Functional Asymmetries After 6 Months of ACL Reconstruction: A Cross-Sectional Study

Functional tests commonly assess athletes' readiness to return to sports after knee surgery. Despite this, there are still more studies on clinical and patient-reported outcomes. The purpose of this study was to determine differences and combinations of various functional performances within and between athletes 6 months after anterior cruciate ligament (ACL)-reconstruction (ACLR) for the first time (ACLR-I group) versus second ACL injury on the same knee (ACLR-II group) versus ACLR procedures on both legs (ACLR-III group). A total of 88 patients with ACLR performed single-leg hop (maximum forward distance hop, SLH; side hop > 40 cm in 30 s, SH), Functional Movement Screen (FMS) and dynamic postural balance (Y Balance Test - YBT). Data were recorded during return-to-sport testing (6 months post-surgery). For each variable, a mixed-model analysis of variance, with a between-subjects factor of group (primary ACL injury, recurrent ACL injury and bilateral ACL injury) and a within-subjects factor of limb (involved, uninvolved), were conducted. Differences between the groups were found in different degrees of inter-limb asymmetry in the single-leg hop (p < 0.001) and side hop test (p < 0.02). There was a main effect of limb for the anterior and posteromedial YBT distances, and the single-leg hop and side hop test distances (p ≤ 0.04). For each variable, performance was worse for the involved limb compared to the uninvolved limb. Individuals after recurrent ACLR showed greater functional asymmetries at 6 months of treatment. Jumping tests detected greater performance deficits compared to YBT and FMS.