PURPOSE: To estimate the excess healthcare use and work disability attributable to knee osteoarthritis (OA) in the first 5 years following diagnosis. METHODS: Among individual aged 40-80 years who resided in Skåne on 31st December 2008, we identified those with a main diagnosis of knee OA during 2009-2014 and no previous diagnosis of any OA from 1998 (n = 16,888). We created a comparison cohort matched (1:1) by sex, age, and municipality from individuals with no OA diagnosis (at any site) during 1998-2016. We compared healthcare use and net disability days for 60 months following diagnosis between the two groups. We applied a survival-adjusted regression technique controlling for sociodemographic characteristics as well as pre-diagnosis outcome and comorbidity. RESULTS: The estimated 5-year incremental effects of knee OA per-patient were 16.8 (95% CI: 15.8, 17.7) healthcare consultations, 0.7 (0.4, 1.1) inpatient days, 420 (372, 490) defined daily dose of prescribed medications, and 21.8 (15.2, 30.0) net disability days. Primary care consultations constituted about 73% of the excess healthcare consultations. Most of these incremental effects occurred in the first year after diagnosis. Better survival in the knee OA group accounted for 0.7 (95% CI: 0.5, 0.8) and 1.4 (0.7, 2.6) of the excess healthcare consultations and net disability days, respectively. Both estimated total and incremental resources use were generally greater for women than men with knee OA. CONCLUSION: Knee OA was associated with considerable excess healthcare use and work disability independent of pre-diagnosis resources use, comorbidity, and sociodemographic characteristics.

@article{kiadaliri_fall-related_2019,
	title = {Fall-related mortality in southern {Sweden}: a multiple cause of death analysis, 1998-2014},
	volume = {25},
	issn = {1475-5785},
	shorttitle = {Fall-related mortality in southern {Sweden}},
	url = {https://doi.org/10.1136/injuryprev-2017-042425},
	doi = {10.1136/injuryprev-2017-042425},
	abstract = {OBJECTIVES: To investigate temporal trend in fall mortality among adults (aged ≥20 years) in southern Sweden using multiple cause of death data.
METHODS: We examined all death certificates (DCs, n=2 01 488) in adults recorded in the Skåne region during 1998-2014. We identified all fall deaths using International Statistical Classification of Diseases (ICD)-10 codes (W00-W19) and calculated the mortality rates by age and sex. Temporal trends were evaluated using joinpoint regression and associated causes were identified by age-adjusted and sex-adjusted observed/expected ratios.
RESULTS: Falls were mentioned on 1.0\% and selected as underlying cause in 0.7\% of all DCs, with the highest frequency among those aged ≥70 years. The majority (75.6\%) of fall deaths were coded as unspecified fall (ICD-10 code: W19) followed by falling on or from stairs/steps (7.7\%, ICD-10 code: W10) and other falls on the same level (6.3\%, ICD-10 code: W18). The mean age at fall deaths increased from 77.5 years in 1998-2002 to 82.9 years in 2010-2014 while for other deaths it increased from 78.5 to 79.8 years over the same period. The overall mean age-standardised rate of fall mortality was 8.3 and 4.0 per 1 00 000 person-years in men and women, respectively, and increased by 1.7\% per year in men and 0.8\% per year in women during 1998-2014. Head injury and diseases of the circulatory system were recorded as contributing cause on 48.7\% of fall deaths.
CONCLUSIONS: There is an increasing trend of deaths due to falls in southern Sweden. Further investigations are required to explain this observation particularly among elderly men.},
	language = {eng},
	number = {2},
	journal = {Injury Prevention: Journal of the International Society for Child and Adolescent Injury Prevention},
	author = {Kiadaliri, Aliasghar A. and Rosengren, Björn E. and Englund, Martin},
	year = {2019},
	pmid = {29056585},
	keywords = {Accidental Falls, Age Distribution, Aged, Aged, 80 and over, Cause of Death, Death Certificates, Female, Health Surveys, Humans, International Classification of Diseases, Male, Mortality, Sweden, descriptive epidemiology, fall, mortality},
	pages = {129--135},
}

OBJECTIVES: To investigate temporal trend in fall mortality among adults (aged ≥20 years) in southern Sweden using multiple cause of death data. METHODS: We examined all death certificates (DCs, n=2 01 488) in adults recorded in the Skåne region during 1998-2014. We identified all fall deaths using International Statistical Classification of Diseases (ICD)-10 codes (W00-W19) and calculated the mortality rates by age and sex. Temporal trends were evaluated using joinpoint regression and associated causes were identified by age-adjusted and sex-adjusted observed/expected ratios. RESULTS: Falls were mentioned on 1.0% and selected as underlying cause in 0.7% of all DCs, with the highest frequency among those aged ≥70 years. The majority (75.6%) of fall deaths were coded as unspecified fall (ICD-10 code: W19) followed by falling on or from stairs/steps (7.7%, ICD-10 code: W10) and other falls on the same level (6.3%, ICD-10 code: W18). The mean age at fall deaths increased from 77.5 years in 1998-2002 to 82.9 years in 2010-2014 while for other deaths it increased from 78.5 to 79.8 years over the same period. The overall mean age-standardised rate of fall mortality was 8.3 and 4.0 per 1 00 000 person-years in men and women, respectively, and increased by 1.7% per year in men and 0.8% per year in women during 1998-2014. Head injury and diseases of the circulatory system were recorded as contributing cause on 48.7% of fall deaths. CONCLUSIONS: There is an increasing trend of deaths due to falls in southern Sweden. Further investigations are required to explain this observation particularly among elderly men.

@article{emery_establishing_2019,
	title = {Establishing outcome measures in early knee osteoarthritis},
	volume = {15},
	issn = {1759-4804},
	url = {https://doi.org/10.1038/s41584-019-0237-3},
	doi = {10.1038/s41584-019-0237-3},
	abstract = {The classification and monitoring of individuals with early knee osteoarthritis (OA) are important considerations for the design and evaluation of therapeutic interventions and require the identification of appropriate outcome measures. Potential outcome domains to assess for early OA include patient-reported outcomes (such as pain, function and quality of life), features of clinical examination (such as joint line tenderness and crepitus), objective measures of physical function, levels of physical activity, features of imaging modalities (such as of magnetic resonance imaging) and biochemical markers in body fluid. Patient characteristics such as adiposity and biomechanics of the knee could also have relevance to the assessment of early OA. Importantly, research is needed to enable the selection of outcome measures that are feasible, reliable and validated in individuals at risk of knee OA or with early knee OA. In this Perspectives article, potential outcome measures for early symptomatic knee OA are discussed, including those measures that could be of use in clinical practice and/or the research setting.},
	language = {eng},
	number = {7},
	journal = {Nature Reviews. Rheumatology},
	author = {Emery, Carolyn A. and Whittaker, Jackie L. and Mahmoudian, Armaghan and Lohmander, L. Stefan and Roos, Ewa M. and Bennell, Kim L. and Toomey, Clodagh M. and Reimer, Raylene A. and Thompson, Dylan and Ronsky, Janet L. and Kuntze, Gregor and Lloyd, David G. and Andriacchi, Thomas and Englund, Martin and Kraus, Virginia B. and Losina, Elena and Bierma-Zeinstra, Sita and Runhaar, Jos and Peat, George and Luyten, Frank P. and Snyder-Mackler, Lynn and Risberg, May Arna and Mobasheri, Ali and Guermazi, Ali and Hunter, David J. and Arden, Nigel K.},
	year = {2019},
	pmid = {31201386},
	keywords = {Arthralgia, Humans, Knee Joint, Magnetic Resonance Imaging, Osteoarthritis, Knee, Patient Reported Outcome Measures, Prognosis, Quality of Life, Range of Motion, Articular},
	pages = {438--448},
}

The classification and monitoring of individuals with early knee osteoarthritis (OA) are important considerations for the design and evaluation of therapeutic interventions and require the identification of appropriate outcome measures. Potential outcome domains to assess for early OA include patient-reported outcomes (such as pain, function and quality of life), features of clinical examination (such as joint line tenderness and crepitus), objective measures of physical function, levels of physical activity, features of imaging modalities (such as of magnetic resonance imaging) and biochemical markers in body fluid. Patient characteristics such as adiposity and biomechanics of the knee could also have relevance to the assessment of early OA. Importantly, research is needed to enable the selection of outcome measures that are feasible, reliable and validated in individuals at risk of knee OA or with early knee OA. In this Perspectives article, potential outcome measures for early symptomatic knee OA are discussed, including those measures that could be of use in clinical practice and/or the research setting.

@article{kiadaliri_educational_2019,
	title = {Educational inequalities in all-cause and cause-specific mortality among people with gout: a register-based matched cohort study in southern {Sweden}},
	volume = {18},
	issn = {1475-9276},
	shorttitle = {Educational inequalities in all-cause and cause-specific mortality among people with gout},
	url = {https://doi.org/10.1186/s12939-019-1076-1},
	doi = {10.1186/s12939-019-1076-1},
	abstract = {BACKGROUND: Gout is the most common inflammatory arthritis with a rising prevalence around the globe. While educational inequalities in incidence and prevalence of gout have been reported, no previous study investigated educational inequality in mortality among people with gout. The aim of this study was to assess absolute and relative educational inequalities in all-cause and cause-specific mortality among people with gout in comparison with an age- and sex-matched cohort free of gout in southern Sweden.
METHODS: We identified all residents aged ≥30 years of Skåne region with doctor-diagnosed gout (ICD-10 code M10, n = 24,877) during 1998-2013 and up to 4 randomly selected age- and sex-matched comparators free of gout (reference cohort, n = 99,504). These were followed until death, emigration, or end of 2014. We used additive hazards models and Cox regression adjusted for age, sex, marital status, and country of birth to estimate slope and relative indices of inequality (SII/RII). Three cause-of-death attribution approaches were considered for RII estimation: "underlying cause", "any mention", and "weighted multiple-cause".
RESULTS: Gout patients with the lowest education had 1547 (95\% CI: 1001, 2092) more deaths per 100,000 person-years compared with those with the highest education. These absolute inequalities were larger than in the reference population (1255, 95\% CI: 1038, 1472). While the contribution of cardiovascular (cancer) mortality to these absolute inequalities was greater (smaller) in men with gout than those without, the opposite was seen among women. Relative inequality in all-cause mortality was smaller in gout (RII 1.29 [1.18, 1.41]) than in the reference population (1.46 [1.38, 1.53]). The weighted multiple-cause approach generally led to larger RIIs than the underlying cause approach.
CONCLUSIONS: Our register-based matched cohort study showed that low level of education was associated with increased mortality among gout patients. Although the magnitude of relative inequality was smaller in people with gout compared with those without, the absolute inequalities were greater reflecting a major mortality burden among those with lower education.},
	language = {eng},
	number = {1},
	journal = {International Journal for Equity in Health},
	author = {Kiadaliri, Ali and Moreno-Betancur, Margarita and Turkiewicz, Aleksandra and Englund, Martin},
	year = {2019},
	pmid = {31660978},
	pmcid = {PMC6819587},
	keywords = {Adult, Aged, Aged, 80 and over, Cause of Death, Cause-specific mortality, Cohort Studies, Education, Educational Status, Female, Gout, Humans, Inequality, Male, Middle Aged, Multiple cause of death, Registries, Socioeconomic Factors, Sweden},
	pages = {164},
}

BACKGROUND: Gout is the most common inflammatory arthritis with a rising prevalence around the globe. While educational inequalities in incidence and prevalence of gout have been reported, no previous study investigated educational inequality in mortality among people with gout. The aim of this study was to assess absolute and relative educational inequalities in all-cause and cause-specific mortality among people with gout in comparison with an age- and sex-matched cohort free of gout in southern Sweden. METHODS: We identified all residents aged ≥30 years of Skåne region with doctor-diagnosed gout (ICD-10 code M10, n = 24,877) during 1998-2013 and up to 4 randomly selected age- and sex-matched comparators free of gout (reference cohort, n = 99,504). These were followed until death, emigration, or end of 2014. We used additive hazards models and Cox regression adjusted for age, sex, marital status, and country of birth to estimate slope and relative indices of inequality (SII/RII). Three cause-of-death attribution approaches were considered for RII estimation: "underlying cause", "any mention", and "weighted multiple-cause". RESULTS: Gout patients with the lowest education had 1547 (95% CI: 1001, 2092) more deaths per 100,000 person-years compared with those with the highest education. These absolute inequalities were larger than in the reference population (1255, 95% CI: 1038, 1472). While the contribution of cardiovascular (cancer) mortality to these absolute inequalities was greater (smaller) in men with gout than those without, the opposite was seen among women. Relative inequality in all-cause mortality was smaller in gout (RII 1.29 [1.18, 1.41]) than in the reference population (1.46 [1.38, 1.53]). The weighted multiple-cause approach generally led to larger RIIs than the underlying cause approach. CONCLUSIONS: Our register-based matched cohort study showed that low level of education was associated with increased mortality among gout patients. Although the magnitude of relative inequality was smaller in people with gout compared with those without, the absolute inequalities were greater reflecting a major mortality burden among those with lower education.

@article{kiadaliri_impact_2019,
	title = {Impact of a national guideline on use of knee arthroscopy: {An} interrupted time-series analysis},
	volume = {31},
	issn = {1464-3677},
	shorttitle = {Impact of a national guideline on use of knee arthroscopy},
	url = {https://doi.org/10.1093/intqhc/mzz089},
	doi = {10.1093/intqhc/mzz089},
	abstract = {OBJECTIVE: To assess the impact of the Swedish health authority recommendation against the use of knee arthroscopy in patients aged ≥40 years with knee osteoarthritis (OA).
DESIGN: Interrupted time series analysis.
SETTING: Public health care in Skåne region.
PARTICIPANTS: Patients aged ≥40 years who underwent knee arthroscopy from January 2010 to December 2015.
INTERVENTION(S): National guideline's recommendation against the use of knee arthroscopy in patients with knee OA.
MAIN OUTCOME MEASURE(S): 1) proportion of patients aged ≥40 years with a main diagnosis of Knee OA and/or degenerative meniscal lesions (DML) who underwent knee arthroscopy, and 2) overall knee arthroscopy rate per 100,000 Skåne population aged ≥40 years.
RESULTS: A total of 6,155 knee arthroscopy were performed among people aged ≥40 years during study period. Of 42,044 patients with Knee OA/DML, 3,728 had knee arthroscopy. The recommendation was associated with reductions in the use of knee arthroscopy and two years after the recommendation, there was a reduction of 28.6\% (95\% CI: 9.3, 47.8) and 34.7\% (23.9, 45.4) in proportion of Knee OA/DML patients with knee arthroscopy and the overall knee arthroscopy rate, respectively, relative to that expected if pre-recommendation trend continued. Our sensitivity analysis showed that the use of total knee replacement was stable over the study period.
CONCLUSION: The national recommendation was associated with reduction in use of knee arthroscopy in public health care in southern Sweden. However, still 4.5\% of these patients underwent knee arthroscopy in 2015 implying that more efforts are required to achieve the recommended target.},
	language = {eng},
	number = {9},
	journal = {International Journal for Quality in Health Care: Journal of the International Society for Quality in Health Care},
	author = {Kiadaliri, Ali and Bergkvist, Dan and Dahlberg, Leif E. and Englund, Martin},
	month = nov,
	year = {2019},
	pmid = {31725873},
	pmcid = {PMC7076349},
	keywords = {Adult, Arthroplasty, Replacement, Knee, Arthroplasty, Replacement, Knee/statistics \& numerical data, Arthroscopy, Arthroscopy/*statistics \& numerical data, Guidelines as Topic, Humans, Interrupted Time Series Analysis, Knee Joint, Knee Joint/*surgery, Meniscus, Meniscus/pathology/surgery, Middle Aged, Osteoarthritis, Knee, Osteoarthritis, Knee/*surgery, Sweden, degenerative knee disease, interrupted time series, knee arthroscopy},
	pages = {G113--G118},
}

OBJECTIVE: To assess the impact of the Swedish health authority recommendation against the use of knee arthroscopy in patients aged ≥40 years with knee osteoarthritis (OA). DESIGN: Interrupted time series analysis. SETTING: Public health care in Skåne region. PARTICIPANTS: Patients aged ≥40 years who underwent knee arthroscopy from January 2010 to December 2015. INTERVENTION(S): National guideline's recommendation against the use of knee arthroscopy in patients with knee OA. MAIN OUTCOME MEASURE(S): 1) proportion of patients aged ≥40 years with a main diagnosis of Knee OA and/or degenerative meniscal lesions (DML) who underwent knee arthroscopy, and 2) overall knee arthroscopy rate per 100,000 Skåne population aged ≥40 years. RESULTS: A total of 6,155 knee arthroscopy were performed among people aged ≥40 years during study period. Of 42,044 patients with Knee OA/DML, 3,728 had knee arthroscopy. The recommendation was associated with reductions in the use of knee arthroscopy and two years after the recommendation, there was a reduction of 28.6% (95% CI: 9.3, 47.8) and 34.7% (23.9, 45.4) in proportion of Knee OA/DML patients with knee arthroscopy and the overall knee arthroscopy rate, respectively, relative to that expected if pre-recommendation trend continued. Our sensitivity analysis showed that the use of total knee replacement was stable over the study period. CONCLUSION: The national recommendation was associated with reduction in use of knee arthroscopy in public health care in southern Sweden. However, still 4.5% of these patients underwent knee arthroscopy in 2015 implying that more efforts are required to achieve the recommended target.

@article{dellisola_understanding_2019,
	title = {Understanding the role of diabetes in the osteoarthritis disease and treatment  process: a study protocol for the {Swedish} {Osteoarthritis} and {Diabetes} ({SOAD}) cohort.},
	volume = {9},
	copyright = {© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY. Published by  BMJ.},
	issn = {2044-6055 2044-6055},
	url = {https://doi.org/10.1136/bmjopen-2019-032923},
	doi = {10.1136/bmjopen-2019-032923},
	abstract = {INTRODUCTION: Osteoarthritis (OA) is the most common form of arthritis and a leading  cause of disability worldwide. Metabolic comorbidities such as type II diabetes  occur with a higher rate in people with OA than in the general population. Several  factors including obesity, hyperglycaemia toxicity and physical inactivity have been  suggested as potential links between diabetes and OA, and have been shown to  negatively impact patients' health and quality of life. However, little is known on  the role of diabetes in determining the outcome of non-surgical and surgical  management of OA, and at the same time, how different OA interventions may affect  diabetes control. Thus, the overall aim of this project is to explore (1) the impact  of diabetes on the outcome of non-surgical and surgical OA treatments and (2) the  impact of non-surgical and surgical OA treatments on diabetes control. METHODS AND  ANALYSIS: The study cohort is based on prospectively ascertained register data on a  national level in Sweden. Data from OA patients who received a first-line  non-surgical intervention and are registered in the National Quality Register for  Better Management of Patients with Osteoarthritis will be merged with data from the  Swedish Knee and Hip Arthroplasty Registers and the National Diabetes Register.  Additional variables regarding patients' use of prescribed drugs, comorbidities,  socioeconomic status and cause of death will be obtained through other national  health and population data registers. The linkage will be performed on an individual  level using unique personal identity numbers. ETHICS AND DISSEMINATION: This study  received ethical approval (2019-02570) from the Swedish Ethical Review Authority.  Results from this cohort will be submitted to peer-reviewed scientific journals and  reported at the leading national and international meetings in the field.},
	language = {eng},
	number = {12},
	journal = {BMJ open},
	author = {Dell'Isola, Andrea and Vinblad, Johanna and Lohmander, Stefan and Svensson, Ann-Marie RN and Turkiewicz, Aleksandra and Franzén, Stefan and Nauclér, Emma and W-Dahl, A. and Abbott, Allan and Dahlberg, L. and Rolfson, Ola and Englund, Martin},
	month = dec,
	year = {2019},
	pmid = {31852705},
	pmcid = {PMC6937096},
	keywords = {*cohort, *exercise, *general diabetes, *osteoarthritis, *register, *surgery, cohort, exercise, general diabetes, osteoarthritis, register, surgery},
	pages = {e032923},
}

INTRODUCTION: Osteoarthritis (OA) is the most common form of arthritis and a leading cause of disability worldwide. Metabolic comorbidities such as type II diabetes occur with a higher rate in people with OA than in the general population. Several factors including obesity, hyperglycaemia toxicity and physical inactivity have been suggested as potential links between diabetes and OA, and have been shown to negatively impact patients' health and quality of life. However, little is known on the role of diabetes in determining the outcome of non-surgical and surgical management of OA, and at the same time, how different OA interventions may affect diabetes control. Thus, the overall aim of this project is to explore (1) the impact of diabetes on the outcome of non-surgical and surgical OA treatments and (2) the impact of non-surgical and surgical OA treatments on diabetes control. METHODS AND ANALYSIS: The study cohort is based on prospectively ascertained register data on a national level in Sweden. Data from OA patients who received a first-line non-surgical intervention and are registered in the National Quality Register for Better Management of Patients with Osteoarthritis will be merged with data from the Swedish Knee and Hip Arthroplasty Registers and the National Diabetes Register. Additional variables regarding patients' use of prescribed drugs, comorbidities, socioeconomic status and cause of death will be obtained through other national health and population data registers. The linkage will be performed on an individual level using unique personal identity numbers. ETHICS AND DISSEMINATION: This study received ethical approval (2019-02570) from the Swedish Ethical Review Authority. Results from this cohort will be submitted to peer-reviewed scientific journals and reported at the leading national and international meetings in the field.

