Exercise-based rehabilitation for ACL injuries: a systematic review and meta-analysis

Background: Despite the lack of clear benefit of surgery for Anterior Cruciate Ligament (ACL) injury and the uncertain cost-effectiveness, the rates of surgery are increasing. Therefore, a better insight in the benefits of exercise is needed. Objective: Evaluate the effectiveness of exercises in people with an ACL injury. Design: Systematic review and meta-analysis. Methods: We searched 5 databases for randomized trials investigating exercise interventions for the management of ACL injuries. We assessed the methodological quality and completeness of exercise reporting and performed a meta-analysis using a random-effects model. The certainty of evidence was assessed using GRADE. Results: We included 18 trials (n = 1433); four compared exercises with no treatment, eight compared various exercises, and six trials compared exercise to surgery. Single studies showed (very uncertain) benefit of Tai Chi and Pilates on pain or recovery compared to no treatment; the pooled evidence showed no differences on function (MD = −2.2; 95 %CI -6.5 to 2.1). Pooled evidence shows no differences (moderate certainty) between various exercises in function (SMD = −0.07; 95 %CI -0.4 to 0.3). Only one single study showed benefit of additional perturbation training on recovery (very uncertain). We found moderate certainty for no differences between exercise and surgery on pain (MD = −3.5; 95 %CI -7.9 to 1.0), and for a small benefit of surgery on function (MD = −4.3; 95 %CI: −6.7 to −1.8). Conclusion: We found very uncertain benefit of exercise over no treatment, but no exercise was likely more beneficial than another. Compared to exercise, surgery shows no benefit on pain, but a small improvement in function.