Adiposity and cartilage lesions following ACL reconstruction.

OBJECTIVE: To determine if global, central, or peripheral adiposity is associated with prevalent and worsening cartilage lesions following anterior cruciate ligament reconstruction (ACLR). METHODS: In 107 individuals one-year post-ACLR, adiposity was assessed globally (body mass index), centrally (waist circumference), and peripherally (knee subcutaneous adipose tissue thickness) from magnetic resonance imaging (MRI). Tibiofemoral and patellofemoral cartilage lesions were assessed from knee MRIs at 1- and 5-years post-ACLR. Poisson regression evaluated the relation of adiposity with prevalent and worsening tibiofemoral and patellofemoral cartilage lesions adjusting for age, sex, and activity level. RESULTS: The prevalence ratios of adiposity with tibiofemoral (presence in 49%) and patellofemoral (44%) cartilage lesions ranged from 0.99 to 1.03. Adiposity was more strongly associated with longitudinal changes in tibiofemoral (worsening in 21%) and patellofemoral (44%) cartilage lesions. One-unit increase in global (kg/m2), central (cm), and peripheral (mm) adiposity was associated with a higher risk of worsening tibiofemoral cartilage lesions by 17% (risk ratios [95% confidence interval (CI)]: 1.17 [1.09 to 1.23]), 5% (1.05 [1.02 to 1.08]), and 9% (1.09 [1.03 to 1.16]), and patellofemoral cartilage lesions by 5% (1.05 [1.00 to 1.12]), 2% (1.02 [1.00 to 1.04]) and 2% (1.02 [1.00 to 1.04]), respectively. CONCLUSION: Greater adiposity was a risk factor for worsening cartilage lesions up to 5 years post-ACLR. Clinical interventions aimed at mitigating excess adiposity may be beneficial in preventive approaches for early post-traumatic osteoarthritis.

No sign of weakness: a systematic review and meta-analysis of hip and calf muscle strength after anterior cruciate ligament injury.

OBJECTIVE: We aimed to determine hip and lower-leg muscle strength in people after ACL injury compared with an uninjured control group (between people) and the uninjured contralateral limb (between limbs). DESIGN: Systematic review with meta-analysis. DATA SOURCES: MEDLINE, EMBASE, CINAHL, Scopus, Cochrane CENTRAL and SportDiscus to 28 February 2023. ELIGIBILITY CRITERIA: Primary ACL injury with mean age 18-40 years at time of injury. Studies had to measure hip and/or lower-leg muscle strength quantitatively (eg, dynamometer) and report muscle strength for the ACL-injured limb compared with: (i) an uninjured control group and/or (ii) the uninjured contralateral limb. Risk of bias was assessed according to Cochrane Collaboration domains. RESULTS: Twenty-eight studies were included (n=23 measured strength ≤12 months post-ACL reconstruction). Most examined hip abduction (16 studies), hip extension (12 studies) and hip external rotation (7 studies) strength. We found no meaningful difference in muscle strength between people or between limbs for hip abduction, extension, internal rotation, flexion or ankle plantarflexion, dorsiflexion (estimates ranged from -9% to +9% of comparator). The only non-zero differences identified were in hip adduction (24% stronger on ACL limb (95% CI 8% to 42%)) and hip external rotation strength (12% deficit on ACL limb (95% CI 6% to 18%)) compared with uninjured controls at follow-ups >12 months, however both results stemmed from only two studies. Certainty of evidence was very low for all outcomes and comparisons, and drawn primarily from the first year post-ACL reconstruction. CONCLUSION: Our results do not show widespread or substantial muscle weakness of the hip and lower-leg muscles after ACL injury, contrasting deficits of 10%-20% commonly reported for knee extensors and flexors. As it is unclear if deficits in hip and lower-leg muscle strength resolve with appropriate rehabilitation or no postinjury or postoperative weakness occurs, individualised assessment should guide training of hip and lower-leg strength following ACL injury. PROSPERO REGISTRATION NUMBER: CRD42020216793.

If we build it together, will they use it? A mixed-methods study evaluating the implementation of Prep-to-Play PRO: an injury prevention programme for women's elite Australian Football.

