EULAR recommendations for the non-pharmacological core management of hip and knee osteoarthritis: 2023 update.

INTRODUCTION: Hip and knee osteoarthritis (OA) are increasingly common with a significant impact on individuals and society. Non-pharmacological treatments are considered essential to reduce pain and improve function and quality of life. EULAR recommendations for the non-pharmacological core management of hip and knee OA were published in 2013. Given the large number of subsequent studies, an update is needed. METHODS: The Standardised Operating Procedures for EULAR recommendations were followed. A multidisciplinary Task Force with 25 members representing 14 European countries was established. The Task Force agreed on an updated search strategy of 11 research questions. The systematic literature review encompassed dates from 1 January 2012 to 27 May 2022. Retrieved evidence was discussed, updated recommendations were formulated, and research and educational agendas were developed. RESULTS: The revised recommendations include two overarching principles and eight evidence-based recommendations including (1) an individualised, multicomponent management plan; (2) information, education and self-management; (3) exercise with adequate tailoring of dosage and progression; (4) mode of exercise delivery; (5) maintenance of healthy weight and weight loss; (6) footwear, walking aids and assistive devices; (7) work-related advice and (8) behaviour change techniques to improve lifestyle. The mean level of agreement on the recommendations ranged between 9.2 and 9.8 (0-10 scale, 10=total agreement). The research agenda highlighted areas related to these interventions including adherence, uptake and impact on work. CONCLUSIONS: The 2023 updated recommendations were formulated based on research evidence and expert opinion to guide the optimal management of hip and knee OA.

Patient acceptable symptom state and treatment failure threshold values for work productivity and activity Impairment and EQ-5D-5L in osteoarthritis.

OBJECTIVE: To estimate patient acceptable symptom state (PASS) and treatment failure (TF) threshold values for Work Productivity and Activity Impairment (WPAI) measure and EQ-5D-5L among people with hip or knee osteoarthritis (OA) 3 and 12 months following participation in a digital self-management intervention (Joint Academy®). METHODS: Among the participants, we computed work and activity impairments scores (both 0-100, with a higher value reflecting higher impairment) and the Swedish hypothetical- (range: - 0.314 to 1) and experience-based (range: 0.243-0.976) EQ-5D-5L index scores (a higher score indicates better health status) at 3- (n = 14,607) and 12-month (n = 2707) follow-ups. Threshold values for PASS and TF were calculated using anchor-based adjusted predictive modeling. We also explored the baseline dependency of threshold values according to pain severity at baseline. RESULTS: Around 42.0% and 48.3% of the participants rated their current state as acceptable, while 4.2% and 2.8% considered the treatment had failed at 3 and 12 months, respectively. The 3-month PASS/TF thresholds were 16/29 (work impairment), 26/50 (activity impairment), 0.92/0.77 (hypothetical EQ-5D-5L), and 0.87/0.77 (the experience-based EQ-5D-5L). The thresholds at 12 months were generally comparable to those estimated at 3 months. There were baseline dependencies in PASS/TF thresholds with participants with more severe baseline pain considering poorer (more severe) level of WPAI/EQ-5D-5L as satisfactory. CONCLUSION: PASS and TF threshold values for WPAI and EQ-5D-5L might be useful for meaningful interpretation of these measures among people with OA. The observed baseline dependency of estimated thresholds limits their generalizability and values should be applied with great caution in other settings/populations.

Weekly pain trajectories among people with knee or hip osteoarthritis participating in a digitally delivered first-line exercise and education treatment.

OBJECTIVE: Digital self-management programs are increasingly used in the management of osteoarthritis (OA). Little is known about heterogeneous patterns in response to these programs. We describe weekly pain trajectories of people with knee or hip OA over up to 52-week participation in a digital self-management program. METHODS: Observational cohort study among participants enrolled between January 2019 and September 2021 who participated at least 4 and up to 52 weeks in the program (n = 16 274). We measured pain using Numeric Rating Scale (NRS 0-10) and applied latent class growth analysis to identify classes with similar trajectories. Associations between baseline characteristics and trajectory classes were examined using multinomial logistic regression and dominance analysis. RESULTS: We identified 4 pain trajectory classes: "mild-largely improved" (30%), "low moderate-largely improved" (34%), "upper moderate-improved" (24%), and "severe-persistent" (12%). For classes with decreasing pain, the most pain reduction occurred during first 20 weeks and was stable thereafter. Male sex, older age, lower body mass index (BMI), better physical function, lower activity impairment, less anxiety/depression, higher education, knee OA, no walking difficulties, no wish for surgery and higher physical activity, all measured at enrolment, were associated with greater probabilities of membership in "mild-largely improved" class than other classes. Dominance analysis suggested that activity impairment followed by wish for surgery and walking difficulties were the most important predictors of trajectory class membership. CONCLUSIONS: Our results highlight the importance of reaching people with OA for first-line treatment prior to developing severe pain, poor health status and a wish for surgery.

