Digas Georgios, Kärrholm Johan, Thanner Jonas, Malchau Henrik, Herberts Peter
Department of Orthopaedics, Institute of Surgical Science, Sahlgrenska University Hospital, Göteborg University, S-41345, Göteborg, Sweden.
Clin Orthop Relat Res. 2004 Dec(429):6-16.
The annual wear rate in polyethylene articulations should be 0.1 mm or less to avoid future osteolysis. Highly cross-linked polyethylene shows an 80 to 90% wear reduction in hip simulator testing, but the clinical documentation of this new polyethylene is still inadequate. We evaluated the highly cross-linked polyethylene in two prospective randomized clinical studies. Thirty-two patients (12 men, 20 women; 64 hips) with a median age of 48 years (range, 29-70 years) with bilateral primary or secondary arthrosis of the hip had hybrid total hip arthroplasty with liners made of highly cross-linked polyethylene on one side and conventional polyethylene on the other. Twenty-seven patients in this study have passed 2 years followup. A further group, comprised of 60 patients (61 hips) with a median age of 55 years (range, 35-70 years), was randomized to receive either highly cross-linked polyethylene or conventional cemented all-polyethylene of the same design. Forty-nine of these 60 patients have been observed for 3 years. In both studies all patients received Spectron stems with 28-mm Co-Cr heads. Radiostereometric examinations with the patient supine or standing were done at regular intervals. Wear was measured in the supine position from the first postoperative week, whereas standing examinations were initiated 3 months after the operation. The penetration rate almost was identical in the study and control groups at 6 months after the operation. Thereafter, the penetration rate leveled out in the two groups with highly cross-linked polyethylene. At 2 years the highly cross-linked polyethylene liner showed 62% lower proximal penetration and 31% lower total (three-dimensional) penetration when the patients were examined in supine position. The highly crosslinked all-polyethylene cemented cups showed lower proximal penetration in both positions. The better wear performance of highly cross-linked polyethylene could increase the implant longevity. Longer followup is needed to evaluate if this new material is associated with less occurrence of osteolysis.
为避免未来发生骨溶解，聚乙烯关节的年磨损率应在0.1毫米或更低。在髋关节模拟器测试中，高交联聚乙烯的磨损减少了80%至90%，但这种新型聚乙烯的临床记录仍不充分。我们在两项前瞻性随机临床研究中对高交联聚乙烯进行了评估。32例患者（12例男性，20例女性；64髋），中位年龄48岁（范围29 - 70岁），患有双侧原发性或继发性髋关节骨关节炎，接受了混合全髋关节置换术，一侧使用高交联聚乙烯内衬，另一侧使用传统聚乙烯内衬。本研究中的27例患者已通过2年随访。另一组由60例患者（61髋）组成，中位年龄55岁（范围35 - 70岁），随机接受相同设计的高交联聚乙烯或传统骨水泥固定全聚乙烯假体。这60例患者中的49例已被观察3年。在两项研究中，所有患者均接受了带有28毫米钴铬合金股骨头的Spectron股骨柄。定期对仰卧或站立的患者进行放射立体测量检查。术后第一周起在仰卧位测量磨损，而站立位检查在术后3个月开始。术后6个月时，研究组和对照组的穿透率几乎相同。此后，两组使用高交联聚乙烯的穿透率趋于平稳。在仰卧位检查患者时，2年时高交联聚乙烯内衬的近端穿透率降低了62%，总（三维）穿透率降低了31%。高交联全聚乙烯骨水泥杯在两个位置的近端穿透率均较低。高交联聚乙烯更好的耐磨性能可能会提高植入物的使用寿命。需要更长时间的随访来评估这种新材料是否与较少的骨溶解发生相关。