@article{zhang_association_2019,
	title = {The association between meniscal body extrusion and the development/enlargement of bone marrow lesions on knee {MRI} in overweight and obese women},
	issn = {2665-9131},
	url = {http://www.sciencedirect.com/science/article/pii/S2665913119300184},
	doi = {10.1016/j.ocarto.2019.100015},
	abstract = {Objective
To determine the association between meniscal body extrusion and bone marrow lesion (BML) development/enlargement in overweight and obese women at high risk of knee osteoarthritis (OA).
Design
We used baseline and 30 months follow-up data of the PROOF study, Netherlands, comprising overweight or obese women aged 50–60 years, free of clinical knee OA. All subjects (n = 395) completed a questionnaire on knee complaints and physical activity, underwent physical examination, radiography, and repeated 1.5 T MRI of both knees. Using the mid-coronal MRI slice, one observer measured tibial plateau width and meniscal body extrusion of both menisci in both knees. BMLs and meniscal damage were read using the semi-quantitative MOAKS scoring system by another observer. The association between BML development and meniscal extrusion was primarily analyzed with a random-effects logistic regression model adjusted for age, body weight, body height, physical activity, meniscus damage, knee alignment, and tibia width. In addition, we used a fixed-effect regression model for evaluation of knee-specific factors.
Results
In our primary model, there was about 24\% increased risk of BML incidence/enlargement per 1 mm extrusion (95\% confidence interval [CI] 0.99, 1.57) for medial compartments and 69\% risk increase (95\% confidence interval [CI] 1.27, 2.25) for the lateral compartments. Results from the fixed-effects regression model were similar, strengthening the validity of the findings.
Conclusions
Meniscal body extrusion is an important factor influencing BML development/enlargement, and thus may be a potential treatment target in knee OA development.},
	language = {en},
	urldate = {2019-12-20},
	journal = {Osteoarthritis and Cartilage Open},
	author = {Zhang, Fan and Bierma-Zeinstra, Sita M. and Oei, Edwin H. G. and Turkiewicz, Aleksandra and Englund, Martin and Runhaar, Jos},
	month = nov,
	year = {2019},
	keywords = {Bone marrow lesions, Meniscal extrusion, Overweight women},
	pages = {100015},
}

Objective To determine the association between meniscal body extrusion and bone marrow lesion (BML) development/enlargement in overweight and obese women at high risk of knee osteoarthritis (OA). Design We used baseline and 30 months follow-up data of the PROOF study, Netherlands, comprising overweight or obese women aged 50–60 years, free of clinical knee OA. All subjects (n = 395) completed a questionnaire on knee complaints and physical activity, underwent physical examination, radiography, and repeated 1.5 T MRI of both knees. Using the mid-coronal MRI slice, one observer measured tibial plateau width and meniscal body extrusion of both menisci in both knees. BMLs and meniscal damage were read using the semi-quantitative MOAKS scoring system by another observer. The association between BML development and meniscal extrusion was primarily analyzed with a random-effects logistic regression model adjusted for age, body weight, body height, physical activity, meniscus damage, knee alignment, and tibia width. In addition, we used a fixed-effect regression model for evaluation of knee-specific factors. Results In our primary model, there was about 24% increased risk of BML incidence/enlargement per 1 mm extrusion (95% confidence interval [CI] 0.99, 1.57) for medial compartments and 69% risk increase (95% confidence interval [CI] 1.27, 2.25) for the lateral compartments. Results from the fixed-effects regression model were similar, strengthening the validity of the findings. Conclusions Meniscal body extrusion is an important factor influencing BML development/enlargement, and thus may be a potential treatment target in knee OA development.

@article{hameed_prevalence_2019,
	title = {Prevalence and incidence of non-gout crystal arthropathy in southern {Sweden}},
	volume = {21},
	issn = {1478-6362},
	url = {https://doi.org/10.1186/s13075-019-2077-6},
	doi = {10.1186/s13075-019-2077-6},
	abstract = {To estimate the prevalence and incidence of non-gout crystal arthropathy in relation to socioeconomic factors in southern Sweden.},
	number = {1},
	urldate = {2020-01-10},
	journal = {Arthritis Research \& Therapy},
	author = {Hameed, Mohaned and Turkiewicz, Aleksandra and Englund, Martin and Jacobsson, Lennart and Kapetanovic, Meliha C.},
	month = dec,
	year = {2019},
	pages = {291},
}

To estimate the prevalence and incidence of non-gout crystal arthropathy in relation to socioeconomic factors in southern Sweden.

@article{daugaard_effects_2019,
	title = {The effects of weight loss on imaging outcomes in osteoarthritis of the hip or knee in people who are overweight or obese: a systematic review},
	volume = {In Press},
	issn = {1063-4584},
	shorttitle = {The effects of weight loss on imaging outcomes in osteoarthritis of the hip or knee in people who are overweight or obese},
	url = {http://www.sciencedirect.com/science/article/pii/S1063458419312622},
	doi = {10.1016/j.joca.2019.10.013},
	abstract = {Objective
To evaluate the structural effects of weight loss on hip or knee osteoarthritis (OA) and to summarize which structural joint pathologies have been examined and the evidence for the outcome measurement instruments applied.
Design
Based on a pre-specified protocol (available: PROSPERO CRD42017065263), we conducted a systematic search of the bibliographic databases, Medline, Embase and Web of Science identifying longitudinal articles reporting the effects of weight loss on structural imaging outcomes in OA of the hip or knee in people who are overweight or obese.
Results
From 1625 potentially eligible records, 14 articles (from 6 cohorts) were included. 2 cohorts were derived from RCTs. Evaluated pathologies were: articular cartilage (n = 7), joint space width (n = 3), bone marrow lesions (n = 5), synovitis (n = 2), effusion (n = 1), meniscus (n = 3), bone marrow density (n = 1) and infrapatellar fat pad (IPFP; n = 2). Cartilage showed conflicting results when evaluating cartilage thickness by direct thickness measurements. Compositional dGEMRIC and T2 mapping measures in early knee OA showed trends towards reduced cartilage degeneration. Joint space width on conventional radiographs showed no change. Weight loss reduced the size of the IPFP. Synovitis and effusion were not affected. Following weight loss DXA showed bone loss at the hip.
Conclusion
We did not find consistent evidence of the effects of weight loss on OA structural pathology in people who are overweight or obese. There is a need to achieve consensus on which structural pathologies and measurements to apply in weight loss and OA research.},
	language = {en},
	urldate = {2019-12-16},
	journal = {Osteoarthritis and Cartilage},
	author = {Daugaard, C. L. and Hangaard, S. and Bartels, E. M. and Gudbergsen, H. and Christensen, R. and Bliddal, H. and Englund, M. and Conaghan, P. G. and Boesen, M.},
	month = nov,
	year = {2019},
	keywords = {Imaging, Osteoarthritis, Review, Weight loss},
}

Objective To evaluate the structural effects of weight loss on hip or knee osteoarthritis (OA) and to summarize which structural joint pathologies have been examined and the evidence for the outcome measurement instruments applied. Design Based on a pre-specified protocol (available: PROSPERO CRD42017065263), we conducted a systematic search of the bibliographic databases, Medline, Embase and Web of Science identifying longitudinal articles reporting the effects of weight loss on structural imaging outcomes in OA of the hip or knee in people who are overweight or obese. Results From 1625 potentially eligible records, 14 articles (from 6 cohorts) were included. 2 cohorts were derived from RCTs. Evaluated pathologies were: articular cartilage (n = 7), joint space width (n = 3), bone marrow lesions (n = 5), synovitis (n = 2), effusion (n = 1), meniscus (n = 3), bone marrow density (n = 1) and infrapatellar fat pad (IPFP; n = 2). Cartilage showed conflicting results when evaluating cartilage thickness by direct thickness measurements. Compositional dGEMRIC and T2 mapping measures in early knee OA showed trends towards reduced cartilage degeneration. Joint space width on conventional radiographs showed no change. Weight loss reduced the size of the IPFP. Synovitis and effusion were not affected. Following weight loss DXA showed bone loss at the hip. Conclusion We did not find consistent evidence of the effects of weight loss on OA structural pathology in people who are overweight or obese. There is a need to achieve consensus on which structural pathologies and measurements to apply in weight loss and OA research.

@article{kestila_three-dimensional_2019,
	title = {Three-dimensional microstructure of human meniscus posterior horn in health and osteoarthritis},
	volume = {In Press},
	issn = {1063-4584},
	url = {http://www.sciencedirect.com/science/article/pii/S1063458419311306},
	doi = {10.1016/j.joca.2019.07.003},
	abstract = {Summary
Objective
To develop and perform ex vivo 3D imaging of meniscus posterior horn microstructure using micro-computed tomography (μCT), and to compare specimens from healthy references against end-stage osteoarthritis (OA) using conventional section-based histology and qualitative μCT.
Design
We retrieved human medial and lateral menisci from 10 deceased donors without knee OA (healthy references) and medial and lateral menisci from 10 patients having total knee replacement for medial compartment OA. Meniscal posterior horns were dissected and fixed in formalin. One subsection underwent hexamethyldisilazane (HMDS) treatment and μCT imaging. Pauli's histopathological scoring was performed for 3 other subsections. The differences in histopathological scores were estimated using mixed linear regression, resulting in fixed effects estimates for within-knee comparisons and adjusted for age and body mass index for between-subjects comparisons.
Results
3D visualization with μCT qualitatively revealed similar microstructural changes in the posterior horns as conventional histology. The mean histopathological score was higher for medial menisci from OA knees vs both medial reference menisci (mean difference [95\% CI], 3.9 [2.6,5.3]), and lateral menisci from OA knees (3.9 [2.9,5.0]). The scores were similar between lateral menisci from OA knees and lateral reference menisci (0.8 [−0.6,2.2]), and between medial and lateral reference menisci (0.8 [−0.3,1.9]).
Conclusions
HMDS-based μCT protocol allows unique 3D visualization of meniscus microstructures. Posterior horns of medial menisci from medial compartment OA knees had higher histopathological scores than both the lateral posterior horns from the same OA knees and medial reference menisci, suggesting a strong association between meniscus degradation and unicompartmental knee OA.},
	urldate = {2019-08-07},
	journal = {Osteoarthritis and Cartilage},
	author = {Kestilä, I. and Folkesson, E. and Finnilä, M. A. and Turkiewicz, A. and Önnerfjord, P. and Hughes, V. and Tjörnstrand, J. and Englund, M. and Saarakkala, S.},
	month = jul,
	year = {2019},
	keywords = {Histopathological score, Meniscus, Micro-computed tomography, Osteoarthritis},
}

Summary Objective To develop and perform ex vivo 3D imaging of meniscus posterior horn microstructure using micro-computed tomography (μCT), and to compare specimens from healthy references against end-stage osteoarthritis (OA) using conventional section-based histology and qualitative μCT. Design We retrieved human medial and lateral menisci from 10 deceased donors without knee OA (healthy references) and medial and lateral menisci from 10 patients having total knee replacement for medial compartment OA. Meniscal posterior horns were dissected and fixed in formalin. One subsection underwent hexamethyldisilazane (HMDS) treatment and μCT imaging. Pauli's histopathological scoring was performed for 3 other subsections. The differences in histopathological scores were estimated using mixed linear regression, resulting in fixed effects estimates for within-knee comparisons and adjusted for age and body mass index for between-subjects comparisons. Results 3D visualization with μCT qualitatively revealed similar microstructural changes in the posterior horns as conventional histology. The mean histopathological score was higher for medial menisci from OA knees vs both medial reference menisci (mean difference [95% CI], 3.9 [2.6,5.3]), and lateral menisci from OA knees (3.9 [2.9,5.0]). The scores were similar between lateral menisci from OA knees and lateral reference menisci (0.8 [−0.6,2.2]), and between medial and lateral reference menisci (0.8 [−0.3,1.9]). Conclusions HMDS-based μCT protocol allows unique 3D visualization of meniscus microstructures. Posterior horns of medial menisci from medial compartment OA knees had higher histopathological scores than both the lateral posterior horns from the same OA knees and medial reference menisci, suggesting a strong association between meniscus degradation and unicompartmental knee OA.

@article{johnsen_association_2019,
	title = {The association between smoking and knee osteoarthritis in a cohort of {Danish} patients undergoing knee arthroscopy},
	volume = {20},
	issn = {1471-2474},
	url = {https://doi.org/10.1186/s12891-019-2518-z},
	doi = {10.1186/s12891-019-2518-z},
	abstract = {It has been suggested that smoking is associated with reduced risk of knee osteoarthritis (OA). However, supplementary studies are needed to further investigate any such potential association. Thus, our aim was to examine the relationship between smoking and early or more established knee OA in a cohort of relatively young patients with meniscal tears.},
	number = {1},
	urldate = {2019-04-04},
	journal = {BMC Musculoskeletal Disorders},
	author = {Johnsen, Marianne Bakke and Pihl, Kenneth and Nissen, Nis and Sørensen, Rasmus Reinholdt and Jørgensen, Uffe and Englund, Martin and Thorlund, Jonas Bloch},
	month = apr,
	year = {2019},
	pages = {141},
}

It has been suggested that smoking is associated with reduced risk of knee osteoarthritis (OA). However, supplementary studies are needed to further investigate any such potential association. Thus, our aim was to examine the relationship between smoking and early or more established knee OA in a cohort of relatively young patients with meniscal tears.

@article{thorlund_conundrum_2019,
	title = {Conundrum of mechanical knee symptoms: signifying feature of a meniscal tear?},
	volume = {53},
	copyright = {© Author(s) (or their employer(s)) 2018. No commercial re-use. See rights and permissions. Published by BMJ.},
	issn = {0306-3674, 1473-0480},
	shorttitle = {Conundrum of mechanical knee symptoms},
	url = {https://bjsm.bmj.com/content/early/2018/08/31/bjsports-2018-099431},
	doi = {10.1136/bjsports-2018-099431},
	abstract = {Background Mechanical knee symptoms are often considered important in the decision to perform knee arthroscopy on the suspicion of a meniscal tear. We investigated if presence of a meniscal tear at knee arthroscopy in adults is associated with presence of preoperative self-reported mechanical knee symptoms.
Methods We used data from Knee Arthroscopy Cohort Southern Denmark (KACS). KACS consists of patients aged 18 years or older referred to knee arthroscopy on the suspicion of a meniscal tear at four recruiting hospitals between 1 February 2013 and 31 January 2015. Of 1259 invited patients, 908 (72\%) replied to the baseline questionnaire. With 91 patients excluded, the study sample consisted of 641 and 176 patients with and without a meniscal tear confirmed at surgery, respectively. Exposure was meniscal tear as determined by the knee surgeon during arthroscopy. Main outcomes were preoperative mechanical knee symptoms defined as self-reported catching/locking or self-reported inability to straighten knee fully.
Results 55\% of all patients reported symptoms of catching/locking and 47\% were unable to straighten their knee fully. Preoperative mechanical symptoms were equally prevalent in patients with and without a meniscal tear (prevalence ratio catching/locking 0.89, 95\% CI 0.77 to 1.03, and inability to straighten knee fully, prevalence ratio 1.02, 95\% CI 0.84 to 1.23).
Interpretation Patient-reported mechanical symptoms were equally common irrespective of presence or absence of a meniscal tear in patients undergoing arthroscopy for suspicion of a meniscal tear. Our findings suggest that mechanical knee symptoms have a limited value when considering indication for meniscal surgery.
Trial registration number NCT01871272; Results.},
	language = {en},
	number = {5},
	urldate = {2018-10-04},
	journal = {British Journal of Sports Medicine},
	author = {Thorlund, Jonas Bloch and Pihl, Kenneth and Nissen, Nis and Jørgensen, Uffe and Fristed, Jakob Vium and Lohmander, L. Stefan and Englund, Martin},
	month = mar,
	year = {2019},
	pmid = {30170997},
	keywords = {Adult, Arthroscopy, Denmark, Female, Humans, Knee Injuries, Male, Prevalence, Prospective Studies, Self Report, Tibial Meniscus Injuries, Young Adult, arthroscopy, epidemiology, knee, meniscal pathology, osteoarthritis},
	pages = {299--303},
}

Background Mechanical knee symptoms are often considered important in the decision to perform knee arthroscopy on the suspicion of a meniscal tear. We investigated if presence of a meniscal tear at knee arthroscopy in adults is associated with presence of preoperative self-reported mechanical knee symptoms. Methods We used data from Knee Arthroscopy Cohort Southern Denmark (KACS). KACS consists of patients aged 18 years or older referred to knee arthroscopy on the suspicion of a meniscal tear at four recruiting hospitals between 1 February 2013 and 31 January 2015. Of 1259 invited patients, 908 (72%) replied to the baseline questionnaire. With 91 patients excluded, the study sample consisted of 641 and 176 patients with and without a meniscal tear confirmed at surgery, respectively. Exposure was meniscal tear as determined by the knee surgeon during arthroscopy. Main outcomes were preoperative mechanical knee symptoms defined as self-reported catching/locking or self-reported inability to straighten knee fully. Results 55% of all patients reported symptoms of catching/locking and 47% were unable to straighten their knee fully. Preoperative mechanical symptoms were equally prevalent in patients with and without a meniscal tear (prevalence ratio catching/locking 0.89, 95% CI 0.77 to 1.03, and inability to straighten knee fully, prevalence ratio 1.02, 95% CI 0.84 to 1.23). Interpretation Patient-reported mechanical symptoms were equally common irrespective of presence or absence of a meniscal tear in patients undergoing arthroscopy for suspicion of a meniscal tear. Our findings suggest that mechanical knee symptoms have a limited value when considering indication for meniscal surgery. Trial registration number NCT01871272; Results.

