Time to normalization of gait following ACL reconstruction compared with healthy controls: A systematic review and meta-analysis.

Abstract

Background: Gait abnormalities often persist after anterior cruciate ligament reconstruction (ACLR) and may increase the risk of reinjury and joint degeneration. This review aimed to assess differences in key gait parameters between ACLR patients and healthy controls, and to estimate when these parameters normalize postoperatively.

Methods: Studies comparing individuals ≥ 3 months post-ACLR with healthy controls were included. A systematic search across five databases yielded 5251 records, with 20 studies (n = 976) retained. A longitudinal multilevel meta-analysis was performed, with pooled effect sizes calculated using Cohen's d, representing the standardized mean difference. Postoperative time was modeled as a moderator in meta-regression analyses.

Results: Compared to healthy controls, ACLR patients assessed at 3-107 months postoperatively exhibited significantly lower peak knee flexion angle (d = -0.48, 95 % CI: -0.87 to -0.10) and peak knee flexion moment (d = -1.06, 95 % CI: -2.06 to -0.07), while walking speed was non-significant (d = -0.17, 95 % CI: -0.47-0.13). Logarithmic modeling indicated that group differences became non-significant at 16.2 months for flexion angle and 10.1 months for flexion moment. Walking speed was statistically non-significant at any timepoint.

Significance: At ≥ 3 months post-ACLR, patients exhibited significantly reduced peak knee flexion angle and flexion moment compared to controls. These deficits normalized at approximately 16.2 and 10.1 months, respectively. Walking speed did not significantly differ at any postoperative timepoint. These findings suggest that early-phase rehabilitation should emphasize quadriceps strengthening and knee flexion restoration within the first 10-16 months to address persistent biomechanical deficits.