OBJECTIVES: We evaluated the implementation of Prep-to-Play PRO, an injury prevention programme for women's elite Australian Football League (AFLW). METHODS: The Reach, Effectiveness, Adoption, Implementation and Maintenance (RE-AIM) of Prep-to-Play PRO were assessed based on the proportion of AFLW players and/or staff who: were aware of the programme (R), believed it may reduce anterior cruciate ligament injury (E), attempted to implement any/all programme components (A), implemented all intended components as practically as possible (I) and intended future programme implementation (M). Quantitative and qualitative data were triangulated to assess 58 RE-AIM items (evidence of yes/no/unsure/no evidence) and the 5 RE-AIM dimensions (fully achieved=evidence of yes on >50% dimension items, partially achieved=50% of items evidence of yes and 50% unsure or 50% mix of unsure and unanswered, or not met=evidence of yes on <50% dimension items). RESULTS: Multiple sources including AFLW training observations (n=7 total), post-implementation surveys (141 players, 25 staff), semistructured interviews (19 players, 13 staff) and internal programme records (9 staff) contributed to the RE-AIM assessment. After the 2019 season, 8 of 10 (80%) AFLW clubs fully met all five RE-AIM dimensions. All 10 clubs participating in the AFLW fully achieved the reach (R) dimension. One club partially achieved the implementation (I) dimension, and one club partially achieved the effectiveness (E) and adoption (A) dimensions. CONCLUSION: The Prep-to-Play PRO injury prevention programme for the AFLW achieved high implementation, possibly due to the programme's deliberately flexible approach coupled with our pragmatic definition of implementation. Engaging key stakeholders at multiple ecological levels (organisation, coaches, athletes) throughout programme development and implementation likely enhanced programme implementation.

Muscle strength and osteoarthritis of the knee: a systematic review and meta-analysis of longitudinal studies.

OBJECTIVE: To evaluate the sex-specific association between low knee extensor and flexor muscle strength and the risk of knee structural worsening. MATERIALS AND METHODS: Systematic searches in five databases identified longitudinal studies (≥ 1 year follow-up) reporting an association between knee extensor or flexor strength and structural decline in individuals with, or at risk of, knee osteoarthritis. Results were pooled for tibiofemoral and patellofemoral osteoarthritis worsening (and stratified by sex/gender where possible) using a random-effects meta-analysis estimating the risk ratio and 95% confidence interval or a best-evidence synthesis. Risk of bias and overall certainty of evidence were assessed. RESULTS: Fourteen studies were included with participants (mean age 27-72 years) with osteoarthritis (n = 8), at risk of osteoarthritis (n = 3), or a combination with, or at risk of, osteoarthritis (n = 3). Low knee extensor strength was associated with an increased risk of worsening tibiofemoral (12 studies: RR 1.18, 95% CI 1.04 to 1.35) and patellofemoral osteoarthritis (4 studies: RR 1.62, 95% CI 1.01 to 2.61). Significant associations between low knee extensor strength and worsening tibiofemoral osteoarthritis were observed for women (4 studies: RR 1.25, 95% CI 1.04 to 1.51) but not men (4 studies: RR 1.10, 95% CI 0.87 to 1.39). Low knee flexor strength increased the risk of worsening tibiofemoral osteoarthritis (5 studies: RR 1.16, 95% CI 1.07 to 1.26). Ten studies were high risk of bias, and all estimates were graded as very low certainty of evidence. CONCLUSION: Low knee extensor and flexor strength increased the risk of worsening tibiofemoral osteoarthritis. Low knee extensor strength increased the risk of worsening patellofemoral osteoarthritis. The relationship between low knee extensor strength and worsening tibiofemoral osteoarthritis may be modified by sex/gender.

Unilateral tests of lower-limb function as prognostic indicators of future knee-related outcomes following anterior cruciate ligament injury: a systematic review and meta-analysis of 13 150 adolescents and adults.

