保留髋臼杯更换聚乙烯衬垫在全髋关节翻修术中的应用

Liner exchange into a well-fixed acetabular shell in revision total hip arthroplasty

目的探讨保留髋臼杯更换聚乙烯衬垫在全髋关节翻修术中的作用。方法1995年4月至2007年12月，80例（93髋）接受保留髋臼杯更换聚乙烯衬垫手术。男41例，女39例；年龄27～82岁，平均53-3岁。初次置换与更换衬垫手术间隔0．3～18．4年，平均10．9年。翻修原因：聚乙烯磨损及骨溶解78髋，聚乙烯接近完全磨损但无骨溶解5髋，聚乙烯磨损及股骨柄假体松动4髋，复发性关节脱位3髋，感染1髋，假体周围骨折1髋，衬垫脱位1髋。翻修衬垫采用高交联聚乙烯60髋、普通聚乙烯33髋，以骨水泥固定47髋、原锁定机制固定46髋。结果随访5～15年，平均7年。术前Harris髋关节评分（86．0±16．9）分，终末随访时（89．4±11．6）分。并发症包括脱位10髋，感染2髋，假体周围骨折1髋，衬垫脱落1髋。10髋再次翻修：髋臼杯翻修5髋，普通聚乙烯磨损2髋，感染2髋，衬垫脱落1髋。普通聚乙烯组新发骨溶解12髋。以假体松动为终点，十年生存率骨水泥固定组100％、原锁定机制固定组84．8％；以再次翻修为终点，十年生存率分别为90．4％和65．0％。结论以骨水泥或原锁定机制固定翻修衬垫均安全有效。高交联聚乙烯耐磨性较好，能降低骨溶解风险，假体存活率更高。

Objective To investigate clinical outcomes and complications of isolated polyethylene liner exchange for revision total hip arthroplasty. Methods From April 1995 to December 2007, 80 patients （93 hips） underwent revision total hip arthroplasty during which only polyethylene liner was exchanged with reservation of acetabular cup. There were 41 males and 39 females, aged from 27 to 82 years （average, 53.3 years）. The duration from the primary THA to the revision surgery ranged from 0.3 to 18.4 years （average, 10.9 years）. The reasons for liner exchange included： polyethylene wear with osteolysis （78 hips）, polyethylene wear without osteolysis （5 hips）, polyethylene wear with stem loosening （4 hips）, recurrent dislocation （3 hips）, infection （1 hip）, periprosthetic fracture （1 hip） and liner dislodgemeut （1 hip）. Forty-seven liners were fixed into the old cup using cement, and 46 were fixed with the original locking mechanism. Sixty cross-linked polyethylene liners and 33 conventional polyethylene liners were used. Results All patients were followed up for 5 to 15 years （average, 7 years）. The average Harris hip score improved from preoperative 86.0 ±16.9 to 89.4±11.6 at final follow-up. Complications included dislocation （10 hips）, infection （2 hips）, periprosthetic fracture （1 hip） and liner dislodgement （1 hip）. Ten hips underwent rerevision due to different reasons： cup exchange （5 hips）, conventional polyethylene wear （2 hips）, infection （2 hips） and liner dislodgement （1 hip）. Using component loosening as the end point, the 10-year survival rate was 100% in the cement fixation group and 84.8% in the original locking group. Using rerevision as the end point, the 10-year survival rate was 90.4% in the cement fixation group and 65.0% in the original locking group. Conclusion Liner exchange either with cement or original locking mechanism is a safe and successful method. Highly cross-linked polyethylene has a higher wear resistance, which can reduce incidence of osteolysis and improve survival rate of prosthesis.