Muscle fatigue in arthritis total hip replacement

背景：在美国，每年有超过124,000例全髋关节置换术（THR）手术，以增加髋关节关节炎、恶化或受伤患者的活动能力和舒适度。THR最常见的术前诊断是骨关节炎。正如美国国立卫生研究院全髋关节置换术共识会议所指出的，关于康复方法产生最佳长期结果的问题仍然存在。以前没有关于肌肉疲劳对THR患者影响的研究。肌肉疲劳和耐力可显著影响该患者的活动功能和继发性损伤的风险。目的/假设：本研究旨在评估接受全髋关节置换术（THR）的关节炎患者的肌肉疲劳，作为评估康复状况的一种手段。我们研究的主要假设是，THR患者表现出更高的疲劳率和水平，这使得他们有更高的跌倒、关节脱臼和其他损伤的风险。如果这一假设被证明是决定性的，康复评价和训练战略应扩大到解决耐力问题。方法。肌电图测量和关节动力学分析相结合将用于评估THR患者对轻度肌肉疲劳的反应。测试条件将包括测功机次极大（80% MVC）等距和等速练习。将患者组手术髋关节的反应与未手术髋关节以及对照组进行比较。THR受试者将在术后4 - 5个月进行评估。身体和社会功能的自我评估也将使用MOSS-SF 36、HAQ和MAQ进行评估。初步结果/发现：我们的初步数据来自一项试点研究（10例病例和10例对照），该研究由西方国家基金会资助。关节炎基金会的章节指出，在肌肉疲劳/耐力和自我评估的身体和社会功能方面，病例和对照组之间存在差异。在所有的生物力学测量中，THR病例的表现或结果都较低。在与髋屈曲、伸展和外展相关的等速运动表现方面，病例和对照组之间存在统计学上的显著差异。通过中位低频移测量，病例与对照组在80% MVC运动相关的肌肉疲劳水平上也有显著差异。我们进一步观察到手术髋关节的等速运动性能低于未手术髋关节。手术和未手术的髋关节屈曲等速运动表现有显著差异。使用MOSS-SF36测量的THR病例的自我评估也一致低于对照组。

Background: More than 124,000 total hip replacement (THR) surgeries are performed annually in the US in an effort to increase mobility and comfort in those having arthritic, deteriorated or injured hips. The most common preoperative diagnosis for THR is osteoarthritis. As indicated in the NIH Total Hip Replacement Consensus Conference, questions remain concerning rehabilitation approaches which yield the best long-term outcomes. No previous investigations regarding the influence of muscle fatigue in THR patients have been identified. Muscle fatigue and endurance can significantly affect mobility1 function and the risk of secondary injury in this patient population. Aim/Hypothesis: This study seeks to evaluate muscle fatigue in arthritis patients who have undergone total hip replacement (THR) surgery as a means to assess rehabilitation status. The primary hypothesis of our study is that THR patients exhibit increased rates and levels of fatigue placing this population at higher risk for falls, joint dislocations and other injuries. Should this hypothesis prove conclusive, rehabilitation evaluation and training strategies should be expanded to address endurance. Methods. A combination of EMG measures and joint kinetic analysis will be utilized to assess THR patient response to mild muscle fatigue. Test conditions will include dynamometer submaximal (80% MVC) isometric and isokinetic exercises. Response of the patient group's operated hip will be compared to the unoperated hip, as well as to a control group. THR subjects will be assessed postoperatively between 4 and 5 months. Self-assessment of physical and social function will also be evaluated using the MOSS-SF 36, HAQ and MAQ. Preliminary Results/Findings: Our preliminary data from a pilot study (10 cases and 10 controls) funded by the Western Pa. Chapter of the Arthritis Foundation indicates that differences exist between cases and controls in muscle fatigue/endurance and self-assessed physical and social function. Across all biomechanical measures THR cases have lower performance or outcome. Statistically significant differences were found between cases and controls in isokinetic performance associated with hip flexion, extension and abduction. Cases also differed significantly from controls in the level of muscle fatigue associated with 80% MVC exercises as measured by median bower frequency shift. We further observed lower isokinetic performance in case operated hips than unoperated hips. Significant differences were found between operated and unoperated isokinetic performance in hip flexion. Self-assessment of THR cases as measured using the MOSS-SF36 was also consistent lower than that of control subjects.