Does preoperative prehabilitation improve lower limb motor function in patients with anterior cruciate ligament rupture? A protocol for a randomised controlled trial.

introductionPostoperative rehabilitation after anterior cruciate ligament reconstruction (ACLR) is crucial for functional recovery. Prehabilitation, performed before surgery, is considered to optimise the patient's condition and improve postoperative outcomes. However, the evidence supporting the effectiveness of standardised prehabilitation protocols remains insufficient, particularly in comparison to conventional home rehabilitation programmes. This study aims to evaluate the impact of a 2-week standardised preoperative prehabilitation programme versus home rehabilitation training on perioperative functional outcomes and medium-term to long-term recovery in ACLR patients through a randomised controlled trial, providing evidence-based guidance for optimising rehabilitation pathways. METHODS AND ANALYSIS: This study is a single-centre, prospective, assessor-blinded, randomised controlled trial. Eligible participants will be randomly assigned in a 1:1 ratio to the experimental group (receiving 2 weeks of standardised preoperative rehabilitation) or the control group (receiving 2 weeks of home-based rehabilitation training). Both groups will undergo 12 weeks of standardised rehabilitation postoperatively. The outcome measures include International Knee Documentation Committee Score (IKDC), Knee Injury and Osteoarthritis Outcome Score, Visual Analogue Scale, muscle strength, joint range of motion, anterior cruciate ligament-Return to Sport after Injury Index and Tegner score. The assessment time points are as follows: baseline (T0), 1-3 days preoperatively (T1), postoperative day 1 (T2), 30 days (T3), 90 days (T4), 180 days (T5) and 360 days (T6). All assessments will be performed at fixed time intervals within the same department of rehabilitation medicine, with the testing order randomised. The primary outcome (IKDC) will be analysed using a linear mixed model (LMM), including time, group and their interaction as fixed effects, with individuals as random effects. Secondary outcomes will be analysed using LMM, repeated measures analysis of variance or χ² tests. Missing data will be handled using the multiple imputation method, under the assumption that data are missing completely at random and effect sizes will be evaluated using Cohen's d (α=0.05). ETHICS AND DISSEMINATION: This study has received approval from the Ethics Committee of the Second Affiliated Hospital of Xi'an Jiaotong University (Number: 2025012). All participants will provide written informed consent after reviewing documentation containing comprehensive details regarding the study procedures, risks and benefits, enabling informed decision-making about participation. The findings generated from this research will be disseminated via publication in an open-access, peer-reviewed journal and presented at relevant scientific conferences. TRIAL REGISTRATION NUMBER: ChiCTR2500097293.