@article{roemer_molecular_2019,
	title = {Molecular and structural biomarkers of inflammation at 2 years after acute anterior cruciate ligament injury do not predict structural knee osteoarthritis at 5 years},
	volume = {71},
	copyright = {This article is protected by copyright. All rights reserved.},
	issn = {2326-5205},
	shorttitle = {Brief {Report}},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/art.40687},
	doi = {10.1002/art.40687},
	abstract = {Objective To determine the role of inflammatory biomarkers at 2 years after anterior cruciate ligament (ACL) injury for predicting radiographic and magnetic resonance imaging (MRI)-defined knee osteoarthritis (OA) 5 years post injury. Secondary aim was to estimate the concordance of inflammatory biomarkers assessed by MRI and synovial fluid. Methods We studied 113 patients with acute ACL injury. 1.5 Tesla knee MRIs were read for Hoffa- and effusion-synovitis. Biomarkers of inflammation included IL-6, IL-8, IL-10, TNF-α and IFN-ɣ in serum and synovial fluid, and IL-12p70 in serum. The outcome was radiographic knee OA (ROA) or MRI-defined OA (MROA) at 5 years. Area under receiver operating characteristic curve (AUC), sensitivity and specificity were evaluated in models including MRI features only (M1), inflammation biomarkers only (serum [M2a] – synovial [M2b]) or both MRI and serum [M3a] or synovial [M3b] markers. Linear regression was used for evaluating association between MRI and synovial biomarkers. Results At 5 years, ROA was present in 26\% and MROA was present in 32\% of patients’ injured knee. The AUCs (95\% CI) for ROA were 0.44 (0.42-0.47;M1), 0.62 (0.59-0.65;M2a), 0.58 (0.55-0.61;M2b), 0.53 (0.50-0.56;M3a) and 0.50 (0.46-0.53;M3b) for each model. The corresponding AUCs for MROA were 0.67 (0.64-0.70), 0.49 (0.47-0.52), 0.65 (0.61-0.68), 0.56 (0.52-0.59) and 0.69 (0.66-0.72). The concordance between MRI and synovial biomarkers was statistically significant only for effusion–synovitis and IL-8. Conclusion Neither MRI-defined inflammation, nor selected synovial/serum inflammation biomarkers at 2 years predicted ROA or MROA at 5 years. Concordance between MRI and synovial inflammatory biomarkers was weak. This article is protected by copyright. All rights reserved.},
	language = {en},
	number = {2},
	urldate = {2018-10-04},
	journal = {Arthritis \& Rheumatology},
	author = {Roemer, Frank W. and Englund, Martin and Turkiewicz, Aleksandra and Struglics, André and Guermazi, Ali and Lohmander, L. Stefan and Larsson, Staffan and Frobell, Richard},
	month = feb,
	year = {2019},
	keywords = {anterior cruciate ligament injury, biomarkers, inflammation, magnetic resonance imaging, osteoarthritis},
	pages = {238--243},
}

Objective To determine the role of inflammatory biomarkers at 2 years after anterior cruciate ligament (ACL) injury for predicting radiographic and magnetic resonance imaging (MRI)-defined knee osteoarthritis (OA) 5 years post injury. Secondary aim was to estimate the concordance of inflammatory biomarkers assessed by MRI and synovial fluid. Methods We studied 113 patients with acute ACL injury. 1.5 Tesla knee MRIs were read for Hoffa- and effusion-synovitis. Biomarkers of inflammation included IL-6, IL-8, IL-10, TNF-α and IFN-ɣ in serum and synovial fluid, and IL-12p70 in serum. The outcome was radiographic knee OA (ROA) or MRI-defined OA (MROA) at 5 years. Area under receiver operating characteristic curve (AUC), sensitivity and specificity were evaluated in models including MRI features only (M1), inflammation biomarkers only (serum [M2a] – synovial [M2b]) or both MRI and serum [M3a] or synovial [M3b] markers. Linear regression was used for evaluating association between MRI and synovial biomarkers. Results At 5 years, ROA was present in 26% and MROA was present in 32% of patients’ injured knee. The AUCs (95% CI) for ROA were 0.44 (0.42-0.47;M1), 0.62 (0.59-0.65;M2a), 0.58 (0.55-0.61;M2b), 0.53 (0.50-0.56;M3a) and 0.50 (0.46-0.53;M3b) for each model. The corresponding AUCs for MROA were 0.67 (0.64-0.70), 0.49 (0.47-0.52), 0.65 (0.61-0.68), 0.56 (0.52-0.59) and 0.69 (0.66-0.72). The concordance between MRI and synovial biomarkers was statistically significant only for effusion–synovitis and IL-8. Conclusion Neither MRI-defined inflammation, nor selected synovial/serum inflammation biomarkers at 2 years predicted ROA or MROA at 5 years. Concordance between MRI and synovial inflammatory biomarkers was weak. This article is protected by copyright. All rights reserved.

@article{zeng_-hospital_2019,
	title = {In-hospital mortality after hip arthroplasty in {China}},
	volume = {101-B},
	issn = {2049-4394},
	url = {https://online.boneandjoint.org.uk/doi/full/10.1302/0301-620X.101B10.BJJ-2018-1608.R1},
	doi = {10.1302/0301-620X.101B10.BJJ-2018-1608.R1},
	abstract = {AimsThere is an increasing demand for hip arthroplasty in China. We aimed to describe trends in in-hospital mortality after this procedure in China and to examine the potential risk factors.Patients and MethodsWe included 210 450 patients undergoing primary hip arthroplasty registered in the Hospital Quality Monitoring System in China between 2013 and 2016. In-hospital mortality after hip arthroplasty and its relation to potential risk factors were assessed using multivariable Poisson regression.ResultsDuring the study period, 626 inpatient deaths occurred within 30 days after hip arthroplasty. Mortality decreased from 2.9\% in 2013 to 2.6\% in 2016 (p for trend = 0.02). Compared with their counterparts, old age, male sex, and divorced or widowed patients had a higher rate of mortality (all p {\textless} 0.05). Risk ratio (RR) for mortality after arthroplasty for fracture was two-fold higher (RR 2.0, 95\% confidence interval (CI) 1.5 to 2.6) than that for chronic disease. RRs for mortality were 3.3 (95\% CI 2.7 to 3.9) and 8.2 (95\% CI 6.5 to 10.4) for patients with Charlson Comorbidity Index (CCI) of 1 to 2 and CCI ≥ 3, respectively, compared with patients with CCI of 0. The rate of mortality varied according to geographical region, the lowest being in the East region (1.8\%), followed by Beijing (2.1\%), the North (2.9\%), South-West (3.6\%), South-Central (3.8\%), North-East (4.1\%), and North-West (5.2\%) regions.ConclusionWhile in-hospital mortality after hip arthroplasty in China appears low and declined during the study period, discrepancies in mortality after this procedure exist according to sociodemographic factors. Healthcare resources should be allocated more to underdeveloped regions to further reduce mortality.Cite this article: Bone Joint J 2019;101-B:1209–1217},
	number = {10},
	urldate = {2019-10-01},
	journal = {The Bone \& Joint Journal},
	author = {Zeng, Chao and Lane, Nancy E. and Englund, Martin and Xie, Dongxing and Chen, Hu and Zhang, Yuqing and Wang, Haibo and Lei, Guanghua},
	month = sep,
	year = {2019},
	pages = {1209--1217},
}

AimsThere is an increasing demand for hip arthroplasty in China. We aimed to describe trends in in-hospital mortality after this procedure in China and to examine the potential risk factors.Patients and MethodsWe included 210 450 patients undergoing primary hip arthroplasty registered in the Hospital Quality Monitoring System in China between 2013 and 2016. In-hospital mortality after hip arthroplasty and its relation to potential risk factors were assessed using multivariable Poisson regression.ResultsDuring the study period, 626 inpatient deaths occurred within 30 days after hip arthroplasty. Mortality decreased from 2.9% in 2013 to 2.6% in 2016 (p for trend = 0.02). Compared with their counterparts, old age, male sex, and divorced or widowed patients had a higher rate of mortality (all p \textless 0.05). Risk ratio (RR) for mortality after arthroplasty for fracture was two-fold higher (RR 2.0, 95% confidence interval (CI) 1.5 to 2.6) than that for chronic disease. RRs for mortality were 3.3 (95% CI 2.7 to 3.9) and 8.2 (95% CI 6.5 to 10.4) for patients with Charlson Comorbidity Index (CCI) of 1 to 2 and CCI ≥ 3, respectively, compared with patients with CCI of 0. The rate of mortality varied according to geographical region, the lowest being in the East region (1.8%), followed by Beijing (2.1%), the North (2.9%), South-West (3.6%), South-Central (3.8%), North-East (4.1%), and North-West (5.2%) regions.ConclusionWhile in-hospital mortality after hip arthroplasty in China appears low and declined during the study period, discrepancies in mortality after this procedure exist according to sociodemographic factors. Healthcare resources should be allocated more to underdeveloped regions to further reduce mortality.Cite this article: Bone Joint J 2019;101-B:1209–1217

@article{stamatis_malignancies_2019,
	title = {Malignancies in giant cell arteritis: a population-based cohort study},
	volume = {46},
	issn = {0315-162X},
	shorttitle = {Malignancies in giant cell arteritis},
	url = {https://doi.org/10.3899/jrheum.190236},
	doi = {10.3899/jrheum.190236},
	abstract = {OBJECTIVE: To investigate the risk of cancer in patients with biopsy-proven giant cell arteritis (GCA) from a defined population in southern Sweden.
METHODS: The study cohort consisted of 830 patients (mean age at GCA diagnosis was 76.3 years, 74 \% women) diagnosed with biopsy-proven GCA between 1997 and 2010. Temporal artery biopsy results were retrieved from a regional database and reviewed to ascertain GCA diagnosis. The cohort was linked to the Swedish Cancer Registry. The patients were followed from GCA diagnosis until death or December 31, 2013. Incident malignancies registered after GCA diagnosis were studied. Based on data on the first malignancy in each organ system, age- and sex standardized incidence ratios (SIR) with 95 \% confidence intervals (CI) were calculated compared to the background population.
RESULTS: 107 patients (13\%) were diagnosed with a total of 118 new malignancies after the onset of GCA. The overall risk for cancer after the GCA diagnosis was not increased (SIR 0.98; 95\% CI 0.81 - 1.17). However, there was an increased risk for myeloid leukemia (2.31; 95\% CI 1.06 - 4.39) and a reduced risk for breast cancer (0.33; 95\% CI 0.12 - 0.72) and upper gastrointestinal tract cancer (0.16; 95\% 0.004- 0.91). Rates of other site-specific cancers were not different from expected.
CONCLUSION: In this Swedish population-based cohort of GCA, the overall risk for cancer was not increased compared to the background population. However, there was an increased risk for leukemia and a decreased risk for breast and upper gastrointestinal tract cancer.},
	language = {eng},
	number = {10},
	journal = {The Journal of Rheumatology},
	author = {Stamatis, Pavlos and Turesson, Carl and Willim, Minna and Nilsson, Jan-Åke and Englund, Martin and Mohammad, Aladdin J.},
	month = jun,
	year = {2019},
	pmid = {31154410},
}

OBJECTIVE: To investigate the risk of cancer in patients with biopsy-proven giant cell arteritis (GCA) from a defined population in southern Sweden. METHODS: The study cohort consisted of 830 patients (mean age at GCA diagnosis was 76.3 years, 74 % women) diagnosed with biopsy-proven GCA between 1997 and 2010. Temporal artery biopsy results were retrieved from a regional database and reviewed to ascertain GCA diagnosis. The cohort was linked to the Swedish Cancer Registry. The patients were followed from GCA diagnosis until death or December 31, 2013. Incident malignancies registered after GCA diagnosis were studied. Based on data on the first malignancy in each organ system, age- and sex standardized incidence ratios (SIR) with 95 % confidence intervals (CI) were calculated compared to the background population. RESULTS: 107 patients (13%) were diagnosed with a total of 118 new malignancies after the onset of GCA. The overall risk for cancer after the GCA diagnosis was not increased (SIR 0.98; 95% CI 0.81 - 1.17). However, there was an increased risk for myeloid leukemia (2.31; 95% CI 1.06 - 4.39) and a reduced risk for breast cancer (0.33; 95% CI 0.12 - 0.72) and upper gastrointestinal tract cancer (0.16; 95% 0.004- 0.91). Rates of other site-specific cancers were not different from expected. CONCLUSION: In this Swedish population-based cohort of GCA, the overall risk for cancer was not increased compared to the background population. However, there was an increased risk for leukemia and a decreased risk for breast and upper gastrointestinal tract cancer.

@article{turkiewicz_cause-specific_2019,
	title = {Cause-specific mortality in osteoarthritis of peripheral joints},
	volume = {27},
	issn = {1063-4584, 1522-9653},
	url = {https://www.oarsijournal.com/article/S1063-4584(19)30851-9/abstract},
	doi = {10.1016/j.joca.2019.02.793},
	abstract = {{\textless}h2{\textgreater}Summary{\textless}/h2{\textgreater}{\textless}h3{\textgreater}Purpose{\textless}/h3{\textgreater}{\textless}p{\textgreater}To estimate cause-specific mortality in osteoarthritis patients compared to the general population.{\textless}/p{\textgreater}{\textless}h3{\textgreater}Methods{\textless}/h3{\textgreater}{\textless}p{\textgreater}We identified all residents in southern Sweden aged 45–84 years in 2003. Through the Skåne Healthcare Register (SHR) we identified those diagnosed with osteoarthritis in peripheral joints between 1998 and 2003. We followed all residents from 2004 until relocation outside of the region, death, or end of 2014. We classified the underlying cause of death from death certificates into: cardiovascular and neoplasms, diabetes, infections, dementia, diseases of digestive system, or other causes. For estimation, we used multi-state adjusted Cox proportional hazards models.{\textless}/p{\textgreater}{\textless}h3{\textgreater}Results{\textless}/h3{\textgreater}{\textless}p{\textgreater}We identified 15,901 patients (mean age [SD] 67 years [10], 41\% men) with prevalent doctor-diagnosed osteoarthritis in knee, 9347 in hip, 4004 in hand and 5447 in other peripheral joints among 469,177 residents. For most causes of death in osteoarthritis patients, we found no increased mortality, with hazard ratios (HRs) close to 1, similar for men and women. However, for knee and hip osteoarthritis and cardiovascular death, HRs were non proportional and increased to 1.19 (95\%CI 1.10, 1.28) and 1.13 (1.03, 1.24) during 9–11 years of follow-up, mostly due to excess mortality from chronic ischemic heart diseases and heart failure.{\textless}/p{\textgreater}{\textless}h3{\textgreater}Conclusions{\textless}/h3{\textgreater}{\textless}p{\textgreater}The risk of cardiovascular excess deaths increases with duration of knee and hip osteoarthritis. The major contributors are chronic ischemic heart diseases and heart failure. Our results call for improved implementation of osteoarthritis treatment guidelines, with major focus on interventions to address mobility limitations and maintaining or increase physical activity level.{\textless}/p{\textgreater}},
	language = {English},
	number = {6},
	urldate = {2019-03-15},
	journal = {Osteoarthritis and Cartilage},
	author = {Turkiewicz, A. and Kiadaliri, A. A. and Englund, M.},
	month = feb,
	year = {2019},
	pmid = {30797945},
	pages = {848--854},
}

\textlessh2\textgreaterSummary\textless/h2\textgreater\textlessh3\textgreaterPurpose\textless/h3\textgreater\textlessp\textgreaterTo estimate cause-specific mortality in osteoarthritis patients compared to the general population.\textless/p\textgreater\textlessh3\textgreaterMethods\textless/h3\textgreater\textlessp\textgreaterWe identified all residents in southern Sweden aged 45–84 years in 2003. Through the Skåne Healthcare Register (SHR) we identified those diagnosed with osteoarthritis in peripheral joints between 1998 and 2003. We followed all residents from 2004 until relocation outside of the region, death, or end of 2014. We classified the underlying cause of death from death certificates into: cardiovascular and neoplasms, diabetes, infections, dementia, diseases of digestive system, or other causes. For estimation, we used multi-state adjusted Cox proportional hazards models.\textless/p\textgreater\textlessh3\textgreaterResults\textless/h3\textgreater\textlessp\textgreaterWe identified 15,901 patients (mean age [SD] 67 years [10], 41% men) with prevalent doctor-diagnosed osteoarthritis in knee, 9347 in hip, 4004 in hand and 5447 in other peripheral joints among 469,177 residents. For most causes of death in osteoarthritis patients, we found no increased mortality, with hazard ratios (HRs) close to 1, similar for men and women. However, for knee and hip osteoarthritis and cardiovascular death, HRs were non proportional and increased to 1.19 (95%CI 1.10, 1.28) and 1.13 (1.03, 1.24) during 9–11 years of follow-up, mostly due to excess mortality from chronic ischemic heart diseases and heart failure.\textless/p\textgreater\textlessh3\textgreaterConclusions\textless/h3\textgreater\textlessp\textgreaterThe risk of cardiovascular excess deaths increases with duration of knee and hip osteoarthritis. The major contributors are chronic ischemic heart diseases and heart failure. Our results call for improved implementation of osteoarthritis treatment guidelines, with major focus on interventions to address mobility limitations and maintaining or increase physical activity level.\textless/p\textgreater

@article{kiadaliri_educational_2019-1,
	title = {Educational inequalities in mortality associated with rheumatoid arthritis and other musculoskeletal disorders in {Sweden}},
	volume = {20},
	issn = {1471-2474},
	url = {https://doi.org/10.1186/s12891-019-2465-8},
	doi = {10.1186/s12891-019-2465-8},
	abstract = {Musculoskeletal (MSK) disorders are less likely to be reported as an underlying cause of death (UCD) and since cause of death studies are generally limited to the UCD, little is known about socioeconomic inequalities in MSK disorders as cause of death in the general population. Using multiple-cause-of-death data, we aimed to quantify and compare educational inequalities in musculoskeletal (MSK) disorders- with non-MSK disorders-related mortality.},
	number = {1},
	urldate = {2019-02-21},
	journal = {BMC Musculoskeletal Disorders},
	author = {Kiadaliri, Aliasghar A. and Petersson, Ingemar F. and Englund, Martin},
	month = feb,
	year = {2019},
	pages = {83},
}

Musculoskeletal (MSK) disorders are less likely to be reported as an underlying cause of death (UCD) and since cause of death studies are generally limited to the UCD, little is known about socioeconomic inequalities in MSK disorders as cause of death in the general population. Using multiple-cause-of-death data, we aimed to quantify and compare educational inequalities in musculoskeletal (MSK) disorders- with non-MSK disorders-related mortality.

