Department of Orthopaedics, Oslo University Hospital, CIRRO, Norway.
Acta Orthop. 2012 Apr;83(2):148-52. doi: 10.3109/17453674.2011.652889. Epub 2012 Jan 17.
Highly crosslinked polyethylene (PE) is in standard use worldwide. Differences in the crosslinking procedure may affect the clinical performance. Experimenatal data from retrieved cups have shown free radicals and excessive wear of annealed highly crosslinked PE. We have previously reported low wear and good clinical performance after 6 years with this implant, and now report on the 10-year results.
In 8 patients, we measured wear of annealed highly crosslinked PE prospectively with radiostereometry after 10 years. Activity was assessed by UCLA activity score and a specifically designed activity score. Conventional radiographs were evaluated for osteolysis and clinical outcome by the Harris hip score (HHS).
The mean (95% CI) proximal head penetration for highly crosslinked PE after 10 years was 0.07 (-0.015 to 0.153) mm, and the 3D wear was 0.2 (0.026 to 0.36) mm. Without creep, proximal head penetration was 0.02 (-0.026 to 0.066) mm and for 3D penetration was 0.016 (-0.47 to 0.08) mm. This represents an annual proximal wear of less than 2 µm. All cups were clinically and radiographically stable but showed a tendency of increased rotation after 5 years.
Wear for annealed highly crosslinked PE is extremely low up to 10 years. Free radicals do not affect mechanical performance or lead to clinically adverse effects. Creep stops after the first 6 months after implantation. Highly crosslinked PE is a true competitor of hard-on-hard bearings.
高度交联聚乙烯（PE）在全球范围内得到广泛应用。交联工艺的差异可能会影响临床性能。从取出的髋臼杯中获得的实验数据表明，退火的高度交联 PE 存在自由基和过度磨损。我们之前报告了使用该植入物 6 年后的低磨损和良好的临床效果，现在报告 10 年的结果。
在 8 名患者中，我们前瞻性地使用放射立体测量术测量了退火的高度交联 PE 在 10 年后的磨损情况。通过 UCLA 活动评分和专门设计的活动评分评估活动度。通过 Harris 髋关节评分（HHS）评估常规 X 线片评估的骨溶解和临床结果。
高度交联 PE 在 10 年后的近端头穿透平均值（95%CI）为 0.07（-0.015 至 0.153）mm，3D 磨损为 0.2（0.026 至 0.36）mm。没有蠕变时，近端头穿透为 0.02（-0.026 至 0.066）mm，3D 穿透为 0.016（-0.47 至 0.08）mm。这代表每年近端磨损小于 2 µm。所有髋臼杯均在临床和影像学上稳定，但在 5 年后出现旋转增加的趋势。
退火的高度交联 PE 在 10 年内的磨损极低。自由基不会影响机械性能或导致临床不良影响。植入后前 6 个月后，蠕变停止。高度交联 PE 是硬对硬轴承的真正竞争者。
