Objective: To estimate knee osteoarthritis (OA) risk following anterior cruciate ligament (ACL), meniscus or combined ACL and meniscus injury.Design: Systematic review and meta-analysis.Data sources: MEDLINE, Embase, SPORTDiscus, CINAHL and Web of Science until November 2018.Eligibility criteria for selecting studies: Prospective or retrospective studies with at least 2-year follow-up including adults with ACL injury, meniscal injury or combined injuries. Knee OA was defined by radiographs or clinical diagnosis and compared with the contralateral knee or non-injured controls.Study appraisal and synthesis: Risk of bias was assessed using the SIGN50 checklist. ORs for developing knee OA were estimated using random effects meta-analysis.Results: 53 studies totalling ∼1 million participants were included: 185 219 participants with ACL injury, mean age 28 years, 35% females, 98% surgically reconstructed; 83 267 participants with meniscal injury, mean age 38 years, 36% females, 22% confirmed meniscectomy and 73% unknown; 725 362 participants with combined injury, mean age 31 years, 26% females, 80% treated surgically. The OR of developing knee OA were 4.2 (95% CI 2.2 to 8.0; I²=92%), 6.3 (95% CI 3.8 to 10.5; I²=95%) and 6.4 (95% CI 4.9 to 8.3; I²=62%) for patients with ACL injury, meniscal injury and combined injuries, respectively.Conclusion: The odds of developing knee OA following ACL injury are approximately four times higher compared with a non-injured knee. A meniscal injury and a combined injury affecting both the ACL and meniscus are associated with six times higher odds compared with a non-injured knee. Large inconsistency (eg, study design, follow-up period and comparator) and few high-quality studies suggest that future studies may change these estimates.Clinical relevance: Patients sustaining a major knee injury have a substantially increased risk of developing knee OA, highlighting the importance of knee injury prevention programmes and secondary prevention strategies to prevent or delay knee OA development.PROSPERO registration number CRD42015016900

Objective To identify and quantify potential risk factors for osteoarthritis (OA) following traumatic knee injury. Design Systematic review and meta-analyses that estimated the odds of OA for individual risk factors assessed in more than four studies using random-effects models. Remaining risk factors underwent semiquantitative synthesis. The modified GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach for prognostic factors guided the assessment. Data sources MEDLINE, EMBASE, CENTRAL, SPORTDiscus, CINAHL searched from inception to 2009–2021. Eligibility Randomised controlled trials and cohort studies assessing risk factors for symptomatic or structural OA in persons with a traumatic knee injury, mean injury age ≤30 years and minimum 2-year follow-up. Results Across 66 included studies, 81 unique potential risk factors were identified. High risk of bias due to attrition or confounding was present in 64% and 49% of studies, respectively. Ten risk factors for structural OA underwent meta-analysis (sex, rehabilitation for anterior cruciate ligament (ACL) tear, ACL reconstruction (ACLR), ACLR age, ACLR body mass index, ACLR graft source, ACLR graft augmentation, ACLR+cartilage injury, ACLR+partial meniscectomy, ACLR+total medial meniscectomy). Very-low certainty evidence suggests increased odds of structural OA related to ACLR+cartilage injury (OR=2.31; 95% CI 1.35 to 3.94), ACLR+partial meniscectomy (OR=1.87; 1.45 to 2.42) and ACLR+total medial meniscectomy (OR=3.14; 2.20 to 4.48). Semiquantitative syntheses identified moderate-certainty evidence that cruciate ligament, collateral ligament, meniscal, chondral, patellar/tibiofemoral dislocation, fracture and multistructure injuries increase the odds of symptomatic OA. Conclusion Moderate-certainty evidence suggests that various single and multistructure knee injuries (beyond ACL tears) increase the odds of symptomatic OA. Risk factor heterogeneity, high risk of bias, and inconsistency in risk factors and OA definition make identifying treatment targets for preventing post-traumatic knee OA challenging.

Objective To update a systematic review on the association between knee extensor muscle weakness and the risk of incident knee osteoarthritis in women and men. Design Systematic review and meta-analysis. Data sources Systematic searches in PubMed, EMBASE, SPORTDiscus, CINAHL, AMED and CENTRAL in May 2021. Eligible criteria for selecting studies Longitudinal studies with at least 2 years follow-up including baseline measure of knee extensor muscle strength, and follow-up measure of symptomatic or radiographic knee osteoarthritis. Studies including participants with known knee osteoarthritis at baseline were excluded. Risk of bias assessment was conducted using six criteria for study validity and bias. Grading of Recommendations Assessments, Development and Evaluation assessed overall quality of evidence. Meta-analysis estimated the OR for the association between knee extensor muscle weakness and incident knee osteoarthritis. Results We included 11 studies with 46 819 participants. Low quality evidence indicated that knee extensor muscle weakness increased the odds of symptomatic knee osteoarthritis in women (OR 1.85, 95% CI 1.29 to 2.64) and in adult men (OR 1.43, 95% CI 1.14 to 1.78), and for radiographic knee osteoarthritis in women: OR 1.43 (95% CI 1.19 to 1.71) and in men: OR 1.39 (95% CI 1.07 to 1.82). No associations were identified for knee injured populations except for radiographic osteoarthritis in men. Discussion There is low quality evidence that knee extensor muscle weakness is associated with incident symptomatic and radiographic knee osteoarthritis in women and men. Optimising knee extensor muscle strength may help to prevent knee osteoarthritis. PROSPERO registration number CRD42020214976.

Cue Exposure Therapy (CET) is a behavioristic psychological approach to treating substance use disorders (SUD). Prior systematic reviews have found CET to be ineffective when targeting SUDs. The effect of this approach on alcohol use disorders (AUD) seems more promising at trial level but has yet to be systematically reviewed and quantitatively analyzed. Therefore, we aimed to examine the effectiveness of CET targeting AUD compared to active control conditions in a meta-analytic review. Following a systematic search of the literature, a total of seven controlled trials were identified. CET showed no to small additional effects on drinking intensity and drinking frequency, a small additional effect on total drinking score and a moderate additional effect on latency to relapse. Stratification and analysis of a-priori defined trial covariates revealed that CET may have an increased effect in the longer term, and that CET combined with urge-specific coping skills may be the better option for treating AUD than conventional CET. Also, CET may prove less effective when comparing it to cognitive behaviour therapy as opposed to other active control conditions. The overall quality of evidence was graded low due to high risk of bias, inconsistency, imprecision and suspected publication bias. Sounder methodological trials are needed to derive a firm conclusion about the effectiveness of CET for treating AUD.