Yang Yuhui, Zuo Jianlin, Liu Tong, Xiao Jianlin, Liu Shuanglu, Gao Zhongli
1Department of Orthopaedics, China-Japan Union Hospital of Jilin University, Changchun, China 2Department of Orthopaedics, Xiangyang Central Hospital, Xiangyang, China.
J Bone Joint Surg Am. 2017 Sep 6;99(17):e92. doi: 10.2106/JBJS.16.00729.
The purpose of this study was to investigate the 3-dimensional (3D) morphological features of the true acetabulum in patients with developmental dysplasia of the hip (DDH).
Seventy-nine hips-53 in patients with developmental dysplasia of the hip (DDH) and 36 normal hips-were included in the present study. According to the Crowe classification, 26 hips were graded as Class I, 31 were Class II or III, and 22 were Class IV. The anterior pelvic plane was defined to standardize the measurements in the study. A selected virtual cup component was implanted into the true acetabulum of a 3D pelvic model of each hip. The acetabular anteversion angle, effective center-edge (CE) angle, effective Sharp angle, and thickness of the medial wall were measured to provide morphological indices of the true acetabulum. Acetabular sector angles and the component coverage ratio were measured to provide coverage indices.
The acetabular anteversion angle increased with the severity of the DDH. Crowe-II/III hips had the smallest effective CE angle and the largest effective Sharp angle. The mean medial wall thickness was greatest in the Crowe-II/III hips (8.72 mm; 95% confidence interval [CI] = 7.52 to 9.92 mm), intermediate in the Crowe-I hips (7.17 mm; 95% CI = 6.24 to 8.11 mm), and smallest in the Crowe-IV hips (6.05 mm; 95% CI = 4.78 to 7.32 mm). The integrated coverage ratio of the Crowe-II/III hips was significantly less than that of the Crowe-I and IV hips.
The morphological features of the true acetabulum in patients with DDH can be evaluated comprehensively by using 3D implantation simulation. Segmental bone deficiency was prevalent in the dysplastic hips, especially those in the Crowe-II/III group. Both the severity and the individual morphology of the acetabular dysplasia should be carefully considered in preoperative planning.
本研究旨在调查发育性髋关节发育不良（DDH）患者真性髋臼的三维（3D）形态特征。
本研究纳入了79个髋关节，其中53个为发育性髋关节发育不良（DDH）患者的髋关节，36个为正常髋关节。根据Crowe分类，26个髋关节为I级，31个为II级或III级，22个为IV级。定义了骨盆前平面以标准化研究中的测量。将选定的虚拟髋臼组件植入每个髋关节的3D骨盆模型的真性髋臼中。测量髋臼前倾角、有效中心边缘（CE）角、有效Sharp角和内侧壁厚度，以提供真性髋臼的形态学指标。测量髋臼扇形角和组件覆盖率，以提供覆盖指标。
髋臼前倾角随DDH严重程度增加。Crowe-II/III级髋关节的有效CE角最小，有效Sharp角最大。Crowe-II/III级髋关节的平均内侧壁厚度最大（8.72 mm；95%置信区间[CI]=7.52至9.92 mm），Crowe-I级髋关节居中（7.17 mm；95%CI=6.24至8.11 mm），Crowe-IV级髋关节最小（6.05 mm；95%CI=4.78至7.32 mm）。Crowe-II/III级髋关节的综合覆盖率显著低于Crowe-I级和IV级髋关节。
使用3D植入模拟可以全面评估DDH患者真性髋臼的形态特征。发育不良的髋关节中节段性骨缺损普遍存在，尤其是Crowe-II/III组中的髋关节。在术前规划中应仔细考虑髋臼发育不良的严重程度和个体形态。
