Lu Hong-Zhang, Zhu Tian-Yue, Chai Wei-Bing
Department of Orthopaedics, Peking University First Hospital, Beijing 100034, China.
Zhonghua Wai Ke Za Zhi. 2008 Jul 1;46(13):966-9.
To investigate the etiologies and prevention of patellar instability after total knee arthroplasty (TKA).
From September 1997 to April 2005, 94 patients (105 knees) underwent TKA without patellar resurfacing. All of them were osteoarthritis. Ten patients (14 knees) were performed with Rotation Knee (RK) prostheses. Forty patients were performed with mobile bearing TACK prostheses, and 44 patients with GEMINI prostheses. Subluxation and tilt of patella were evaluated by X-rays before or after operation.
The incidence of patellar instability after operation was 28.6% in patients who had genu valgus deformity, and was 29.5% in whom had patellar instability preoperative. The incidence of patellar instability in RK, TACK, and GEMINI group was 28.6%, 20.9%, and 16.7% respectively after operations. Four patients had obvious femoral or tibial components malrotation.
The etiologies of patellofemoral instability include pre-operative conditions, prosthetic design, and improper positioning of the prosthetic component. So the suitable component design and skillful operative technique will help the surgeon to avoid this complication.
探讨全膝关节置换术（TKA）后髌骨不稳定的病因及预防措施。
1997年9月至2005年4月，94例患者（105膝）接受了未进行髌骨表面置换的TKA手术。所有患者均为骨关节炎。10例患者（14膝）使用旋转膝（RK）假体进行手术。40例患者使用活动平台TACK假体进行手术，44例患者使用GEMINI假体进行手术。通过术前或术后X线评估髌骨半脱位和倾斜情况。
膝外翻畸形患者术后髌骨不稳定发生率为28.6%，术前有髌骨不稳定的患者术后发生率为29.5%。术后RK、TACK和GEMINI组的髌骨不稳定发生率分别为28.6%、20.9%和16.7%。4例患者存在明显的股骨或胫骨假体部件旋转不良。
髌股关节不稳定的病因包括术前情况、假体设计以及假体部件定位不当。因此，合适的部件设计和熟练的手术技术将有助于外科医生避免这种并发症。
