The Effectiveness of Blood Flow Restriction Training on Rehabilitation After Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-Analysis

Background/Objective: Blood flow restriction (BFR) training has emerged as a promising adjunct to rehabilitation following anterior cruciate ligament reconstruction (ACLR), but its effectiveness across postoperative outcomes remains uncertain. To systematically evaluate and quantify the effects of BFR training on rehabilitation outcomes after ACLR. Methods: A systematic review and meta-analysis were conducted according to PRISMA guidelines. Ten electronic databases were searched from inception to December 2025. Eligible studies included randomized and non-randomized clinical trials investigating BFR after ACLR. Risk of bias was assessed using RoB 2 and ROBINS-I. Pooled standardized mean differences (SMDs) with 95% confidence intervals (CIs) were calculated using random-effects models, and certainty of evidence was evaluated using GRADE. Results: Seventeen studies involving 643 participants were included, of which 12 contributed to the meta-analysis. Most studies combined low-load resistance training with BFR at 40–80% limb occlusion pressure (LOP), initiated within 0–12 weeks after surgery and continued for 2–16 weeks. Compared with conventional rehabilitation, BFR significantly improved quadriceps strength (n = 9; SMD = 0.77, 95% CI 0.42–1.13; p < 0.0001; moderate-certainty evidence) and functional recovery (n = 6; SMD = 1.47, 95% CI 0.08–2.87; p = 0.04; I2 = 91%; low-certainty evidence). Larger effects were observed at occlusion pressures >80% LOP. No serious BFR-related adverse events were reported. No significant effects were found for balance (n = 5; SMD = 0.22, 95% CI −0.96 to 1.40; p = 0.72) or pain (n = 5; SMD = 0.82, 95% CI −0.28 to 1.92; p = 0.14), both supported by very low-certainty evidence. Conclusions: Moderate-certainty evidence supports BFR training for improving quadriceps strength after ACLR. Evidence for functional recovery is limited by substantial heterogeneity, while effects on pain, postural balance, and muscle morphology remain inconclusive. Findings regarding optimal occlusion pressure should be considered exploratory pending confirmation in future trials.