An over-six-year follow-up of highly cross-linked polyethylene in total hip arthroplasty for young Chinese patients

Abstract

Objective To study the clinical outcomes and linear wear rate of highly cross-linked polyethylene liner in young Chinese patients aged 50 years or below.Methods We reviewed the results of 38 total hip arthroplasty(THA) using Marathon highly-cross linked polyethylene liner and Duraloc cementless cup in 29 patients in our institute.Clinical outcomes were evaluated by Harris Hip Score.Annual X-rays were measured for linear wear and osteolysis.Results Mean age at operation was(41.0±6.86) years(29-50 years). All femoral heads were 28mm in diameter. 26 stems were cementless and the other 12 were cemented. Mean duration of follow-up was ( 7.2±1.3) years ( 6 - 9.6 years) . Harris Hip Score improved significantly from a mean of ( 45.3±18.0) points ( 12 - 73 points) at pre-operation to a mean of ( 93.26± 9.9) points ( 64 - 100 points) at the latest follow-up ( P < 0 10001) . The latest X-rays showed no osteolysis. The creep value of polyethylene occurred in the first year was ( 0.26± 0.21) mm ( 0.01 - 0.91 mm) . The mean cumulative linear penetration for the subsequent years was: ( 0.31±0.19)mm ( 0.04 - 0.76 mm) in two years, ( 0.31± 0.21) mm ( 0.07 - 0.93 mm) in three years, ( 0.34 ± 0.31 ) mm ( 0.07 - 1.68 mm) in four years, ( 0.38± 0.22) mm ( 0.07 - 0.97 mm) in five years and ( 0.38± 0.25) mm ( 0.08 - 1.26 mm) in six years respectively. The average linear wear rate was 0.025 mm per year since the second year after operation. Conclusions XLPE has low linear wear rate in young Chinese patients and may reduce the chance of wear and subsequent osteolysis. Clinical outcomes are satisfactory.

目的回顧性分析50歲或以下的中國年輕全髖關節置換術(THA)患者中應用高交聯聚乙烯內襯的臨床效果和線性磨損率。方法對本中心應用Marathon高交聯聚乙烯內襯和Duraloc非骨水泥臼杯的38髖,29例THA患者的治療結果進行了回顧性分析。通過Harris髖關節評分對臨床效果進行評估。在隨訪期間,測量每一年的X線片,對比分析臼杯內襯的線性磨損和周圍的骨溶解情況。結果患者手術時的平均年齡為(41.0±6.86)歲(2950歲)。所有股骨假體的球頭直徑為28 mm。26髖應用了非骨水泥假體柄,12髖應用了骨水泥假體柄。平均隨訪時間(7.2±1.3)年(69.6年)。平均Harris髖關節評分由術前的(45.3±18.0)分(1273分)顯著提高到術后的(93.26±9.9)分(64100分)。末次隨訪X線片上未見髖臼周圍骨溶解改變。高交聯聚乙烯內襯的第一年蠕變量為:(0.26±0.21)mm(0.010.91 mm),聚乙烯內襯在術后2年的平均累積線性磨損量為:(0.31±0.19)mm(0.040.76 mm),術后3年的平均累積線性磨損量為:(0.31±0.21)mm(0.070.93 mm), 术后4 年的平均累积线性磨损量为: ( 0.34±0.31) mm( 0.07 1.68 mm) , 术后5 年和6 年的平均累积线性磨损量分 别为: ( 0.38 ±0.22) mm( 0.07 0.97 mm) 和( 0.38±0.25) mm( 0.08 1.26 mm) 。手术2 年后的聚乙烯平均线性 磨损率为: 0.025 mm/年。结论 应用于中国年青患者THA 术中的高交联聚乙烯内衬具有低的线性磨损率, 从而可以降低磨损和由此而引起的骨溶解的发生。Marathon 高交联聚乙烯内衬材料具有满意的临床应用效果。