@article{watt_towards_2019,
	title = {Towards prevention of post-traumatic osteoarthritis: report from an international expert working group on considerations for the design and conduct of interventional studies following acute knee injury},
	volume = {27},
	issn = {1063-4584},
	shorttitle = {Towards prevention of post-traumatic osteoarthritis},
	url = {http://www.sciencedirect.com/science/article/pii/S1063458418314122},
	doi = {10.1016/j.joca.2018.08.001},
	abstract = {Summary
Objective
There are few guidelines for clinical trials of interventions for prevention of post-traumatic osteoarthritis (PTOA), reflecting challenges in this area. An international multi-disciplinary expert group including patients was convened to generate points to consider for the design and conduct of interventional studies following acute knee injury.
Design
An evidence review on acute knee injury interventional studies to prevent PTOA was presented to the group, alongside overviews of challenges in this area, including potential targets, biomarkers and imaging. Working groups considered pre-identified key areas: eligibility criteria and outcomes, biomarkers, injury definition and intervention timing including multi-modality interventions. Consensus agreement within the group on points to consider was generated and is reported here after iterative review by all contributors.
Results
The evidence review identified 37 studies. Study duration and outcomes varied widely and 70\% examined surgical interventions. Considerations were grouped into 3 areas: justification of inclusion criteria including the classification of injury and participant age (as people over 35 may have pre-existing OA); careful consideration in the selection and timing of outcomes or biomarkers; definition of the intervention(s)/comparator(s) and the appropriate time-window for intervention (considerations may be particular to intervention type). Areas for further research included demonstrating the utility of patient-reported outcomes, biomarkers and imaging outcomes from ancillary/cohort studies in this area, and development of surrogate clinical trial endpoints that shorten the duration of clinical trials and are acceptable to regulatory agencies.
Conclusions
These considerations represent the first international consensus on the conduct of interventional studies following acute knee joint trauma.},
	number = {1},
	urldate = {2018-09-03},
	journal = {Osteoarthritis and Cartilage},
	author = {Watt, Fiona E. and Corp, Nadia and Kingsbury, Sarah R. and Frobell, Richard and Englund, Martin and Felson, David and Levesque, Marc and Majumdar, Sharmila and Wilson, Chris and Beard, David J. and Lohmander, Stefan and Kraus, Virginia B. and Roemer, Frank and Conaghan, Philip G. and Mason, Deborah J. and Adams, Jo and Blank, Mike and {Mark Batt} and Biggs, Paul and Busse-Morris, Monica and Button, Kate and Calder, James and {Jonathan Cook} and {Christopher Edwards} and Fisheleva, Elena and {David F Hamilton} and Harrison, Heather and {Cathy Holt} and Jones, Mary and {Richard Jones} and Kluzek, Stefan and Knight, Thomas and {George Nuki} and Parekh, Sanjay and {George Peat} and Pothet, Caroline and {Timothy Rainer} and Robinson, Nicky and Sawle, Leanne and {Tonia Vincent} and Williams, Andy and Wise, Elspeth and {Weiya Zhang} and {Sita Bierma-Zeinstra}},
	month = jan,
	year = {2019},
	keywords = {Clinical trial, Considerations, Injury, Knee, Osteoarthritis, Outcome},
	pages = {23--33},
}

Summary Objective There are few guidelines for clinical trials of interventions for prevention of post-traumatic osteoarthritis (PTOA), reflecting challenges in this area. An international multi-disciplinary expert group including patients was convened to generate points to consider for the design and conduct of interventional studies following acute knee injury. Design An evidence review on acute knee injury interventional studies to prevent PTOA was presented to the group, alongside overviews of challenges in this area, including potential targets, biomarkers and imaging. Working groups considered pre-identified key areas: eligibility criteria and outcomes, biomarkers, injury definition and intervention timing including multi-modality interventions. Consensus agreement within the group on points to consider was generated and is reported here after iterative review by all contributors. Results The evidence review identified 37 studies. Study duration and outcomes varied widely and 70% examined surgical interventions. Considerations were grouped into 3 areas: justification of inclusion criteria including the classification of injury and participant age (as people over 35 may have pre-existing OA); careful consideration in the selection and timing of outcomes or biomarkers; definition of the intervention(s)/comparator(s) and the appropriate time-window for intervention (considerations may be particular to intervention type). Areas for further research included demonstrating the utility of patient-reported outcomes, biomarkers and imaging outcomes from ancillary/cohort studies in this area, and development of surrogate clinical trial endpoints that shorten the duration of clinical trials and are acceptable to regulatory agencies. Conclusions These considerations represent the first international consensus on the conduct of interventional studies following acute knee joint trauma.

@article{pihl_association_2019,
	title = {Association of specific meniscal pathologies and other structural pathologies with self-reported mechanical symptoms: {A} cross-sectional study of 566 patients undergoing meniscal surgery},
	volume = {22},
	issn = {1878-1861},
	shorttitle = {Association of specific meniscal pathologies and other structural pathologies with self-reported mechanical symptoms},
	url = {https://doi.org/10.1016%2Fj.jsams.2018.07.018},
	doi = {10.1016/j.jsams.2018.07.018},
	abstract = {OBJECTIVES: We explored associations between specific meniscal pathologies and other concurrent structural knee pathologies with presence of self-reported mechanical symptoms in patients undergoing meniscal surgery.
DESIGN: Cross-sectional study.
METHODS: We included patients undergoing surgery for a meniscal tear from Knee Arthroscopy Cohort Southern Denmark (KACS). Pre-surgery, patients completed online questionnaires including self-reported presence of mechanical symptoms. At arthroscopy, surgeons recorded information about specific meniscal pathologies and other concurrent structural knee pathologies. Relative risks (RR) were estimated to assess associations between specific meniscal pathologies and other structural knee pathologies with preoperative mechanical symptoms from multivariable logistic regression.
RESULTS: 566 of 641 patients (mean age 48.6[SD 12.9] years, 57\% men) with complete data were included. 386 (68\%) patients reported mechanical symptoms of knee catching/locking and/or extension deficit. Most evaluated joint pathologies were not associated with mechanical symptoms of any kind with RRs close to 1.0. Meniscal tears involving both the posterior and anterior horn (n=22) were associated with knee catching/locking (RR: 1.49[95\%CI:1.15-1.93]), and a tear in both menisci (n=49) was associated with extension deficit of the knee (RR: 1.32[95\%CI:1.01-1.73]). A partial (n=29) and total ACL rupture (n=37) were each associated with extension deficit (RR: 1.83[95\%CI:1.47-2.28] and RR: 1.44[95\%CI:1.05-1.98], respectively).
CONCLUSIONS: Limited associations between specific meniscal pathology and other concurrent knee joint pathologies with presence of self-reported mechanical symptoms were found in patients undergoing meniscal surgery. The findings question the clinical importance of mechanical symptoms as an indicator for arthroscopy for specific meniscal tears with the specific aim to relieve such symptoms.},
	language = {eng},
	number = {2},
	journal = {Journal of Science and Medicine in Sport},
	author = {Pihl, Kenneth and Turkiewicz, Aleksandra and Englund, Martin and Lohmander, L. Stefan and Jørgensen, Uffe and Nissen, Nis and Schjerning, Jeppe and Thorlund, Jonas B.},
	year = {2019},
	pmid = {30100169},
	keywords = {Adolescent, Adult, Aged, Arthroscopy, Cross-Sectional Studies, Denmark, Female, Humans, Knee Joint, Knee joint, Male, Mechanical symptoms, Menisci, Tibial, Meniscus, Middle Aged, Osteoarthritis, Self Report, Tibial Meniscus Injuries, Tibial meniscus injuries, Young Adult},
	pages = {151--157},
}

OBJECTIVES: We explored associations between specific meniscal pathologies and other concurrent structural knee pathologies with presence of self-reported mechanical symptoms in patients undergoing meniscal surgery. DESIGN: Cross-sectional study. METHODS: We included patients undergoing surgery for a meniscal tear from Knee Arthroscopy Cohort Southern Denmark (KACS). Pre-surgery, patients completed online questionnaires including self-reported presence of mechanical symptoms. At arthroscopy, surgeons recorded information about specific meniscal pathologies and other concurrent structural knee pathologies. Relative risks (RR) were estimated to assess associations between specific meniscal pathologies and other structural knee pathologies with preoperative mechanical symptoms from multivariable logistic regression. RESULTS: 566 of 641 patients (mean age 48.6[SD 12.9] years, 57% men) with complete data were included. 386 (68%) patients reported mechanical symptoms of knee catching/locking and/or extension deficit. Most evaluated joint pathologies were not associated with mechanical symptoms of any kind with RRs close to 1.0. Meniscal tears involving both the posterior and anterior horn (n=22) were associated with knee catching/locking (RR: 1.49[95%CI:1.15-1.93]), and a tear in both menisci (n=49) was associated with extension deficit of the knee (RR: 1.32[95%CI:1.01-1.73]). A partial (n=29) and total ACL rupture (n=37) were each associated with extension deficit (RR: 1.83[95%CI:1.47-2.28] and RR: 1.44[95%CI:1.05-1.98], respectively). CONCLUSIONS: Limited associations between specific meniscal pathology and other concurrent knee joint pathologies with presence of self-reported mechanical symptoms were found in patients undergoing meniscal surgery. The findings question the clinical importance of mechanical symptoms as an indicator for arthroscopy for specific meniscal tears with the specific aim to relieve such symptoms.

@article{thorlund_opioid_2019,
	title = {Opioid use in knee or hip osteoarthritis: a region-wide population-based cohort study},
	volume = {27},
	issn = {1522-9653},
	shorttitle = {Opioid use in knee or hip osteoarthritis},
	url = {https://doi.org/10.1016%2Fj.joca.2019.01.005},
	doi = {10.1016/j.joca.2019.01.005},
	abstract = {OBJECTIVE: To quantify opioid use in knee and hip osteoarthritis (OA) patients, and to estimate the proportion of opioids in the population attributable to OA patients.
DESIGN: Population-based cohort study.
METHODS: We included 751579 residents in southern Sweden, aged ≥35 years in 2015. Doctor-diagnosed knee or hip OA between 1998 and 2015 was the exposure. Dispensed weak and strong opioids were identified between November 2013 and October 2015 from the Swedish Prescribed Drug Register. We determined age- and sex-standardized 12-month period prevalence of opioid use from November 2014 until October 2015 and calculated prevalence ratios and incidence rate ratios adjusted for age, sex, and other socio-demographic variables. We estimated the population attributable fraction (PAF) of incident opioid use attributable to OA patients.
RESULTS: The 12-month prevalence of opioid use among OA patients was 23.7\% [95\% CI 23.3-24.2], which was two-fold higher compared to individuals without knee or hip OA: prevalence ratio: 2.1 [95\% CI 2.1-2.1]. Similarly, OA patients were more likely to have an incident opioid dispensation, especially for strong opioids (incidence rate ratio: 2.6 [95\% CI 2.5-2.7]). PAF of incident opioid use attributable to OA patients was 12\%, 9\% for weak and 17\% for strong opioids.
CONCLUSIONS: Every fourth patient with knee or hip OA has opioids dispensed over a one-year period, and 12\% of incident opioid dispensations are attributable to OA and/or its related comorbidities. These results highlight that patients with knee and hip OA constitute a group of patients with an alarmingly high use of opioids.},
	language = {eng},
	number = {6},
	journal = {Osteoarthritis and Cartilage},
	author = {Thorlund, Jonas Bloch and Turkiewicz, Aleksandra and Prieto-Alhambra, Daniel and Englund, Martin},
	year = {2019},
	pmid = {30682417},
	keywords = {Analgesics, Epidemiology, Opioids, Osteoarthritis, Pain, Pharmacology},
	pages = {871--877},
}

OBJECTIVE: To quantify opioid use in knee and hip osteoarthritis (OA) patients, and to estimate the proportion of opioids in the population attributable to OA patients. DESIGN: Population-based cohort study. METHODS: We included 751579 residents in southern Sweden, aged ≥35 years in 2015. Doctor-diagnosed knee or hip OA between 1998 and 2015 was the exposure. Dispensed weak and strong opioids were identified between November 2013 and October 2015 from the Swedish Prescribed Drug Register. We determined age- and sex-standardized 12-month period prevalence of opioid use from November 2014 until October 2015 and calculated prevalence ratios and incidence rate ratios adjusted for age, sex, and other socio-demographic variables. We estimated the population attributable fraction (PAF) of incident opioid use attributable to OA patients. RESULTS: The 12-month prevalence of opioid use among OA patients was 23.7% [95% CI 23.3-24.2], which was two-fold higher compared to individuals without knee or hip OA: prevalence ratio: 2.1 [95% CI 2.1-2.1]. Similarly, OA patients were more likely to have an incident opioid dispensation, especially for strong opioids (incidence rate ratio: 2.6 [95% CI 2.5-2.7]). PAF of incident opioid use attributable to OA patients was 12%, 9% for weak and 17% for strong opioids. CONCLUSIONS: Every fourth patient with knee or hip OA has opioids dispensed over a one-year period, and 12% of incident opioid dispensations are attributable to OA and/or its related comorbidities. These results highlight that patients with knee and hip OA constitute a group of patients with an alarmingly high use of opioids.

@article{svensson_meniscal_2019,
	title = {Meniscal body extrusion and cartilage coverage in middle-aged and elderly without radiographic knee osteoarthritis},
	volume = {29},
	issn = {1432-1084},
	url = {https://doi.org/10.1007%2Fs00330-018-5741-3},
	doi = {10.1007/s00330-018-5741-3},
	abstract = {OBJECTIVES: To determine meniscal extrusion and cartilage coverage on magnetic resonance (MR) images and factors associated with these parameters in knees of middle-aged and elderly persons free from radiographic tibiofemoral osteoarthritis (OA).
METHODS: Seven hundred eighteen persons, free of radiographic tibiofemoral OA, aged 50-90 years from Framingham, MA, USA, were included. We measured meniscal extrusion on 1.5 T MRI of both knees to evaluate both medial and lateral meniscal body extrusion and cartilage coverage. We also determined meniscal morphology and structural integrity. The multivariable association with age, body mass index (BMI), and ipsilateral meniscal damage was also evaluated.
RESULTS: The mean meniscal body extrusion medially was 2.7 mm and laterally 1.8 mm. The tibial cartilage coverage was about 30\% of ipsilateral cartilage surface (both compartments). The presence of ipsilateral meniscal damage was associated with more extrusion in only the medial compartment, 1.0 mm in men and 0.6 mm in women, and less cartilage coverage proportion, -5.5\% in men and -4.6\% in women.
CONCLUSIONS: Mean medial meniscal body extrusion in middle-aged or older persons without radiographic tibiofemoral OA approximates the commonly used cutoff (3 mm) to denote pathological extrusion. Medial meniscal damage is a factor associated with medial meniscal body extrusion and less cartilage coverage.
KEY POINTS: • Medial meniscal extrusion in middle-aged/older persons without OA is around 3 mm. • Lateral meniscal extrusion in middle-aged/older persons without OA is around 2 mm. • Meniscal damage is associated with medial meniscal extrusion and less cartilage coverage.},
	language = {eng},
	number = {4},
	journal = {European Radiology},
	author = {Svensson, Fredrik and Felson, David T. and Zhang, Fan and Guermazi, Ali and Roemer, Frank W. and Niu, Jingbo and Aliabadi, Piran and Neogi, Tuhina and Englund, Martin},
	year = {2019},
	pmid = {30280250},
	keywords = {Coverage, Knee, Magnetic resonance imaging, Meniscus, Osteoarthritis},
	pages = {1848--1854},
}

OBJECTIVES: To determine meniscal extrusion and cartilage coverage on magnetic resonance (MR) images and factors associated with these parameters in knees of middle-aged and elderly persons free from radiographic tibiofemoral osteoarthritis (OA). METHODS: Seven hundred eighteen persons, free of radiographic tibiofemoral OA, aged 50-90 years from Framingham, MA, USA, were included. We measured meniscal extrusion on 1.5 T MRI of both knees to evaluate both medial and lateral meniscal body extrusion and cartilage coverage. We also determined meniscal morphology and structural integrity. The multivariable association with age, body mass index (BMI), and ipsilateral meniscal damage was also evaluated. RESULTS: The mean meniscal body extrusion medially was 2.7 mm and laterally 1.8 mm. The tibial cartilage coverage was about 30% of ipsilateral cartilage surface (both compartments). The presence of ipsilateral meniscal damage was associated with more extrusion in only the medial compartment, 1.0 mm in men and 0.6 mm in women, and less cartilage coverage proportion, -5.5% in men and -4.6% in women. CONCLUSIONS: Mean medial meniscal body extrusion in middle-aged or older persons without radiographic tibiofemoral OA approximates the commonly used cutoff (3 mm) to denote pathological extrusion. Medial meniscal damage is a factor associated with medial meniscal body extrusion and less cartilage coverage. KEY POINTS: • Medial meniscal extrusion in middle-aged/older persons without OA is around 3 mm. • Lateral meniscal extrusion in middle-aged/older persons without OA is around 2 mm. • Meniscal damage is associated with medial meniscal extrusion and less cartilage coverage.

@article{prietoalhambra_smoking_2019,
	title = {Smoking and alcohol intake but not muscle strength in young men increase fracture risk at middle age: a cohort study linked to the {Swedish} national patient registry},
	volume = {In Press},
	copyright = {© 2019 American Society for Bone and Mineral Research},
	issn = {1523-4681},
	shorttitle = {Smoking and alcohol intake but not muscle strength in young men increase fracture risk at middle age},
	url = {https://asbmr.onlinelibrary.wiley.com/doi/abs/10.1002/jbmr.3917},
	doi = {10.1002/jbmr.3917},
	abstract = {We aimed to determine the relationship between handgrip strength, smoking, and alcohol consumption in young men and fracture risk at middle age. Thus, we carried out a cohort study including young men undergoing conscription examination in Sweden from September 1969 to May 1970 at a typical age of 18 years. Data on muscle strength, height, weight, and lifestyle factors were linked to the National Patient Register 1987–2010. Handgrip strength was considered the main exposure and smoking and alcohol consumption as secondary exposures. Outcomes were all fractures (except face, skull, digits), major osteoporotic fractures (thoracic/lumbar spine, proximal humerus, distal forearm or hip), and major traumatic fractures (shaft of humerus, forearm, femur, or lower leg) based on ICD-9 and -10 codes. We used Cox regression models to estimate hazard ratios (HR) and 95\% confidence intervals (CI) according to handgrip strength as a continuous variable (per 1 SD), after adjustment for weight, height, parental education, smoking, and alcohol consumption. A total of 40,112 men were included, contributing 892,572 person-years. Overall, 3974 men fractured in middle age with the incidence rate (95\% CI) of 44.5 (43.2–45.9) per 1000 person-years. The corresponding rates were12.2 and 5.6 per 1000 person-years for major osteoporotic and traumatic fractures, respectively. Handgrip strength-adjusted HR (95\% CI) was 1.01 (0.98–1.05), 0.94 (0.88–1.00), and 0.98 (0.88–1.08) per SD for all, major osteoporotic, and major traumatic fractures, respectively. Adjusted HR (95\% CI) for smokers ({\textgreater}21 cigarettes/d) was 1.44 (1.21, 1.71) for all fractures, while the association between alcohol consumption and hazards of fracture was J-shaped. Therefore, young adult handgrip strength was not associated with fracture risk in middle-age men, although smoking and high alcohol consumption did confer an increased risk. © 2019 American Society for Bone and Mineral Research. © 2019 American Society for Bone and Mineral Research.},
	language = {en},
	urldate = {2019-12-16},
	journal = {Journal of Bone and Mineral Research},
	author = {Prieto‐Alhambra, Daniel and Turkiewicz, Aleksandra and Reyes, Carlen and Timpka, Simon and Rosengren, Björn and Englund, Martin},
	year = {2019},
	keywords = {EPIDEMIOLOGY, FRACTURE, GENERAL POPULATION, PREVENTION, SKELETAL MUSCLE},
}

We aimed to determine the relationship between handgrip strength, smoking, and alcohol consumption in young men and fracture risk at middle age. Thus, we carried out a cohort study including young men undergoing conscription examination in Sweden from September 1969 to May 1970 at a typical age of 18 years. Data on muscle strength, height, weight, and lifestyle factors were linked to the National Patient Register 1987–2010. Handgrip strength was considered the main exposure and smoking and alcohol consumption as secondary exposures. Outcomes were all fractures (except face, skull, digits), major osteoporotic fractures (thoracic/lumbar spine, proximal humerus, distal forearm or hip), and major traumatic fractures (shaft of humerus, forearm, femur, or lower leg) based on ICD-9 and -10 codes. We used Cox regression models to estimate hazard ratios (HR) and 95% confidence intervals (CI) according to handgrip strength as a continuous variable (per 1 SD), after adjustment for weight, height, parental education, smoking, and alcohol consumption. A total of 40,112 men were included, contributing 892,572 person-years. Overall, 3974 men fractured in middle age with the incidence rate (95% CI) of 44.5 (43.2–45.9) per 1000 person-years. The corresponding rates were12.2 and 5.6 per 1000 person-years for major osteoporotic and traumatic fractures, respectively. Handgrip strength-adjusted HR (95% CI) was 1.01 (0.98–1.05), 0.94 (0.88–1.00), and 0.98 (0.88–1.08) per SD for all, major osteoporotic, and major traumatic fractures, respectively. Adjusted HR (95% CI) for smokers (\textgreater21 cigarettes/d) was 1.44 (1.21, 1.71) for all fractures, while the association between alcohol consumption and hazards of fracture was J-shaped. Therefore, young adult handgrip strength was not associated with fracture risk in middle-age men, although smoking and high alcohol consumption did confer an increased risk. © 2019 American Society for Bone and Mineral Research. © 2019 American Society for Bone and Mineral Research.