OBJECTIVE: To investigate the prognostic capacity of individual hop tests, hop test batteries and other unilateral functional performance tests following anterior cruciate ligament (ACL) injury. DESIGN: Systematic review with meta-analysis. DATA SOURCES: Six databases searched up to June 2021. ELIGIBILITY CRITERIA: Studies reporting associations between unilateral lower-limb function (eg, hop tests) following ACL injury and future (≥3 months) knee-related outcomes. RESULTS: Of 42 included studies (13 150 participants), all assessed the single-forward hop test and 32 assessed a repeated-forward hop test (crossover hop, triple hop, 6m-timed hop), mostly within a year after ACL injury/reconstruction. Results of meta-analyses indicated that higher single-forward and repeated-forward hop limb symmetry were associated with higher odds of return-to-sport 1-3 years post-ACL reconstruction (OR 2.15; 95% CI 1.30 to 3.54; OR 2.11; 95% CI 1.23 to 3.60, respectively). Higher single-forward and repeated-forward hop limb symmetry was associated with better self-reported symptoms and function 1-37 years after ACL injury (OR 2.51; 95% CI 1.62 to 3.88; OR 4.28; 95% CI 1.65 to 11.08, respectively). Higher limb symmetry on a repeated-forward hop does not appear to be associated with higher odds of successful rehabilitation without ACL reconstruction (OR 1.51; 95% CI 0.94 to 2.44). Achieving ≥90% limb symmetry on the single-forward hop was associated with reduced odds of knee osteoarthritis 5-37 years after ACL injury (OR 0.46; 95% CI 0.23 to 0.94). CONCLUSION: Very low certainty evidence suggests single-forward and repeated-forward hop tests are prognostic indicators for important knee-related outcomes in individuals after ACL injury and may help stratify individuals at risk of poor outcomes to target rehabilitation interventions. PROSPERO REGISTRATION NUMBER: CRD42018092197.

Let's talk about sex (and gender) after ACL injury: a systematic review and meta-analysis of self-reported activity and knee-related outcomes.

OBJECTIVE: Investigate sex/gender differences in self-reported activity and knee-related outcomes after anterior cruciate ligament (ACL) injury. DESIGN: Systematic review with meta-analysis. DATA SOURCES: Seven databases were searched in December 2021. ELIGIBILITY CRITERIA: Observational or interventional studies with self-reported activity (including return to sport) or knee-related outcomes after ACL injury. RESULTS: We included 242 studies (n=123 687, 43% females/women/girls, mean age 26 years at surgery). One hundred and six studies contributed to 1 of 35 meta-analyses (n=59 552). After ACL injury/reconstruction, very low-certainty evidence suggests females/women/girls had inferior self-reported activity (ie, return to sport, Tegner Activity Score, Marx Activity Scale) compared with males/men/boys on most (88%, 7/8) meta-analyses. Females/women/girls had 23%-25% reduced odds of returning to sport within 1-year post-ACL injury/reconstruction (12 studies, OR 0.76 95% CI 0.63 to 0.92), 1-5 years (45 studies, OR 0.75 95% CI 0.69 to 0.82) and 5-10 years (9 studies, OR 0.77 95% CI 0.57 to 1.04). Age-stratified analysis (<19 years) suggests female athletes/girls had 32% reduced odds of returning to sport compared with male athletes/boys (OR 0.68, 95% CI 0.41 to 1.13, I2 0.0%). Very low-certainty evidence suggests females/women/girls experienced inferior knee-related outcomes (eg, function, quality of life) on many (70%, 19/27) meta-analyses: standardised mean difference ranging from -0.02 (Knee injury and Osteoarthritis Outcome Score, KOOS-activities of daily living, 9 studies, 95% CI -0.05 to 0.02) to -0.31 (KOOS-sport and recreation, 7 studies, 95% CI -0.36 to -0.26). CONCLUSIONS: Very low-certainty evidence suggests inferior self-reported activity and knee-related outcomes for females/women/girls compared with males/men/boys after an ACL injury. Future studies should explore factors and design targeted interventions to improve outcomes for females/women/girls. PROSPERO REGISTRATION NUMBER: CRD42021205998.

Evaluation and Treatment of Knee Pain: A Review.

Importance: Approximately 5% of all primary care visits in adults are related to knee pain. Osteoarthritis (OA), patellofemoral pain, and meniscal tears are among the most common causes of knee pain. Observations: Knee OA, affecting an estimated 654 million people worldwide, is the most likely diagnosis of knee pain in patients aged 45 years or older who present with activity-related knee joint pain with no or less than 30 minutes of morning stiffness (95% sensitivity; 69% specificity). Patellofemoral pain typically affects people younger than 40 years who are physically active and has a lifetime prevalence of approximately 25%. The presence of anterior knee pain during a squat is approximately 91% sensitive and 50% specific for patellofemoral pain. Meniscal tears affect an estimated 12% of the adult population and can occur following acute trauma (eg, twisting injury) in people younger than 40 years. Alternatively, a meniscal tear may be a degenerative condition present in patients with knee OA who are aged 40 years or older. The McMurray test, consisting of concurrent knee rotation (internal or external to test lateral or medial meniscus, respectively) and extension (61% sensitivity; 84% specificity), and joint line tenderness (83% sensitivity; 83% specificity) assist diagnosis of meniscal tears. Radiographic imaging of all patients with possible knee OA is not recommended. First-line management of OA comprises exercise therapy, weight loss (if overweight), education, and self-management programs to empower patients to better manage their condition. Surgical referral for knee joint replacement can be considered for patients with end-stage OA (ie, no or minimal joint space with inability to cope with pain) after using all appropriate conservative options. For patellofemoral pain, hip and knee strengthening exercises in combination with foot orthoses or patellar taping are recommended, with no indication for surgery. Conservative management (exercise therapy for 4-6 weeks) is also appropriate for most meniscal tears. For severe traumatic (eg, bucket-handle) tears, consisting of displaced meniscal tissue, surgery is likely required. For degenerative meniscal tears, exercise therapy is first-line treatment; surgery is not indicated even in the presence of mechanical symptoms (eg, locking, catching). Conclusions and Relevance: Knee OA, patellofemoral pain, and meniscal tears are common causes of knee pain, can be diagnosed clinically, and can be associated with significant disability. First-line treatment for each condition consists of conservative management, with a focus on exercise, education, and self-management.