Digital Self-Management, Analgesic Use, and Patient-Reported Outcomes in Knee or Hip Osteoarthritis.

OBJECTIVE: To investigate changes in analgesic use before and after participation in a digital first-line treatment program (exercise, patient education) in persons with knee or hip osteoarthritis (OA) and to explore associations between these changes in medication use and participant-reported pain and function. DESIGN: Retrospective cohort study with pre-post measures. SETTING: Community setting. PARTICIPANTS: Individuals (N=4100; mean age ± SD, 64.5±9.3y; 73.3% women) participating in the digital program. INTERVENTIONS: A digital supervised education and exercise therapy. MAIN OUTCOME MEASURES: Self-reported analgesic use for knee/hip pain during the past month at baseline and 12-week follow-up, knee/hip numeric rating scale pain (0-10, a higher value indicating more pain), and Knee Injury and Osteoarthritis Outcome Score 12 or Hip Disability and Osteoarthritis Outcome Score 12 function subscale (0-100, higher values indicating better function). McNemar test, multivariable logistic regression, and linear random intercept model were used for statistical analyses. RESULTS: Among participants, 61.4% and 49.4% were analgesic users at baseline and 12-week follow-up, respectively, (absolute reduction 12.0%; 95% confidence interval, 10.5-13.5). Being female, having hip OA, lower education, higher body mass index, living outside large metropolitan cities, coexisting rheumatoid arthritis, and walking difficulties were associated with higher odds of analgesic use at baseline. At both time points, persons not using analgesics at the time reported better outcomes. All groups but "new users" experienced improvements in their pain and function following participation in digital program with the greatest improvements observed among "quitters." CONCLUSIONS: Engaging in a digital exercise and patient education program as a primary treatment for knee or hip OA was associated with a reduction in the use of analgesics. The greatest improvements were seen for those who stopped analgesic use. These results highlight the importance of providing effective first-line treatment to people with knee or hip OA.

Within-person change in patient-reported outcomes and their association with the wish to undergo joint surgery during a digital first-line intervention for osteoarthritis.

AIM: To study the association between within-person changes in patient-reported outcomes (PROMs) and wish for joint surgery during participation in a digital first-line intervention comprising exercise and education for knee/hip osteoarthritis (OA). METHODS: Retrospective observational registry study. Participants enrolled between June 1, 2018 and October 30, 2021, with follow-up data at three months (n = 13,961). We used asymmetric fixed effect (conditional) logistic regressions to study the association between change in wish to undergo surgery at last available time point (3, 6, 9, or 12 months) and improvement or worsening of PROMs pain (0-10), quality of life (QoL) (EQ5D-5L, 0.243-0.976), overall health (0-10), activity impairment (0-10), walking difficulties (yes/no), fear of movement (yes/no), and Knee/Hip injury and Osteoarthritis Outcome Score 12 Items (KOOS-12/HOOS-12, 0-100) function and QoL subscales. RESULTS: The proportion of participants wishing to undergo surgery declined by 2% (95% CI: 1.9, 3.0), from 15.7% at the baseline to 13.3% at 3 months. Generally, improvements in PROMs were associated with reduced likelihood of wishing for surgery, while worsening was associated with increased likelihood. For pain, activity impairment EQ-5D and KOOS/HOOS QoL, a worsening led to a change in the probability of wish for surgery of larger absolute magnitude than an improvement in the same PROM. CONCLUSIONS: Within-person improvements in PROMs are associated with reduced wish for surgery while worsenings with an increased wish for surgery. Larger improvements in PROMs may be needed to match the magnitude of the change in wish for surgery associated with a worsening in the same PROM.

A scoping review of how early-stage knee osteoarthritis has been defined.

