Assessing the efficacy of the Stop OsteoARthritis (SOAR) program: A randomized delayed-controlled trial in persons at increased risk of early onset post-traumatic knee osteoarthritis.

OBJECTIVE: Assess the efficacy of an 8-week virtual, physiotherapist (PT)-guided knee health program (Stop OsteoARthritis (SOAR)) to improve knee extensor strength in individuals at risk of post-traumatic knee osteoarthritis (PTOA). METHOD: In this superiority, randomized delayed-control trial, persons aged 16-35 years, 1-4 years after a self-reported knee joint injury were randomly assigned (1:1) to receive the SOAR program immediately (experimental group) or after a 9-week delay (control group). SOAR includes 1) one-time Knee Camp (virtual PT-guided group education, knee assessment, 1:1 exercise and physical activity (PA) goal-setting); 2) Weekly personalized home-based exercise and PA program with tracking; 3) Weekly 1:1 PT counseling (virtual). The primary outcome was a change in isokinetic knee extensor strength (baseline to 9-weeks). Additional outcomes included change in self-reported knee-related quality-of-life (QOL), self-efficacy, self-management and kinesiophobia, and PA (accelerometer) at 9 and 18-weeks. Linear regression models estimated the effect of the 8-week intervention at the primary endpoint (9-week). RESULTS: 49 of 54 randomized participants completed the study (91%). Participants were a mean ± standard deviation age of 27 ± 5.0 years, and 2.4 ± 0.9 years post-injury. No mean between group differences for the primary (0.05; 95% confidence interval (CI): -0.10, 0.19) or other outcomes were seen at 9 weeks except for greater improvements in perceived self-management (Partner in Health Scale; 11.3/96, 95%CI: 5.5, 17.1) and kinesiophobia (Tampa Scale of Kinesiophobia; -4.4/33, 95%CI: -7.0, -1.8). CONCLUSION: For active persons with elevated risk of PTOA, an 8-week SOAR program did not change knee-related strength, QOL, self-efficacy, or PA, on average, but may benefit the ability to self-manage knee health and kinesiophobia.

Anterior Cruciate Ligament Return to Sport after Injury Scale (ACL-RSI) Scores over Time After Anterior Cruciate Ligament Reconstruction: A Systematic Review with Meta-analysis.

BACKGROUND: Psychological readiness is an important consideration for athletes and clinicians when making return to sport decisions following anterior cruciate ligament reconstruction (ACLR). To improve our understanding of the extent of deficits in psychological readiness, a systematic review is necessary. OBJECTIVE: To investigate psychological readiness (measured via the Anterior Cruciate Ligament-Return to Sport after Injury scale (ACL-RSI)) over time after ACL tear and understand if time between injury and surgery, age, and sex are associated with ACL-RSI scores. METHODS: Seven databases were searched from the earliest date available to March 22, 2022. Articles reporting ACL-RSI scores after ACL tear were included. Risk of bias was assessed using the ROBINS-I, RoB-2, and RoBANS tools based on the study design. Evidence certainty was assessed for each analysis. Random-effects meta-analyses pooled ACL-RSI scores, stratified by time post-injury and based on treatment approach (i.e., early ACLR, delayed ACLR, and unclear approach). RESULTS: A total of 83 studies were included in this review (78% high risk of bias). Evidence certainty was 'weak' or 'limited' for all analyses. Overall, ACL-RSI scores were higher at 3 to 6 months post-ACLR (mean = 61.5 [95% confidence interval (CI) 58.6, 64.4], I2 = 94%) compared to pre-ACLR (mean = 44.4 [95% CI 38.2, 50.7], I2 = 98%), remained relatively stable, until they reached the highest point 2 to 5 years after ACLR (mean = 70.7 [95% CI 63.0, 78.5], I2 = 98%). Meta-regression suggests shorter time from injury to surgery, male sex, and older age were associated with higher ACL-RSI scores only 3 to 6 months post-ACLR (heterogeneity explained R2 = 47.6%), and this reduced 1-2 years after ACLR (heterogeneity explained R2 = 27.0%). CONCLUSION: Psychological readiness to return to sport appears to improve early after ACL injury, with little subsequent improvement until ≥ 2-years after ACLR. Longer time from injury to surgery, female sex and older age might be negatively related to ACL-RSI scores 12-24 months after ACLR. Due to the weak evidence quality rating and the considerable importance of psychological readiness for long-term outcomes after ACL injury, there is an urgent need for well-designed studies that maximize internal validity and identify additional prognostic factors for psychological readiness at times critical for return to sport decisions. REGISTRATION: Open Science Framework (OSF), https://osf.io/2tezs/ .