An anti-inflammatory diet intervention for knee osteoarthritis: a feasibility study.

BACKGROUND: Knee osteoarthritis has an inflammatory component that is linked to pain and joint pathology, yet common non-surgical and non-pharmacological interventions (e.g., exercise, calorie restricting diets) do not typically target inflammation. We aimed to evaluate the feasibility of a telehealth delivered anti-inflammatory diet intervention for knee osteoarthritis. METHODS: This 9-week single-arm feasibility study recruited participants aged 40-85 years with symptomatic knee osteoarthritis (inclusion criteria: average pain ≥4/10 or maximal pain ≥5/10 during past week). All participants received a telehealth-delivered anti-inflammatory dietary education intervention involving 1:1 consultations at baseline, 3- and 6-week follow-up. The diet emphasised nutrient-dense wholefoods and minimally processed anti-inflammatory foods and discouraged processed foods considered to be pro-inflammatory. The primary outcome of feasibility was assessed via: i) eligibility, recruitment and retention rates; ii) self-reported dietary adherence; iii) adverse events; and iv) treatment satisfaction. Post-intervention interviews evaluated the acceptability of the dietary intervention delivered via telehealth. Secondary outcomes included changes in self-reported body mass, Knee injury and Osteoarthritis Outcome Score (KOOS), health-related quality of life (EuroQoL-5D), analgesic use and global rating of change. Worthwhile effects were determined by the minimal detectable change (MDC) for all five KOOS-subscales (pain, symptoms, activities of daily living, sport/recreation, quality of life) being contained within the 95% confidence interval. RESULTS: Forty-eight of seventy-three (66%) individuals screened were eligible and 28 enrolled over 2 months (82% female, mean age 66 ± 8 years, body mass index 30.7 ± 4.8 kg.m-2). Six participants withdrew prior to final follow-up (21% drop-out). Of those with final follow-up data, attendance at scheduled telehealth consultations was 99%. Self-reported adherence to diet during the 9-week intervention period: everyday = 27%, most of time = 68% and some of time = 5%. Two minor adverse events were reported. Change scores contained the MDC within the 95% confidence interval for all five KOOS subscales. Suggestions to improve study design and limit drop-out included an initial face-to-face consultation and more comprehensive habitual dietary intake data collection. CONCLUSION: This study supports the feasibility of a full-scale randomised controlled trial to determine the efficacy of a primarily telehealth-delivered anti-inflammatory dietary education intervention in adults with symptomatic knee osteoarthritis. TRIAL REGISTRATION: ACTRN12620000229976 prospectively on 25/2/2020.

Knee extensor muscle weakness is a risk factor for the development of knee osteoarthritis: an updated systematic review and meta-analysis including 46 819 men and women.

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.

Strategies to prevent and manage running-related knee injuries: a systematic review of randomised controlled trials.

