Pienkowski David, Resig JoAnne, Talwalkar Vishwas, Tylkowski Chester
Department of Orthopaedic Surgery, University of Kentucky College of Medicine, K401 Kentucky Clinic, 740 S. Limestone, Lexington, Kentucky 40536-0284, USA.
J Orthop Res. 2009 Aug;27(8):981-8. doi: 10.1002/jor.20909.
Treatment of Legg-Calvé-Perthes disease (LCPD) may improve if new knowledge can be obtained regarding how articular cartilage changes shape during the course of this disorder. A new technique is presented showing how analyses of magnetic resonance images can be used to quantify the three-dimensional changes in the femoral and acetabular articulating cartilage surfaces of children with LCPD. Ten male subjects (8 +/- 1 years) with unilateral LCPD were enrolled in this IRB approved study. Sets of magnetic resonance images of both hips were obtained at three different times. Three-dimensional virtual models of the cartilage were created from these images, and mathematical spheres were fit to the articulating surfaces. Five parameters (size, shape deformity (sphericity error), radial growth rate, joint fit, and joint incongruity) were used to quantify cartilage surface shape. Data were analyzed by using a linear mixed-model. Joint incongruity, i.e., the distance between the centers of the femoral and acetabular spheres, was slightly more than 2.5 times larger (p = 0.001) in LCPD hips than the contralateral normal hips. Cartilage shape deformity was 65% larger in hips with LCPD than in normal hips. Growth rates of the femoral head and the opposing acetabular surface showed that distortion of the femoral surface occurred first and the opposing acetabular surface followed. Mean radial difference (acetabular surface radius minus femoral surface radius) in LCPD hips was less than half (p < 0.01) the value of normal hips. Interobserver variability was approximately 10% of the value attributable to LCPD. This is the first known report presenting a technique that quantifies the three-dimensional size, deformity, growth, fit. and incongruity of the femoral and acetabular articulating cartilaginous surfaces of LCPD and contralateral normal hips. The data obtained support the use of this technique and provide pilot data for a future clinical study of LCPD. Objective assessment of cartilage shape enabled by this technique may aid future diagnoses, enable monitoring of three-dimensional femoral and acetabular remodeling, and permit quantitative assessment of treatment efficacy.
如果能够获取有关Legg-Calvé-Perthes病（LCPD）病程中关节软骨如何改变形状的新知识，那么对该病的治疗可能会得到改善。本文介绍了一种新技术，展示了如何利用磁共振图像分析来量化LCPD患儿股骨和髋臼关节软骨表面的三维变化。十名患有单侧LCPD的男性受试者（8±1岁）参与了这项经机构审查委员会批准的研究。在三个不同时间获取了双侧髋关节的磁共振图像集。从这些图像创建了软骨的三维虚拟模型，并将数学球体拟合到关节表面。使用五个参数（大小、形状畸形（球度误差）、径向生长速率、关节匹配度和关节不匹配度）来量化软骨表面形状。采用线性混合模型对数据进行分析。LCPD髋关节的关节不匹配度，即股骨和髋臼球体中心之间的距离，比健侧正常髋关节大2.5倍多（p = 0.001）。LCPD髋关节的软骨形状畸形比正常髋关节大65%。股骨头和相对髋臼表面的生长速率表明，股骨表面的变形先发生，随后是相对的髋臼表面。LCPD髋关节的平均径向差异（髋臼表面半径减去股骨表面半径）不到正常髋关节值的一半（p < 0.01）。观察者间的变异性约为LCPD所致值的10%。这是已知的第一份报告，介绍了一种量化LCPD和健侧正常髋关节股骨和髋臼关节软骨表面三维大小、畸形、生长、匹配度和不匹配度的技术。所获得的数据支持该技术的应用，并为未来LCPD的临床研究提供了初步数据。该技术实现的软骨形状客观评估可能有助于未来的诊断，能够监测股骨和髋臼的三维重塑，并允许对治疗效果进行定量评估。