@article{magnusson_prediction_2019,
	title = {A prediction model for the 40-year risk of knee osteoarthritis in adolescent men},
	volume = {71},
	issn = {2151-4658},
	url = {https://doi.org/10.1002%2Facr.23685},
	doi = {10.1002/acr.23685},
	abstract = {OBJECTIVES: To simplify the previously published Nottingham 12-year risk prediction model for knee osteoarthritis (OA) and examine whether it can be used to predict the 40-year risk of knee OA in young men.
METHODS: We included 40 118 men aged 18 undergoing military conscription in Sweden 1969-70. Diagnostic OA codes were obtained from the Swedish National Patient Register 1987-2010. The original Nottingham model included predictors age, sex, body mass index (BMI), knee injury, occupational risk and family history of OA with area under receiver operating characteristics curve (AUC)=0.70, 95\% CI=0.61-0.79 in the model development sample and AUC=0.60, 95\% CI=0.58-0.63 in an external validation sample. We used predictors available in adolescence only (age, BMI and knee injury) and studied the discrimination of the simplified model using AUC in our sample.
RESULTS: The AUC-statistic of the modified knee OA model to predict 40-year risk was 0.60 (95\% CI=0.59-0.61). Hence, using the reduced model; an 18-year old man having a BMI of 30 and a knee injury would have a three times higher risk of developing knee OA within 40 years compared to a similarly aged man having a BMI of 25 and no knee injury (predicted risks 22\% and 7\%, respectively).
CONCLUSION: The individual and population 40-year risk of knee OA is predictable in 18-year olds from a few easily measured covariates with moderate discrimination. The discrimination of this simplified model based on data available in adolescence was comparable to that of the full Nottingham model in middle age. This article is protected by copyright. All rights reserved.},
	language = {eng},
	number = {4},
	journal = {Arthritis Care \& Research},
	author = {Magnusson, Karin and Turkiewicz, Aleksandra and Timpka, Simon and Englund, Martin},
	year = {2019},
	pmid = {29953751},
	pages = {558--562},
}

OBJECTIVES: To simplify the previously published Nottingham 12-year risk prediction model for knee osteoarthritis (OA) and examine whether it can be used to predict the 40-year risk of knee OA in young men. METHODS: We included 40 118 men aged 18 undergoing military conscription in Sweden 1969-70. Diagnostic OA codes were obtained from the Swedish National Patient Register 1987-2010. The original Nottingham model included predictors age, sex, body mass index (BMI), knee injury, occupational risk and family history of OA with area under receiver operating characteristics curve (AUC)=0.70, 95% CI=0.61-0.79 in the model development sample and AUC=0.60, 95% CI=0.58-0.63 in an external validation sample. We used predictors available in adolescence only (age, BMI and knee injury) and studied the discrimination of the simplified model using AUC in our sample. RESULTS: The AUC-statistic of the modified knee OA model to predict 40-year risk was 0.60 (95% CI=0.59-0.61). Hence, using the reduced model; an 18-year old man having a BMI of 30 and a knee injury would have a three times higher risk of developing knee OA within 40 years compared to a similarly aged man having a BMI of 25 and no knee injury (predicted risks 22% and 7%, respectively). CONCLUSION: The individual and population 40-year risk of knee OA is predictable in 18-year olds from a few easily measured covariates with moderate discrimination. The discrimination of this simplified model based on data available in adolescence was comparable to that of the full Nottingham model in middle age. This article is protected by copyright. All rights reserved.

@article{magnusson_nature_2019,
	title = {Nature vs. nurture in knee osteoarthritis - the importance of age, sex and body mass index},
	volume = {27},
	issn = {1522-9653},
	url = {https://doi.org/10.1016%2Fj.joca.2018.12.018},
	doi = {10.1016/j.joca.2018.12.018},
	abstract = {OBJECTIVE: 1) To estimate the life-time genetic contribution for knee osteoarthritis (OA) surgery and 2) to explore any differences in the genetic contribution across age, sex and body mass index (BMI).
METHODS: We studied the sex-specific genetic contribution to knee OA surgery in a prospective cohort study of 62 490 twins aged 35 years or older with a follow-up period of up to 47 years (10 092 identical and 21 153 non-identical twin pairs, 54\% women). To study interactions with age, we graphed the heritabilities over the lifespan for men and women. We also studied the sex-specific heritability across strata of the median BMI to explore any interactions with BMI.
RESULTS: The overall heritability of knee OA surgery was 0.53 (95\% CI=0.31-0.75), with higher heritability among women (H2=0.80 (95\% CI=0.73-0.87)) than men (H2=0.39 (95\% CI=0.10-0.69)). For men, the heritability started to rise after age 68.The genetic contribution was particularly low in men above median BMI (H2≥23.7 kg/m2 =0.08, 95\% CI=-0.32-0.48). For women, the heritability was consistently high from age 50 to death, independently of BMI (H2≥22.5 kg/m2 =0.77, 95\% CI=0.66-0.87).
CONCLUSION: There is a higher and more consistent genetic contribution for knee OA surgery in women than men. In men the genetic contribution was relatively low and varied with age and BMI.},
	language = {eng},
	number = {4},
	journal = {Osteoarthritis and Cartilage},
	author = {Magnusson, Karin and Turkiewicz, Aleksandra and Englund, Martin},
	year = {2019},
	pmid = {30634033},
	keywords = {Knee osteoarthritis, gene-environment interaction, genetics, heritability},
	pages = {586--592},
}

OBJECTIVE: 1) To estimate the life-time genetic contribution for knee osteoarthritis (OA) surgery and 2) to explore any differences in the genetic contribution across age, sex and body mass index (BMI). METHODS: We studied the sex-specific genetic contribution to knee OA surgery in a prospective cohort study of 62 490 twins aged 35 years or older with a follow-up period of up to 47 years (10 092 identical and 21 153 non-identical twin pairs, 54% women). To study interactions with age, we graphed the heritabilities over the lifespan for men and women. We also studied the sex-specific heritability across strata of the median BMI to explore any interactions with BMI. RESULTS: The overall heritability of knee OA surgery was 0.53 (95% CI=0.31-0.75), with higher heritability among women (H2=0.80 (95% CI=0.73-0.87)) than men (H2=0.39 (95% CI=0.10-0.69)). For men, the heritability started to rise after age 68.The genetic contribution was particularly low in men above median BMI (H2≥23.7 kg/m2 =0.08, 95% CI=-0.32-0.48). For women, the heritability was consistently high from age 50 to death, independently of BMI (H2≥22.5 kg/m2 =0.77, 95% CI=0.66-0.87). CONCLUSION: There is a higher and more consistent genetic contribution for knee OA surgery in women than men. In men the genetic contribution was relatively low and varied with age and BMI.

@article{kiadaliri_temporal_2019,
	title = {Temporal trend and regional disparity in osteoarthritis hospitalisations in {Sweden} 1998–2015},
	volume = {47},
	issn = {1403-4948},
	url = {https://doi.org/10.1177/1403494818766785},
	doi = {10.1177/1403494818766785},
	abstract = {Aim: This study investigated time trend and regional disparities in hospitalisations due to osteoarthritis (OA) among people aged ≥20 years in Sweden from 1998 through 2015. Methods: National and regional data on hospital admissions with a primary diagnosis of OA were collected from the National Patient Register. The absolute and relative regional disparities were assessed using the absolute weighted mean difference from overall mean and the index of disparity. We applied joinpoint regression for temporal trend analysis of hospitalisations and the Mann–Kendall trend test for disparity measures. Changes in number of OA hospitalisations between 1998–2000 and 2013–2015 were analysed using two counterfactual scenarios. Results: During 1998–2015, OA hospitalisations constituted 2.0\% of all hospitalisations, with higher proportions among women (58.7\%) and those aged 70–74 years (18.0\%). The age-standardised rate of OA hospitalisation and its proportions from all and musculoskeletal disorders hospitalisations rose, on average, by {\textgreater}2.0\% per year during the study period. OA hospitalisation rates rose statistically significantly in all age groups except for the youngest and oldest age groups. The proportion of hip OA from all OA hospitalisations declined, while the opposite was observed for knee OA. The relative regional disparities declined in men, and the absolute regional disparities rose among women over time. The population growth and ageing could explain only about one third of the observed increases in the absolute number of OA hospitalisations between 1998–2000 and 2013–2015. Conclusions: OA hospitalisations have increased substantially, suggesting the need to improve OA prevention and primary-care management in Sweden.},
	language = {en},
	number = {1},
	journal = {Scandinavian Journal of Public Health},
	author = {Kiadaliri, Aliasghar A. and Rinaldi, Giulia and Lohmander, L. Stefan and Petersson, Ingemar F. and Englund, Martin},
	year = {2019},
	keywords = {Adult, Aged, Aged, 80 and over, Female, Healthcare Disparities, Hospitalisation, Hospitalization, Humans, Male, Middle Aged, Osteoarthritis, Sweden, Young Adult, osteoarthritis, regional disparity, temporal trend},
	pages = {53--60},
}

Aim: This study investigated time trend and regional disparities in hospitalisations due to osteoarthritis (OA) among people aged ≥20 years in Sweden from 1998 through 2015. Methods: National and regional data on hospital admissions with a primary diagnosis of OA were collected from the National Patient Register. The absolute and relative regional disparities were assessed using the absolute weighted mean difference from overall mean and the index of disparity. We applied joinpoint regression for temporal trend analysis of hospitalisations and the Mann–Kendall trend test for disparity measures. Changes in number of OA hospitalisations between 1998–2000 and 2013–2015 were analysed using two counterfactual scenarios. Results: During 1998–2015, OA hospitalisations constituted 2.0% of all hospitalisations, with higher proportions among women (58.7%) and those aged 70–74 years (18.0%). The age-standardised rate of OA hospitalisation and its proportions from all and musculoskeletal disorders hospitalisations rose, on average, by \textgreater2.0% per year during the study period. OA hospitalisation rates rose statistically significantly in all age groups except for the youngest and oldest age groups. The proportion of hip OA from all OA hospitalisations declined, while the opposite was observed for knee OA. The relative regional disparities declined in men, and the absolute regional disparities rose among women over time. The population growth and ageing could explain only about one third of the observed increases in the absolute number of OA hospitalisations between 1998–2000 and 2013–2015. Conclusions: OA hospitalisations have increased substantially, suggesting the need to improve OA prevention and primary-care management in Sweden.

@article{kiadaliri_intersectional_2019,
	title = {Intersectional inequalities and individual heterogeneity in chronic rheumatic diseases: {An} intersectional multilevel analysis},
	volume = {In press},
	copyright = {© 2019, American College of Rheumatology},
	issn = {2151-4658},
	shorttitle = {Intersectional inequalities and individual heterogeneity in chronic rheumatic diseases},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/acr.24109},
	doi = {10.1002/acr.24109},
	abstract = {Objective To examine how intersections of multiple sociodemographic variables explain the individual heterogeneity in risk of being diagnosed with any of following chronic rheumatic diseases (CRDs): osteoarthritis (OA), gout, rheumatoid arthritis (RA), or spondyloarthritis (SpA). Methods We identified people aged 40-65 years residing in Skåne, Sweden, by 31st December 2013 and having done so from 1st January 2000 (N=342,542). We used Skåne healthcare register to identify those with a diagnosis of the CRD of interest between 1st January 2014 and 31st December 2015 with no previous such diagnosis during 2000-2013. We created 144 intersectional social strata (ISS) using categories of age, gender, education, income, civil status, and immigration. With individuals nested within ISS, we applied multilevel logistic regression models to estimate: 1) variance partition coefficient (VPC) as a measure of discriminatory accuracy of the ISS and 2) predicted absolute risks and 95\% credible intervals for each stratum. Results In overall, 3.5\%, 0.5\%, 0.2\%, and 0.2\% of the study population were diagnosed with OA, gout, RA, and SpA, respectively. The VPC ranged from 16.2\% for gout to 0.5\% for SpA. Gender explained the largest proportion of between-strata variation in risk of RA, gout, and SpA while age was the most important factor for OA. The most between-strata differences in risk of these CRDs were due to the additive main effects. Conclusion Despite meaningful between-strata inequalities in the risk of being diagnosed with CRDs (except SpA), there were substantial within-strata heterogeneities that remains unexplained. There were limited evidence of intersectional interaction effects.},
	language = {en},
	urldate = {2019-11-18},
	journal = {Arthritis Care \& Research},
	author = {Kiadaliri, Ali and Englund, Martin},
	year = {2019},
}

Objective To examine how intersections of multiple sociodemographic variables explain the individual heterogeneity in risk of being diagnosed with any of following chronic rheumatic diseases (CRDs): osteoarthritis (OA), gout, rheumatoid arthritis (RA), or spondyloarthritis (SpA). Methods We identified people aged 40-65 years residing in Skåne, Sweden, by 31st December 2013 and having done so from 1st January 2000 (N=342,542). We used Skåne healthcare register to identify those with a diagnosis of the CRD of interest between 1st January 2014 and 31st December 2015 with no previous such diagnosis during 2000-2013. We created 144 intersectional social strata (ISS) using categories of age, gender, education, income, civil status, and immigration. With individuals nested within ISS, we applied multilevel logistic regression models to estimate: 1) variance partition coefficient (VPC) as a measure of discriminatory accuracy of the ISS and 2) predicted absolute risks and 95% credible intervals for each stratum. Results In overall, 3.5%, 0.5%, 0.2%, and 0.2% of the study population were diagnosed with OA, gout, RA, and SpA, respectively. The VPC ranged from 16.2% for gout to 0.5% for SpA. Gender explained the largest proportion of between-strata variation in risk of RA, gout, and SpA while age was the most important factor for OA. The most between-strata differences in risk of these CRDs were due to the additive main effects. Conclusion Despite meaningful between-strata inequalities in the risk of being diagnosed with CRDs (except SpA), there were substantial within-strata heterogeneities that remains unexplained. There were limited evidence of intersectional interaction effects.

@article{olsson_ultra-high_2018,
	title = {Ultra-high field magnetic resonance imaging parameter mapping in the posterior horn of ex vivo human menisci},
	volume = {27},
	issn = {1522-9653},
	url = {https://doi.org/10.1016/j.joca.2018.12.003},
	doi = {10.1016/j.joca.2018.12.003},
	abstract = {OBJECTIVE: To investigate the relationship between meniscus magnetic resonance (MR) relaxation parameters and meniscus degradation through quantitative imaging of ex vivo posterior horns of menisci from subjects with and without knee osteoarthritis (OA).
DESIGN: We sampled medial and lateral menisci from ten medial compartment knee OA patients (mean age 63 years) undergoing total knee replacement and from ten deceased donors (references, mean age 51 years). MR relaxation parameters T2*, T2 and T1 of the posterior horn were measured at a 9.4 T scanner. Comparisons were made between OA patients and references (with adjustment for age) as well as between medial and lateral menisci from the same knees.
RESULTS: Mean values (standard deviation) of mean T2* were 13 (3.8), 6.9 (2.3), 7.2 (1.9) and 7.2 (1.7) ms for the medial and lateral patient menisci and the medial and lateral reference menisci, respectively. Corresponding values were 17 (3.7), 9.0 (2.2), 12 (4) and 9.0 (1.3) ms for T2 and 1810 (150), 1630 (30), 1580 (90) and 1560 (50) ms for T1. All three relaxation times were significantly longer in medial OA menisci compared to the other groups. Among medial reference menisci, relaxation times (mainly T1) tended to increase with age.
CONCLUSIONS: MR relaxation times T2*, T2 and T1 in the posterior horn are longer in the medial menisci of patients with end-stage medial compartment knee OA compared to the corresponding lateral menisci and to reference menisci. The meniscus seems to undergo intrasubstance alterations related to both OA and ageing.},
	language = {eng},
	number = {3},
	journal = {Osteoarthritis and Cartilage},
	author = {Olsson, E. and Folkesson, E. and Peterson, P. and Önnerfjord, P. and Tjörnstrand, J. and Hughes, H. V. and Englund, M. and Svensson, J.},
	month = dec,
	year = {2018},
	pmid = {30552967},
	keywords = {MRI, Meniscus, OA, T2*, UTE},
	pages = {476--483},
}

OBJECTIVE: To investigate the relationship between meniscus magnetic resonance (MR) relaxation parameters and meniscus degradation through quantitative imaging of ex vivo posterior horns of menisci from subjects with and without knee osteoarthritis (OA). DESIGN: We sampled medial and lateral menisci from ten medial compartment knee OA patients (mean age 63 years) undergoing total knee replacement and from ten deceased donors (references, mean age 51 years). MR relaxation parameters T2*, T2 and T1 of the posterior horn were measured at a 9.4 T scanner. Comparisons were made between OA patients and references (with adjustment for age) as well as between medial and lateral menisci from the same knees. RESULTS: Mean values (standard deviation) of mean T2* were 13 (3.8), 6.9 (2.3), 7.2 (1.9) and 7.2 (1.7) ms for the medial and lateral patient menisci and the medial and lateral reference menisci, respectively. Corresponding values were 17 (3.7), 9.0 (2.2), 12 (4) and 9.0 (1.3) ms for T2 and 1810 (150), 1630 (30), 1580 (90) and 1560 (50) ms for T1. All three relaxation times were significantly longer in medial OA menisci compared to the other groups. Among medial reference menisci, relaxation times (mainly T1) tended to increase with age. CONCLUSIONS: MR relaxation times T2*, T2 and T1 in the posterior horn are longer in the medial menisci of patients with end-stage medial compartment knee OA compared to the corresponding lateral menisci and to reference menisci. The meniscus seems to undergo intrasubstance alterations related to both OA and ageing.