BACKGROUND: Early-stage knee osteoarthritis (KOA) classification criteria will enable consistent identification and trial recruitment of individuals with knee osteoarthritis (OA) at an earlier stage of the disease when interventions may be more effective. Toward this goal, we identified how early-stage KOA has been defined in the literature. METHODS: We performed a scoping literature review in PubMed, EMBASE, Cochrane, and Web of Science, including human studies where early-stage KOA was included as a study population or outcome. Extracted data included demographics, symptoms/history, examination, laboratory, imaging, performance-based measures, gross inspection/histopathologic domains, and the components of composite early-stage KOA definitions. RESULTS: Of 6142 articles identified, 211 were included in data synthesis. An early-stage KOA definition was used for study inclusion in 194 studies, to define study outcomes in 11 studies, and in the context of new criteria development or validation in six studies. The element most often used to define early-stage KOA was Kellgren-Lawrence (KL) grade (151 studies, 72%), followed by symptoms (118 studies, 56%), and demographic characteristics (73 studies, 35%); 14 studies (6%) used previously developed early-stage KOA composite criteria. Among studies defining early-stage KOA radiographically, 52 studies defined early-stage KOA by KL grade alone; of these 52, 44 (85%) studies included individuals with KL grade 2 or higher in their definitions. CONCLUSION: Early-stage KOA is variably defined in the published literature. Most studies included KL grades of 2 or higher within their definitions, which reflects established or later-stage OA. These findings underscore the need to develop and validate classification criteria for early-stage KOA.

Digital self-management of hip and knee osteoarthritis and trajectories of work and activity impairments.

OBJECTIVE: To investigate the trajectories of work and activity impairments among people participating in a digital self-management program for osteoarthritis (OA). METHODS: We conducted an observational longitudinal study using data for baseline, 3, 6, 9 and 12 months follow ups from people participating in a digital OA treatment between June 2018 and September 2021. The Work Productivity and Activity Impairment-Osteoarthritis (WPAI-OA) questionnaire was used to measure work and activity impairments. We applied linear mixed models and group-based trajectory modelling (GBTM) to assess the trajectories of work and activity impairments and their variability. Dominance analysis was performed to explore the relative importance of baseline characteristics in predicting the trajectory subgroup membership. RESULTS: A total of 14,676 participants with mean (± standard deviation) age 64.0 (± 9.1) years and 75.5% females were included. The adjusted mean improvements in work impairment from baseline were 5.8% (95% CI 5.3, 6.4) to 6.1% (95% CI 5.5, 6.8). The corresponding figures for activity impairment were 9.4% (95% CI 9.0, 9.7) to 11.3% (95% CI 10.8, 11.8). GBTM identified five (low baseline-declining, moderate baseline-declining, high baseline-declining, very high baseline-substantially declining, and very high baseline-persistent) and three (low baseline-declining, mild baseline-declining, high baseline-declining) subgroups with distinct trajectories of activity and work impairments. Dominance analysis showed that baseline pain was the most important predictor of membership in trajectory subgroups. CONCLUSION: While participation in a digital self-management program for OA was, on average, associated with improvements in work and activity impairments, there were substantial variations among the participants. Baseline pain may provide useful insights to predict trajectories of work and activity impairments.

Evidence of ACL healing on MRI following ACL rupture treated with rehabilitation alone may be associated with better patient-reported outcomes: a secondary analysis from the KANON trial.