Social support and therapeutic relationships intertwine to influence exercise behavior in people with sport-related knee injuries.

OBJECTIVE: Explore how social support influences exercise therapy participation and adherence before and after enrolling in an education and exercise therapy intervention (Stop OsteoARthritis, SOAR). METHODS: Study design: Interpretative description. We sampled participants with sport-related knee injuries from the SOAR randomized controlled trial. SOAR is a virtual, physiotherapist-guided, education and exercise therapy-based knee health program that targets individuals at risk of early osteoarthritis. One-on-one semi-structured interviews were completed, and an inductive approach was guided by Braun & Clarke's reflexive thematic analysis. RESULTS: Fifteen participants (67% female, median age 26 [19-35] years) were interviewed. Three themes were generated that encapsulated participants' social support experiences that fostered exercise participation: 1) Treat me as a whole person represented the value of social support that went beyond participants' physical needs, 2) Work with me highlighted the working partnership between the clinician and the participant, and 3) Journey with me indicated a need for on-going support is necessary for the long-term management of participants' knee health. A theme of the therapeutic relationship was evident across the findings. CONCLUSIONS: Insight was gained into how and why perceived support may be linked to exercise behavior, with the therapeutic relationship being potentially linked to perceived support. Social support strategies embedded within an education and exercise therapy program may boost exercise adherence after sport-related knee injuries.

The association between knee muscle performance and clinical outcomes of knee function 1-4 years after a sport-related knee joint injury.

OBJECTIVE: Estimate the association between index leg knee muscle strength and rate of torque development (RTD), and self-reported and performance-based (i.e., hop) knee function in persons 1-4 years after a sport-related knee joint injury. METHODS: Data were collected at baseline of a clinical trial. Assessments included the Knee injury and Osteoarthritis Outcome Score Sport & Recreation subscale (KOOSsport), 6-m timed hop (TH), and peak concentric isokinetic knee extensor and flexor torque and isometric RTD. Associations between peak torque and RTD with KOOSsport and TH were assessed using multivariable regression with nonlinear transformations. RESULTS: 53 participants (64.2% female) were included. Knee extensor peak torque was nonlinearly related to TH time, with a strong inverse relationship at lower torque values that changed as torque increased. Results were inconsistent for flexor peak torque, extensor RTD and flexor RTD, with inconsistencies in relationship shape and estimates of association between primary and sensitivity analyses. There was no association between strength/RTD and KOOSsport. CONCLUSION: There was a nonlinear relationship between knee extensor strength and hop function, with lower strength being associated with a stronger relationship. As strength values increased, the relationship attenuated. Knee extensor and flexor strength, or RTD, were not associated with self-reported function.

Comparing Short-Term Knee-Related Quality of Life and Associated Clinical Outcomes Between Youth With and Without a Sport-Related Knee Injury.

