Chung Kyu Sung, Ha Jeong Ku, Yeom Cheol Hyun, Ra Ho Jong, Lim Jin Woo, Kwon Min Soo, Kim Jin Goo
Department of Orthopedic Surgery, KEPCO Medical Center, Seoul, Korea.
Department of Orthopedic Surgery and Sports Medical Center and Sports Medical Research Institute, Seoul Paik Hospital, College of Medicine, Inje University, Seoul, Korea.
Am J Sports Med. 2015 Dec;43(12):3013-21. doi: 10.1177/0363546515606126. Epub 2015 Oct 12.
After an anterior cruciate ligament (ACL) injury, the uninjured contralateral lower limb may become weakened because of neuromuscular changes, proprioceptive deficits, and disuse of the limb; this weakness predisposes the limb to ACL injury. However, no results have been reported regarding weakness in the contralateral limb after ACL injury.
Muscle strength and functional status of the contralateral lower limb are reduced after unilateral ACL injury.
Cohort study; Level of evidence, 3.
The ACL group consisted of 75 patients who underwent primary unilateral ACL reconstruction and were followed at 3, 6, 12, and 24 months postoperatively. A group of 75 healthy individuals (controls) were matched one-to-one with the ACL group for age, sex, body mass index, and initial Tegner activity level. The side that was evaluated in each control subject corresponded to the injured limb in the matched ACL subject. Isokinetic muscle strength, including extension peak torque per body weight (EPT) and flexion peak torque per body weight (FPT), was evaluated at angular velocities of 60 and 180 deg/s. Patients were also evaluated by single-legged hop test.
Compared with the EPT at 60 deg/s in the control group (290.9 ± 40.1 N · m/kg), the value in the ACL group 24-month follow-up (276.6 ± 42.8 N · m/kg) as well as other follow-up times was significantly lower (P < .05), whereas the EPT at 180 deg/s and the FPT at 60 and 180 deg/s in the ACL group were significantly lower than the control group at 3-month follow-up but were restored to normal levels at final follow-up. Results from the single-legged hop test demonstrated that the ACL group performed at a significantly lower level than the control group at 24-month follow-up (158.4 ± 25.3 vs 176.3 ± 24.7 cm; P < .05) as well as other follow-up times. However, both measurements improved significantly as the follow-up time progressed.
After ACL injury, isokinetic extensor muscle strength and functional status of the contralateral limb were reduced, even at 24 months after ACL reconstruction. However, both measurements improved significantly as the follow-up time progressed. In contrast, flexion muscle strength was restored to normal levels. Therefore, care should be taken to restore muscle strength and functional status in not only the ACL-reconstructed knee but also the uninjured limb.
前交叉韧带（ACL）损伤后，未受伤的对侧下肢可能会因神经肌肉变化、本体感觉缺陷和肢体废用而变弱；这种虚弱会使该肢体更容易发生ACL损伤。然而，关于ACL损伤后对侧肢体虚弱的情况尚无报道。
单侧ACL损伤后对侧下肢的肌肉力量和功能状态会降低。
队列研究；证据等级，3级。
ACL组由75例行初次单侧ACL重建术的患者组成，并在术后3、6、12和24个月进行随访。75名健康个体（对照组）与ACL组在年龄、性别、体重指数和初始Tegner活动水平方面进行一对一匹配。每个对照受试者接受评估的一侧与匹配的ACL受试者的受伤肢体相对应。在60和180度/秒的角速度下评估等速肌肉力量，包括每体重的伸展峰值扭矩（EPT）和每体重的屈曲峰值扭矩（FPT）。患者还通过单腿跳测试进行评估。
与对照组在60度/秒时的EPT（290.9±40.1N·m/kg）相比，ACL组在24个月随访时（276.6±42.8N·m/kg）以及其他随访时间的值均显著降低（P<.05），而ACL组在180度/秒时的EPT以及在60和180度/秒时的FPT在3个月随访时显著低于对照组，但在最终随访时恢复到正常水平。单腿跳测试结果表明，ACL组在24个月随访时（158.4±25.3对176.3±24.7cm；P<.05）以及其他随访时间的表现明显低于对照组。然而，随着随访时间的推移，这两项测量结果均有显著改善。
ACL损伤后，即使在ACL重建术后24个月，对侧肢体的等速伸肌力量和功能状态仍会降低。然而，随着随访时间的推移，这两项测量结果均有显著改善。相比之下，屈肌力量恢复到了正常水平。因此，不仅要注意恢复ACL重建膝关节的肌肉力量和功能状态，还要注意恢复未受伤肢体的肌肉力量和功能状态。
