Shirai Yasuhiro, Wakabayashi Kenjiro, Wada Ikuo, Tsuboi Yoshiaki, Ha Myongsu, Otsuka Takanobu
Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Nagoya City University, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan.
Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Nagoya City University, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan.
J Orthop Sci. 2018 Jan;23(1):161-167. doi: 10.1016/j.jos.2017.11.009. Epub 2017 Nov 20.
The Herring lateral pillar classification is widely used for the classification of Legg-Calvé-Perthes disease, but is not applied at the early stage of Legg-Calvé-Perthes disease because it is typically applied at the late fragmentation stage. The purpose of this study was to investigate the correlation between the early appearance on magnetic resonance imaging of the acetabular labrum and lateral pillar involvement in Legg-Calvé-Perthes disease.
Non-contrast magnetic resonance images of 26 hips in 25 children with early-stage Legg-Calvé-Perthes disease were retrospectively reviewed. The extent of labral horizontalization was quantitatively evaluated with a new method, the labral angle, on T2*-weighted magnetic resonance images. A small labral angle indicates strong labral horizontalization. Calculation of the teardrop distance and acetabular head index on radiographs was modified for application to magnetic resonance imaging, and the extent of cartilaginous lateral subluxation (cartilaginous tear drop distance) and cartilaginous lateral extrusion (cartilaginous acetabular head index) were evaluated. The outcome measure was the lateral pillar classification.
There were statistically significant correlations between the labral angle and the cartilaginous tear drop distance (p = 0.002, ɤ = -0.58) and the cartilaginous acetabular head index (p < 0.001, ɤ = 0.65) on magnetic resonance images. The labral angle was small in order of groups C, B, and A, and there were significant differences between groups A and C (p < 0.001) and B and C (p = 0.006).
Greater labral horizontalization observed on magnetic resonance imaging at the early stage of Legg-Calvé-Perthes disease correlated with strong cartilaginous lateral subluxation and extrusion, and with increased lateral pillar collapse at the maximum fragmentation stage. Our finding suggests that a quantitative evaluation of labral horizontalization using magnetic resonance imaging in the early-stage of Legg-Calvé-Perthes disease can predict the later lateral pillar classification.
鲱鱼外侧柱分类法广泛用于Legg-Calvé-Perthes病的分类，但由于通常应用于晚期碎裂阶段，因此在Legg-Calvé-Perthes病的早期阶段并不适用。本研究的目的是探讨髋臼盂唇在磁共振成像上的早期表现与Legg-Calvé-Perthes病中外侧柱受累之间的相关性。
回顾性分析25例患有Legg-Calvé-Perthes病早期儿童的26个髋关节的非增强磁共振图像。在T2*加权磁共振图像上，采用一种新的方法——盂唇角，对盂唇水平化程度进行定量评估。盂唇角小表明盂唇水平化程度高。对X线片上泪滴距离和髋臼头指数的计算方法进行了修改，以应用于磁共振成像，并评估软骨性外侧半脱位（软骨性泪滴距离）和软骨性外侧挤压（软骨性髋臼头指数）的程度。观察指标为外侧柱分类。
磁共振图像上，盂唇角与软骨性泪滴距离（p = 0.002，ɤ = -0.58）和软骨性髋臼头指数（p < 0.001，ɤ = 0.65）之间存在统计学显著相关性。按C组、B组和A组顺序，盂唇角逐渐变小，A组与C组（p < 0.001）以及B组与C组（p = 0.006）之间存在显著差异。
在Legg-Calvé-Perthes病早期磁共振成像上观察到的更高程度的盂唇水平化与严重的软骨性外侧半脱位和挤压相关，并且与最大碎裂阶段外侧柱塌陷增加相关。我们的研究结果表明，在Legg-Calvé-Perthes病早期使用磁共振成像对盂唇水平化进行定量评估可以预测后期的外侧柱分类。
