Abstract
Predicting successful return to play (RTP) during mid-stage rehabilitation after anterior cruciate ligament reconstruction (ACLR) remains a critical, unresolved clinical challenge. High-sports demanders (HSDs)-non-professional athletes participating in level-1 sports (cutting, pivoting, jumping) ≥ 3 times/week with Tegner score > 5-represent a distinct subgroup who face unique rehabilitation challenges yet lack evidence-based mid-stage prediction tools. The primary objective of this study was to identify multidimensional predictors at 24 weeks post-ACLR for successful RTP at 48 weeks, and to construct a clinical scoring tool to guide individualized intervention decisions during mid-stage rehabilitation. This single-blind randomized controlled trial was conducted at the First Affiliated Hospital of Xi'an Medical University, Xi'an, China (April 2024-May 2025). Sixty-four HSDs post-primary ACLR were randomized to a functional rehabilitation model (FRM; n = 32) or traditional rehabilitation model (TRM; n = 32). At 24 weeks, isokinetic strength, hop tests, mSEBT, proprioception, and patient-reported outcomes (IKDC, Lysholm, ACL-RSI) were assessed. Forward stepwise logistic regression with bootstrap internal validation (1,000 iterations) identified independent predictors of 48-week RTP success. Among 57 completers (89.1% follow-up), the overall RTP rate was 75.4%. FRM significantly outperformed TRM (89.3% vs. 62.1%; P = 0.038; NNT = 3.7). Six independent predictors were identified: FRM vs. TRM (OR = 3.49), 60°/s extensor LSI ≥ 77.8% (OR = 2.13), single-leg hop ≥ 68.5 cm (OR = 1.87), ACL-RSI ≥ 67.5 (OR = 1.69), mSEBT anterior ≥ 63.2 cm (OR = 1.39), and 45° proprioceptive error ≤ 6.1° (OR = 0.62). Apparent AUC = 0.87 (95% CI: 0.79-0.95); bootstrap-corrected AUC = 0.81 (95% CI: 0.72-0.90). This exploratory six-factor model demonstrates promising discriminative ability (apparent AUC = 0.87; bootstrap-corrected AUC = 0.81) for mid-rehabilitation RTP prediction in HSDs. The identified predictive associations, rather than established causal relationships, may facilitate early risk identification and individualized intervention planning. External validation in independent, multicenter cohorts is required before clinical implementation.