Zirconia陶瓷头-聚乙烯全髋关节的长期随访

Long-term follow-up of Zirconia-Polyethylene total hip arthroplasty

目的:通过对28例(30髋)zirconia-聚乙烯全髋关节的长期随访,了解Zirconia陶瓷头的实际临床使用效果.方法:用Harris评分分别评价术前和最后一次随访时髋关节功能.比较术后1年及最后随访时的X线片,记录假体松动、假体周围骨溶解、透亮线、及股骨矩吸收情况.根据Livermore的方法测量聚乙烯杯的磨损率.比较有骨溶解发生的髋关节与无骨溶解发生的髋关节的聚乙烯磨损率有无差别.结果:共有24例(26髋)获长期随访,平均随访9年(6～13年).术前平均Harris评分46分(20～78分),最后随访时平均Harris评分86分(48～98分).13髋(50%)有假体周围的骨溶解发生.有10髋(38%)因髋臼假体的松动或髋臼周围骨溶解而接受翻修手术.平均聚乙烯髋臼磨损率为0.118mm/年.结论:在本组研究病例中,其髋臼磨损率并不比文献报道的传统的金属头低.而临床平均9年翻修率更达38%.其临床实际效果有待更深入的研究.

Objective:The asceptic loosening of the implants is the main complication to the long-term failure of hip arthroplasty.One of the alternatives is to choose ceramic head instead of the traditional cobalt-chrome head.This study was conducted to determine the clinical efficacy of a Zirconia ceramic head.Method:Thirty cementless total hip arthroplasties in 28 patients were performed using a Zirconia head coupled with polyethylene.All hips were followed up for average of 9 years(ranged,6～13years).This group of patients was evaluated clinically and radiographically respectively.The function of the hips was evaluated with the method of Harris hip score.The X-ray films were assessed to see if there were any evidence of loosening,osteolysis,transparent belts and calcar resorption.The authors also measured the linear wear rate of the cup using the method of Livermore's and compared the wear rate of the hips with the evidence of osteolysis with that of those without the evidence of osteolysis.Result:The average functional hip scores according to Harris improved from 46 preoperatively to 86 at the final follow-up.The mean liner wear rate of Zirconia-polyethylene coupling using the technique of Livermore's was 0.118mm/year(ranged,0.064～(0.175)mm/year).There were 10 hips(38.5%)revised due to loosening or extensive osteolysis of the cup.There was no difference between the wear rates of the cups with osteolysis and those without osteolysis.Conclusion:Results of the current study suggest that a Zirconia ceramic femoral head has little advantage over the traditional cobaltchrome head in decreasing in vivo polyethylene wear.The study demonstrates that although changes in component designs and materials may offer theoretical advantages over current components,their effects in vivo remain questionable.