OBJECTIVE: To compare short-term changes in knee-related quality of life (QOL) and associated clinical outcomes between youth with and without a sport-related knee injury. DESIGN: Prospective cohort study. SETTING: Sport medicine and physiotherapy clinics. PARTICIPANTS: Youth (11-19 years old) who sustained an intra-articular, sport-related knee injury in the past 4 months and uninjured youth of similar age, sex, and sport. INDEPENDENT VARIABLE: Injury history. MAIN OUTCOME MEASURES: Knee-related QOL (Knee injury and Osteoarthritis Outcome Score, KOOS), knee extensor and flexor strength (dynamometry), physical activity (accelerometer), fat mass index (FMI; bioelectrical impedance), and kinesiophobia (Tampa Scale for Kinesiophobia, TSK) were measured at baseline (within 4 months of injury) and at 6-month follow-up. Wilcoxon rank sum tests assessed between-group differences for all outcomes. Regression models assessed the association between injury history and outcome change (baseline to 6-month follow-up), considering sex. The influence of injury type, baseline values, and physiotherapy attendance was explored. RESULTS: Participants' (93 injured youth, 73 uninjured control subjects) median age was 16 (range 11-20) years and 66% were female. Despite greater improvements in KOOS QOL scores (20; 95% confidence interval, 15-25), injured participants demonstrated deficits at 6-month follow-up (z = 9.3, P < 0.01) compared with control subjects, regardless of sex. Similar findings were observed for knee extensor and flexor strength and TSK scores but not for physical activity or FMI. Lower baseline values were associated with greater outcome changes in injured youth. CONCLUSIONS: Youth have worse knee-related QOL, muscle strength, and kinesiophobia early after a sport-related knee injury than control subjects. Despite improvements, deficits persist 6 months later.

Description, Prediction, and Causation in Sport and Exercise Medicine Research: Resolving the Confusion to Improve Research Quality and Patient Outcomes.

SYNOPSIS: Researchers often assign a label (such as a risk factor or predictor) to a characteristic that is statistically associated with an outcome (such as future injury). Labeling signifies that the characteristic has an established clinical value. More often than not, these labels are assigned prematurely and haphazardly. The rampant practice conflates research goals, the ultimate clinical value of the findings, and many risk factors/predictors that may not warrant the label. To address these issues and improve injury prevention research, we (1) outline the problem; (2) clarify the key differences between the research goals of description, causation, and prediction/prognosis (along with labeling conventions); (3) differentiate the clinical implications for each label; and (4) frame an appropriate scientific process to follow before applying a label. J Orthop Sports Phys Ther 2023;53(7):1-7. Epub: 26 April 2023. doi:10.2519/jospt.2023.11773.

Combined hormonal contraceptive use is not protective against musculoskeletal conditions or injuries: a systematic review with data from 5 million females.

OBJECTIVE: Assess the association between combined hormonal contraceptives (CHC) use and musculoskeletal tissue pathophysiology, injuries or conditions. DESIGN: Systematic review with semiquantitative analyses and certainty of evidence assessment, guided by the Grading of Recommendations Assessment, Development and Evaluation approach. DATA SOURCES: MEDLINE, EMBASE, CENTRAL, SPORTDiscus, CINAHL searched from inception to April 2022. ELIGIBILITY: Intervention and cohort studies that assessed the association between new or ongoing use of CHC and an outcome of musculoskeletal tissue pathophysiology, injury or condition in postpubertal premenopausal females. RESULTS: Across 50 included studies, we assessed the effect of CHC use on 30 unique musculoskeletal outcomes (75% bone related). Serious risk of bias was judged present in 82% of studies, with 52% adequately adjusting for confounding. Meta-analyses were not possible due to poor outcome reporting, and heterogeneity in estimate statistics and comparison conditions. Based on semiquantitative synthesis, there is low certainty evidence that CHC use was associated with elevated future fracture risk (risk ratio 1.02-1.20) and total knee arthroplasty (risk ratio 1.00-1.36). There is very low certainty evidence of unclear relationships between CHC use and a wide range of bone turnover and bone health outcomes. Evidence about the effect of CHC use on musculoskeletal tissues beyond bone, and the influence of CHC use in adolescence versus adulthood, is limited. CONCLUSION: Given a paucity of high certainty evidence that CHC use is protective against musculoskeletal pathophysiology, injury or conditions, it is premature and inappropriate to advocate, or prescribe CHC for these purposes. PROSPERO REGISTRATION NUMBER: This review was registered on PROSPERO CRD42021224582 on 8 January 2021.

Feasibility of the SOAR (Stop OsteoARthritis) program.