OBJECTIVE: To evaluate the effectiveness of interventions to prevent and manage knee injuries in runners. DESIGN: Systematic review and meta-analysis. DATA SOURCES: MEDLINE, EMBASE, CINAHL, Web of Science and SPORTDiscus up to May 2022. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Randomised controlled trials (RCTs) with a primary aim of evaluating the effectiveness of intervention(s) to prevent or manage running-related knee injury. RESULTS: Thirty RCTs (18 prevention, 12 management) analysed multiple interventions in novice and recreational running populations. Low-certainty evidence (one trial, 320 participants) indicated that running technique retraining (to land softer) reduced the risk of knee injury compared with control treadmill running (risk ratio (RR) 0.32, 95% CI 0.16 to 0.63). Very low-certainty to low-certainty evidence from 17 other prevention trials (participant range: 24 -3287) indicated that various footwear options, multicomponent exercise therapy, graduated running programmes and online and in person injury prevention education programmes did not influence knee injury risk (RR range: 0.55-1.06). In runners with patellofemoral pain, very low-certainty to low-certainty evidence indicated that running technique retraining strategies, medial-wedged foot orthoses, multicomponent exercise therapy and osteopathic manipulation can reduce knee pain in the short-term (standardised mean difference range: -4.96 to -0.90). CONCLUSION: There is low-certainty evidence that running technique retraining to land softer may reduce knee injury risk by two-thirds. Very low-certainty to low-certainty evidence suggests that running-related patellofemoral pain may be effectively managed through a variety of active (eg, running technique retraining, multicomponent exercise therapy) and passive interventions (eg, foot orthoses, osteopathic manipulation). PROSPERO REGISTRATION NUMBER: CRD42020150630.

May the force be with you: understanding how patellofemoral joint reaction force compares across different activities and physical interventions-a systematic review and meta-analysis.

OBJECTIVE: To systematically review and synthesise patellofemoral joint reaction force (PFJRF) in healthy individuals and those with patellofemoral pain and osteoarthritis (OA), during everyday activities, therapeutic exercises and with physical interventions (eg, foot orthotics, footwear, taping, bracing). DESIGN: A systematic review with meta-analysis. DATA SOURCES: Medline, Embase, Scopus, CINAHL, SportDiscus and Cochrane Library databases were searched. ELIGIBILITY CRITERIA: Observational and interventional studies reporting PFJRF during everyday activities, therapeutic exercises, and physical interventions. RESULTS: In healthy individuals, the weighted average of mean (±SD) peak PFJRF for everyday activities were: walking 0.9±0.4 body weight (BW), stair ascent 3.2±0.7 BW, stair descent 2.8±0.5 BW and running 5.2±1.2 BW. In those with patellofemoral pain, peak PFJRF were: walking 0.8±0.2 BW, stair ascent 2.5±0.5 BW, stair descent 2.6±0.5 BW, running 4.1±0.9 BW. Only single studies reported peak PFJRF during everyday activities in individuals with patellofemoral OA/articular cartilage defects (walking 1.3±0.5 BW, stair ascent 1.6±0.4 BW, stair descent 1.0±0.5 BW). The PFJRF was reported for many different exercises and physical interventions; however, considerable variability precluded any pooled estimates. SUMMARY: Everyday activities and exercises involving larger knee flexion (eg, squatting) expose the patellofemoral joint to higher PFJRF than those involving smaller knee flexion (eg, walking). There were no discernable differences in peak PFJRF during everyday activities between healthy individuals and those with patellofemoral pain/OA. The information on PFJRF may be used to select appropriate variations of exercises and physical interventions.

Measurement properties for muscle strength tests following anterior cruciate ligament and/or meniscus injury: What tests to use and where do we need to go? A systematic review with meta-analyses for the OPTIKNEE consensus.

OBJECTIVES: Critically appraise and summarise the measurement properties of knee muscle strength tests after anterior cruciate ligament (ACL) and/or meniscus injury using the COnsensus-based Standards for the selection of health Measurement INstruments Risk of Bias checklist. DESIGN: Systematic review with meta-analyses. The modified Grading of Recommendations Assessment, Development and Evaluation-guided assessment of evidence quality. DATA SOURCES: Medline, Embase, CINAHL and SPORTSDiscus searched from inception to 5 May 2022. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Studies evaluating knee extensor or flexor strength test reliability, measurement error, validity, responsiveness or interpretability in individuals with ACL and/or meniscus injuries with a mean injury age of ≤30 years. RESULTS: Thirty-six studies were included involving 31 different muscle strength tests (mode and equipment) in individuals following an ACL injury and/or an isolated meniscus injury. Strength tests were assessed for reliability (n=8), measurement error (n=7), construct validity (n=27) and criterion validity (n=7). Isokinetic concentric extensor and flexor strength tests were the best rated with sufficient intrarater reliability (very low evidence quality) and construct validity (moderate evidence quality). Isotonic extensor and flexor strength tests showed sufficient criterion validity, while isometric extensor strength tests had insufficient construct and criterion validity (high evidence quality). CONCLUSION: Knee extensor and flexor strength tests of individuals with ACL and/or meniscus injury lack evidence supporting their measurement properties. There is an urgent need for high-quality studies on these measurement properties. Until then, isokinetic concentric strength tests are most recommended, with isotonic strength tests a good alternative.