OBJECTIVES: Evaluate the natural course of anterior cruciate ligament (ACL) healing on MRI within 5 years of acute ACL rupture and compare 2-year and 5-year outcomes based on healing status and treatment group. METHODS: Secondary analysis of 120 Knee Anterior Cruciate Ligament Nonsurgical vs Surgical Treatment (KANON) trial participants randomised to rehabilitation and optional delayed ACL reconstruction (ACLR) or early ACLR and rehabilitation. ACL continuity on MRI (Anterior Cruciate Ligament OsteoArthritis Score 0-2) was considered evidence of ACL healing. Outcomes included Knee Injury and Osteoarthritis Outcome Score (KOOS), KOOS patient acceptable symptomatic state (PASS) and treatment failure criteria. Linear mixed models were used to estimate adjusted mean differences (95% CIs) in patient-reported sport and recreational function (KOOS-Sport/Rec) and quality of life (KOOS-QOL) at 2 and 5 years, between participants with MRI evidence of ACL healing and those who had (1) no evidence of ACL healing, (2) delayed ACLR or (3) early ACLR. RESULTS: MRI evidence of ACL healing at 2-year follow-up was observed in 16 of 54 (30%, 95% CI 19 to 43%) participants randomised to optional delayed ACLR. Excluding participants who had delayed ACLR, 16 of 30 (53%, 36-70%) participants managed with rehabilitation-alone displayed MRI evidence of ACL healing. Two-year outcomes were better in the healed ACL group (n=16) compared with the non-healed (n=14) (mean difference (95% CI) KOOS-Sport/Rec: 25.1 (8.6-41.5); KOOS-QOL: 27.5 (13.2-41.8)), delayed ACLR (n=24) (KOOS-Sport/Rec: 24.9 (10.2-39.6); KOOS-QOL: 18.1 (5.4-30.8)) and early ACLR (n=62) (KOOS-Sport/Rec: 17.4 (4.1-30.7); KOOS-QOL: 11.4 (0.0-22.9)) groups. Five-year KOOS-QOL was better in the healed versus non-healed group (25.3 (9.4-41.2)). Of participants with MRI evidence of ACL healing, 63-94% met the PASS criteria for each KOOS subscale, compared with 29-61% in the non-healed or reconstructed groups. CONCLUSIONS: MRI appearance of ACL healing after ACL rupture occurred in one in three adults randomised to initial rehabilitation and one in two who did not cross-over to delayed ACLR and was associated with favourable outcomes. The potential for spontaneous healing of the ACL to facilitate better clinical outcomes may be greater than previously considered. TRIAL REGISTRATION NUMBER: ISRCTN84752559.

OPTIKNEE 2022: consensus recommendations to optimise knee health after traumatic knee injury to prevent osteoarthritis.

The goal of the OPTIKNEE consensus is to improve knee and overall health, to prevent osteoarthritis (OA) after a traumatic knee injury. The consensus followed a seven-step hybrid process. Expert groups conducted 7 systematic reviews to synthesise the current evidence and inform recommendations on the burden of knee injuries; risk factors for post-traumatic knee OA; rehabilitation to prevent post-traumatic knee OA; and patient-reported outcomes, muscle function and functional performance tests to monitor people at risk of post-traumatic knee OA. Draft consensus definitions, and clinical and research recommendations were generated, iteratively refined, and discussed at 6, tri-weekly, 2-hour videoconferencing meetings. After each meeting, items were finalised before the expert group (n=36) rated the level of appropriateness for each using a 9-point Likert scale, and recorded dissenting viewpoints through an anonymous online survey. Seven definitions, and 8 clinical recommendations (who to target, what to target and when, rehabilitation approach and interventions, what outcomes to monitor and how) and 6 research recommendations (research priorities, study design considerations, what outcomes to monitor and how) were voted on. All definitions and recommendations were rated appropriate (median appropriateness scores of 7-9) except for two subcomponents of one clinical recommendation, which were rated uncertain (median appropriateness score of 4.5-5.5). Varying levels of evidence supported each recommendation. Clinicians, patients, researchers and other stakeholders may use the definitions and recommendations to advocate for, guide, develop, test and implement person-centred evidence-based rehabilitation programmes following traumatic knee injury, and facilitate data synthesis to reduce the burden of knee post-traumatic knee OA.

Declining trends in arthroscopic meniscus surgery and other arthroscopic knee procedures in Denmark: a nationwide register-based study.

BACKGROUND AND PURPOSE: A doubling of arthroscopic meniscal procedures was observed in Denmark from 2000 to 2011, but arthroscopic meniscal procedures for degenerative meniscal tears are no longer recommended. We performed an updated investigation of Danish meniscal procedure trends in the private and public healthcare sectors in Denmark from 2006 to 2018, including trends for other arthroscopic knee procedures. PATIENTS AND METHODS: We extracted data on the 5 most commonly registered arthroscopic knee procedures (diagnostic arthroscopy, meniscal surgery, anterior cruciate ligament reconstruction, synovectomy, and cartilage resection) from the Danish National Patient Register from January 1, 2006 to December 31, 2018, linked with the Danish Population Statistic Register, to obtain data on age and sex. RESULTS: 414,253 arthroscopic knee procedures were registered during 315,290 surgeries on 244,113 individual patients in the study period. For meniscal procedures, the highest incidence was observed in 2010 (319 per 105 persons/year, 95% CI 314-323) and the lowest in 2018 (173 per 105 persons/year, CI 169-176), corresponding to relative decrease of 46% from 2010 to 2018. Remaining arthroscopic procedures also showed declining trends, with lowest incidence for all procedures in 2018. INTERPRETATION: A large decrease in the incidence for arthroscopic meniscal procedures was observed from 2010 to 2018, possibly in response to mounting evidence of limited benefit of this procedure for degenerative knee disease. All other investigated arthroscopic knee procedures also declined in the same period.