Objective: Assess the feasibility of a virtually-delivered, physiotherapist-guided knee health program (SOAR) that targets self-management of knee health and osteoarthritis risk after an activity-related knee injury. Design: In this quasi-experimental feasibility study, individuals with varied lived experience of knee trauma completed a 4-week SOAR program. This included: 1) Knee Camp (group education, 1:1 exercise and activity goal-setting); 2) weekly home-based exercise and activity program with tracking, and; 3) weekly 1:1 physiotherapy-guided action-planning. SOAR program feasibility was assessed with implementation (attrition, adherence, intervention fidelity), practicality (adverse events, goal completion), acceptability and efficacy (change in Knee injury and Osteoarthritis Outcome Score subscales, Patient Specific Functional Scale (PSFS), Godin Leisure-Time Exercise Questionnaire (GLTEQ), Partner in Health Scale (PHS)) outcomes. Descriptive statistics, disaggregated by gender, were calculated. Results: Thirty participants (60% women, median (min-max) age 30 years (19-50), time from injury 5.6 years (1.2-25.2)) were enrolled. No participant attrition or adverse events were reported, and 90% of mandatory program components were completed. Participants rated their adherence at 80%, and 96% of exercise-therapy and 95% of activity goals were fully or partially achieved. Both women and men reported significant group mean (95%CI) improvements in GLTEQ scores (women: 22 METS (6,37), men: 31 METS (8,54)), while women alone reported improvements in PHS (-7 (-11,-3) and PSFS (1.7 (0.6,2.8) scores. Conclusion: The SOAR program is feasible for persons at various timepoints post-knee trauma, and gender may be an important consideration for SOAR implementation and assessment. A randomized controlled trial to assess intervention efficacy is warranted.

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.

Efficacy of the SOAR knee health program: protocol for a two-arm stepped-wedge randomized delayed-controlled trial.

BACKGROUND: Knee trauma permanently elevates one's risk for knee osteoarthritis. Despite this, people at-risk of post-traumatic knee osteoarthritis rarely seek or receive care, and accessible and efficacious interventions to promote knee health after injury are lacking. Exercise can ameliorate some mechanisms and independent risk factors for osteoarthritis and, education and action-planning improve adherence to exercise and promote healthy behaviours. METHODS: To assess the efficacy of a virtually-delivered, physiotherapist-guided exercise-based program (SOAR) to improve knee health in persons discharged from care after an activity-related knee injury, 70 people (16-35 years of age, 12-48 months post-injury) in Vancouver Canada will be recruited for a two-arm step-wedged assessor-blinded delayed-control randomized trial. Participants will be randomly allocated to receive the intervention immediately or after a 10-week delay. The program consists of 1) one-time Knee Camp (group education, 1:1 individualized exercise and activity goal-setting); 2) weekly individualized home-based exercise and activity program with tracking, and; 3) weekly 1:1 physiotherapy-guided action-planning with optional group exercise class. Outcomes will be measured at baseline, 9- (primary endpoint), and 18-weeks. The primary outcome is 9-week change in knee extension strength (normalized peak concentric torque; isokinetic dynamometer). Secondary outcomes include 9-week change in moderate-to-vigorous physical activity (accelerometer) and self-reported knee-related quality-of-life (Knee injury and OA Outcome Score subscale) and self-efficacy (Knee Self Efficacy Scale). Exploratory outcomes include 18-week change in primary and secondary outcomes, and 9- and 18- week change in other components of knee extensor and flexor muscle function, hop function, and self-reported symptoms, function, physical activity, social support, perceived self-care and kinesiophobia. Secondary study objectives will assess the feasibility of a future hybrid effectiveness-implementation trial protocol, determine the optimal intervention length, and explore stakeholder experiences. DISCUSSION: This study will assess the efficacy of a novel, virtually-delivered, physiotherapist-guided exercise-based program to optimize knee health in persons at increased risk of osteoarthritis due to a past knee injury. Findings will provide valuable information to inform the management of osteoarthritis risk after knee trauma and the conduct of a future effectiveness-implementation trial. TRIAL REGISTRATION: Clinicaltrials.gov reference: NTC04956393. Registered August 5, 2021, https://clinicaltrials.gov/ct2/show/NCT04956393?term=SOAR&cond=osteoarthritis&cntry=CA&city=Vancouver&draw=2&rank=1.

