Multicenter Retrospective Study of Blood Flow Restriction Training After Anterior Cruciate Ligament Reconstruction

Quadriceps weakness and delayed functional recovery are common following anterior cruciate ligament reconstruction (ACLR). Conventional rehabilitation protocols often fail to deliver adequate muscle loading in the early postoperative stage. Blood flow restriction training (BFRT), which combines low-load resistance with vascular occlusion, has the potential to enhance muscle hypertrophy and function early postoperatively. This study aimed to evaluate whether BFRT offers superior outcomes compared to standard rehabilitation in early ACLR recovery. This multicenter retrospective cohort study included 428 ACLR patients treated between December 2021 and December 2024 across three hospitals. To minimize selection bias and achieve balanced and comparable baseline characteristics, 1:1 propensity score matching (PSM) was performed using a caliper width of 0.02. After screening and propensity score matching, 316 patients (158 per group) were included in the final analysis. Functional outcomes, including 30 s sit-to-stand repetitions, 1 min single-leg heel raises, 6 min walk distance (6MWD), and the International Knee Documentation Committee (IKDC) scores, were evaluated at 0 week, 4 weeks, 8 weeks, and 12 weeks postoperatively. Significant time, group, and interaction effects were observed across all measures (p < 0.05). At all postoperative follow-up assessments (4 weeks, 8 weeks, and 12 weeks), the BFRT group demonstrated statistically superior outcomes compared to the control group across all functional measures, including 30 s sit-to-stand repetitions, 1 min single-leg heel raises, 6MWD, and IKDC scores (p< 0.05 for all comparisons). Conclusively, BFRT accelerates early functional recovery following ACLR. Given its safety and feasibility, it may be recommended as an adjunct to standard rehabilitation protocols in clinical practice.