What tests should be used to assess functional performance in youth and young adults following anterior cruciate ligament or meniscal injury? A systematic review of measurement properties for the OPTIKNEE consensus.

OBJECTIVES: To critically appraise and summarise measurement properties of functional performance tests in individuals following anterior cruciate ligament (ACL) or meniscal injury. DESIGN: Systematic review. DATA SOURCES: Systematic searches were performed in Medline (Ovid), Embase (Ovid), CINAHL (EBSCO) and SPORTSDiscus (EBSCO) on 7 July 2021. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Studies evaluating at least one measurement property of a functional performance test including individuals following an ACL tear or meniscal injury with a mean injury age of ≤30 years. The COnsensus-based Standards for the selection of health Measurement INstruments Risk of Bias checklist was used to assess methodological quality. A modified Grading of Recommendations Assessment, Development and Evaluation assessed evidence quality. RESULTS: Thirty studies evaluating 26 functional performance tests following ACL injury were included. No studies were found in individuals with an isolated meniscal injury. Included studies evaluated reliability (n=5), measurement error (n=3), construct validity (n=26), structural validity (n=1) and responsiveness (n=1). The Single Leg Hop and Crossover Hop tests showed sufficient intrarater reliability (high and moderate quality evidence, respectively), construct validity (low-quality and moderate-quality evidence, respectively) and responsiveness (low-quality evidence). CONCLUSION: Frequently used functional performance tests for individuals with ACL or meniscal injury lack evidence supporting their measurement properties. The Single Leg Hop and Crossover Hop are currently the most promising tests following ACL injury. High-quality studies are required to facilitate stronger recommendations of performance-based outcomes following ACL or meniscal injury.

Rehabilitation after anterior cruciate ligament and meniscal injuries: a best-evidence synthesis of systematic reviews for the OPTIKNEE consensus.

OBJECTIVE: Synthesise evidence for effectiveness of rehabilitation interventions following ACL and/or meniscal tear on symptomatic, functional, clinical, psychosocial, quality of life and reinjury outcomes. DESIGN: Overview of systematic reviews with Grading of Recommendations Assessment, Development and Evaluation certainty of evidence. DATA SOURCES: MEDLINE, EMBASE, CINAHL, SPORTDiscus and Cochrane Library. ELIGIBILITY CRITERIA: Systematic reviews of randomised controlled trials investigating rehabilitation interventions following ACL and/or meniscal tears in young adults. RESULTS: We included 22 systematic reviews (142 trials of mostly men) evaluating ACL-injured individuals and none evaluating isolated meniscal injuries. We synthesised data from 16 reviews evaluating 12 different interventions. Moderate-certainty evidence was observed for: (1) neuromuscular electrical stimulation to improve quadriceps strength; (2) open versus closed kinetic chain exercises to be similarly effective for quadriceps strength and self-reported function; (3) structured home-based versus structured in-person rehabilitation to be similarly effective for quadriceps and hamstring strength and self-reported function; and (4) postoperative knee bracing being ineffective for physical function and laxity. There was low-certainty evidence that: (1) preoperative exercise therapy improves self-reported and physical function postoperatively; (2) cryotherapy reduces pain and analgesic use; (3) psychological interventions improve anxiety/fear; and (4) whole body vibration improves quadriceps strength. There was very low-certainty evidence that: (1) protein-based supplements improve quadriceps size; (2) blood flow restriction training improves quadriceps size; (3) neuromuscular control exercises improve quadriceps and hamstring strength and self-reported function; and (4) continuous passive motion has no effect on range of motion. CONCLUSION: The general level of evidence for rehabilitation after ACL or meniscal tear was low. Moderate-certainty evidence indicates that several rehabilitation types can improve quadriceps strength, while brace use has no effect on knee function/laxity.

Meaningful thresholds for patient-reported outcomes following interventions for anterior cruciate ligament tear or traumatic meniscus injury: a systematic review for the OPTIKNEE consensus.

