■臀小肌(GMin)和臀中肌(GMed)是髋部重要的动态稳定剂,但是目前缺乏关于它们在稳定髋关节中的生物力学作用的定量数据。
■要(1)建立髋关节外展肌复合体的可再现的生物力学尸体模型,以及(2)表征加载GMin和GMed对股骨外旋转和牵引的影响。
■对照实验室研究。
■在4种肌肉负荷状态下对总共10个半骨盆进行了测试:(1)无负荷,(2)加载的GMin,(3)装载的GMed,和(4)GMin和GMed加载。通过电缆施加肌肉负荷,滑轮,和附着在肌腱上的重量来复制解剖作用线。试样在内部旋转、外部旋转和0°的轴向牵引力下进行了测试,15°,30°,60°,髋关节弯曲90°。
■当一起加载时,GMin和GMed在除60°外的所有髋关节屈曲角度(P<.05)下减少了内部旋转运动,在除0°外的所有髋关节屈曲角度(P<.05)下减少了外部旋转运动。同样,当GMin和GMed都被装载时,在所有髋部屈曲角度下,股骨牵张减少(P<.05)。
■这项研究的结果表明,GMin和GMed提供了抵抗旋转扭矩和分散力的稳定性,并且贡献量取决于髋关节屈曲的程度。
■提高对GMin和GMed在防止髋关节旋转和分散不稳定中的作用的理解将更好地指导髋关节病变的治疗,并优化非手术和手术治疗。
UNASSIGNED: The gluteus minimus (GMin) and gluteus medius (GMed) are important dynamic stabilizers of the hip, but quantitative data on their biomechanical roles in stabilizing the hip are currently lacking.
UNASSIGNED: To (1) establish a reproducible biomechanical cadaveric model of the hip abductor complex and (2) characterize the effects of loading the GMin and GMed on extraneous femoral rotation and distraction.
UNASSIGNED: Controlled laboratory study.
UNASSIGNED: A total of 10 hemipelvises were tested in 4 muscle loading states: (1) unloaded, (2) the GMin loaded, (3) the GMed loaded, and (4) both the GMin and GMed loaded. Muscle loads were applied via cables, pulleys, and weights attached to the tendons to replicate the anatomic lines of action. Specimens were tested under internal rotation; external rotation; and axial traction forces at 0°, 15°, 30°, 60°, and 90° of hip flexion.
UNASSIGNED: When loaded together, the GMin and GMed reduced internal rotation motion at all hip flexion angles (P < .05) except 60° and reduced external rotation motion at all hip flexion angles (P < .05) except 0°. Likewise, when both the GMin and GMed were loaded, femoral distraction was decreased at all angles of hip flexion (P < .05).
UNASSIGNED: The results of this study demonstrated that the GMin and GMed provide stability against rotational torques and distractive forces and that the amount of contribution depends on the degree of hip flexion.
UNASSIGNED: Improved understanding of the roles of the GMin and GMed in preventing rotational and distractive instability of the hip will better guide treatment of hip pathologies and optimize nonoperative and operative therapies.