Foucher Kharma C, Cinnamon Christopher C, Ryan Colleen A, Chmell Samuel J, Dapiton Kris
Department of Kinesiology and Nutrition, University of Illinois at Chicago, 1919 W. Taylor St., 650 AHSB, Chicago, 60612, Illinois.
Department of Orthopedics, University of Illinois at Chicago, 835 South Wood Street, Room E270, Chicago, 60612, Illinois.
J Orthop Res. 2018 May;36(5):1519-1525. doi: 10.1002/jor.23783. Epub 2017 Nov 28.
Despite improvements in pain and function, people who undergo total hip arthroplasty (THR) may not always return to desired levels of physical activity (PA). The factors associated with low activity levels are not fully understood. Abductor weakness and fatigue have both been proposed as factors that limit activity in older adults or people with hip osteoarthritis, but have not been investigated after THR. We hypothesized that abductor weakness and fatigue are associated with lower activity levels in people who have undergone a THR and that fatigue mediates the association between abductor strength and activity. We evaluated 16 subjects (24 ± 10 months post-THR; age 56.8 ± 8.4 yrs; BMI 31 ± 7 kg/m ). Fatigue was assessed using the PROMIS fatigue short-form 7a. Peak isometric hip abductor torque was assessed using a dynamometer with subjects in a sidelying position. We assessed activity level using the UCLA activity score. We used Pearson correlations to explore the associations among the variables. Next we used a three-step linear regression procedure to test whether or not fatigue acted as a mediator between abductor torque and UCLA activity scores. Higher abductor torque was associated with less fatigue (R = 0.275; p = 0.037) and with higher UCLA scores (R = 0.488, p = 0.003). Higher fatigue was associated with lower UCLA scores (R = 0. 307, p = 0.017), however there was no evidence of mediation. This suggests that addressing both abductor strength and fatigue may increase physical activity. Statement of Clinical Significance: Fatigue and abductor weakness should be evaluated in sedentary THR patients presenting for long-term follow-up. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1519-1525, 2018.
尽管疼痛和功能有所改善，但接受全髋关节置换术（THR）的患者可能并不总能恢复到期望的身体活动（PA）水平。与低活动水平相关的因素尚未完全明确。外展肌无力和疲劳都被认为是限制老年人或髋骨关节炎患者活动的因素，但在全髋关节置换术后尚未进行过研究。我们假设外展肌无力和疲劳与全髋关节置换术后患者的低活动水平有关，且疲劳介导了外展肌力量与活动之间的关联。我们评估了16名受试者（全髋关节置换术后24±10个月；年龄56.8±8.4岁；体重指数31±7kg/m²）。使用PROMIS疲劳简表7a评估疲劳情况。使用测力计在受试者侧卧位时评估髋外展肌等长峰值扭矩。我们使用加州大学洛杉矶分校（UCLA）活动评分评估活动水平。我们使用Pearson相关性分析来探讨变量之间的关联。接下来，我们使用三步线性回归程序来测试疲劳是否在外展肌扭矩和UCLA活动评分之间起中介作用。较高的外展肌扭矩与较少的疲劳相关（R² = 0.275；p = 0.037），且与较高的UCLA评分相关（R² = 0.488，p = 0.003）。较高的疲劳与较低的UCLA评分相关（R² = 0.307，p = 0.017），然而没有中介作用的证据。这表明解决外展肌力量和疲劳问题可能会增加身体活动。临床意义声明：对于前来进行长期随访的久坐不动的全髋关节置换术患者，应评估其疲劳和外展肌无力情况。©2017骨科学研究协会。由威利期刊公司出版。《矫形外科学研究杂志》36:1519 - 1525，2018年。