Passing return-to-sport criteria and landing biomechanics in young athletes following anterior cruciate ligament reconstruction.

We sought to evaluate the sagittal plane knee joint loading patterns during a double-leg landing task among young athletes who passed or failed return-to-sport (RTS) criteria following anterior cruciate ligament reconstruction reconstruction (ACLR), and in uninjured athletes. Participants completed quadriceps strength testing, a hop test battery, and the International Knee Documentation Committee subjective form following medical RTS clearance. ACLR participants "passed" RTS criteria (RTS-PASS) if they met ≥90 limb symmetry (%) or score on all measures and were categorized as "failing" (RTS-FAIL) if not. All participants completed three-dimensional motion analysis testing. Sagittal plane kinematic and kinetic variables were calculated during a double-leg drop vertical jump task. Mean limb values and limb symmetry indices (LSI; %) were calculated and compared using a one-way analysis of variance (ANOVA) (for LSI) and mixed between-within ANOVA (for group × limb differences). A total of 205 participants were included, with 39 in the RTS-PASS group, 109 in the RTS-FAIL group, and 57 control groups (CTRLs). The RTS-FAIL group demonstrated lower symmetry values for peak vertical ground reaction force, peak internal knee extension moment, and peak knee flexion angle. Group × limb interactions were observed for peak vertical ground reaction force and peak internal knee extension moment. Involved limb values were reduced in the RTS-PASS and RTS-FAIL groups compared to CTRLs, while the RTS-PASS groups had lower uninvolved limb values compared to the RTS-FAIL and CTRLs. Clinical Significance: Young athletes who pass RTS criteria after ACLR land symmetrically during a double-leg task, but symmetry was achieved by reducing loading on both limbs.

Does sex affect second ACL injury risk? A systematic review with meta-analysis.

OBJECTIVE: To determine sex-based differences in risk of a second ACL injury (overall and by laterality) following primary ACL reconstruction in athletes who are attempting to return to sport. DESIGN: Systematic review with meta-analysis. DATA SOURCES: Systematic search of five databases conducted in August 2019. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Studies reporting sex-based differences in the incidence of second ACL injury in athletes attempting to return-to-sports and who were followed for at least 1 year following primary ACL reconstruction. RESULTS: Nineteen studies were included in this review, with seven studies excluded from the primary meta-analysis due to high risk of bias. The remaining 12 studies (n=1431 females, n=1513 males) underwent meta-analysis, with all 19 studies included in a sensitivity analysis. Total second ACL injury risk was 21.9% (females: 22.8%, males: 20.3%). Females were found to have 10.7% risk of an ipsilateral ACL injury and 11.8% risk of a contralateral ACL injury. Males were found to have 12.0% risk of an ipsilateral ACL injury and 8.7% risk of a contralateral ACL injury. No statistically significant differences were observed for total second ACL injury risk (risk difference=-0.6%, 95% CI -4.9 to 3.7, p=0.783, I2=41%) or contralateral ACL injury risk (risk difference=1.9%, 95% CI -0.5% to 4.4%, p=0.113, I2=15%) between sexes. Females were found to have a 3.4% absolute risk reduction in subsequent ipsilateral ACL injury risk compared with males (risk difference=-3.4%, 95% CI -6.7% to -0.02%, p=0.037, I2=35%). CONCLUSION: Both sexes have >20% increased risk of experiencing a second ACL injury. Any difference in the absolute risk of either a subsequent ipsilateral or contralateral ACL injury between sexes appears to be small. REGISTRATION: PROSPERO (CRD42020148369).

Hop Testing Lacks Strong Association With Key Outcome Variables After Primary Anterior Cruciate Ligament Reconstruction: A Systematic Review.

