Department of Orthopaedic Surgery, Caphri Research Institute, Maastricht University Medical Centre, 6202 AZ Maastricht, The Netherlands.
Orthopaedic Research Laboratory, Radboud University Medical Centre, 6500 HB Nijmegen, The Netherlands.
Med Eng Phys. 2014 Mar;36(3):345-53. doi: 10.1016/j.medengphy.2013.12.006. Epub 2013 Dec 27.
This study assessed whether the Symax™ implant, a modification of the Omnifit(®) stem (in terms of shape, proximal coating and distal surface treatment), would yield improved bone remodelling in a clinical DEXA study, and if these results could be predicted in a finite element (FE) simulation study. In a randomized clinical trial, 2 year DEXA measurements between the uncemented Symax™ and Omnifit(®) stem (both n=25) showed bone mineral density (BMD) loss in Gruen zone 7 of 14% and 20%, respectively (p<0.05). In contrast, the FE models predicted a 28% (Symax™) and 26% (Omnifit(®)) bone loss. When the distal treatment to the Symax™ was not modelled in the simulation, bone loss of 35% was predicted, suggesting the benefit of this surface treatment for proximal bone maintenance. The theoretical concept for enhanced proximal bone loading by the Symax™, and the predicted remodelling pattern were confirmed by DEXA-results, but there was no quantitative match between clinical and FE findings. This was due to a simulation based on incomplete assumptions concerning the yet unknown biological and mechanical effects of the new coating and surface treatment. Study listed under ClinicalTrials.gov with number NCT01695213.
本研究评估了 Symax™ 植入物（在形状、近端涂层和远端表面处理方面对 Omnifit(®) 柄的改进）是否会在临床 DEXA 研究中改善骨重塑，以及这些结果是否可以通过有限元（FE）模拟研究预测。在一项随机临床试验中，2 年未固定的 Symax™ 和 Omnifit(®) 柄之间的 DEXA 测量（每组 n=25）显示，Gruen 区 7 的骨矿物质密度（BMD）分别损失了 14%和 20%（p<0.05）。相比之下，FE 模型预测会出现 28%（Symax™）和 26%（Omnifit(®)）的骨丢失。当模拟中未对 Symax™ 的远端处理进行建模时，预测会出现 35%的骨丢失，这表明这种表面处理对近端骨维持有益。Symax™ 通过增强近端骨加载的理论概念和预测的重塑模式通过 DEXA 结果得到了证实，但临床和 FE 结果之间没有定量匹配。这是由于模拟基于对新涂层和表面处理的未知生物和机械效应的不完整假设。该研究已在 ClinicalTrials.gov 上注册，编号为 NCT01695213。
