氧化锆陶瓷头与金属头聚乙烯全髋关节的比较研究

Compare the clinical effects of zirconia ceramic with cobalt-chrome femoral heads on the total hip replacement

目的讨氧化锆陶瓷头非骨水泥全髋关节的长期实际临床运用效果。方法在同一医院,由同一医生完成的钴铬金属头(CoCr)非骨水泥全髋的病例中,寻找26例(26髋)与氧化锆组进行配对研究。使配对病例的年龄、性别、体重指数、术前诊断、术后随访时间相匹配。通过Harris评分进行关节功能评价。研究术后一年和最后一次随访的X线片,对比两组病例假体松动发生率、假体周围骨溶解及透明带的形成、股骨矩吸收及聚乙烯髋臼的磨损率。结果氧化锆组26髋皆获随访,平均随访9年(6～13年)。术前和最后一次随访时平均Harris评分分别为46分和86分。钴铬金属头组26髋平均随访10年(5～14年),术前和最后随访时平均Harris评分分别为50分和88分。两组比较无明显差异。氧化锆组在随访期间共有10髋(38%)由于髋臼假体松动或广泛髋臼骨溶解而翻修,钴铬金属头组有4例(11.5%)。氧化锆组共发现有13髋(50%)有髋臼和股骨假体周围的骨溶解发生,钴铬金属头组有9髋(34.6%)。氧化锆组聚乙烯平均磨损率为0.118mm/年(0.064mm/年～0.175mm/年),金属头组为0.113mm/年(0.056mm/年～0.19mm/年)。两组比较无明显差异。结论在本组研究中,氧化锆陶瓷头组有较高的假体松动和翻修率,聚乙烯髋臼磨损率与钴铬金属头组相当。提示虽然氧化锆陶瓷头在体外研究中具有明显的抗磨损优势,但在实际临床运用中可能与体外实验有较大的差别。

Objective This study was conducted to determine the long-term clinical efficacy of a zirconia ceramic head. Methods 26 cementless total hip arthroplasties in 24 patients were performed using a zirconia head coupled with polyethylene. A matched group of 26 hips in 26 patients using cobalt-chrome heads performed by the same doctor coupled with polyethylene were also followed for average of 10 years （range, 5 - 14 years） . The two groups of patients were evaluated clinically and radiographically respectively including Harris score, joint loosening, periprosthetic osteolysis, offset absorption and wear rate of polyethylene. Results All hips were followed up for average of 9 years （range, 6 - 13 years）. The average functional hip scores according to Harris improved from 46 preoperatively to 86 at the final follow-up in the Zirconia group, and from 50 to 88 in the Cr-Co group. The mean liner wear rate of zirconia-polyethylene coupling using the technique of Livermore＇s was 0. 118 mm/year （range, 0. 064 mm/year - 0. 175 mm/ year）, and the linear wear rate of CrCo-polyethylene was 0. 113 mm/year （range, 0. 056 mm/year - 0. 19 mm/year） . There was no significant difference in two groups. There were 10 hips （38.5%） revised due to loosening or extensive osteolysis of the cup in the Zirconia group, and only 4 hips （ 11.5% ） in Cr-Co group. Conclusion Results of the current study suggest that a zirconia ceramic femoral head has little advantage than a cobalt- chrome head in decreasing in vivo polyethylene wear. Our study demonstrates that although changes in component designs and materials may offer theoretical advantages over current components, their effect in vivo remains questionable.