Orthopedic Biomechanics Research Laboratory, Department of Orthopedics and Sports Medicine, Houston Methodist Hospital, Houston, Texas.
Sports Health. 2023 May;15(3):361-371. doi: 10.1177/19417381221101006. Epub 2022 Jun 27.
Muscle atrophy is common after an injury to the knee and anterior cruciate ligament reconstruction (ACLR). Blood flow restriction therapy (BFR) combined with low-load resistance exercise may help mitigate muscle loss and improve the overall condition of the lower extremity (LE).
To determine whether BFR decreases the loss of LE lean mass (LM), bone mass, and bone mineral density (BMD) while improving function compared with standard rehabilitation after ACLR.
Randomized controlled clinical trial.
A total of 32 patients undergoing ACLR with bone-patellar tendon-bone autograft were randomized into 2 groups (CONTROL: N = 15 [male = 7, female = 8; age = 24.1 ± 7.2 years; body mass index [BMI] = 26.9 ± 5.3 kg/m2] and BFR: N = 17 [male = 12, female = 5; age = 28.1 ± 7.4 years; BMI = 25.2 ± 2.8 kg/m2]) and performed 12 weeks of postsurgery rehabilitation with an average follow-up of 2.3 ± 1.0 years. Both groups performed the same rehabilitation protocol. During select exercises, the BFR group exercised under 80% arterial occlusion of the postoperative limb (Delfi tourniquet system). BMD, bone mass, and LM were measured using DEXA (iDXA, GE) at presurgery, week 6, and week 12 of rehabilitation. Functional measures were recorded at week 8 and week 12. Return to sport (RTS) was defined as the timepoint at which ACLR-specific objective functional testing was passed at physical therapy. A group-by-time analysis of covariance followed by a Tukey's post hoc test were used to detect within- and between-group changes. Type I error; α = 0.05.
Compared with presurgery, only the CONTROL group experienced decreases in LE-LM at week 6 (-0.61 ± 0.19 kg, -6.64 ± 1.86%; < 0.01) and week 12 (-0.39 ± 0.15 kg, -4.67 ± 1.58%; = 0.01) of rehabilitation. LE bone mass was decreased only in the CONTROL group at week 6 (-12.87 ± 3.02 g, -2.11 ± 0.47%; < 0.01) and week 12 (-16.95 ± 4.32 g,-2.58 ± 0.64%; < 0.01). Overall, loss of site-specific BMD was greater in the CONTROL group ( < 0.05). Only the CONTROL group experienced reductions in proximal tibia (-8.00 ± 1.10%; < 0.01) and proximal fibula (-15.0±2.50%, < 0.01) at week 12 compared with presurgery measures. There were no complications. Functional measures were similar between groups. RTS time was reduced in the BFR group (6.4 ± 0.3 months) compared with the CONTROL group (8.3 ± 0.5 months; = 0.01).
After ACLR, BFR may decrease muscle and bone loss for up to 12 weeks postoperatively and may improve time to RTS with functional outcomes comparable with those of standard rehabilitation.
膝关节损伤和前交叉韧带重建（ACLR）后常发生肌肉萎缩。血流限制疗法（BFR）结合低负荷阻力运动可能有助于减轻肌肉损失，并改善下肢（LE）的整体状况。
与 ACLR 后的标准康复相比，确定 BFR 是否能减少 LE 瘦体重（LM）、骨量和骨矿物质密度（BMD）的丢失，同时改善功能。
随机对照临床试验。
32 名接受骨-髌腱-骨自体移植物 ACLR 的患者被随机分为 2 组（CONTROL：N = 15[男性=7，女性=8；年龄=24.1 ± 7.2 岁；体重指数（BMI）=26.9 ± 5.3 kg/m2]和 BFR：N = 17[男性=12，女性=5；年龄=28.1 ± 7.4 岁；BMI = 25.2 ± 2.8 kg/m2]），并在平均随访 2.3 ± 1.0 年后进行 12 周的术后康复。两组均采用相同的康复方案。在选择的运动中，BFR 组在术后肢体动脉闭塞 80%的情况下进行运动（Delfi 止血带系统）。在术前、康复第 6 周和第 12 周使用 DEXA（iDXA，GE）测量 BMD、骨量和 LM。在第 8 周和第 12 周记录功能测量结果。重返运动（RTS）定义为在物理治疗中通过 ACLR 特定的客观功能测试的时间点。采用组内和组间协方差分析，然后进行 Tukey 事后检验。I 型错误；α=0.05。
与术前相比，只有 CONTROL 组在康复第 6 周（-0.61 ± 0.19 kg，-6.64 ± 1.86%；<0.01）和第 12 周（-0.39 ± 0.15 kg，-4.67 ± 1.58%；=0.01）时出现 LE-LM 减少。仅在 CONTROL 组中，在第 6 周（-12.87 ± 3.02 g，-2.11 ± 0.47%；<0.01）和第 12 周（-16.95 ± 4.32 g，-2.58 ± 0.64%；<0.01）时出现 LE 骨量减少。总体而言，CONTROL 组的特定部位 BMD 丢失更大（<0.05）。与术前测量相比，仅 CONTROL 组在第 12 周时出现胫骨近端（-8.00 ± 1.10%；<0.01）和腓骨近端（-15.0±2.50%；<0.01）减少。无并发症。两组的功能测量结果相似。BFR 组的 RTS 时间（6.4 ± 0.3 个月）较 CONTROL 组（8.3 ± 0.5 个月；=0.01）缩短。
在 ACLR 后，BFR 可能会减少术后长达 12 周的肌肉和骨骼丢失，并可能通过与标准康复相当的功能结果来改善 RTS 时间。
