Effect of leg dominance on early functional outcomes and return to sports after anterior cruciate ligament reconstruction

Abstract

Introduction: The effect of leg dominance on anterior cruciate ligament (ACL) injuries has been studied with some studies noting a propensity for injuries in the non-dominant leg. Its effect on post-ACL reconstruction recovery, however, is not well known. The authors hypothesize that dominant limb injuries undergo rehabilitation faster and positively affect early functional outcome scores and return to sports and set about studying these effects. Methods: This is a retrospective study of 254 patients from a single institution who underwent ACL reconstruction for acute ACL ruptures and the results were compared between patients with dominant and non-dominant limb injuries. Objective measurements including the KT-1000, single-leg hop distance and Biodex knee extension peak torque were used to evaluate recovery. Pre- and post-operative functional outcome scores such as the International Knee Documentation Committee (IKDC), Tegner activity score and Lysholm knee scale were documented. Results: Early functional outcomes were similar. Minimal clinically important difference (MCID) improvement in IKDC scores was achieved in 69.7% of the dominant versus 66.0% of the non-dominant injury group ( p = 0.99), 75.2% versus 79.6% ( p = 0.45) for the Lysholm knee scale, and 81.6% versus 84.9% ( p = 0.50) for the Tegner activity score. The majority of patients in both subgroups had a return of at least 80% of peak knee flexion and extension peak torque at 5.4 months post-operatively; 92.9% of subjects with a non-dominant leg injury and 87.2% with a dominant leg injury had returned to their pre-injury sports 1 year from surgery. Conclusions: Results from this study suggest that despite theoretical differences, leg dominance does not have a significant impact on short-term functional outcomes and return to sports. Objective measurements suggest that limb strength recovers at a comparable rate. Injuries to either leg demonstrate equally positive improvement post-ACL reconstruction given the same post-operative rehabilitation. Level of Evidence: III, retrospective comparative study. Level of Evidence: III, retrospective cohort study.