Background Knee reinjury after anterior cruciate ligament (ACL) reconstruction is common and increases the risk of osteoarthritis. There is sparse evidence to guide return to sport (RTS) decisions in this population. Objectives To assess the relationship between knee reinjury after ACL reconstruction and 1) return to level I sports, 2) timing of return to sports, and 3) knee function prior to return. Methods 106 patients who participated in pivoting sports participated in this prospective two year cohort study. Sports participation and knee reinjury were recorded monthly. Knee function was assessed with the Knee Outcome Survey–Activities of Daily Living Scale, global rating scale of function, and quadriceps strength and hop test symmetry. Pass RTS criteria was defined as scores >90 on all tests, failure as failing any. Results Patients who returned to level I sports had 4.32 (p=0.048) higher reinjury rate than those who did not. The reinjury rate was significantly reduced by 51 % for each month RTS was delayed until 9 months after surgery, after which no further risk reduction was observed. 38.2 % of those who failed RTS criteria suffered reinjuries versus 5.6 % of those who passed (HR: 0.16, p=0.075). More symmetrical quadriceps strength prior to return significantly reduced the knee reinjury rate. Conclusion Returning to level I sports after ACL reconstruction leads to a more than 4-fold increase in reinjury rates over 2 years. Return to sport 9 months or later after surgery and more symmetrical quadriceps strength prior to return substantially reduces the reinjury rate.

Deciding when to return to sport after injury is complex and multifactorial-an exercise in risk management. Return to sport decisions are made every day by clinicians, athletes and coaches, ideally in a collaborative way. The purpose of this consensus statement was to present and synthesise current evidence to make recommendations for return to sport decision-making, clinical practice and future research directions related to returning athletes to sport. A half day meeting was held in Bern, Switzerland, after the First World Congress in Sports Physical Therapy. 17 expert clinicians participated. 4 main sections were initially agreed upon, then participants elected to join 1 of the 4 groups-each group focused on 1 section of the consensus statement. Participants in each group discussed and summarised the key issues for their section before the 17-member group met again for discussion to reach consensus on the content of the 4 sections. Return to sport is not a decision taken in isolation at the end of the recovery and rehabilitation process. Instead, return to sport should be viewed as a continuum, paralleled with recovery and rehabilitation. Biopsychosocial models may help the clinician make sense of individual factors that may influence the athlete's return to sport, and the Strategic Assessment of Risk and Risk Tolerance framework may help decision-makers synthesise information to make an optimal return to sport decision. Research evidence to support return to sport decisions in clinical practice is scarce. Future research should focus on a standardised approach to defining, measuring and reporting return to sport outcomes, and identifying valuable prognostic factors for returning to sport

STUDY DESIGN Prospective cohort study without a control group. OBJECTIVES Firstly, to present our 5-week progressive exercise therapy program in the early stage after anterior cruciate ligament (ACL) injury. Secondly, to evaluate changes in knee function after completion of the program for patients with ACL injury in general and also when classified as potential copers or noncopers, and, finally, to examine potential adverse events. BACKGROUND Few studies concerning early-stage ACL rehabilitation protocols exist. Consequently, little is known about the tolerance for, and outcomes from, short-term exercise therapy programs in the early stage after injury. METHODS One-hundred patients were included in a 5-week progressive exercise therapy program, within 3 months after injury. Knee function before and after completion of the program was evaluated from isokinetic quadriceps and hamstrings muscle strength tests, 4 single-leg hop tests, 2 different self-assessment questionnaires, and a global rating of knee function. A 2-way mixed-model analysis of variance was conducted to evaluate changes from pretest to posttest for the limb symmetry index for muscle strength and single-leg hop tests, and the change in scores for the patient-reported questionnaires. In addition, absolute values and the standardized response mean for muscle strength and single-leg hop tests were calculated at pretest and posttest for the injured and uninjured limb. Adverse events during the 5-week period were recorded. RESULTS The progressive 5-week exercise therapy program led to significant improvements (P<.05) in knee function from pretest to posttest both for patients classified as potential copers and noncopers. Standardized response mean values for changes in muscle strength and single-leg hop performance from pretest to posttest for the injured limb were moderate to strong (0.49–0.84), indicating the observed improvements to be clinically relevant. Adverse events occurred in 3.9% of the patients. CONCLUSION Short-term progressive exercise therapy programs are well tolerated and should be incorporated in early-stage ACL rehabilitation, either to improve knee function before ACL reconstruction or as a first step in further nonoperative management.

Background Previous studies have found significant predictors for functional outcome after ACL reconstruction, however, studies examining predictors for functional outcome in non-operatively treated individuals are lacking. Hypothesis Single-legged hop tests predict self-reported knee function (IKDC2000) in non-operatively treated ACL-injured individuals 1 year after baseline testing. Study Design Cohort study (prognosis); Level of evidence, 2. Methods Ninety-one non-operatively treated subjects with an ACL injury were tested using 4 one-legged hop tests on average 74 ± 30 days after injury in a prospective cohort study. Eighty-one subjects (89 %) completed the IKDC2000 1 year later. Subjects with an IKDC2000 score equal to or higher than the age- and gender-specific 15th percentile score from previously published data on an uninjured population were classified as having self-reported function within normal ranges. Logistic regression analyses were performed to identify predictors of self-reported knee function. The Area Under the Curve (AUC) from Receiver Operating Characteristic curves was used as a measure of discriminative accuracy. Optimal limb symmetry index (LSI) cutoff for the best single-legged hop test was defined as the LSI with the highest product of sensitivity and specificity. Results Single hop for distance symmetry indexes predicted self-reported knee function at the 1-year follow-up (p=0.036). Combinations of any 2 hop tests (AUC=0.64–0.71) did not give a higher discriminative accuracy than the single hop alone (AUC=0.71). A cutoff of 88 % (LSI) for the single hop revealed a sensitivity of 71.4 % and a specificity of 71.7 %. Conclusion The single hop for distance (LSI) significantly predicted self-reported knee function after 1 year in non-operatively treated ACL-injured subjects. Combinations of 2 single-legged hop tests did not lead to higher discriminative accuracy than the single hop alone.