人工髋关节置换术后假体周围骨质丢失的分析

Bone loss of periprosthetic after total hip arisplasty (THA).

目的 观察人工髋关节置换术（THA）后随时间推移假体周围骨密度和溶骨的改变情况及THA术后假体松动和骨重建的时间，分析假体周围骨量丢失的原因及相关影响因素。方法 THA术后患者83例，对比观察THA术侧髋关节和健侧髋关节，同时按固定方式分为骨水泥组和非骨水泥组。应用双能X线骨密度仪测量各组THA术后股骨柄假体及髋臼假体周围的骨密度。结果 不论是骨水泥固定还是非骨水泥固定，髋臼周围骨密度在1年以内和7年以后下降明显，4～7年没有明显变化。同时，骨水泥固定方式髋臼周围骨质丢失的情况比非骨水泥组出现的时间早而且范围广。结论 髋臼假体底周的骨质丢失较股骨柄假体更早、更快、更严重，尤其在髋臼的负重区。其改变的时相规律为：THA术后1年之内骨密度下降明显，4～7年内相对稳定，7年后骨丢失呈持续性日趋下降的趋势。采用髋臼假体用非骨水泥、股骨柄假体用骨水泥固定这种混合型固定方式有利于防止髋臼假体底周的骨质丢失。

Objective To evaluate the change of periprosthetic bone mineral density （ BMD ） after total hip arisplasty by Dual Energy X-Ray Absorptiometry; to analyse the time of osteolysis and bone reconstruction and find the irfluenting factors to it. Methods 83 eases with THA were divided into bone cement group and bone uncemented group according to fixed means. The operation side were compared with nonoperation side. Periprosthetic BMD of 11 regions of interests was determined with DEXA operatively in both femor and hip cup and nonoperatively. Results The BMD around hip cup decreased significantly within 1 year and 7 years later in both groups. During 4-7 years after THA ,there was little change of BMD around hip cup. Bone loss around cement hip cup was more early and more widely in both cement group than those in uncement group. Conclusion The BMD around hip cup decreased more early, rapidly and seriously, especially in heavy burdon district. It began to drop in 1 year and get heavier after 7 years. There＇s no obvious change of BMD during 4-7 years. It will be helpful to prevent bone loss of hip cup when hybrid prosthesis consisted of a cemented femoral component and an uncemented acetabular component is used in THA cases.