OBJECTIVE: We synthesised and assessed credibility (ie, trustworthiness) of thresholds that define meaningful scores for patient-reported outcome measures (PROMs) following interventions for anterior cruciate ligament (ACL) tear or traumatic meniscus injury. DESIGN: Systematic review, narrative synthesis. DATA SOURCES: We searched five databases, handsearched references of included studies and tracked citations. ELIGIBILITY: Included studies investigated: individuals with ACL tear or meniscus injury; mean age <35 years; and PROM thresholds calculated using any method to define a minimal important change (MIC) or a meaningful post-treatment score (Patient Acceptable Symptom State (PASS) or Treatment Failure). RESULTS: We included 18 studies (15 ACL, 3 meniscus). Three different methods were used to calculate anchor-based MICs across 9 PROMs, PASS thresholds across 4 PROMs and treatment failure for 1 PROM. Credibility was rated 'high' for only one study-an MIC of 18 for the Knee injury and Osteoarthritis Outcome Score Quality-of-life (KOOS-QOL) subscale (using the MID Credibility Assessment Tool). Where multiple thresholds were calculated among 'low' credibility thresholds in ACL studies, MICs converged to within a 10-point range for KOOS-Symptoms (-1.2 to 5.4) and function in daily living (activities of daily living, ADL 0.5-8.1) subscales, and the International Knee Documentation Committee Subjective Knee Form (7.1-16.2). Other PROM thresholds differed up to 30 points. PASS thresholds converged to within a 10-point range in KOOS-ADL for ACL tears (92.3-100), and KOOS-Symptoms (73-78) and KOOS-QOL (53-57) in meniscus injuries. CONCLUSION: Meaningful PROM thresholds were highly susceptible to study heterogeneity. While PROM thresholds can aid interpretability in research and clinical practice, they should be cautiously interpreted.

Long-term quality of life, work limitation, physical activity, economic cost and disease burden following ACL and meniscal injury: a systematic review and meta-analysis for the OPTIKNEE consensus.

OBJECTIVE: Determine the long-term health-related quality-of-life (HRQoL), work limitation, physical activity, health/economic cost and disease burden of traumatic ACL and/or meniscal injury. Findings will inform OPTIKNEE evidence-based consensus recommendations. DESIGN: Random-effects meta-analysis evaluated HRQoL (SF-36/SF-12/VR-12 Physical Component Scores (PCS) and Mental Component Scores (MCS), EuroQol-5D (EQ-5D)) stratified by time postinjury, and pooled mean differences (95% CI) between ACL-injured and uninjured controls. Other outcomes were synthesised descriptively. Risk-of-bias (RoB) and certainty of evidence (Grading of Recommendations Assessment, Development and Evaluation) were assessed. DATA SOURCES: MEDLINE, EMBASE, CENTRAL, SPORTDiscus, CINAHL searched inception: 22 November 2021. ELIGIBILITY: Studies reporting HRQoL, work limitations, physical activity levels, health/economic costs or disease burden, ≥2 years post-ACL and/or meniscal injury. RESULTS: Fifty studies were included (10 high-RoB, 28 susceptible-to-some-bias and 12 low-RoB). Meta-analysis (27 studies, very low certainty of evidence) estimated a pooled mean (95% CI) PCS of 52.4 (51.4 to 53.4) and MCS of 54.0 (53.0 to 55.0) 2-14 years post-ACL injury. Pooled PCS scores were worse >10 years (50.8 (48.7 to 52.9)) compared with 2-5 years (53.9 (53.1 to 54.7)) postinjury. Excluding high-RoB studies, PCS scores were worse in ACL-injured compared with uninjured controls (-1.5 (-2.9 to -0.1)). Six studies (low certainty of evidence) informed a pooled EQ-5D score of 0.83 (0.81 to 0.84). Some individuals experienced prolonged work absenteeism and modified activities ≥2 years post-ACL injury. ACL injury was associated with significant direct and indirect costs, and early ACL reconstruction may be less cost-effective than rehabilitation. Only three studies evaluated meniscal injury outcomes (all evaluated HRQoL). CONCLUSION: There is a very-low certainty of evidence that PCS scores ≥2 years post-ACL injury are worse than uninjured controls and decline over time, whereas MCS scores remain high. ACL injury can result in prolonged work absenteeism and high health/economic costs. Further studies are needed to determine the long-term burden of traumatic meniscal injury.

Risk factors for knee osteoarthritis after traumatic knee injury: a systematic review and meta-analysis of randomised controlled trials and cohort studies for the OPTIKNEE Consensus.

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.

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.

Exercise-therapy and education for individuals one year after anterior cruciate ligament reconstruction: a pilot randomised controlled trial.

