Department of Orthopedic Surgery, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Department of Radiology, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Int Orthop. 2020 Sep;44(9):1677-1683. doi: 10.1007/s00264-020-04600-2. Epub 2020 May 13.
This study examined the hip morphology of paediatric patients with mucopolysaccharidosis (MPS) type IVA (MPS IVA).
This was a retrospective chart review of 42 hips in 21 children with MPS IVA. Pelvic radiographs and magnetic resonance imaging (MRI) scans of 42 hips and arthrograms of 13 hips were analysed. The bony, cartilaginous and labral coverage of the acetabulum was determined by acetabular index (AI), centre edge angle (CEA) and femoral head coverage (FHC).
The mean age at the time of radiography was 66.3 ± 21.7 months. The bony, cartilaginous and labral AI in the MRI assessment were 36.3 ± 5.3, 18.3 ± 4.7 and 12.1 ± 4.6 degrees, respectively. The inter-class correlation coefficients (ICCs) for the bony AI, CEA and FHC measurements on radiographs and MRI were 0.936, 0.879 and 0.810, respectively. In the MRI assessment, labrum in 12 of 42 hips appeared as a regular triangle, and it was flat on 30/42 hips. The average arthrographic AI (AAI) was 11.1 ± 2.7 degrees. The ICCs value of AAI versus cartilaginous and labral AI on MRI indicates good agreement but higher in labral AI.
Hips in MPS IVA exhibited obvious cartilage and labrum compensation in response to abnormal ossification of bony acetabulum. Cartilage in MPS IVA hip increases the thickness in the longitudinal direction, while the labrum becomes flatten in the horizontal direction. The AAI may represent intraoperative labrum coverage. The femora-acetabular harmony is difficult to determine using radiography only, and pre-operative MRI and an intraoperative arthrogram are very important in a hip assessment in MPS IVA.
本研究旨在探讨黏多糖贮积症四型（MPS IVA）患儿的髋关节形态。
这是一项对 21 例 MPS IVA 患儿的 42 髋进行的回顾性图表分析。对 42 髋的骨盆 X 线片和磁共振成像（MRI）扫描以及 13 髋的关节造影进行分析。髋臼指数（AI）、中心边缘角（CEA）和股骨头覆盖（FHC）用于确定髋臼的骨性、软骨性和盂唇覆盖范围。
影像学检查时的平均年龄为 66.3±21.7 个月。MRI 评估中骨性、软骨性和盂唇 AI 分别为 36.3±5.3、18.3±4.7 和 12.1±4.6 度。骨盆 X 线片和 MRI 上骨性 AI、CEA 和 FHC 测量的组内相关系数（ICC）分别为 0.936、0.879 和 0.810。在 MRI 评估中，42 髋中有 12 髋的盂唇呈规则三角形，有 30/42 髋的盂唇变平。平均关节造影 AI（AAI）为 11.1±2.7 度。AAI 与 MRI 上软骨性和盂唇 AI 的 ICC 值表明两者具有良好的一致性，但盂唇 AI 的一致性更高。
MPS IVA 患儿的髋关节在骨髋臼异常骨化的情况下表现出明显的软骨和盂唇代偿。MPS IVA 髋关节的软骨在纵向方向上增加厚度，而盂唇在水平方向上变平。AAI 可能代表术中盂唇覆盖范围。仅通过 X 线片很难确定股骨髋臼的协调性，因此在 MPS IVA 的髋关节评估中，术前 MRI 和术中关节造影非常重要。
