Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, Utah, USA.
Department of Orthopaedics, University of Utah, Salt Lake City, Utah, USA.
J Orthop Res. 2022 Sep;40(9):2113-2126. doi: 10.1002/jor.25227. Epub 2021 Dec 5.
Developmental dysplasia of the hip (DDH) is commonly described as reduced femoral head coverage due to anterolateral acetabular deficiency. Although reduced coverage is the defining trait of DDH, more subtle and localized anatomic features of the joint are also thought to contribute to symptom development and degeneration. These features are challenging to identify using conventional approaches. Herein, we assessed the morphology of the full femur and hemi-pelvis using an articulated statistical shape model (SSM). The model determined the morphological and pose-based variations associated with DDH in a population of Japanese females and established which of these variations predict coverage. Computed tomography (CT) images of 83 hips from 47 patients were segmented for input into a correspondence-based SSM. The dominant modes of variation in the model initially represented scale and pose. After removal of these factors through individual bone alignment, femoral version and neck-shaft angle, pelvic curvature, and acetabular version dominated the observed variation. Femoral head oblateness and prominence of the acetabular rim and various muscle attachment sites of the femur and hemi-pelvis were found to predict 3D CT-based coverage measurements (R = 0.5-0.7 for the full bones, R = 0.9 for the joint). Statement of Clinical Significance: Currently, clinical measurements of DDH only consider the morphology of the acetabulum. However, the results of this study demonstrated that variability in femoral head shape and several muscle attachment sites were predictive of femoral head coverage. These morphological differences may provide insight into improved clinical diagnosis and surgical planning based on functional adaptations of patients with DDH.
发育性髋关节发育不良（DDH）通常被描述为由于髋臼前外侧发育不良导致股骨头覆盖减少。尽管覆盖减少是 DDH 的特征，但关节的更细微和局部解剖特征也被认为会导致症状发展和退化。这些特征使用常规方法难以识别。在此，我们使用铰接统计形状模型（SSM）评估了整个股骨和半骨盆的形态。该模型确定了日本女性人群中与 DDH 相关的形态和基于姿势的变化，并确定了哪些变化可以预测覆盖范围。将来自 47 名患者的 83 个髋关节的 CT 图像进行分割，作为对应 SSM 的输入。模型中的初始主导变化模式代表了规模和姿势。通过对个体骨骼进行对齐、股骨扭转和颈干角、骨盆曲率以及髋臼扭转等因素进行去除后，髋臼版本和股骨颈干角主导了观察到的变化。发现股骨头的扁平和髋臼缘的突出，以及股骨和半骨盆的各种肌肉附着点与基于 3D CT 的覆盖测量值相关（全骨的 R = 0.5-0.7，关节的 R = 0.9）。临床意义的陈述：目前，DDH 的临床测量仅考虑髋臼的形态。然而，这项研究的结果表明，股骨头形状和几个肌肉附着点的变化可预测股骨头的覆盖范围。这些形态差异可能为基于 DDH 患者的功能适应性的改进临床诊断和手术计划提供见解。
