Chapel Hill Orthopedics Surgery & Sports Medicine, Chapel Hill, NC.
Department of Orthopaedic Surgery and Rehabilitation Medicine, University of Chicago Medical Center, Chicago, IL.
J Arthroplasty. 2018 Jul;33(7):2187-2191. doi: 10.1016/j.arth.2018.02.063. Epub 2018 Feb 23.
Highly cross-linked polyethylene (XLPE) is reported to have low rates of linear and volumetric wear at 10-14 years. In a prior study, larger (36 and 40 mm) femoral heads were associated with more volumetric wear, but there were only 12 hips with these heads.
We evaluated 107 hips (93 patients, with a mean age of 76 years) with one design of uncemented acetabular component, a 36 (90 hips) or 40 mm (17 hips) metal femoral head, and one electron beam 100 kGy irradiated and remelted XLPE at a mean follow-up of 8 years (range 5-13 years). Selection of these femoral heads was based on several factors, including the perceived risk of dislocation, the outer diameter size of the acetabular component, and liner availability. Measurements of linear and volumetric wear were performed in one experienced laboratory by the Martell method and analyzed using the first-to-last method. Standard radiographs, with additional Judet views, were used to detect periprosthetic osteolysis. Clinical records were used to determine the complications of dislocation, liner fracture, and painful trunnion corrosion.
For the entire cohort, the median linear wear rate was 0.041 mm/y (95% confidence interval, 0.031-0.057) and the median volumetric wear rate was 34.6 mm/y (95% confidence interval, 31.4-53.5). With the numbers available, there was no difference in linear or volumetric wear between the 36 and 40 mm head sizes. Small, asymptomatic osteolytic lesions were noted in 3 hips (2%). There were 3 patients (3%) with dislocation (2 early and 1 late), but these have not had a revision. There were no revisions for loosening, no liner fracture, and no patient with symptomatic trunnion corrosion.
This acetabular component and XLPE with large metal heads had low rates of linear and volumetric wear. Large metal femoral heads did not lead to liner fracture, loosening, or symptomatic trunnion corrosion in this patient population. However, we recommend longer clinical follow-up studies and caution in the routine use of larger metal femoral heads in other, younger patient populations.
交联聚乙烯（XLPE）在 10-14 年内线性和体积磨损率较低。在之前的一项研究中，较大的（36 和 40 毫米）股骨头与更大的体积磨损有关，但只有 12 个髋部有这些头。
我们评估了 107 个髋部（93 例患者，平均年龄 76 岁），使用一种未固定的髋臼组件，一个 36（90 个髋部）或 40 毫米（17 个髋部）金属股骨头，以及一种电子束 100 kGy 辐照和重熔的 XLPE，平均随访 8 年（5-13 年）。这些股骨头的选择基于多种因素，包括脱位风险、髋臼组件的外径大小和衬垫的可用性。线性和体积磨损的测量由一个经验丰富的实验室使用 Martell 方法进行，并使用第一到最后方法进行分析。标准 X 线片，外加 Judet 视图，用于检测假体周围骨溶解。临床记录用于确定脱位、衬垫骨折和疼痛的轴腐蚀并发症。
对于整个队列，中位线性磨损率为 0.041 毫米/年（95%置信区间，0.031-0.057），中位体积磨损率为 34.6 毫米/年（95%置信区间，31.4-53.5）。根据可用数据，36 和 40 毫米头大小之间的线性或体积磨损没有差异。3 个髋部（2%）有小的、无症状的溶骨性病变。有 3 例患者（3%）发生脱位（2 例早期和 1 例晚期），但未进行翻修。无松动、无衬垫骨折、无患者出现症状性轴腐蚀。
这种髋臼组件和 XLPE 与大金属头结合使用，线性和体积磨损率较低。在这个患者群体中，大金属股骨头不会导致衬垫骨折、松动或症状性轴腐蚀。然而，我们建议进行更长时间的临床随访研究，并谨慎在其他年轻患者群体中常规使用更大的金属股骨头。
