<b>Early Weight-Bearing Physiotherapy vs Delayed Weight-Bearing in ACL Reconstruction Rehabilitation</b>

Background: Anterior cruciate ligament (ACL) injury is among the most frequent causes of functional knee instability, particularly in athletes and individuals engaged in pivoting or high-load activities. Surgical reconstruction reliably restores mechanical stability, but postoperative rehabilitation critically determines the quality and speed of functional recovery. The timing of weight-bearing remains a key point of clinical contention: while early weight-bearing (EWB) can stimulate mechanotransduction, maintain muscle strength, and reduce arthrogenic inhibition, delayed weight-bearing (DWB) has historically been used to protect graft integrity during early biological healing. Clarifying the trade-off between these strategies is essential to guide evidence-based rehabilitation and minimize long-term morbidity. Objective: To compare the effects of early versus delayed weight-bearing rehabilitation protocols on pain, range of motion, quadriceps strength, extension deficit, and functional outcomes following ACL reconstruction, and to determine whether criterion-based early loading enhances recovery without increasing short-term complications. Methods: A prospective controlled trial was conducted on 40 patients undergoing ACL reconstruction with autografts. Participants were allocated to either EWB (n=20) or DWB (n=20) rehabilitation. The EWB group initiated partial loading within 7 days and progressed to full weight-bearing as tolerated, whereas the DWB group delayed weight-bearing for ~4 weeks. All patients followed a standardized physiotherapy program including ROM exercises, strengthening, and neuromuscular re-education. Primary outcomes included pain (VAS), ROM (flexion and extension), quadriceps strength, prevalence of extension deficit (≥3°), and Lysholm functional score. Assessments were performed at 6 weeks, 12 weeks, and 6 months. Statistical analysis used independent t-tests and chi-square tests, with baseline- mixed models and Holm-Bonferroni correction to control for multiple comparisons. Results: Baseline characteristics were comparable between groups (mean age ~27 years, BMI ~24 kg/m², baseline VAS ~6.6, flexion ~110°, and strength ~15 kg). EWB produced greater early improvements: VAS pain was significantly lower at 6 weeks (4.2 ± 1.1 vs. 5.1 ± 1.3) and 12 weeks (2.3 ± 0.9 vs. 3.0 ± 1.0). Knee flexion was higher in EWB at both 6 weeks (105° vs. 95°) and 12 weeks (125° vs. 118°). Extension deficits were consistently less frequent (25% vs. 40% at 6 weeks; 10% vs. 20% at 12 weeks). Quadriceps strength showed a notable advantage at 6 months (32.5 ± 5.2 kg vs. 29.1 ± 4.9 kg), and Lysholm scores favored EWB (89.3 ± 6.8 vs. 84.6 ± 7.5). Although effect sizes were moderate to large, none of the differences remained statistically significant after multiplicity correction. Conclusion: Criterion-based early weight-bearing rehabilitation after ACL reconstruction enhances early functional recovery by improving pain, motion, strength, and functional outcomes without increasing short-term complications. While larger randomized trials with structural endpoints are needed, these findings support early, closely monitored loading as a patient-centered strategy to improve mobility, reduce deconditioning, and accelerate return to daily activities and sport.