Banka Trevor R, Ast Michael P, Parks Michael L
Orthopedics. 2014 Apr;37(4):e395-7. doi: 10.3928/01477447-20140401-63.
This article presents a case of early intraprosthetic dislocation of a dual-mobility hip prosthesis after revision total hip arthroplasty for instability. A 70-year-old woman was revised to a dual-mobility cup for multiple hip dislocations. She dislocated the dual-mobility construct twice, which was closed reduced. Postreduction radiographs after the second closed reduction showed that the femoral head was eccentrically positioned within the acetabular shell, raising suspicion for intraprosthetic dislocation or disassociation between the femoral head and the mobile polyethylene liner. After closed reduction, the patient reported a mobile, golf ball-size mass deep to the posterior lateral incision and new onset of crepitus. Magnetic resonance imaging verified complete intraprosthetic dissociation between the femoral head and mobile polyethylene liner, which was located between the gluteus medius and minimus. The dual-mobility cup was revised to a constrained socket with retention of the femoral stem. The patient recovered uneventfully without further instability.
本文介绍了一例翻修全髋关节置换术后因不稳定而行双动髋关节假体早期假体内部脱位的病例。一名70岁女性因多次髋关节脱位而翻修为双动髋臼杯。她的双动结构脱位了两次，均通过闭合复位处理。第二次闭合复位后的复位后X线片显示股骨头在髋臼壳内偏心定位，这引发了对假体内部脱位或股骨头与活动聚乙烯内衬之间分离的怀疑。闭合复位后，患者报告在外侧后切口深处有一个可活动的、高尔夫球大小的肿块，并出现了新的摩擦音。磁共振成像证实股骨头与活动聚乙烯内衬之间完全发生了假体内部分离，分离处位于臀中肌和臀小肌之间。双动髋臼杯翻修为限制性髋臼，保留了股骨干。患者恢复顺利，未再出现不稳定情况。
