Limited correlation between physical performance and patient-reported outcomes at 1-year follow-up after anterior cruciate ligament reconstruction.

Purpose: The majority of anterior cruciate ligament reconstruction (ACLr) patients wish to return to sport. Clinical evaluations after ACLr often do not include physical testing, making it difficult to determine the patient's readiness to return to sport. Thus, it would be helpful to identify easily assessable factors associated with physical function in ACLr patients that could inform planning of patients' return to sport. This study sought to evaluate the associations between physical test performance in ACLr patients and known ACL injury risk factors, knee laxity and patient-reported outcomes at 1-year follow-up. Methods: The cohort included isolated primary ACLr patients operated between 2009 and 2014. Patients were invited to a 1-year visit to clarify their readiness to return to sport. A test battery was performed, including clinical evaluation, patient-reported outcomes and three physical tests, from which the Leg Symmetry Index (LSI) was calculated. Multivariate regression analyses were performed for each of the physical tests, including known risk factors, clinical outcomes and patient-reported outcomes. Laxity <3 mm, pivot shift = 0, Knee Injury and Osteoarthritis Outcome Score (KOOS) sport >75, International Knee Documentation Committee (IKDC) >75.9, and Single Assessment Numeric Evaluation (SANE) >92.7 were applied as cut-off values for good versus poor status. Results: A total of 480 ACLr patients were included in the study. Laxity <3 mm had a negative impact on the single-hop LSI, whereas a pivot shift = 0 or IKDC >75.9 had a positive impact on the single-hop LSI. Age <20, a pivot shift grade of 0 and KOOSsport >75 were positively associated with the triple-hop LSI. Finally, age <20 and IKDC >75.9 were positively associated with the leg extension strength LSI. Conclusions: Age, sagittal laxity, pivot shift and patient-reported outcomes were associated with physical test performance 1 year after ACLr. However, the associations were not completely uniform and strong, so information on age, sagittal laxity, pivot shift and patient-reported outcomes cannot replace a return-to-sport functional test battery in determining when it is safe to return to sport after ACLr. Level of Evidence: Level III.