Arvidsson I, Arvidsson H, Eriksson E, Jansson E
Orthopedics. 1986 Nov;9(11):1519-28. doi: 10.3928/0147-7447-19861101-08.
Eighteen male and 20 female patients who underwent reconstruction of their anterior cruciate ligament (ACL) with a flap from the patellar tendon were randomly assigned into either closed cast, isometric muscle training and electric stimulation (ES group), or closed cast and isometric training alone (control group). The degree of quadriceps wasting was determined from computerized tomographic scans (CT) before and 6 weeks after surgery. Electrical stimulation was given with a battery operated stimulator that produced a rectangular asymmetric balanced biphasic pulse shape. The pulse rate was 40 Hz and the pulse width 300 microseconds. Patients received 30 min of stimulation three times daily during 5.5 weeks. Female control patients showed a larger decrease in quadriceps area on CT than male control patients (P less than .001). No significant difference was found between male electrically stimulated patients and control patients. In female patients, there was on the contrary, a highly significant difference in favor of electrical stimulation (P less than .001) When the different parts of the quadriceps were studied, a significantly lower degree of atrophy of the vastus medialis was found after electrical stimulation. Vastus lateralis did not show any difference. Measurements of CT attenuation, pre- and post-operatively, showed a decrease in attenuation of 17% for the vastus medialis and lateralis of the operated leg after immobilization, indicating an increase in fat content. In the rectus femoris, however, there was an increase in attenuation of 14.6%. Percutaneous muscle biopsies from the vastus lateralis obtained before, one week after, and 6 weeks after surgery revealed that the cross-sectional area of the individual muscle fibers decreased less in the electrically stimulated than in controls, but the difference was not significant. There were no differences between the two groups in the activity of an oxidative enzyme, citrate synthase, or a glycolytic enzyme, phosphofructokinase (PFK). We conclude that females reacted more favorably than males to electrical stimulation of quadriceps during an immobilization period after knee surgery.
18名男性和20名女性患者接受了髌腱瓣重建前交叉韧带（ACL）手术，他们被随机分为两组，一组采用闭合石膏固定、等长肌肉训练和电刺激（电刺激组），另一组仅采用闭合石膏固定和等长训练（对照组）。通过计算机断层扫描（CT）在手术前和术后6周测定股四头肌萎缩程度。使用电池驱动的刺激器进行电刺激，该刺激器产生矩形不对称平衡双相脉冲形状。脉冲频率为40Hz，脉冲宽度为300微秒。患者在5.5周内每天接受3次，每次30分钟的刺激。女性对照组患者CT上股四头肌面积的减少幅度大于男性对照组患者（P＜0.001）。男性电刺激患者与对照组患者之间未发现显著差异。相反，在女性患者中，电刺激显示出高度显著的差异（P＜0.001）。当研究股四头肌的不同部位时，发现电刺激后股内侧肌萎缩程度明显较低。股外侧肌未显示出任何差异。术前和术后CT衰减测量显示，固定后手术侧股内侧肌和股外侧肌的衰减降低了17%，表明脂肪含量增加。然而，股直肌的衰减增加了14.6%。在手术前、术后1周和术后6周从股外侧肌获取的经皮肌肉活检显示，电刺激组单个肌纤维的横截面积减少幅度小于对照组，但差异不显著。两组在氧化酶柠檬酸合酶或糖酵解酶磷酸果糖激酶（PFK）的活性方面没有差异。我们得出结论，在膝关节手术后的固定期，女性对股四头肌电刺激的反应比男性更有利。
