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

Summary

This study evaluated the advantages of blood flow restriction training in enhancing muscle strength and functional recovery following anterior cruciate ligament reconstruction.

Abstract

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.

Introduction

Anterior cruciate ligament (ACL) injuries are among the most common sports-related knee injuries. Anterior cruciate ligament reconstruction (ACLR) is the primary surgical treatment, but it is frequently associated with postoperative quadriceps atrophy, muscle weakness, and delayed functional recovery¹. Epidemiological data suggest an incidence of approximately 68.6 cases per 100,000 individuals annually, with nearly 75% of patients requiring ACLR in 1 year². Postoperative muscle atrophy and strength deficits prolong recovery time and increase the risk of reinjury. Patients fail to return to sport due to persistent muscle....

Protocol

Ethical approval was granted by the Ethics Committee of Suining County Hospital of Traditional Chinese Medicine (Approval No.20240116001). Written informed consent was obtained from all participants prior to their enrollment in the study. Details of the instruments and software used in this study can be found in the Table of Materials.

Participant demographic and general information

A total of 428 patients who underwent ACLR between December 2021 and December 2024 at Suining County Hospital of Traditional Chinese Medicine, The First Affiliated Hospital of Soochow University, and ....

Results

As determined by the chi-square (χ²) test, the baseline demographic characteristics of the two groups, including sex (p = 0.822), age (p = 0.053), and affected side (p = 0.733), were comparable with no statistically significant differences. At the start of the study (T0), independent t-tests revealed that all functional outcome measures were also similar between the BFRT group and the control group.

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Discussion

The core challenge of postoperative rehabilitation following ACL reconstruction lies not only in graft strength and fixation techniques, but also in muscle atrophy-induced strength loss-particularly quadriceps atrophy-which more directly impacts functional recovery and the timeline for return to sport¹⁹. High-load training is often not feasible early after surgery. BFRT has emerged as a low-load alternative, with its mechanism thought to involve the promotion of hypertrophy through hormonal and me.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Blood Flow Restriction Cuff	Zhengzhou Dongheng New Material Technology Co., Ltd.	T-BFR-0355	Used for proximal thigh occlusion during low-load resistance training
Doppler flow detector	SonoSite Inc., Bothell, WA, USA	HFL38x (REF P07682-30)	Used for vascular assessment and verification of blood flow restriction
IBM SPSS Statistics Software	IBM Corp., USA	Version 26.0	Used for data analysis and statistics