Liu Tong, Yang Yuhui, Shen Xianyue, Xiao Jianlin, Zuo Jianlin, Gao Zhongli
Department of Orthopaedics, China-Japan Union Hospital of Jilin University, Changchun, Jilin, China.
Department of Orthopaedics, Guangdong General Hospital (Guangdong Academy of Medical Sciences), Guangzhou, Guangdong, China.
J Int Med Res. 2020 Aug;48(8):300060520947888. doi: 10.1177/0300060520947888.
This study was performed to evaluate the proximal anatomical compatibility of stems for treatment of Crowe IV developmental dysplasia of the hip (DDH) using a previously developed three-dimensional comparison technique.
Patients with Crowe IV DDH who underwent computed tomography were retrospectively analyzed. The femoral medullary canals were three-dimensionally reconstructed, and models of cementless modular (S-ROM; DePuy Synthes) and conical (Wagner Cone; Zimmer Biomet) implants were used for virtual implantation. The negative point percentages (NPPs) were applied to verify fitting. The average distance (deviation) and the root mean square of the distance (RMSd) were used to quantify geometric compatibilities.
Four (16.7%) and 12 (50.0%) femoral medullary canals could not be fitted properly with either the modular or conical implant. The NPPs in the distal comparison region were significantly greater in the conical than modular group. The deviation was significantly smaller in the modular than conical group. The RMSd was also significantly smaller in the modular than conical group.
Compared with conical implants, modular implants might be more effectively used in patients with Crowe type IV DDH. However, some Crowe IV DDH femurs with severe deformity cannot be fitted with either of these two on-shelf implants.
本研究采用先前开发的三维比较技术，评估用于治疗Crowe IV型发育性髋关节发育不良（DDH）的股骨柄假体近端的解剖学适配性。
对接受计算机断层扫描的Crowe IV型DDH患者进行回顾性分析。对股骨髓腔进行三维重建，并使用非骨水泥模块化（S-ROM；DePuy Synthes）和锥形（Wagner Cone；Zimmer Biomet）假体模型进行虚拟植入。应用负点百分比（NPPs）来验证适配情况。使用平均距离（偏差）和距离的均方根（RMSd）来量化几何适配性。
分别有4例（16.7%）和12例（50.0%）股骨髓腔与模块化或锥形假体无法良好适配。在远端比较区域，锥形假体组的NPPs显著高于模块化假体组。模块化假体组的偏差显著小于锥形假体组。模块化假体组的RMSd也显著小于锥形假体组。
与锥形假体相比，模块化假体可能更有效地用于Crowe IV型DDH患者。然而，一些严重畸形的Crowe IV型DDH股骨无法与这两种现成的假体适配。
