McCalden Richard W, MacDonald Steven J, Rorabeck Cecil H, Bourne Robert B, Chess David G, Charron Kory D
University Hospital, University of Western Ontario, Division of Orthopaedic Surgery, London Health Sciences Centre, University Campus, 339 Windermere Road, London, ON N6A 5A5, Canada.
J Bone Joint Surg Am. 2009 Apr;91(4):773-82. doi: 10.2106/JBJS.H.00244.
Highly cross-linked polyethylene was introduced for clinical use in total hip arthroplasty with the expectation that it would exhibit less wear when compared with conventional polyethylene. The purpose of this study was to report the clinical and radiographic results, after a minimum of five years of follow-up, of a randomized, blinded, controlled trial comparing a conventional polyethylene with a first-generation highly cross-linked polyethylene.
One hundred patients were enrolled in a prospective, randomized controlled study comparing highly cross-linked and conventional polyethylene acetabular liners in total hip arthroplasty. Fifty patients were in each group. At the time of follow-up, clinical outcomes were assessed and steady-state femoral head penetration rates (after bedding-in) for each patient were calculated with use of a validated radiographic technique. In addition, a statistical comparison of polyethylene wear between groups was performed with use of generalized estimating equations.
At a mean of 6.8 years postoperatively, there were no differences between the two polyethylene groups with regard to the Harris hip score, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), or Short Form-12 (SF-12) score. The mean femoral head penetration rate in the first through fifth years was found to be significantly lower in the group treated with the highly cross-linked polyethylene (0.003 mm/yr [95% confidence interval, +/-0.027]) than it was in the group treated with conventional polyethylene (0.051 mm/yr [95% confidence interval, +/-0.022]) (p=0.006). Men treated with a conventional polyethylene liner had a significantly higher (p<or=0.012) femoral head penetration rate (0.081 mm/yr [95% confidence interval, +/-0.065]) than both men and women with a highly cross-linked liner (-0.013 mm/yr [95% confidence interval, +/-0.074] and 0.009 mm/yr [95% confidence interval, +/-0.028], respectively). The general estimating equations demonstrated that the group with a highly cross-linked polyethylene liner had a significantly lower femoral head penetration rate than the group with a conventional polyethylene liner (p=0.025), and a significantly higher femoral head penetration rate was demonstrated in men with a conventional polyethylene liner when compared with both men and women with a highly cross-linked liner (p=0.003).
At a minimum of five years postoperatively, the steady-state femoral head penetration rate associated with this first-generation highly cross-linked polyethylene liner was significantly lower than that associated with a conventional polyethylene liner. Long-term follow-up is required to demonstrate the clinical benefit of this new material.
高交联聚乙烯被引入全髋关节置换术的临床应用，期望与传统聚乙烯相比，它能表现出更少的磨损。本研究的目的是报告一项随机、盲法、对照试验的临床和影像学结果，该试验将传统聚乙烯与第一代高交联聚乙烯进行比较，随访时间至少为五年。
100例患者纳入一项前瞻性随机对照研究，比较全髋关节置换术中高交联和传统聚乙烯髋臼衬垫。每组50例患者。随访时，评估临床结果，并使用经过验证的影像学技术计算每位患者的稳态股骨头穿透率（磨合后）。此外，使用广义估计方程对两组之间的聚乙烯磨损进行统计学比较。
术后平均6.8年时，两组聚乙烯在Harris髋关节评分、西安大略和麦克马斯特大学骨关节炎指数（WOMAC）或简明健康调查量表（SF-12）评分方面无差异。发现高交联聚乙烯治疗组在第一至五年的平均股骨头穿透率（0.003mm/年[95%置信区间，±0.027]）显著低于传统聚乙烯治疗组（0.051mm/年[95%置信区间，±0.022]）（p=0.006）。接受传统聚乙烯衬垫治疗的男性股骨头穿透率（0.081mm/年[95%置信区间，±0.065]）显著高于接受高交联衬垫治疗的男性和女性（分别为-0.013mm/年[95%置信区间，±0.074]和0.009mm/年[95%置信区间，±0.028]）。广义估计方程表明，高交联聚乙烯衬垫组的股骨头穿透率显著低于传统聚乙烯衬垫组（p=0.025），与接受高交联衬垫治疗的男性和女性相比，接受传统聚乙烯衬垫治疗的男性股骨头穿透率显著更高（p=0.003）。
术后至少五年时，与第一代高交联聚乙烯衬垫相关的稳态股骨头穿透率显著低于与传统聚乙烯衬垫相关的穿透率。需要长期随访以证明这种新材料的临床益处。