Placebo Surgery Controlled Trials: Do They Achieve What They Set Out To Do? A Systematic Review.

OBJECTIVE: To explore whether placebo surgery controlled trials achieve what they set out to do by investigating discrepancy between projected and actual design aspects of trials identified through systematic review methods. SUMMARY BACKGROUND: Interest in placebo surgery controlled trials is growing in response to concerns regarding unnecessary surgery and the societal cost of low-value healthcare. As questions about the justifiability of using placebo controls in surgery have been addressed, attention is now being paid to more practical concerns. METHODS: Six databases were searched from inception - May 2020 (MEDLINE, Embase, Emcare, APA PsycInfo, CINAHL, Cochrane Library). Placebo surgery controlled trials with a published protocol were included. Three authors extracted "projected" design aspects from protocols and "actual" design aspects from main findings papers. Absolute and relative difference between projected and actual design aspects were presented for each trial. Trials were grouped according to whether they met their target sample size ("completed") and were concluded in a timely fashion. Pairs of authors assessed risk of bias. RESULTS: Of 24 trials with data available to analyse; 3 were completed and concluded within target timeframe; 10 were completed and concluded outside the target timeline; 4 were completed without clear target timeframes; 2 were incomplete and concluded within the target framework; 5 were incomplete and concluded outside the target timeline. Trials which reached the recruitment target underestimated trial duration by 88% and number of recruitment sites by 87%. CONCLUSIONS: Trialists need to factor additional time and sites into future placebo surgery controlled trials. A robust reporting framework of projected and actual trial design is imperative for trialists to learn from their predecessors. REVIEW REGISTRATION: PROSPERO (CRD42019133296).

Considerations and methods for placebo controls in surgical trials (ASPIRE guidelines).

Placebo comparisons are increasingly being considered for randomised trials assessing the efficacy of surgical interventions. The aim of this Review is to provide a summary of knowledge on placebo controls in surgical trials. A placebo control is a complex type of comparison group in the surgical setting and, although powerful, presents many challenges. This Review outlines what a placebo control entails and present understanding of this tool in the context of surgery. We consider when placebo controls in surgery are acceptable (and when they are desirable) in terms of ethical arguments and regulatory requirements, how a placebo control should be designed, how to identify and mitigate risk for participants in these trials, and how such trials should be done and interpreted. Use of placebo controls is justified in randomised controlled trials of surgical interventions provided there is a strong scientific and ethical rationale. Surgical placebos might be most appropriate when there is poor evidence for the efficacy of the procedure and a justified concern that results of a trial would be associated with high risk of bias, particularly because of the placebo effect. Feasibility work is recommended to optimise the design and implementation of randomised controlled trials. This Review forms an outline for best practice and provides guidance, in the form of the Applying Surgical Placebo in Randomised Evaluations (known as ASPIRE) checklist, for those considering the use of a placebo control in a surgical randomised controlled trial.

Development of MRI-defined Structural Tissue Damage after Anterior Cruciate Ligament Injury over 5 Years: The KANON Study.

Background MRI is used to evaluate structural joint changes after anterior cruciate ligament (ACL) injury, but no long-term data are available for comparing different treatment approaches. Purpose To describe structural joint damage with MRI over a 5-year period in the Knee Anterior Cruciate Ligament, Nonsurgical versus Surgical Treatment (KANON) study and to compare frequencies of such tissue damage for a nonsurgical versus a surgical treatment strategy. Materials and Methods In this secondary analysis of a prospective trial (ISRCTN 84752559), 119 participants with an acute ACL injury were evaluated. Participants were enrolled from 2002 through 2006, the 2-year follow-up started in 2008, and the 5-year follow-up started in 2011. A 1.5-T MRI examination was performed at baseline and at 2- and 5-year follow-up. MRI scans were read according to a validated scoring instrument. Kruskal-Wallis tests were used to assess whether the frequencies of structural damage differed between the three as-treated groups. Results Of 119 participants (mean age, 26 years ± 5 [standard deviation]), 91 men were evaluated. At 2- and 5-year follow-up, respectively, 13% (15 of 117) and 13% (15 of 115) of knees showed incident cartilage damage in the medial tibiofemoral joint, 11% (13 of 117) and 17% (20 of 115) of knees showed incident cartilage damage in the lateral tibiofemoral joint, and 4% (five of 117) and 8% (nine of 115) of knees showed incident cartilage damage in the patellofemoral joint. Osteophyte development was seen in 23% (27 of 117) and 29% (33 of 115) of knees in the medial tibiofemoral joint, in 36% (42 of 117) and 43% (49 of 115) of knees in the lateral tibiofemoral joint, and in 35% (41 of 117) and 37% (42 of 115) of knees in the patellofemoral joint. No major differences between the groups were found for incident or worsening cartilage damage, bone marrow lesions, and osteophytes at 2 or 5 years. The rehabilitation-alone group showed less Hoffa-synovitis at 2 (P = .02) and 5 (P = .008) years. Conclusion Young adults with anterior cruciate ligament injury showed no major difference in frequency of structural tissue damage on MRI scans at 2 and 5 years regardless of treatment. However, the rehabilitation-alone group had less inflammation at 2 and 5 years. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Andreisek in this issue.

