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.

Background Single-legged hop tests are commonly used functional performance measures that can capture limb asymmetries in patients after anterior cruciate ligament (ACL) reconstruction. Hop tests hold potential as predictive factors of self-reported knee function in individuals after ACL reconstruction. Hypothesis Single-legged hop tests conducted preoperatively would not and 6 months after ACL reconstruction would predict self-reported knee function (International Knee Documentation Committee [IKDC] 2000) 1 year after ACL reconstruction. Study Design Cohort study (prognosis); Level of evidence, 2. Methods One hundred twenty patients who were treated with ACL reconstruction performed 4 single-legged hop tests preoperatively and 6 months after ACL reconstruction. Self-reported knee function within normal ranges was defined as IKDC 2000 scores greater than or equal to the age- and sex-specific normative 15th percentile score 1 year after surgery. Logistic regression analyses were performed to identify predictors of self-reported knee function within normal ranges. The area under the curve (AUC) from receiver operating characteristic curves was used as a measure of discriminative accuracy. Results Eighty-five patients completed single-legged hop tests 6 months after surgery and the 1-year follow-up with 68 patients classified as having self-reported knee function within normal ranges 1 year after reconstruction. The crossover hop and 6-m timed hop limb symmetry index (LSI) 6 months after ACL reconstruction were the strongest individual predictors of self-reported knee function (odds ratio, 1.09 and 1.10) and the only 2 tests in which the confidence intervals of the discriminatory accuracy (AUC) were above 0.5 (AUC = 0.68). Patients with knee function below normal ranges were over 5 times more likely of having a 6-m timed hop LSI lower than the 88% cutoff than those with knee function within normal ranges. Patients with knee function within normal ranges were 4 times more likely to have a crossover hop LSI greater than the 95% cutoff than those with knee function below normal ranges. No preoperative single-legged hop test predicted self-reported knee function within normal ranges 1 year after ACL reconstruction (all P > .353). Conclusion Single-legged hop tests conducted 6 months after ACL reconstruction can predict the likelihood of successful and unsuccessful outcome 1 year after ACL reconstruction. Patients demonstrating less than the 88% cutoff score on the 6-m timed hop test at 6 months may benefit from targeted training to improve limb symmetry in an attempt to normalize function. Patients with minimal side-to-side differences on the crossover hop test at 6 months possibly will have good knee function at 1 year if they continue with their current training regimen. Preoperative single-legged hop tests are not able to predict postoperative outcomes.

Background No gold standard exists for identifying successful outcomes 1 and 2 years after operative and non-operative management of anterior cruciate ligament (ACL) injury. This limits the ability of researcher and clinicians to compare and contrast results of interventions. Purpose to establish a consensus based on expert consensus of measures that define successful outcomes 1 and 2 years after ACL injury or reconstruction. Methods Members of international sports medicine associations, including the American Orthopaedic Society for Sports Medicine (AOSSM), the European Society for Sports Traumatology, Surgery, and Knee Arthroscopy (ESSKA), and the American Physical Therapy Association (APTA), were sent a survey via e-mail. Blinded responses were analyzed for trends with frequency counts. A summed importance percentage (SIP) was calculated and 80% SIP operationally indicated consensus. Results 1779 responses were obtained. Consensus was achieved for six measures in operative and non-operative management: the absence of giving way, patient return to sports, quadriceps and hamstrings strength greater than 90% of the uninvolved limb, the patient having no more than a mild knee joint effusion, and using patient reported outcomes (PRO). No single PRO achieved consensus, but threshold scores between 85 and 90 were established for PROs concerning patient performance. Conclusion The consensus identified six measures important for successful outcome after ACL injury or reconstruction. These represent all levels of the International Classification of Functioning; effusion, giving way, muscle strength (body structure and function), PRO (activity and participation), and return to sport (participation) and should be included to allow for comparison between interventions.

Anterior cruciate ligament (ACL) rupture occurs most commonly in young and active individuals and can have negative long-term physical and psychological impacts. The diagnosis is made with a combination of patient's history, clinical examination, and, if appropriate, magnetic resonance imaging. The objectives of management are to restore knee function, address psychological barriers to activity participation, prevent further injury and osteoarthritis, and optimize long-term quality of life. The three main treatment options for ACL rupture are (1) rehabilitation as first-line treatment (followed by ACL reconstruction (ACLR) in patients, who develop functional instability), (2) ACLR and post-operative rehabilitation as the first-line treatment, and (3) pre-operative rehabilitation followed by ACLR and post-operative rehabilitation. We provide practical recommendations for informing and discussing management options with patients, and describe patient-related factors associated with a worse ACL-rupture outcome. Finally, we define evidence-based rehabilitation and present phase-specific rehabilitation recommendations and criteria to inform return to sport decisions.