@article{kiadaliri_hospitalizations_2018,
	title = {Hospitalizations due to systemic connective tissue diseases: {Secular} trends and regional disparities in {Sweden}, 1998-2016},
	volume = {21},
	copyright = {© 2018 Asia Pacific League of Associations for Rheumatology and John Wiley \& Sons Australia, Ltd},
	issn = {1756-185X},
	shorttitle = {Hospitalizations due to systemic connective tissue diseases},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/1756-185X.13341},
	doi = {10.1111/1756-185X.13341},
	abstract = {Aim To investigate secular trends and regional disparities in hospitalizations due to systemic connective tissue diseases (SCTD) in Sweden from 1998 to 2016. Method We identified all hospital admissions with a principal diagnosis of SCTD (ICD-10 codes: M30-M36) from the Swedish National Patient Register. Joinpoint regression was used to assess secular trends in age-standardized hospitalization rates (ASHR) and proportions of SCTD from all and musculoskeletal disorders hospitalizations. We also assessed the secular trends in the absolute and relative regional disparities of SCTD hospitalizations. Results We identified 89 333 SCTD hospitalizations (0.3\% of all hospitalizations), of these about 69\% were for women and 49\% of patients were aged 15-64 years. Polyarteritis nodosa and related conditions (PANRC) and systemic lupus erythematosus (SLE) were the most frequent SCTD among those aged {\textless}10 years and 10-54 years, respectively. Joinpoint regression suggested that both rates and proportions of SCTD hospitalizations declined over time. These trends persisted among sex, age and diagnosis subgroups except for PANRC in patients aged 0-19 years who observed an average annual increase of 3.4\% (95\% CI: 1.8, 5.1) over the study period. There were 2.4-fold (95\% CI: 2.3-2.5) difference between the regions with the highest and lowest mean ASHR. There was no statistically significant secular trend in the relative regional disparities, whereas the absolute regional disparity declined over time. Conclusion There were substantial decreases in the absolute and relative burden of SCTD hospitalizations reflecting possible improvements in disease management in Sweden. The rising trend in PANRC among the youngest children warrants further investigation.},
	language = {en},
	number = {11},
	urldate = {2018-10-04},
	journal = {International Journal of Rheumatic Diseases},
	author = {Kiadaliri, Aliasghar A. and Mohammad, Aladdin J. and Englund, Martin},
	month = nov,
	year = {2018},
	keywords = {Sjögren's syndrome, epidemiology, soft tissue rheumatism and regional pain syndromes, systemic lupus erythematous, vasculitides},
	pages = {1900--1906},
}

Aim To investigate secular trends and regional disparities in hospitalizations due to systemic connective tissue diseases (SCTD) in Sweden from 1998 to 2016. Method We identified all hospital admissions with a principal diagnosis of SCTD (ICD-10 codes: M30-M36) from the Swedish National Patient Register. Joinpoint regression was used to assess secular trends in age-standardized hospitalization rates (ASHR) and proportions of SCTD from all and musculoskeletal disorders hospitalizations. We also assessed the secular trends in the absolute and relative regional disparities of SCTD hospitalizations. Results We identified 89 333 SCTD hospitalizations (0.3% of all hospitalizations), of these about 69% were for women and 49% of patients were aged 15-64 years. Polyarteritis nodosa and related conditions (PANRC) and systemic lupus erythematosus (SLE) were the most frequent SCTD among those aged \textless10 years and 10-54 years, respectively. Joinpoint regression suggested that both rates and proportions of SCTD hospitalizations declined over time. These trends persisted among sex, age and diagnosis subgroups except for PANRC in patients aged 0-19 years who observed an average annual increase of 3.4% (95% CI: 1.8, 5.1) over the study period. There were 2.4-fold (95% CI: 2.3-2.5) difference between the regions with the highest and lowest mean ASHR. There was no statistically significant secular trend in the relative regional disparities, whereas the absolute regional disparity declined over time. Conclusion There were substantial decreases in the absolute and relative burden of SCTD hospitalizations reflecting possible improvements in disease management in Sweden. The rising trend in PANRC among the youngest children warrants further investigation.

@article{magnusson_naturally_2018,
	title = {A naturally aging knee, or development of early knee osteoarthritis?},
	volume = {26},
	issn = {1522-9653},
	url = {https://doi.org/10.1016%2Fj.joca.2018.04.020},
	doi = {10.1016/j.joca.2018.04.020},
	abstract = {AIM: To study the development of early knee osteoarthritis (OA) in subjects with and without risk factors for knee OA.
METHODS: We studied 340 subjects from the Osteoarthritis Initiative (OAI), aged 45-55 years (51\% women), free of radiographic knee OA at baseline (n = 294 with and n = 46 without knee pain and other OA risk factors). At baseline, 24, 48, 72 and 96 months we compared the two groups for prevalence and overlap of knee OA as defined by magnetic resonance imaging (MRI-based OA), x-rays (Kellgren-Lawrence grade [KLG] ≥ 1), and pain, using a logistic mixed model. We studied the group differences (\%) over time by subtracting the OA prevalence of those without risk factors from the group with risk factors.
RESULTS: The group with OA risk factors had higher proportions of MRI-based OA than the group without OA risk factors at all visits, but the difference diminished at 72 months (72 months difference = 11.9\%, 95\% confidence intervals [CI] = -2.3-26.1). Further, at 72 months, the presence of KLG ≥ 1 were similar in the two groups (-3.5\%, 95\% CI = -15.2-8.2). The proportion fulfilling all three OA definitions was 1.7\% at 24 months and 4.8\% at 72 months of those with OA risk factors and 0\% and 2.2\%, respectively, in those without.
CONCLUSION: Structural changes of the knee are common irrespective of the presence of pain or other OA risk factors. Such structural changes in absence of knee symptoms should probably be considered as risk factors for early OA rather than disease.},
	language = {eng},
	number = {11},
	journal = {Osteoarthritis and Cartilage},
	author = {Magnusson, K. and Kumm, J. and Turkiewicz, A. and Englund, M.},
	month = jul,
	year = {2018},
	pmid = {30041054},
	keywords = {Early knee OA, MRI-based OA, Radiographic OA, Risk factors},
	pages = {1447--1452},
}

AIM: To study the development of early knee osteoarthritis (OA) in subjects with and without risk factors for knee OA. METHODS: We studied 340 subjects from the Osteoarthritis Initiative (OAI), aged 45-55 years (51% women), free of radiographic knee OA at baseline (n = 294 with and n = 46 without knee pain and other OA risk factors). At baseline, 24, 48, 72 and 96 months we compared the two groups for prevalence and overlap of knee OA as defined by magnetic resonance imaging (MRI-based OA), x-rays (Kellgren-Lawrence grade [KLG] ≥ 1), and pain, using a logistic mixed model. We studied the group differences (%) over time by subtracting the OA prevalence of those without risk factors from the group with risk factors. RESULTS: The group with OA risk factors had higher proportions of MRI-based OA than the group without OA risk factors at all visits, but the difference diminished at 72 months (72 months difference = 11.9%, 95% confidence intervals [CI] = -2.3-26.1). Further, at 72 months, the presence of KLG ≥ 1 were similar in the two groups (-3.5%, 95% CI = -15.2-8.2). The proportion fulfilling all three OA definitions was 1.7% at 24 months and 4.8% at 72 months of those with OA risk factors and 0% and 2.2%, respectively, in those without. CONCLUSION: Structural changes of the knee are common irrespective of the presence of pain or other OA risk factors. Such structural changes in absence of knee symptoms should probably be considered as risk factors for early OA rather than disease.

@article{friberger_pajalic_update_2018,
	title = {Update on the risks of complications after knee arthroscopy},
	volume = {19},
	issn = {1471-2474},
	url = {https://doi.org/10.1186/s12891-018-2102-y},
	doi = {10.1186/s12891-018-2102-y},
	abstract = {Knee arthroscopy is one of the most common surgical procedures worldwide and the number of arthroscopies has substantially increased in the last 30 years. Thus, our aim was to provide updated estimates on the risk of complications and compare it with the background risk in the general population.},
	number = {1},
	urldate = {2018-10-05},
	journal = {BMC Musculoskeletal Disorders},
	author = {Friberger Pajalic, Katarina and Turkiewicz, Aleksandra and Englund, Martin},
	month = jun,
	year = {2018},
	pages = {179},
}

Knee arthroscopy is one of the most common surgical procedures worldwide and the number of arthroscopies has substantially increased in the last 30 years. Thus, our aim was to provide updated estimates on the risk of complications and compare it with the background risk in the general population.

@article{folkesson_differential_2018,
	title = {Differential protein expression in human knee articular cartilage and medial meniscus using two different proteomic methods: a pilot analysis},
	volume = {19},
	issn = {1471-2474},
	shorttitle = {Differential protein expression in human knee articular cartilage and medial meniscus using two different proteomic methods},
	url = {https://doi.org/10.1186%2Fs12891-018-2346-6},
	doi = {10.1186/s12891-018-2346-6},
	abstract = {BACKGROUND: Proteomics is an emerging field in the study of joint disease. Our two aims with this pilot analysis were to compare healthy human knee articular cartilage with meniscus, two tissues both known to become affected in the osteoarthritic disease process, and to compare two mass spectrometry (MS)-based methods: data-dependent acquisition (DDA) and data-independent acquisition (DIA).
METHODS: Healthy knee articular cartilage taken from the medial tibial condyle and medial meniscus samples taken from the body region were obtained from three adult forensic medicine cases. Proteins were extracted from tissue pieces and prepared for MS analysis. Each sample was subjected to liquid chromatography (LC)-MS/MS analysis using an Orbitrap mass spectrometer, and run in both DDA and DIA mode. Linear mixed effects models were used for statistical analysis.
RESULTS: A total of 653 proteins were identified in the DDA analysis, of which the majority was present in both tissue types. Only proteins with quantitation information in both tissues (n = 90) were selected for more detailed analysis, of which the majority did not statistically significantly differ in abundance between the two tissue types, in either of the MS analyses. However, 21 proteins were statistically significantly different (p {\textless} 0.05) between meniscus and cartilage in the DIA analysis. Out of these, 11 proteins were also significantly different in the DDA analysis. Aggrecan core protein was the most abundant protein in articular cartilage and significantly differed between the two tissues in both methods. The corresponding protein in meniscus was serum albumin. Dermatopontin exhibited the highest meniscus vs articular cartilage ratio among the statistically significant proteins. The DIA method led to narrower confidence intervals for the abundance differences between the two tissue types than DDA.
CONCLUSIONS: Although articular cartilage and meniscus had similar proteomic composition, we detected several differences by MS. Between the two analyses, DIA yielded more precise estimates and more statistically significant different proteins than DDA, and had no missing values, which makes it preferable for future LC-MS/MS analyses.},
	language = {eng},
	number = {1},
	journal = {BMC musculoskeletal disorders},
	author = {Folkesson, Elin and Turkiewicz, Aleksandra and Englund, Martin and Önnerfjord, Patrik},
	month = nov,
	year = {2018},
	pmid = {30497455},
	pmcid = {PMC6267052},
	keywords = {Adult, Algorithms, Articular cartilage, Cartilage, Articular, Chromatography, High Pressure Liquid, Data-dependent acquisition, Data-independent acquisition, Female, Healthy Volunteers, Humans, Knee, Male, Menisci, Tibial, Meniscus, Osteoarthritis, Pilot Projects, Proteome, Proteomics, Software, Tandem Mass Spectrometry},
	pages = {416},
}

BACKGROUND: Proteomics is an emerging field in the study of joint disease. Our two aims with this pilot analysis were to compare healthy human knee articular cartilage with meniscus, two tissues both known to become affected in the osteoarthritic disease process, and to compare two mass spectrometry (MS)-based methods: data-dependent acquisition (DDA) and data-independent acquisition (DIA). METHODS: Healthy knee articular cartilage taken from the medial tibial condyle and medial meniscus samples taken from the body region were obtained from three adult forensic medicine cases. Proteins were extracted from tissue pieces and prepared for MS analysis. Each sample was subjected to liquid chromatography (LC)-MS/MS analysis using an Orbitrap mass spectrometer, and run in both DDA and DIA mode. Linear mixed effects models were used for statistical analysis. RESULTS: A total of 653 proteins were identified in the DDA analysis, of which the majority was present in both tissue types. Only proteins with quantitation information in both tissues (n = 90) were selected for more detailed analysis, of which the majority did not statistically significantly differ in abundance between the two tissue types, in either of the MS analyses. However, 21 proteins were statistically significantly different (p \textless 0.05) between meniscus and cartilage in the DIA analysis. Out of these, 11 proteins were also significantly different in the DDA analysis. Aggrecan core protein was the most abundant protein in articular cartilage and significantly differed between the two tissues in both methods. The corresponding protein in meniscus was serum albumin. Dermatopontin exhibited the highest meniscus vs articular cartilage ratio among the statistically significant proteins. The DIA method led to narrower confidence intervals for the abundance differences between the two tissue types than DDA. CONCLUSIONS: Although articular cartilage and meniscus had similar proteomic composition, we detected several differences by MS. Between the two analyses, DIA yielded more precise estimates and more statistically significant different proteins than DDA, and had no missing values, which makes it preferable for future LC-MS/MS analyses.

@article{kapetanovic_risk_2018,
	title = {The risk of clinically diagnosed gout by serum urate levels: results from 30 years follow-up of the {Malmö} {Preventive} {Project} cohort in southern {Sweden}},
	volume = {20},
	issn = {1478-6362},
	shorttitle = {The risk of clinically diagnosed gout by serum urate levels},
	url = {https://doi.org/10.1186/s13075-018-1697-6},
	doi = {10.1186/s13075-018-1697-6},
	abstract = {Hyperuricemia (HU) is in the causal pathway for developing clinical gout. There are few population-based assessments of the absolute and relative risk of clinically diagnosed incident gout in subjects with HU. We aimed to explore the long-term risk of developing incident gout among asymptomatic adults with different levels of serum urate (SU).},
	number = {1},
	urldate = {2018-10-04},
	journal = {Arthritis Research \& Therapy},
	author = {Kapetanovic, Meliha C. and Nilsson, Peter and Turesson, Carl and Englund, Martin and Dalbeth, Nicola and Jacobsson, Lennart},
	month = aug,
	year = {2018},
	pages = {190},
}

Hyperuricemia (HU) is in the causal pathway for developing clinical gout. There are few population-based assessments of the absolute and relative risk of clinically diagnosed incident gout in subjects with HU. We aimed to explore the long-term risk of developing incident gout among asymptomatic adults with different levels of serum urate (SU).

@article{pihl_change_2018,
	title = {Change in patient-reported outcomes in patients with and without mechanical symptoms undergoing arthroscopic meniscal surgery: {A} prospective cohort study},
	volume = {26},
	issn = {1522-9653},
	shorttitle = {Change in patient-reported outcomes in patients with and without mechanical symptoms undergoing arthroscopic meniscal surgery},
	url = {https://doi.org/10.1016%2Fj.joca.2018.05.004},
	doi = {10.1016/j.joca.2018.05.004},
	abstract = {OBJECTIVE: Patients with degenerative or traumatic meniscal tears are at high risk of developing knee osteoarthritis. We investigated if younger (≤40 years) and older ({\textgreater}40 years) patients with preoperative mechanical symptoms improved more in patient-reported outcomes after meniscal surgery than those without mechanical symptoms.
DESIGN: Patients from Knee Arthroscopy Cohort Southern Denmark (KACS) undergoing arthroscopic surgery for a meniscal tear completed online questionnaires before surgery, and at 12 and 52 weeks follow-up. Questionnaires included self-reported presence of mechanical symptoms (i.e. sensation of catching and/or locking) and the Knee Injury and Osteoarthritis Outcome Score (KOOS). We analyzed between-group differences in change in KOOS4 from baseline to 52 weeks, using an adjusted mixed linear model.
RESULTS: 150 younger patients (mean age 31 (SD 7), 67\% men) and 491 older patients (mean age 54 (SD 9), 53\% men) constituted the baseline cohorts. Patients with mechanical symptoms generally had worse self-reported outcomes before surgery. At 52 weeks follow-up, younger patients with preoperative mechanical symptoms had improved more in KOOS4 scores than younger patients without preoperative mechanical symptoms (adjusted mean difference 10.5, 95\%CI: 4.3, 16.6), but did not exceed the absolute postoperative KOOS4 scores observed for those without mechanical symptoms. No difference in improvement was observed between older patients with or without mechanical symptoms (adjusted mean difference 0.7, 95\%CI: -2.6, 3.9).
CONCLUSIONS: Younger patients (≤40 years) with preoperative mechanical symptoms experienced greater improvements after arthroscopic surgery compared to younger patients without mechanical symptoms. Our observational study result needs to be confirmed in randomized trials.},
	language = {eng},
	number = {8},
	journal = {Osteoarthritis and Cartilage},
	author = {Pihl, Kenneth and Turkiewicz, Aleksandra and Englund, Martin and Stefan Lohmander, L. and Jørgensen, Uffe and Nissen, Nis and Schjerning, Jeppe and Thorlund, Jonas B.},
	month = aug,
	year = {2018},
	pmid = {29792925},
	keywords = {Arthroscopy, Knee, Mechanical symptoms, Meniscal tears, Osteoarthritis, Patient-reported outcomes, knee, mechanical symptoms, meniscal tears, osteoarthritis, patient-reported outcomes},
	pages = {1008--1016},
}

OBJECTIVE: Patients with degenerative or traumatic meniscal tears are at high risk of developing knee osteoarthritis. We investigated if younger (≤40 years) and older (\textgreater40 years) patients with preoperative mechanical symptoms improved more in patient-reported outcomes after meniscal surgery than those without mechanical symptoms. DESIGN: Patients from Knee Arthroscopy Cohort Southern Denmark (KACS) undergoing arthroscopic surgery for a meniscal tear completed online questionnaires before surgery, and at 12 and 52 weeks follow-up. Questionnaires included self-reported presence of mechanical symptoms (i.e. sensation of catching and/or locking) and the Knee Injury and Osteoarthritis Outcome Score (KOOS). We analyzed between-group differences in change in KOOS4 from baseline to 52 weeks, using an adjusted mixed linear model. RESULTS: 150 younger patients (mean age 31 (SD 7), 67% men) and 491 older patients (mean age 54 (SD 9), 53% men) constituted the baseline cohorts. Patients with mechanical symptoms generally had worse self-reported outcomes before surgery. At 52 weeks follow-up, younger patients with preoperative mechanical symptoms had improved more in KOOS4 scores than younger patients without preoperative mechanical symptoms (adjusted mean difference 10.5, 95%CI: 4.3, 16.6), but did not exceed the absolute postoperative KOOS4 scores observed for those without mechanical symptoms. No difference in improvement was observed between older patients with or without mechanical symptoms (adjusted mean difference 0.7, 95%CI: -2.6, 3.9). CONCLUSIONS: Younger patients (≤40 years) with preoperative mechanical symptoms experienced greater improvements after arthroscopic surgery compared to younger patients without mechanical symptoms. Our observational study result needs to be confirmed in randomized trials.

