Prediction of 12-Month Clinical Outcomes Postsurgery Based on 3-Month Knee Examination After Primary Anterior Cruciate Ligament Reconstruction

Abstract

Context: Active management of modifiable factors during the early rehabilitation stage can help patients who have undergone anterior cruciate ligament (ACL) reconstruction successfully return to sports. This study aimed to determine predictors for performance on the single-leg hop test and Tegner activity score 12-month post-ACL reconstruction, based on knee function assessed 3-month postsurgery.

Design: Prospective cohort study.

Methods: Ninety-one patients who underwent ACL reconstruction were recruited. Multivariate logistic regression analysis was performed to identify predictors of the one hop test and Tegner activity score 12-month postsurgery, based on a knee examination performed 3 months after ACL reconstruction. Factors evaluated at 3 months included the Biodex balance system anteroposterior and mediolateral indexes; Y balance test anterior, posteromedial, and posterolateral reaches; knee extensors and flexors peak torque per body weight; and knee extensors and flexors average power per body weight.

Results: The knee extensor peak torque per body weight (PT/BW) and Biodex balance system-mediolateral index with cutoff values of 132 N·m/kg and 0.45, respectively were identified as predictors for achieving a limb symmetric index within 10% on the hop test. Furthermore, achieving a Tegner activity score over 6 was predicted by Y balance test-posteromedial reach and knee flexors average power per body weight, with cutoff values of 92.5 cm and 122 W/kg, respectively.

Conclusion: Three months following ACL reconstruction, knee extensor peak torque, and mediolateral balance predicted performance on the hop test, while dynamic posteromedial balance and knee flexors average power predicted rotational ability, at the 12-month assessment.

Keywords: balance; functional performance; muscle strength; rehabilitation.