Biomechanical Mechanisms of Early Gait Training on Knee Cartilage Degeneration After Anterior Cruciate Ligament Reconstruction：a protocol for RCT

Objective The primary objective of this study is to investigate the effects and biomechanical mechanisms of early gait retraining (GRT) on knee cartilage degeneration following anterior cruciate ligament reconstruction (ACLR). Methods This study is a single-blind randomized controlled trial involving two independent groups. A total of 60 participants scheduled for their first unilateral ACLR surgery will be recruited. Participants will be randomly assigned to either the experimental group (receiving conventional training plus gait training) or the control group (receiving conventional training only). Gait training will commence in the third postoperative week and continue for 6 weeks, with sessions conducted 2–3 times per week, each lasting 15–20 minutes. Data will be collected at baseline, 3 months, 6 months, 1 year, and 2 years postoperatively. Outcome measures include gait analysis, surface electromyography, isokinetic muscle strength testing, functional MRI, Y-balance testing, single-leg hop testing, IKDC subjective knee evaluation score, Lysholm knee score, and Tegner activity level score. Repeated measures multivariate analysis of variance (MANOVA) will be used to assess the treatment effects on outcome measures. Conclusion Early gait correction training using a body weight support treadmill after ACLR may significantly improve postoperative gait biomechanics. Furthermore, early gait correction can optimize standard rehabilitation protocols, thereby preventing and delaying cartilage degeneration. This approach holds clinical significance for restoring normal gait and preventing secondary injuries in individuals with sports-related injuries. Trial registration All procedures and interventions will comply with the 1964 Declaration of Helsinki and its subsequent amendments or equivalent ethical standards, as well as the ethical standards of the institutional review board. Ethical approval was obtained from the Peking Universiy Third Hospital Medical Science Research Ethics Committee (Approval No. M2023816) before the study commenced. Additionally, the study was registered on ClinicalTrials.gov (ID NCT06368544).