Simpson D J, Kendrick B J L, Kaptein B L, Price A J, Murray D W, Gill H S
Biomedical Research Unit, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Nuffield Orthopaedic Centre, Windmill Road, Oxford OX3 7LD, UK.
Proc Inst Mech Eng H. 2010 Nov;224(11):1235-43. doi: 10.1243/09544119JEIM812.
One of the most important causes of failure in unicompartmental knee replacement (UKR) is polyethylene wear. The aim of this study was to develop and assess a novel Roentgen stereophotogrammetric analysis (RSA)-based method for the measurement of linear wear suitable for UKR. Model-based RSA was used to estimate the linear wear of polyethylene bearings in UKR. A phantom was used to validate the method using in vitro measured bearing thicknesses and the linear wear of ten control bearings was estimated in vivo. Computer aided design (CAD) models for the UKRs were used in the model-based RSA system. There was no statistically significant difference between the estimated and measured bearing thicknesses using the CAD models (p = 0.386). The precision of the linear wear measurement, expressed as the standard deviation of the difference between the estimated and measured bearing thickness was 0.163 mm. The bias (mean difference) was 0.030 mm. The use of RSA to measure in vivo wear in a UKR has been shown to be accurate in a phantom, and has been verified with in vivo measured controls. The technique does not require surgical implantation of marker balls and can be used retrospectively.
单髁膝关节置换术（UKR）失败的最重要原因之一是聚乙烯磨损。本研究的目的是开发并评估一种基于新型X线立体摄影测量分析（RSA）的方法，用于测量适用于UKR的线性磨损。基于模型的RSA用于估计UKR中聚乙烯轴承的线性磨损。使用一个体模，通过体外测量的轴承厚度来验证该方法，并在体内估计了十个对照轴承的线性磨损。UKR的计算机辅助设计（CAD）模型用于基于模型的RSA系统。使用CAD模型时，估计的轴承厚度与测量的轴承厚度之间无统计学显著差异（p = 0.386）。线性磨损测量的精度，以估计的轴承厚度与测量的轴承厚度之间差异的标准差表示为0.163 mm。偏差（平均差异）为0.030 mm。已证明使用RSA测量UKR的体内磨损在体模中是准确的，并已通过体内测量的对照进行了验证。该技术不需要手术植入标记球，并且可以进行回顾性分析。
