Chen Pei-Yu, Wu Chen-Tu, Hou Chun-Han, Hou Sheng-Mou
Department of Orthopedic Surgery, National Taiwan University Hospital, Taipei, Taiwan.
J Formos Med Assoc. 2005 May;104(5):370-3.
In total hip arthroplasty, a modular femoral head with a flange increases the head-neck strength and compensates the leg length, but results in a decreased head-to-neck diameter ratio. Studies have shown increased chance of impingement and incidence of dislocation associated with a skirted femoral head component. However, the relation between implant loosening and the skirted neck has not been well demonstrated. We report a 41-year-old male patient with aseptic loosening of total hip arthroplasty due to osteolysis of both acetabular and femoral components 5 years after surgery. The retrieved prostheses demonstrated polyethylene wear due to impingement of the skirted head during hip flexion. Pathologic examination showed prominent foreign body reaction. Prosthetic impingement occurs due to malposition of components and extreme posture. A decreased head-to-neck diameter ratio further compromises prosthetic range of motion. A skirted femoral head component should be used with caution.
在全髋关节置换术中，带凸缘的模块化股骨头可增加头颈强度并补偿肢体长度，但会导致头颈直径比降低。研究表明，带裙边的股骨头组件会增加撞击的几率和脱位的发生率。然而，植入物松动与带裙边颈部之间的关系尚未得到充分证实。我们报告了一名41岁男性患者，术后5年因髋臼和股骨组件的骨溶解导致全髋关节置换术无菌性松动。取出的假体显示，由于髋关节屈曲时裙边头部的撞击，聚乙烯发生磨损。病理检查显示有明显的异物反应。假体撞击是由于组件位置不当和极端姿势引起的。头颈直径比降低会进一步损害假体的活动范围。带裙边的股骨头组件应谨慎使用。
