J Orthop Surg Res. 2025 Jul 12;20(1):644. doi: 10.1186/s13018-025-06054-x.ABSTRACTBACKGROUND: Early physical therapy (PT) following ACL reconstruction is widely advocated for optimizing post-operative recovery. However, its impact on functional recovery, proprioception, return-to-sport (RTS) rates, and graft integrity remains debated. This study aims to evaluate whether early PT initiation enhances functional and proprioceptive outcomes without compromising knee stability.OBJECTIVES: To compare the effects of early (≤ 2 weeks) vs. delayed (≥ 4 weeks) PT initiation on functional recovery, proprioception, RTS success, and graft integrity following ACL reconstruction.METHODS: A cross-sectional study included 132 participants (n = 66 per group) who were evaluated using standardized assessments, including IKDC scores, quadriceps strength (hand-held dynamometer), knee range of motion (digital inclinometer), proprioception (joint position sense error, Y-Balance Test, and postural stability via force platform), RTS success, and graft integrity (Lachman and Pivot-Shift tests). All outcome measures were assessed between 6 and 12 months post-operatively during routine clinical follow-up, providing a standardized timeframe for evaluating recovery and RTS readiness.RESULTS: The early PT group demonstrated significantly higher IKDC scores (85.60 ± 6.80 vs. 80.40 ± 7.30, p < 0.001), greater quadriceps strength (2.30 ± 0.40 vs. 2.00 ± 0.50 Nm/kg, p = 0.001), and improved knee ROM (135.20 ± 4.80° vs. 130.80 ± 5.20°, p < 0.001). The proprioceptive function was superior in early PT, with lower JPS error (p < 0.001), higher Y-Balance scores (p = 0.001), and greater postural stability (p < 0.001). RTS rates were higher in the early PT group (78.79% vs. 65.15%), but the difference was not statistically significant (p = 0.121). No significant differences were observed in graft integrity (p = 0.715) or knee stability tests (p > 0.05).CONCLUSION: Early PT initiation significantly enhances functional recovery and proprioception without increasing the risk of graft failure or knee instability. These findings support the safety and efficacy of early rehabilitation in optimizing post-operative ACL recovery and RTS readiness.PMID:40652287 | DOI:10.1186/s13018-025-06054-x