Comparison of two different on-shelf femoral stems for Crowe type IV developmental dysplasia of the hip

• Published in: Journal of international medical research Vol. 48; no. 8; p. 300060520947888
• Main Authors: Liu, Tong, Yang, Yuhui, Shen, Xianyue, Xiao, Jianlin, Zuo, Jianlin, Gao, Zhongli
• Format: Journal Article
• Language: English
• Published: London, England SAGE Publications 01.08.2020; Sage Publications Ltd; SAGE Publishing
• Subjects: Arthroplasty, Replacement, Hip; Developmental Dysplasia of the Hip; Femur - diagnostic imaging; Femur - surgery; Hip Dislocation, Congenital - diagnostic imaging; Hip Dislocation, Congenital - surgery; Hip joint; Humans; Joint replacement surgery; Musculoskeletal diseases; Retrospective Clinical Research Report; Retrospective Studies; Transplants & implants; total hip arthroplasty; three-dimensional; modular; conical; Developmental dysplasia of the hip; implant; Crowe type IV
• ISSN: 0300-0605; 1473-2300
• DOI: 10.1177/0300060520947888

Objective 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. Methods 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. Results 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. Conclusions 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.