Less improvement following meniscal repair compared with arthroscopic partial meniscectomy: a prospective cohort study of patient-reported outcomes in 150 young adults at 1- and 5-years' follow-up.

Background and purpose - Meniscal repair may reduce long-term risk of knee osteoarthritis compared with arthroscopic partial meniscectomy (APM), whereas patient-reported outcomes may be poorer at short term than for APM. We compared patient-reported outcomes in young adults undergoing meniscal repair or APM up to ∼5 years after surgery.Patients and methods - We included 150 patients aged 18-40 years from the Knee Arthroscopy Cohort Southern Denmark (KACS) undergoing meniscal repair or APM. Between-group differences in change in a composite of 4 of 5 Knee injury and Osteoarthritis Outcome Score (KOOS) subscales (pain, symptoms, sport and recreation, and quality of life-KOOS4) from baseline, 12, and 52 weeks, and a median of 5 years (range 4-6 years) were analyzed using adjusted mixed linear models, with 52 weeks being the primary endpoint.Results - 32 patients had meniscal repair (mean age 26 [SD 6]), and 118 patients underwent APM (mean age 32 [SD 7]). The repair and APM groups improved in KOOS4 from before to 52 weeks after surgery (least square means 7 and 19, respectively; adjusted mean difference -12, [95% CI -19 to -4] in favor of APM). Both groups improved further from 52 weeks to 5 years after surgery with the difference in KOOS4 scores between the groups remaining similar.Interpretation - Patients having meniscal repair experienced less improvements in patient-reported outcomes from baseline to 52 weeks and 5 years post-surgery. The findings highlight the need for randomized trials comparing these interventions in terms of patient-reported outcomes and knee OA development.

Higher aggrecan 1-F21 epitope concentration in synovial fluid early after anterior cruciate ligament injury is associated with worse knee cartilage quality assessed by gadolinium enhanced magnetic resonance imaging 20 years later.

BACKGROUND: To investigate if cartilage related biomarkers in synovial fluid are associated with knee cartilage status 20 years after an anterior cruciate ligament (ACL) injury. METHODS: We studied 25 patients with a complete ACL rupture without subsequent ACL reconstruction or radiographic knee OA. All had a delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) 20 years after the ACL injury, using the T1 transverse relaxation time in the presence of gadolinium (T1Gd) which estimates the concentration of glycosaminoglycans in hyaline cartilage. Synovial fluid samples were aspirated acutely (between 0 and 18 days) and during 1 to 5 follow up visits between 0.5 and 7.5 years after injury. We quantified synovial fluid concentrations of aggrecan (epitopes 1-F21 and ARGS), cartilage oligomeric matrix protein, matrix metalloproteinase-3 and tissue inhibitor of metalloproteinase-1 by immunoassays, and sulfated glycosaminoglycans by Alcian blue precipitation. Western blot was used for qualitative analyses of aggrecan fragments in synovial fluid and cartilage samples. RESULTS: Western blot indicated that the 1-F21 epitope was located within the chondroitin sulfate 2 region of aggrecan. Linear regression analyses (adjusted for age, sex, body mass index and time between injury and sampling) showed that acute higher synovial fluid 1-F21-aggrecan concentrations were associated with shorter T1Gd values 20 years after injury, i.e. inferior cartilage quality (standardized effects between - 0.67 and - 1.0). No other statistically significant association was found between molecular biomarkers and T1Gd values. CONCLUSION: Higher acute synovial fluid 1-F21-aggrecan concentrations in ACL injured patients, who managed to cope without ACL reconstruction and were without radiographic knee OA, were associated with inferior knee cartilage quality assessed by dGEMRIC 20 years after injury.