@article{magnusson_prediction_2018,
	title = {Prediction of midlife hand osteoarthritis in young men},
	volume = {26},
	issn = {1522-9653},
	url = {https://doi.org/10.1016%2Fj.joca.2018.05.010},
	doi = {10.1016/j.joca.2018.05.010},
	abstract = {OBJECTIVES: Improved prediction modeling in osteoarthritis (OA) may encourage risk reduction through calculation of individual and population lifetime risks. There are currently no prediction models for hand OA. Thus, we aimed to i) develop a prediction model for hand OA in men and ii) to contrast its discriminative performance to a prediction model for lung cancer and chronic obstructive pulmonary disease (COPD).
METHODS: We included 40 118 men aged 18 years undergoing mandatory conscription in Sweden 1969-70. Incident hand OA and lung cancer/COPD were obtained from diagnostic codes in the Swedish National Patient Register 1987-2010, i.e. until subjects were 59 years of age. We studied the strongest candidate predictors from 5 domains; socioeconomic, local biomechanical, systemic, lifestyle-related and general health factors, using logistic regression with backward elimination of candidate predictors with p{\textgreater}0.2 to determine final models. To avoid overfitting we used bootstrapping.
RESULTS: The strongest predictors for hand OA were body mass index, elbow flexor strength, systolic blood pressure, lower education and sleep problems. We observed excellent agreement between observed and predicted values, yet the discrimination was moderate (Area Under the Curve [AUC]=0.62, 95\% CI=0.58-0.64). The discrimination in the prediction model for lung cancer/COPD was good (AUC=0.74, 95\% CI=0.72-0.76).
CONCLUSION: This prediction model for hand OA was capable of discriminating between persons with and without hand OA to a similar extent that has been previously reported for knee OA. Still, prediction of OA is more challenging than for chronic pulmonary disease.},
	language = {eng},
	number = {8},
	journal = {Osteoarthritis and Cartilage},
	author = {Magnusson, Karin and Turkiewicz, Aleksandra and Timpka, Simon and Englund, Martin},
	month = aug,
	year = {2018},
	pmid = {29792926},
	keywords = {Discrimination, Hand osteoarthritis, Prediction, Risk},
	pages = {1027--1032},
}

OBJECTIVES: Improved prediction modeling in osteoarthritis (OA) may encourage risk reduction through calculation of individual and population lifetime risks. There are currently no prediction models for hand OA. Thus, we aimed to i) develop a prediction model for hand OA in men and ii) to contrast its discriminative performance to a prediction model for lung cancer and chronic obstructive pulmonary disease (COPD). METHODS: We included 40 118 men aged 18 years undergoing mandatory conscription in Sweden 1969-70. Incident hand OA and lung cancer/COPD were obtained from diagnostic codes in the Swedish National Patient Register 1987-2010, i.e. until subjects were 59 years of age. We studied the strongest candidate predictors from 5 domains; socioeconomic, local biomechanical, systemic, lifestyle-related and general health factors, using logistic regression with backward elimination of candidate predictors with p\textgreater0.2 to determine final models. To avoid overfitting we used bootstrapping. RESULTS: The strongest predictors for hand OA were body mass index, elbow flexor strength, systolic blood pressure, lower education and sleep problems. We observed excellent agreement between observed and predicted values, yet the discrimination was moderate (Area Under the Curve [AUC]=0.62, 95% CI=0.58-0.64). The discrimination in the prediction model for lung cancer/COPD was good (AUC=0.74, 95% CI=0.72-0.76). CONCLUSION: This prediction model for hand OA was capable of discriminating between persons with and without hand OA to a similar extent that has been previously reported for knee OA. Still, prediction of OA is more challenging than for chronic pulmonary disease.

@article{kumm_structural_2018,
	title = {Structural abnormalities detected by knee magnetic resonance imaging are common in middle-aged subjects with and without risk factors for osteoarthritis},
	volume = {89},
	issn = {1745-3682},
	url = {https://doi.org/10.1080%2F17453674.2018.1495164},
	doi = {10.1080/17453674.2018.1495164},
	abstract = {Background and purpose - Few data are available regarding structural changes present in knees without radiographically evident osteoarthritis (OA). We evaluated the prevalence of findings suggestive of knee OA by magnetic resonance imaging (MRI) in middle-aged subjects without radiographic OA with or without OA risk factors. Patients and methods - 340 subjects from the Osteoarthritis Initiative, aged 45-55 years (51\% women) with Kellgren-Lawrence grade 0 in both knees, who had 3T knee MR images were eligible. 294 subjects had risk factors and 46 were without risk factors. MR images were assessed using the MOAKS scoring system. Results - At least 1 MR-detected feature was found in 96\% (283/294) of subjects with risk factors and in 87\% (40/46) of those without. Cartilage damage (82\%), bone marrow lesions (60\%), osteophytes (45\%), meniscal body extrusion (32\%), and synovitis-effusion (29\%) were the most common findings in subjects with risk factors, while cartilage damage (67\%), osteophytes (46\%), meniscal body extrusion (37\%), and bone marrow lesions (35\%) were most common in subjects without. The prevalence of any abnormality was higher in subjects with OA risk factors than in subjects without (prevalence ratio adjusted for age and sex 1.3 [95\% CI 1.1-1.6]), so was prevalence of subchondral cysts and bone marrow lesions. MR-detected structural changes were more frequent in patellofemoral joints. Interpretation - Our findings highlight the great challenge in distinguishing pathological features of early knee OA from what could be considered part of "normal ageing." Bone marrow lesions were more frequently found in subjects with multiple OA risk factors.},
	language = {eng},
	number = {5},
	journal = {Acta Orthopaedica},
	author = {Kumm, Jaanika and Turkiewicz, Aleksandra and Zhang, Fan and Englund, Martin},
	month = jul,
	year = {2018},
	pmid = {30014747},
	pages = {535--540},
}

Background and purpose - Few data are available regarding structural changes present in knees without radiographically evident osteoarthritis (OA). We evaluated the prevalence of findings suggestive of knee OA by magnetic resonance imaging (MRI) in middle-aged subjects without radiographic OA with or without OA risk factors. Patients and methods - 340 subjects from the Osteoarthritis Initiative, aged 45-55 years (51% women) with Kellgren-Lawrence grade 0 in both knees, who had 3T knee MR images were eligible. 294 subjects had risk factors and 46 were without risk factors. MR images were assessed using the MOAKS scoring system. Results - At least 1 MR-detected feature was found in 96% (283/294) of subjects with risk factors and in 87% (40/46) of those without. Cartilage damage (82%), bone marrow lesions (60%), osteophytes (45%), meniscal body extrusion (32%), and synovitis-effusion (29%) were the most common findings in subjects with risk factors, while cartilage damage (67%), osteophytes (46%), meniscal body extrusion (37%), and bone marrow lesions (35%) were most common in subjects without. The prevalence of any abnormality was higher in subjects with OA risk factors than in subjects without (prevalence ratio adjusted for age and sex 1.3 [95% CI 1.1-1.6]), so was prevalence of subchondral cysts and bone marrow lesions. MR-detected structural changes were more frequent in patellofemoral joints. Interpretation - Our findings highlight the great challenge in distinguishing pathological features of early knee OA from what could be considered part of "normal ageing." Bone marrow lesions were more frequently found in subjects with multiple OA risk factors.

@article{kiadaliri_high_2018,
	title = {High and rising burden of hip and knee osteoarthritis in the {Nordic} region, 1990–2015},
	volume = {89},
	issn = {1745-3674},
	url = {https://doi.org/10.1080/17453674.2017.1404791},
	doi = {10.1080/17453674.2017.1404791},
	abstract = {Background and purpose — Osteoarthritis (OA) imposes a substantial burden on individuals and societies. We report on the burden of knee and hip OA in the Nordic region.Patients and methods — We used the findings from the 2015 Global Burden of Diseases Study to explore prevalence, years lived with disability (YLDs), and disability-adjusted life-years (DALYs) of OA in the 6 Nordic countries during 1990–2015 (population of about 27 million in 2015).Results — During 1990–2015, the number of prevalent OA cases increased by 43\% to 1,507,587 (95\% uncertainty interval [UI] 1,454,338–1,564,778) in the region. OA accounted for 1.3\% (UI 1.0–1.7) of YLDs in 1990, increasing to 1.6\% (UI 1.2–2.0) in 2015. Of 315 causes studied, OA was the 15th leading cause of YLDs, causing 52,661 (UI 34,056–77,499) YLDs in 2015; of these 23\% were attributable to high body mass index. The highest relative importance of OA was reported for women aged 65–74 years (8th leading cause of YLDs in 2015). Among the top 30 leading causes of YLDs in the region, OA had the 5th greatest relative increase in total YLDs during 1990–2015. From 1990 to 2015, increase in age-standardized YLDs from OA in the region was slightly lower than increase at the global level (7.5\% vs. 10.5\%). OA was, however, responsible for a higher proportional burden of DALYs in the region compared with the global level.Interpretation — The OA burden is high and rising in the Nordic region. With population growth, aging, and the obesity epidemic, a substantial rise in the burden of OA is expected and should be addressed in health policies.},
	number = {2},
	journal = {Acta Orthopaedica},
	author = {Kiadaliri, Aliasghar A. and Lohmander, L. Stefan and Moradi-Lakeh, Maziar and Petersson, Ingemar F. and Englund, Martin},
	month = mar,
	year = {2018},
	pmid = {29160139},
	keywords = {Adult, Age Distribution, Aged, Aged, 80 and over, Body Mass Index, Cost of Illness, Female, Humans, Male, Middle Aged, Osteoarthritis, Hip, Osteoarthritis, Knee, Prevalence, Quality-Adjusted Life Years, Scandinavian and Nordic Countries, Sex Distribution},
	pages = {177--183},
}

Background and purpose — Osteoarthritis (OA) imposes a substantial burden on individuals and societies. We report on the burden of knee and hip OA in the Nordic region.Patients and methods — We used the findings from the 2015 Global Burden of Diseases Study to explore prevalence, years lived with disability (YLDs), and disability-adjusted life-years (DALYs) of OA in the 6 Nordic countries during 1990–2015 (population of about 27 million in 2015).Results — During 1990–2015, the number of prevalent OA cases increased by 43% to 1,507,587 (95% uncertainty interval [UI] 1,454,338–1,564,778) in the region. OA accounted for 1.3% (UI 1.0–1.7) of YLDs in 1990, increasing to 1.6% (UI 1.2–2.0) in 2015. Of 315 causes studied, OA was the 15th leading cause of YLDs, causing 52,661 (UI 34,056–77,499) YLDs in 2015; of these 23% were attributable to high body mass index. The highest relative importance of OA was reported for women aged 65–74 years (8th leading cause of YLDs in 2015). Among the top 30 leading causes of YLDs in the region, OA had the 5th greatest relative increase in total YLDs during 1990–2015. From 1990 to 2015, increase in age-standardized YLDs from OA in the region was slightly lower than increase at the global level (7.5% vs. 10.5%). OA was, however, responsible for a higher proportional burden of DALYs in the region compared with the global level.Interpretation — The OA burden is high and rising in the Nordic region. With population growth, aging, and the obesity epidemic, a substantial rise in the burden of OA is expected and should be addressed in health policies.

@article{mossberg_epidemiology_2018,
	title = {Epidemiology of primary systemic vasculitis in children: a population-based study from southern {Sweden}},
	volume = {47},
	issn = {0300-9742},
	shorttitle = {Epidemiology of primary systemic vasculitis in children},
	url = {https://doi.org/10.1080/03009742.2017.1412497},
	doi = {10.1080/03009742.2017.1412497},
	abstract = {Objectives: To estimate the annual incidence rate of paediatric primary systemic vasculitis (PSV) in a defined geographical area in southern Sweden.Methods: Potential cases of PSV [IgA vasculitis (IgAV, Henoch–Schönlein purpura), Kawasaki disease (KD), granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), eosinophilic granulomatosis with polyangiitis (EGPA), polyarteritis nodosa (PAN), and Takayasu’s arteritis (TAK)] were identified in a comprehensive regional healthcare register. The study area is Skåne, the southernmost county of Sweden (population 1.29 million; 21.4\% aged {\textless}18 years). Case records for children (0–17 years) assigned a diagnosis code between M300 and M319 and/or D690 were reviewed to ascertain diagnosis. Only patients diagnosed between 2004 and 2014 were included.Results: In total, 556 patients with PSV were identified. The annual incidence rate per million children (95\% confidence interval) was estimated to be 200 (183–217) for all PSV, 175.5 for IgAV (160–191), 20.1 for KD (14.9–25.4), 1.4 (0–2.8) for each of GPA and MPA, 0.7 (0–1.7) for PAN, and 0.4 (0–1.1) for each of EGPA and TAK. Among children aged {\textless}10 years, 99.5\% of cases were either IgAV or KD, both exhibiting a seasonal pattern paralleling infections. There were no deaths, but three cases of end-stage renal disease were noted, all in MPA.Conclusions: Vasculitis is relatively common during childhood. Mild cases associated with the infection season are most common in the youngest age groups, while during adolescence a substantial proportion has more severe forms of vasculitis.},
	number = {4},
	journal = {Scandinavian Journal of Rheumatology},
	author = {Mossberg, M. and Segelmark, M. and Kahn, R. and Englund, M. and Mohammad, A. J.},
	month = feb,
	year = {2018},
	pmid = {29409373},
	pages = {295--302},
}

Objectives: To estimate the annual incidence rate of paediatric primary systemic vasculitis (PSV) in a defined geographical area in southern Sweden.Methods: Potential cases of PSV [IgA vasculitis (IgAV, Henoch–Schönlein purpura), Kawasaki disease (KD), granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), eosinophilic granulomatosis with polyangiitis (EGPA), polyarteritis nodosa (PAN), and Takayasu’s arteritis (TAK)] were identified in a comprehensive regional healthcare register. The study area is Skåne, the southernmost county of Sweden (population 1.29 million; 21.4% aged \textless18 years). Case records for children (0–17 years) assigned a diagnosis code between M300 and M319 and/or D690 were reviewed to ascertain diagnosis. Only patients diagnosed between 2004 and 2014 were included.Results: In total, 556 patients with PSV were identified. The annual incidence rate per million children (95% confidence interval) was estimated to be 200 (183–217) for all PSV, 175.5 for IgAV (160–191), 20.1 for KD (14.9–25.4), 1.4 (0–2.8) for each of GPA and MPA, 0.7 (0–1.7) for PAN, and 0.4 (0–1.1) for each of EGPA and TAK. Among children aged \textless10 years, 99.5% of cases were either IgAV or KD, both exhibiting a seasonal pattern paralleling infections. There were no deaths, but three cases of end-stage renal disease were noted, all in MPA.Conclusions: Vasculitis is relatively common during childhood. Mild cases associated with the infection season are most common in the youngest age groups, while during adolescence a substantial proportion has more severe forms of vasculitis.

@article{kiadaliri_fracture-related_2018,
	title = {Fracture-related mortality in southern {Sweden}: {A} multiple cause of death analysis, 1998–2014},
	volume = {49},
	issn = {0020-1383},
	shorttitle = {Fracture-related mortality in southern {Sweden}},
	url = {http://www.sciencedirect.com/science/article/pii/S0020138317308586},
	doi = {10.1016/j.injury.2017.12.005},
	abstract = {Purpose
To assess fracture-related mortality among adults (aged ≥20years) in southern Sweden using multiple causes of death approach.
Methods
All death certificates (n=201 488) in adults recorded in the region of Skåne from 1998 to 2014 were examined. We identified fracture-related deaths and computed mortality rates by sex, age group, and fracture site. Temporal trends were evaluated using joinpoint regression and associated causes were identified by age- and sex-adjusted observed/expected ratios.
Results
Fractures were mentioned on 6 226 (3.1\%) death certificates, with majority of these occurred among women (60\%) and those aged≥80years (77\%). While hip was the most common site overall (61\% of all fracture-related deaths), skull was the most common site in people {\textless}60years (60\% of all fracture-related deaths). Proportion of death certificates mentioning fracture was stable in women but increased by 0.4\% (95\% CI: 0.1 to 0.6) in men between 1998–2002 and 2010–2014. The mean age at death was higher in death certificates mentioning fracture than those without and this gap widened over time. The mean age-standardized fracture-related mortality rate was 18.8 (14.0) per 100 000 person-year in men (women) and declined by 1.5\% (1.3\%) per year during 1998–2014. Injuries (84.6\%) and cardiovascular disorders (64.6\%) were the most common comorbidities on death certificates mentioning fracture.
Conclusions
Fracture is a contributing cause of death in more than 3\% of all deaths in southern Sweden with hip in lead among older and skull fracture among younger people. There was a slight increase in proportion of deaths associated with fracture in men but not women during the study period.},
	number = {2},
	journal = {Injury},
	author = {Kiadaliri, Aliasghar A. and Rosengren, Björn E. and Englund, Martin},
	month = feb,
	year = {2018},
	keywords = {Fracture, Mortality, Multiple cause of death, Sweden},
	pages = {236--242},
}

Purpose To assess fracture-related mortality among adults (aged ≥20years) in southern Sweden using multiple causes of death approach. Methods All death certificates (n=201 488) in adults recorded in the region of Skåne from 1998 to 2014 were examined. We identified fracture-related deaths and computed mortality rates by sex, age group, and fracture site. Temporal trends were evaluated using joinpoint regression and associated causes were identified by age- and sex-adjusted observed/expected ratios. Results Fractures were mentioned on 6 226 (3.1%) death certificates, with majority of these occurred among women (60%) and those aged≥80years (77%). While hip was the most common site overall (61% of all fracture-related deaths), skull was the most common site in people \textless60years (60% of all fracture-related deaths). Proportion of death certificates mentioning fracture was stable in women but increased by 0.4% (95% CI: 0.1 to 0.6) in men between 1998–2002 and 2010–2014. The mean age at death was higher in death certificates mentioning fracture than those without and this gap widened over time. The mean age-standardized fracture-related mortality rate was 18.8 (14.0) per 100 000 person-year in men (women) and declined by 1.5% (1.3%) per year during 1998–2014. Injuries (84.6%) and cardiovascular disorders (64.6%) were the most common comorbidities on death certificates mentioning fracture. Conclusions Fracture is a contributing cause of death in more than 3% of all deaths in southern Sweden with hip in lead among older and skull fracture among younger people. There was a slight increase in proportion of deaths associated with fracture in men but not women during the study period.

@article{wolski_trabecular_2018,
	title = {Trabecular bone texture detected by plain radiography is associated with {MRI}-defined osteophytes in finger joints of women without radiographic osteoarthritis},
	volume = {26},
	issn = {1063-4584},
	url = {http://www.sciencedirect.com/science/article/pii/S106345841831166X},
	doi = {10.1016/j.joca.2018.04.007},
	abstract = {Summary
Objective
To examine associations between trabecular bone (TB) texture and MRI-defined osteophytes in finger joints without radiographic osteoarthritis (OA) using an augmented variance orientation transform (AVOT) method.
Design
In a cross-sectional study, associations of the TB texture and osteophytes were examined in 21 women with mean (standard deviation) age of 69.9 (5.3) from the Oslo Hand OA cohort. The AVOT was applied to distal and proximal TB regions selected on hand radiographs of the subjects. The regions were adjacent to 57 finger joints (24 distal and 33 proximal interphalangeal) without radiographic OA (Kellgren-Lawrence [KL] grade 0), without MRI-defined joint space narrowing, bone marrow lesions, attrition, erosion, cysts, sclerosis, malalignment (all MRI grades 0) and without or only with mild synovitis (MRI grade 0 or 1). Bone texture parameters were calculated: mean fractal dimension (FDMEAN), FDs in the horizontal (FDH) and vertical (FDV) directions, and along the roughest part (FDSta). Associations between the parameters categorized into groups using tertiles and osteophytes were evaluated using logistic regression adjusted for age.
Results
Lower FDSta and FDV in the distal TB regions were associated with increased odds of MRI-defined osteophytes (P{\textless}0.037 for linear trend). No statistically significant associations were found for the proximal regions.
Conclusions
Lower mean roughness and lower roughness in vertical and roughest directions of the proximal TB texture are associated with MRI-defined osteophytes in finger joints without radiographic OA. These findings suggest that TB texture may be a useful marker for detecting early hand OA.},
	number = {7},
	journal = {Osteoarthritis and Cartilage},
	author = {Wolski, M. and Podsiadlo, P. and Stachowiak, G. W. and Englund, M. and Haugen, I. K.},
	month = apr,
	year = {2018},
	keywords = {Fractals, MRI, Trabecular bone, hand radiographs},
	pages = {924--928},
}

Summary Objective To examine associations between trabecular bone (TB) texture and MRI-defined osteophytes in finger joints without radiographic osteoarthritis (OA) using an augmented variance orientation transform (AVOT) method. Design In a cross-sectional study, associations of the TB texture and osteophytes were examined in 21 women with mean (standard deviation) age of 69.9 (5.3) from the Oslo Hand OA cohort. The AVOT was applied to distal and proximal TB regions selected on hand radiographs of the subjects. The regions were adjacent to 57 finger joints (24 distal and 33 proximal interphalangeal) without radiographic OA (Kellgren-Lawrence [KL] grade 0), without MRI-defined joint space narrowing, bone marrow lesions, attrition, erosion, cysts, sclerosis, malalignment (all MRI grades 0) and without or only with mild synovitis (MRI grade 0 or 1). Bone texture parameters were calculated: mean fractal dimension (FDMEAN), FDs in the horizontal (FDH) and vertical (FDV) directions, and along the roughest part (FDSta). Associations between the parameters categorized into groups using tertiles and osteophytes were evaluated using logistic regression adjusted for age. Results Lower FDSta and FDV in the distal TB regions were associated with increased odds of MRI-defined osteophytes (P\textless0.037 for linear trend). No statistically significant associations were found for the proximal regions. Conclusions Lower mean roughness and lower roughness in vertical and roughest directions of the proximal TB texture are associated with MRI-defined osteophytes in finger joints without radiographic OA. These findings suggest that TB texture may be a useful marker for detecting early hand OA.

