全膝关节置换术中股骨假体矢状面置入角度与假体中远期磨损的相关性研究

Correlation between angle of femoral prosthesis component in sagittal plane and midand long-term polyethylene liner wearing after total knee arthroplasty

目的探讨初次全膝关节置换术中股骨假体矢状面置入角度与假体中远期磨损的相关性。方法回顾性分析自2004-09-2015-04行初次全膝关节置换术的33例膝关节骨性关节炎,术后患者均因股骨假体组件矢状位放置角度异常导致胫骨平台聚乙烯垫片立柱异常磨损而断裂,具有膝关节翻修手术指证。于标准侧位X线片上测量股骨前方皮质线与股骨假体前髁线之间的夹角β,初次全膝关节置换术与确定需要行翻修术的间隔时间即为假体使用寿命T,对变量β与变量T进行Pearson相关性分析。结果 33例β角为14.1°~29.5°(17.16±4.04)°,T值为36~158(90.64±25.24)个月,Pearson相关性分析结果显示,β角与T值呈负相关(r=-0.851,P <0.001)。结论全膝关节置换术中股骨假体在矢状面的置入角度会影响假体使用时间,矢状面上股骨假体前髁线与股骨干前方皮质夹角越大则假体使用寿命越短。

Objective To investigate the correlation between the implant angle of the femoral component in sagittal plane in primary TKA and mid-and long-term wear of the prosthesis. Methods Thirty-three patients with knee osteoarthritis treated with TKA from September 2004 to April 2015 were retrospectively analyzed. All the patients had revision indication with abnormal wear and fracture of the liner center post fracture due to a bad angle of the femoral component implant. The angle(β) of the femoral component and femoral shaft on the lateral radiograph was measured, and record the life span(T) of the prosthesis, and a Pearson correlation analysis between variable β and T was performed. Results The β was 14.1°-29.5°(17.16 ±4.04)°, T was 36-158(90.64 ±25.24) months, Pearson correlation analysis showed there was a negative correlation between β and T(r =-0.851, P <0.001). Conclusion Abnormal angle of prosthesis implant on sagittal plane may affect the life-span of the prosthesis, the bigger the angle of the femoral component and femoral shaft on the lateral radiograph on lateral radiograph, the shorter the life-span of the prosthesis.