Temporal trend and regional disparity in osteoarthritis hospitalisations in Sweden 1998-2015.

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 >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.

It is good to feel better, but better to feel good: whether a patient finds treatment 'successful' or not depends on the questions researchers ask.

INTRODUCTION: In sports physiotherapy, medicine and orthopaedic randomised controlled trials (RCT), the investigators (and readers) focus on the difference between groups in change scores from baseline to follow-up. Mean score changes are difficult to interpret ('is an improvement of 20 units good?'), and follow-up scores may be more meaningful. We investigated how applying three different responder criteria to change and follow-up scores would affect the 'outcome' of RCTs. Responder criteria refers to participants' perceptions of how the intervention affected them. METHODS: We applied three different criteria-minimal important change (MIC), patient acceptable symptom state (PASS) and treatment failure (TF)-to the aggregate Knee injury and Osteoarthritis Outcome Score (KOOS4) and the five KOOS subscales, the primary and secondary outcomes of the KANON trial (ISRCTN84752559). This trial included young active adults with an acute ACL injury and compared two treatment strategies: exercise therapy plus early reconstructive surgery, and exercise therapy plus delayed reconstructive surgery, if needed. RESULTS: MIC: At 2 years, more than 90% in the two treatment arms reported themselves to be minimally but importantly improved for the primary outcome KOOS4. PASS: About 50% of participants in both treatment arms reported their KOOS4 follow-up scores to be satisfactory. TF: Almost 10% of participants in both treatment arms found their outcomes so unsatisfactory that they thought their treatment had failed. There were no statistically significant or meaningful differences between treatment arms using these criteria. CONCLUSION: We applied change criteria as well as cross-sectional follow-up criteria to interpret trial outcomes with more clinical focus. We suggest researchers apply MIC, PASS and TF thresholds to enhance interpretation of KOOS and other patient-reported scores. The findings from this study can improve shared decision-making processes for people with an acute ACL injury.

Loss of patellofemoral cartilage thickness over 5 years following ACL injury depends on the initial treatment strategy: results from the KANON trial.

OBJECTIVES: To evaluate changes in patellofemoral cartilage thickness over 5 years after anterior cruciate ligament (ACL) injury and to determine the impact of treatment strategy. METHODS: 121 adults (ages 18-35 years, 26% women) had an ACL injury and participated in the KANON randomised controlled trial. Of those, 117 had available MRIs at baseline (<4 weeks post-ACL rupture) and at least one follow-up measurement (2, 5 years). Patellofemoral cartilage thickness was analysed by manual segmentation (blinded to acquisition order). Patellar, trochlear and total patellofemoral cartilage thickness changes were compared between as-randomised (rehabilitation+early ACL reconstruction (ACLR) (n=59) vs rehabilitation+optional delayed ACLR (n=58)) and as-treated groups (rehabilitation+early ACLR (n=59) vs rehabilitation +delayed ACLR (n=29) vs rehabilitation alone (n=29)). RESULTS: Patellofemoral cartilage thickness decreased -58 µm (95% CI -104 to -11 µm) over 5 years post-ACL rupture, with the greatest loss observed in trochlea during the first 2 years. Participants randomised to rehabilitation+early ACLR had significantly greater loss of patellar cartilage thickness compared with participants randomised to rehabilitation+optional delayed ACLR over the first 2 years (-25 µm (-52, 1 µm) vs +14 µm (-6 to 34 µm), p=0.02) as well as over 5 years (-36 µm (-78 to 5 µm) vs +18 µm (-7, 42 µm), p=0.02). There were no statistically significant differences in patellofemoral cartilage thickness changes between as-treated groups. CONCLUSION: Patellofemoral (particularly trochlear) cartilage thickness loss was observed in young adults following acute ACL rupture. Early ACLR was associated with greater patellofemoral (particularly patellar) cartilage thickness loss over 5 years compared with optional delayed ACLR, indicating that early surgical intervention may be associated with greater short-term structural patellofemoral cartilage deterioration compared with optional delayed surgery. TRIAL REGISTRATION NUMBER: ISRCTN84752559; Post-results.