BACKGROUND: Single-legged hop tests are commonly used assessments in return to sport (RTS) testing after anterior cruciate ligament reconstruction (ACLR). Although these tests are commonly used, their predictive validity has not yet been established. PURPOSE: To determine the strength of association between hop testing and RTS, knee reinjury, subjective report of knee function, and posttraumatic knee osteoarthritis (PTOA) after primary ACLR. Secondarily, to determine whether hop testing is able to predict a favorable result on the same outcome variables. STUDY DESIGN: Systematic review. METHODS: A systematic, computer-assisted literature search was performed in PubMed/MEDLINE, CINAHL, EMBASE, SPORTDiscus, Cochrane Library, and ClinicalTrials.gov. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed when conducting and reporting this review. Primary outcome variables for this review were self-report of knee function, return to preinjury level of activity, presence of reinjury, and presence of PTOA. The Oxford Centre for Evidence-Based Medicine Levels of Evidence tool was used to assess the level of evidence for each included study. Quality assessment of each included study was performed through use of a modified Downs and Black scale. Available metrics were tabulated based on outcome variables. RESULTS: Overall, 21 studies (4476 patients) met inclusion for this review. The majority of evidence (95.2%) was of moderate to high methodologic quality. The most commonly associated outcome measure was the International Knee Documentation Committee (IKDC) score, with Pearson correlation coefficients ranging from 0.20 to 0.60. The strength of association between the Knee injury and Osteoarthritis Outcome Score (KOOS) and hop testing ranged from -0.10 to 0.62 in 4 studies. In all, 10 studies examined the relationship between hop testing and RTS, with variable association statistics reported. No meaningful association was found between hop testing and knee reinjury in 2 studies. Worse preoperative hop testing was associated with PTOA in 1 study. CONCLUSION: Hop testing appears to possess fair association to subjective report of knee function measured by the KOOS and IKDC and a patient's ability to RTS after ACLR. Insufficient evidence is available to determine the relationship between hop testing and PTOA and knee reinjury. Predictive validity cannot be established based on available literature.

The Association Between Passing Return-to-Sport Criteria and Second Anterior Cruciate Ligament Injury Risk: A Systematic Review With Meta-analysis.

BACKGROUND: There is no consensus on the components of return-to-sport (RTS) testing following anterior cruciate ligament (ACL) reconstruction or whether passing RTS criteria can reduce a patient's risk of reinjury. OBJECTIVES: To determine whether impartial, criteria-based RTS decisions are associated with less risk of a second ACL injury (either graft failure or contralateral ACL injury). METHODS: In this systematic review with meta-analysis, the authors conducted an electronic literature search in PubMed/MEDLINE, Embase, CINAHL, SPORTDiscus, and ProQuest Dissertations and Theses Global using database-specific vocabulary related to ACL reconstruction and return to sport. Individual study quality was assessed using the modified Downs and Black checklist, and overall quality of evidence was determined with the Grading of Recommendations Assessment, Development and Evaluation scale. Pooled risk difference (passed versus failed RTS criteria), injury incidence proportion, and the diagnostic accuracy of each RTS criterion were calculated. RESULTS: Four studies met the selection criteria. Overall, 42.7% (95% confidence interval [CI]: 18%, 69%) of patients passed RTS criteria, and 14.4% (95% CI: 8%, 21%) of those who passed experienced a second ACL injury (graft rupture or contralateral ACL injury). There was a nonsignificant 3% reduced risk of a second ACL injury after passing RTS criteria (risk difference, -3%; 95% CI: -16%, 10%; I2 = 74%, P = .610). The evidence rating of the Grading of Recommendations Assessment, Development and Evaluation scale was "very low quality," due to imprecision and heterogeneity of the pooled risk difference estimate. CONCLUSION: Passing RTS criteria did not show a statistically significant association with risk of a second ACL injury. The quality-of-evidence rating prevents a definitive conclusion on this question and indicates an opportunity for future research. LEVEL OF EVIDENCE: Prognosis, Level 2a-. J Orthop Sports Phys Ther 2019;49(2):43-54. Epub 30 Nov 2018. doi:10.2519/jospt.2019.8190.