BACKGROUND: Guided rehabilitation beyond 6-months is rare following anterior cruciate ligament reconstruction (ACLR), despite high prevalence of unacceptable symptoms and quality of life (QoL). Our primary aim was to determine the feasibility of a randomised controlled trial (RCT) evaluating a physiotherapist-guided intervention for individuals 1-year post-ACLR with persistent symptoms. Our secondary aim was to determine if a worthwhile treatment effect could be observed for the lower-limb focussed intervention (compared to the trunk-focussed intervention), for improvement in knee-related QoL, symptoms, and function. DESIGN: Participant- and assessor-blinded, pilot feasibility RCT. METHODS: Participant eligibility criteria: i) 12-15 months post-ACLR; ii) < 87.5/100 on the Knee injury and Osteoarthritis Outcome Score (KOOS) QoL subscale; and either a one-leg rise test < 22 repetitions, single-hop < 90% limb symmetry; or Anterior Knee Pain Scale < 87/100. Participants were randomised to lower-limb or trunk-focussed focussed exercise and education. Both interventions involved 8 face-to-face physiotherapy sessions over 16-weeks. Feasibility was assessed by eligibility rate (> 1 in 3 screened), recruitment rate (> 4 participants/month), retention (< 20% drop-out), physiotherapy attendance and unsupervised exercise adherence (> 80%). Between-group differences for knee-related QoL (KOOS-QoL, ACL-QoL), symptoms (KOOS-Pain, KOOS-Symptoms), and function (KOOS-Sport, functional performance tests) were used to verify that the worthwhile effect (greater than the minimal detectable change for each measure) was contained within the 95% confidence interval. RESULTS: 47% of those screened were eligible, and 27 participants (3 participants/month; 48% men, 34±12 years) were randomised. Two did not commence treatment, and two were lost to follow-up (16% drop-out). Physiotherapy attendance was > 80% for both groups but reported adherence to unsupervised exercise was low (< 55%). Both interventions had potentially worthwhile effects for KOOS-QoL and ACL-QoL, while the lower-limb focussed intervention had potentially greater effects for KOOS-Sport, KOOS-Pain, and functional performance. CONCLUSIONS: A larger-scale RCT is warranted. All feasibility criteria were met, or reasonable recommendations could be made to achieve the criteria in future trials. Strategies to increase recruitment rate and exercise adherence are required. The potential worthwhile effects for knee-related QoL, symptoms, and function indicates a fully-powered RCT may detect a clinically meaningful effect. TRIAL REGISTRATION: Prospectively registered ( ACTRN12616000564459 ).

Is patellofemoral pain preventable? A systematic review and meta-analysis of randomised controlled trials.

OBJECTIVE: To evaluate the effectiveness of interventions to reduce the risk of incident patellofemoral pain. DESIGN: Systematic review and meta-analysis, with strength of evidence evaluated separately for each intervention type. DATA SOURCES: MEDLINE, EMBASE, CINAHL, Web of Science and SPORTDiscus. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Randomised controlled trials evaluating the effectiveness of interventions to reduce patellofemoral pain risk compared with a control/non-exposed group. RESULTS: Thirteen trials of mostly military recruits and young athletes analysed six different interventions. There was low certainty evidence from two trials (227 participants) that patellofemoral braces worn during physical activity (compared with no brace) effectively reduced the risk of patellofemoral pain (risk ratio (RR) 0.40, 95% CI 0.22 to 0.73; I2=24.0%). There was low certainty evidence from one trial (320 participants) that running technique retraining to (run softer) reduced patellofemoral pain risk (RR 0.21, 95% CI 0.07 to 0.60). There was low certainty evidence from four trials (3364 participants) that multicomponent (strengthening/neuromuscular) exercise programmes did not significantly reduce the risk of patellofemoral pain (RR 0.49, 95% CI 0.18 to 1.36; I2=64.9%), although broad CIs may reflect exercise dose variations among studies. There was very low certainty evidence from four trials (2314 participants) that foot orthoses (compared with flat inserts/no orthosis) did not significantly reduce the risk of patellofemoral pain (RR 0.63, 95% CI 0.35 to 1.13; I2=0.0%). Static stretching and a running programme that progressed intensity (compared with volume) did not significantly influence patellofemoral pain risk (single studies). CONCLUSION: There is low-level evidence that patellofemoral braces and running technique retraining can reduce the risk of patellofemoral pain by 60%-79%.