Saito Shu, Tokuhashi Yasuaki, Ishii Takao, Mori Sei, Hosaka Kunihiro, Ryu Keinosuke, Suzuki Gen
Department of Orthopedic Surgery, Nihon University School of Medicine, Tokyo, Japan.
Orthopedics. 2011 Oct 5;34(10):e688-91. doi: 10.3928/01477447-20110826-26.
This article reports a case of bilateral fatigue fracture of the femoral components in a cruciate-retaining uncemented total knee arthroplasty (TKA). A 75-year-old woman (height, 158 cm; weight, 72 kg; body mass index, 29.2) had undergone one-stage bilateral TKA for osteoarthritis 11 years previously at the author's institution. Surgery was performed using an uncemented Flexible Nichidai Knee. Equal tension of the collateral ligaments and normal mechanical axis were achieved during the primary procedure. The patient was an ardent lover of the game of badminton and had higher activity levels with daily playing. At 8 years postoperatively, she started complaining of mild pain in both knees. The pain gradually increased, and at 11 years postoperatively, she had difficulty walking. Anteroposterior radiographs showed narrowing of the medial joint space, indicating wear of the polyethylene insert. Lateral radiographs showed signs of broken implants in both knees. There were no signs of gross implant loosening or osteolysis. One-stage revision surgery was performed, and the knees were converted to cemented posterior-stabilized TKAs. At revision, the bilateral femoral components were found to be fractured at the junction between the trochlear flange and the medial condyle, anteriorly to the medial peg. The polyethylene insert showed mild wear at the medial middle portion. In the majority of case reports, stress fractures of the femoral component have predominantly affected the medial condyle, following uncemented implantation of fixed-bearing knees. In this case, failure of bone ingrowth in uncemented components, higher body mass index, and a higher athletic activity led to fatigue fracture of the femoral components.
本文报道了一例保留交叉韧带的非骨水泥型全膝关节置换术（TKA）中股骨部件双侧疲劳骨折的病例。一名75岁女性（身高158厘米；体重72千克；体重指数29.2）11年前在作者所在机构因骨关节炎接受了一期双侧TKA手术。手术使用的是非骨水泥型Flexible Nichidai膝关节。初次手术时实现了侧副韧带等张力和正常机械轴。该患者是羽毛球运动的狂热爱好者，日常活动量较大。术后8年，她开始抱怨双膝轻度疼痛。疼痛逐渐加重，术后11年，她行走困难。前后位X线片显示内侧关节间隙变窄，提示聚乙烯内衬磨损。侧位X线片显示双膝有植入物断裂迹象。没有明显的植入物松动或骨溶解迹象。进行了一期翻修手术，双膝转换为骨水泥固定的后稳定型TKA。翻修时发现双侧股骨部件在滑车凸缘与内侧髁之间的连接处、内侧栓钉前方发生骨折。聚乙烯内衬在内侧中部有轻度磨损。在大多数病例报告中，非骨水泥固定膝关节植入后，股骨部件的应力骨折主要影响内侧髁。在本病例中，非骨水泥部件骨长入失败、较高的体重指数和较高的运动活动导致了股骨部件的疲劳骨折。
