Liner Exchange Into A Well Fixed Acetabular Shell In Revision Total Hip Arthroplasty

Abstract

OBJECTIVE To investigate clinical outcomes and complications of isolated polyethylene liner exchange for revision total hip arthroplasty. METHODS From April 1 995 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 dislodgement (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.

目的探討保留髖臼杯更換聚乙烯襯墊在全髖關節翻修術中的作用.方法1995年4月至2007年12月,80例(93髖)接受保留髖臼杯更換聚乙烯襯墊手術.男41例,女39例;年齡2782歲,平均53.3歲.初次置換與更換襯墊手術間隔0.318.4年,平均10.9年.翻修原因:聚乙烯磨損及骨溶解78髖,聚乙烯接近完全磨損但無骨溶解5髖,聚乙烯磨損及股骨柄假體鬆動4髖,復發性關節脫位3髖,感染1髖,假體周圍骨折1髖,襯墊脫位1髖.翻修襯墊採用高交聯聚乙烯60髖、普通聚乙烯33髖,以骨水泥固定47髖、原鎖定機制固定46髖.結果隨訪515年,平均7年.術前Harris髖關節評分(86.0±16.9)分,終末隨訪時(89.4±11.6)分.並發症包括脫位10髖,感染2髖,假體周圍骨折1髖,襯墊脫落1髖.10髖再次翻修:髖臼杯翻修5髖,普通聚乙烯磨損2髖,感染2髖,襯墊脫落1髖.普通聚乙烯組新發骨溶解12髖.以假體鬆動為終點,十年生存率骨水泥固定組100%、原鎖定機制固定組84.8 %;以再次翻修為終點,十年生存率分別為90.4%和65.0%.結論以骨水泥或原鎖定機制固定翻修襯墊均安全有效.高交聯聚乙烯耐磨性較好,能降低骨溶解風險,假體存活率更高.