@article{kiadaliri_temporal_2018,
	title = {Temporal trends and regional disparity in rheumatoid arthritis and gout hospitalizations in {Sweden}, 1998–2015},
	volume = {37},
	issn = {0770-3198, 1434-9949},
	url = {https://link.springer.com/article/10.1007/s10067-018-3983-8},
	doi = {10.1007/s10067-018-3983-8},
	abstract = {Hospitalization is an important component of rheumatoid arthritis (RA) and gout economic burden. This study aimed to assess temporal trends and regional disparities in RA and gout hospitalizations among people aged ≥ 20 years in Sweden during 1998–2015. Data on hospital admissions with a principal diagnosis of RA or gout were collected from the National Patient Register. Age-standardized hospitalization rates (ASHRs) were calculated by means of direct standardization. The absolute and relative regional disparities were assessed. The temporal trends in ASHR and proportion of RA and gout hospitalizations from all and musculoskeletal disorders hospitalizations were analyzed using joinpoint regression. Between 1998–2000 and 2013–2015, the ASHR for RA declined by 78.9\% from 109.9 to 23.2 per 100,000 Swedish adults, while it almost doubled for gout (from 10.5 to 20.8 per 100,000 Swedish adults). While in 1998–2000, RA hospitalizations were 10.3 times more frequent than gout (0.54 vs 0.05\% of all hospitalizations), this ratio declined to 1.1 in 2013–2015 (0.13 vs 0.11\% of all hospitalizations). The joinpoint regression revealed that, on average, the ASHR for RA declined by 10.2\% (95\% CI: 9.3–11.1) per year whereas for gout, it rose by 4.3\% (3.2–5.4) per year during 1998–2015. While the relative regional disparities were stable, the absolute regional disparity declined for RA and increased for gout over the study period. While substantial decline in RA hospitalization is encouraging, the substantial rise in gout hospitalization is of concern, reflecting potential increase in prevalence of gout and suboptimal management of the disease.},
	language = {en},
	number = {3},
	urldate = {2018-05-02},
	journal = {Clinical Rheumatology},
	author = {Kiadaliri, Aliasghar A. and Englund, Martin},
	month = mar,
	year = {2018},
	pages = {825--830},
}

Hospitalization is an important component of rheumatoid arthritis (RA) and gout economic burden. This study aimed to assess temporal trends and regional disparities in RA and gout hospitalizations among people aged ≥ 20 years in Sweden during 1998–2015. Data on hospital admissions with a principal diagnosis of RA or gout were collected from the National Patient Register. Age-standardized hospitalization rates (ASHRs) were calculated by means of direct standardization. The absolute and relative regional disparities were assessed. The temporal trends in ASHR and proportion of RA and gout hospitalizations from all and musculoskeletal disorders hospitalizations were analyzed using joinpoint regression. Between 1998–2000 and 2013–2015, the ASHR for RA declined by 78.9% from 109.9 to 23.2 per 100,000 Swedish adults, while it almost doubled for gout (from 10.5 to 20.8 per 100,000 Swedish adults). While in 1998–2000, RA hospitalizations were 10.3 times more frequent than gout (0.54 vs 0.05% of all hospitalizations), this ratio declined to 1.1 in 2013–2015 (0.13 vs 0.11% of all hospitalizations). The joinpoint regression revealed that, on average, the ASHR for RA declined by 10.2% (95% CI: 9.3–11.1) per year whereas for gout, it rose by 4.3% (3.2–5.4) per year during 1998–2015. While the relative regional disparities were stable, the absolute regional disparity declined for RA and increased for gout over the study period. While substantial decline in RA hospitalization is encouraging, the substantial rise in gout hospitalization is of concern, reflecting potential increase in prevalence of gout and suboptimal management of the disease.

@article{wolf_sick_2018,
	title = {Sick leave after surgery for thumb carpometacarpal osteoarthritis: {A} population-based study},
	volume = {43},
	issn = {0363-5023, 1531-6564},
	shorttitle = {Sick {Leave} {After} {Surgery} for {Thumb} {Carpometacarpal} {Osteoarthritis}},
	url = {http://www.jhandsurg.org/article/S0363-5023(17)30808-0/fulltext},
	doi = {10.1016/j.jhsa.2017.11.019},
	language = {English},
	number = {5},
	urldate = {2018-04-05},
	journal = {Journal of Hand Surgery},
	author = {Wolf, Jennifer Moriatis and Atroshi, Isam and Zhou, Caddie and Karlsson, Jon and Englund, Martin},
	month = feb,
	year = {2018},
	pmid = {29428245},
	keywords = {Disability, Sick leave, thumb CMC, trapeziometacarpal},
	pages = {439--447},
}

@article{persson_risk_2018,
	title = {The risk of symptomatic knee osteoarthritis after arthroscopic meniscus repair vs partial meniscectomy vs the general population},
	volume = {26},
	issn = {1063-4584},
	url = {http://www.sciencedirect.com/science/article/pii/S1063458417313146},
	doi = {10.1016/j.joca.2017.08.020},
	abstract = {Summary
Objective
To compare consultation rate for knee osteoarthritis (OA) after meniscus repair, arthroscopic partial meniscectomy (APM), and in general population, respectively.
Method
We identified patients aged 16–45 years having had meniscus surgery due to traumatic meniscus tear in 1998–2010 in southern Sweden by a healthcare register. Patients were followed from surgery until a diagnosis of knee OA, relocation, death, or December 31st, 2015. We studied the consultation rate for knee OA compared to the general population.
Results
We identified 2,487 patients diagnosed with traumatic meniscus tear (mean [SD] age 30.5 [8.6] years); 229 (9.2\%) of them had had meniscus repair. The absolute risk of having consulted for knee OA during the study was 17\% after APM, 10.0\% after meniscus repair, and 2.3\% in the general population. Hazard ratio (HR) (95\% confidence interval (CI)) for knee OA after repair vs APM was: 0.74 (0.48, 1.15). Excluding cases with OA within 2 years post-surgery, yielded the HR of 0.51 (0.27, 0.96). The consultation rate for knee OA standardized to the general population was then 42 per 10,000 person-years (95\% CI 12, 71) in the meniscus repair group, 118 per 10,000 person-years (95\% CI 101, 135) after APM, and 20 per 10,000 person-years (95\% CI 19.9, 20.1) in the general population.
Conclusion
The point estimates suggests about 25–50\% lower risk of consultation for knee OA after meniscus repair as compared to APM. However, the consultation rate for knee OA after repair was still at least two times higher as compared to the general population.},
	number = {2},
	journal = {Osteoarthritis and Cartilage},
	author = {Persson, F. and Turkiewicz, A. and Bergkvist, D. and Neuman, P. and Englund, M.},
	month = feb,
	year = {2018},
	keywords = {Arthroscopy, Cartilage loss, Meniscus, Meniscus repair, Osteoarthritis, Partial meniscectomy},
	pages = {195--201},
}

Summary Objective To compare consultation rate for knee osteoarthritis (OA) after meniscus repair, arthroscopic partial meniscectomy (APM), and in general population, respectively. Method We identified patients aged 16–45 years having had meniscus surgery due to traumatic meniscus tear in 1998–2010 in southern Sweden by a healthcare register. Patients were followed from surgery until a diagnosis of knee OA, relocation, death, or December 31st, 2015. We studied the consultation rate for knee OA compared to the general population. Results We identified 2,487 patients diagnosed with traumatic meniscus tear (mean [SD] age 30.5 [8.6] years); 229 (9.2%) of them had had meniscus repair. The absolute risk of having consulted for knee OA during the study was 17% after APM, 10.0% after meniscus repair, and 2.3% in the general population. Hazard ratio (HR) (95% confidence interval (CI)) for knee OA after repair vs APM was: 0.74 (0.48, 1.15). Excluding cases with OA within 2 years post-surgery, yielded the HR of 0.51 (0.27, 0.96). The consultation rate for knee OA standardized to the general population was then 42 per 10,000 person-years (95% CI 12, 71) in the meniscus repair group, 118 per 10,000 person-years (95% CI 101, 135) after APM, and 20 per 10,000 person-years (95% CI 19.9, 20.1) in the general population. Conclusion The point estimates suggests about 25–50% lower risk of consultation for knee OA after meniscus repair as compared to APM. However, the consultation rate for knee OA after repair was still at least two times higher as compared to the general population.

@article{kiadaliri_burden_2018,
	title = {Burden of gout in the {Nordic} region, 1990–2015: findings from the {Global} {Burden} of {Disease} {Study} 2015},
	volume = {47},
	issn = {0300-9742},
	shorttitle = {Burden of gout in the {Nordic} region, 1990–2015},
	url = {https://doi.org/10.1080/03009742.2017.1405461},
	doi = {10.1080/03009742.2017.1405461},
	abstract = {Objective: To explore the burden of gout in the Nordic region, with a population around 27 million in 2015 distributed across six countries.Method: We used the findings of the 2015 Global Burden of Diseases study to report prevalence and disability associated with gout in the Nordic region.Results: From 1990 to 2015, the number of prevalent gout cases rose by 30\% to 252 967 [95\% uncertainty interval (UI) 223 478‒287 288] in the Nordic region. In 2015, gout contributed to 7982 (95\% UI 5431‒10 800) years lived with disability (YLDs) in the region, an increase of 29\% (95\% UI 24‒35\%) from 1990. While the crude YLD rate of gout increased by 12.9\% (95\% UI 7.8‒18.1\%) between 1990 and 2015, the age-standardized YLD rate remained stable. Gout was ranked as the 63rd leading cause of total YLDs in the region in 2015, with the highest rank in men aged 55–59 years (38th leading cause of YLDs). The corresponding rank at the global level was 94. Of 195 countries studied, four Nordic countries [Greenland (2nd), Iceland (12th), Finland (14th), and Sweden (15th)] were among the top 15 countries with the highest age-standardized YLD rate of gout.Conclusion: The burden of gout is rising in the Nordic region. Gout’s contribution to the total burden of diseases in the region is more significant than the global average. Expected increases in gout burden owing to population growth and ageing call for stronger preventive and therapeutic strategies for gout management in Nordic countries.},
	number = {5},
	journal = {Scandinavian Journal of Rheumatology},
	author = {Kiadaliri, A. A. and Uhlig, T. and Englund, M.},
	month = jan,
	year = {2018},
	pmid = {29376465},
	pages = {410--417},
}

Objective: To explore the burden of gout in the Nordic region, with a population around 27 million in 2015 distributed across six countries.Method: We used the findings of the 2015 Global Burden of Diseases study to report prevalence and disability associated with gout in the Nordic region.Results: From 1990 to 2015, the number of prevalent gout cases rose by 30% to 252 967 [95% uncertainty interval (UI) 223 478‒287 288] in the Nordic region. In 2015, gout contributed to 7982 (95% UI 5431‒10 800) years lived with disability (YLDs) in the region, an increase of 29% (95% UI 24‒35%) from 1990. While the crude YLD rate of gout increased by 12.9% (95% UI 7.8‒18.1%) between 1990 and 2015, the age-standardized YLD rate remained stable. Gout was ranked as the 63rd leading cause of total YLDs in the region in 2015, with the highest rank in men aged 55–59 years (38th leading cause of YLDs). The corresponding rank at the global level was 94. Of 195 countries studied, four Nordic countries [Greenland (2nd), Iceland (12th), Finland (14th), and Sweden (15th)] were among the top 15 countries with the highest age-standardized YLD rate of gout.Conclusion: The burden of gout is rising in the Nordic region. Gout’s contribution to the total burden of diseases in the region is more significant than the global average. Expected increases in gout burden owing to population growth and ageing call for stronger preventive and therapeutic strategies for gout management in Nordic countries.

@article{jonsson_plasma_2018,
	title = {Plasma lactate at admission does not predict mortality and complications in hip fracture patients: a prospective observational study},
	volume = {78},
	issn = {1502-7686},
	shorttitle = {Plasma lactate at admission does not predict mortality and complications in hip fracture patients},
	url = {https://doi.org/10.1080%2F00365513.2018.1514650},
	doi = {10.1080/00365513.2018.1514650},
	abstract = {Hip fractures in elderly carry a high mortality. Our objective was to test the hypothesis that plasma lactate concentration at hospital admission can be used to identify patients with a high risk for poor outcome. Hip fracture patients admitted to a university hospital in Sweden from January 2011 to August 2014 in whom a venous lactate was obtained at admission were included in this prospective observational study. Primary outcome measure was 30-d mortality and secondary outcome measure was a composite outcome of 30-d mortality and postoperative complications. Lactate concentration was evaluated as a continuous predictor using logistic regression, crude and adjusted for age, gender and American Society of Anesthesiology Physical Status (ASA PS) score. Discrimination was evaluated using receiver operating characteristics (ROC) analysis. Totally, 690 patients were included. Median age was 84 years (interquartile range [IQR] 77-90). At 30-d follow-up, mortality was 7.2\%, and 45\% of the patients had suffered the composite outcome. Median lactate level was 1.3 mmol/L (IQR 1.0-1.8 mmol/L). The odds ratio (OR) by each 1.0 mmol/L increase in the lactate concentration for 30-d mortality was 1.13 (95\% CI 0.77-1.68) while for the composite outcome it was 1.06 (95\% CI 0.85-1.3). Similar results were obtained after adjustment for age, sex and ASA PS classification for both outcomes. Area under the ROC curve for lactate as a predictor of 30-d mortality was 0.51 (95\% CI 0.45-0.57). In our cohort, plasma lactate at admission does not appear to be a useful biomarker to identify high-risk patients after hip fracture.},
	language = {eng},
	number = {6},
	journal = {Scandinavian Journal of Clinical and Laboratory Investigation},
	author = {Jonsson, Magnus H. and Hommel, Ami and Turkiewicz, Aleksandra and Ekelund, Ulf and Melander, Olle and Englund, Martin and Bentzer, Peter},
	year = {2018},
	pmid = {30270678},
	keywords = {Aged, Aged, 80 and over, Biomarkers, Comorbidity, Diagnostic Tests, Routine, Female, Hip Fractures, Hip fracture, Humans, Kaplan-Meier Estimate, Lactic Acid, Logistic Models, Male, Prospective Studies, Sweden, emergency department, lactate, mortality, orthopaedics, postoperative complications},
	pages = {508--514},
}

Hip fractures in elderly carry a high mortality. Our objective was to test the hypothesis that plasma lactate concentration at hospital admission can be used to identify patients with a high risk for poor outcome. Hip fracture patients admitted to a university hospital in Sweden from January 2011 to August 2014 in whom a venous lactate was obtained at admission were included in this prospective observational study. Primary outcome measure was 30-d mortality and secondary outcome measure was a composite outcome of 30-d mortality and postoperative complications. Lactate concentration was evaluated as a continuous predictor using logistic regression, crude and adjusted for age, gender and American Society of Anesthesiology Physical Status (ASA PS) score. Discrimination was evaluated using receiver operating characteristics (ROC) analysis. Totally, 690 patients were included. Median age was 84 years (interquartile range [IQR] 77-90). At 30-d follow-up, mortality was 7.2%, and 45% of the patients had suffered the composite outcome. Median lactate level was 1.3 mmol/L (IQR 1.0-1.8 mmol/L). The odds ratio (OR) by each 1.0 mmol/L increase in the lactate concentration for 30-d mortality was 1.13 (95% CI 0.77-1.68) while for the composite outcome it was 1.06 (95% CI 0.85-1.3). Similar results were obtained after adjustment for age, sex and ASA PS classification for both outcomes. Area under the ROC curve for lactate as a predictor of 30-d mortality was 0.51 (95% CI 0.45-0.57). In our cohort, plasma lactate at admission does not appear to be a useful biomarker to identify high-risk patients after hip fracture.

@article{kiadaliri_educational_2018,
	title = {Educational inequalities in falls mortality among older adults: population-based multiple cause of death data from {Sweden}},
	volume = {72},
	copyright = {© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.},
	issn = {0143-005X, 1470-2738},
	shorttitle = {Educational inequalities in falls mortality among older adults},
	url = {http://jech.bmj.com/content/early/2017/11/03/jech-2017-209616},
	doi = {10.1136/jech-2017-209616},
	abstract = {Background Falls are the leading cause of fatal injuries among elderly adults. While socioeconomic status including education is a well-documented predictor of many individual health outcomes including mortality, little is known about socioeconomic inequalities in falls mortality among adults. This study aimed to assess educational inequalities in falls mortality among older adults in Sweden using multiple cause of death data.
Methods All residents aged 50‒75 years in the Skåne region, Sweden, during 1998‒2013 (n=566 478) were followed until death, relocation outside Skåne or end of 2014. We identified any mention of falls on death certificates (n=1047). We defined three levels of education. We used an additive hazards model and Cox regression with age as time scale adjusted for marital status and country of birth to calculate slope and relative indices of inequality (SII/RII). We also computed the population attributable fraction of lower educational attainment. Analyses were performed separately for men and women.
Results Both SII and RII revealed statistically significant educational inequalities in falls mortality among men in favour of high educated (SII (95\% CI): 15.5 (9.8 to 21.3) per 100 000 person-years; RII: 2.19 (1.60 to 3.00)) but not among women. Among men, 34\% (95\% CI 19 to 46) of falls deaths were attributable to lower education.
Conclusions There was an inverse association between education and deaths from falls among men but not women. The results suggest that individual’s education should be considered in falls reduction interventions.},
	language = {en},
	number = {1},
	urldate = {2017-11-06},
	journal = {Journal of Epidemiology and Community Health},
	author = {Kiadaliri, Aliasghar Ahmad and Turkiewicz, Aleksandra and Englund, Martin},
	year = {2018},
	pmid = {29101216},
	keywords = {Educational inequality, Sweden, falls mortality, multiple-cause-of-death},
	pages = {68--70},
}

Background Falls are the leading cause of fatal injuries among elderly adults. While socioeconomic status including education is a well-documented predictor of many individual health outcomes including mortality, little is known about socioeconomic inequalities in falls mortality among adults. This study aimed to assess educational inequalities in falls mortality among older adults in Sweden using multiple cause of death data. Methods All residents aged 50‒75 years in the Skåne region, Sweden, during 1998‒2013 (n=566 478) were followed until death, relocation outside Skåne or end of 2014. We identified any mention of falls on death certificates (n=1047). We defined three levels of education. We used an additive hazards model and Cox regression with age as time scale adjusted for marital status and country of birth to calculate slope and relative indices of inequality (SII/RII). We also computed the population attributable fraction of lower educational attainment. Analyses were performed separately for men and women. Results Both SII and RII revealed statistically significant educational inequalities in falls mortality among men in favour of high educated (SII (95% CI): 15.5 (9.8 to 21.3) per 100 000 person-years; RII: 2.19 (1.60 to 3.00)) but not among women. Among men, 34% (95% CI 19 to 46) of falls deaths were attributable to lower education. Conclusions There was an inverse association between education and deaths from falls among men but not women. The results suggest that individual’s education should be considered in falls reduction interventions.