School of Engineering, Newcastle University, UK.
Tornier SAS, Montbonnot, France.
J Mech Behav Biomed Mater. 2024 Dec;160:106768. doi: 10.1016/j.jmbbm.2024.106768. Epub 2024 Oct 9.
The history of joint replacement can be framed as a battle to reduce wear. Pyrocarbon has been shown to be a low wear material, but can low wear against an ultra high molecular weight polyethylene (UHMWPE) counterface be achieved? To investigate this research question, a 50-station, clinically validated wear screening machine was used. Half the stations tested UHMWPE pins against pyrocarbon discs, and half the stations tested UHMWPE pins against cobalt chromium (CoCr) discs. The test rig ran at 1Hz, the nominal contact stress was 2.07 MPa, and testing ran to 5 million cycles. A biomimetic lubricant was used, it was replaced every 500,000 cycles. At the end of testing, the UHMWPE pins rubbing against pyrocarbon discs had a statistically significant reduced wear, compared with the UHMWPE pins rubbing against CoCr discs (p ≤ 0.01). Analysis of the discs at the end of testing showed greater adherence of phospholipids on the pyrocarbon discs than the CoCr discs. In turn, it was also seen that far less UHMWPE was attached to the pyrocarbon discs than to the CoCr discs. Based on this evidence, it is suggested that pyrocarbon surfaces are associated with reduced adhesive wear of UHMWPE compared with CoCr surfaces. In addition, at the end of testing, the CoCr discs were found to be significantly rougher than the pyrocarbon discs. Therefore, pyrocarbon maintained a smoother surface than CoCr, likely meaning that abrasive wear of UHMWPE was reduced compared with CoCr.
关节置换的历史可以被描述为一场减少磨损的斗争。热解碳已被证明是一种低磨损材料，但能否在超高分子量聚乙烯（UHMWPE）对磨面上实现低磨损？为了研究这个问题，使用了一台经过 50 站临床验证的磨损筛选机。其中一半的工位测试 UHMWPE 销与热解碳盘对磨，另一半工位测试 UHMWPE 销与钴铬（CoCr）盘对磨。测试装置以 1Hz 的频率运行，名义接触应力为 2.07MPa，测试运行至 500 万次循环。使用了一种仿生润滑剂，每 50 万次循环更换一次。在测试结束时，与 CoCr 盘对磨的 UHMWPE 销的磨损明显减少，与与热解碳盘对磨的 UHMWPE 销相比具有统计学意义（p≤0.01）。在测试结束时对圆盘进行分析表明，热解碳盘上的磷脂附着量明显多于 CoCr 盘。反过来，附着在热解碳盘上的 UHMWPE 也明显少于 CoCr 盘。根据这些证据，有人认为与 CoCr 表面相比，热解碳表面与 UHMWPE 的粘着磨损减少有关。此外，在测试结束时，发现 CoCr 盘比热解碳盘明显更粗糙。因此，热解碳保持比 CoCr 更光滑的表面，这可能意味着与 CoCr 相比，UHMWPE 的磨料磨损减少。
