Acetabular reinforcement ring with additional hook improves stability in three-dimensional finite element analyses of dysplastic hip arthroplasty

• Main Authors: Koji Totoribe, Etsuo Chosa, Go Yamako, Xin Zhao, Koki Ouchi, Hiroaki Hamada, Gang Deng
• Format: Article
• Language: English
• Published: BMC 2018-12-01
• Series: Journal of Orthopaedic Surgery and Research
• Subjects: Finite element method; Total hip arthroplasty; Acetabular reinforcement ring; Primary implant stability
• Online Access: http://link.springer.com/article/10.1186/s13018-018-1023-7

Abstract Background The stability of acetabulum reconstructions using reinforcement rings and hooks is important for successful replacement surgery. The objective of this study was to biomechanically determine the effects of the hook on stress and the related micromotions of the acetabular reinforcement ring during the immediate postoperative period. Methods Acetabular reinforcement ring models were developed using a nonlinear, three-dimensional, finite element method. Using a pre-prepared template, we constructed without-hook and bone graft models of varying volumes and material properties. Results The stress on the inferior margin of the acetabulum was higher in the with-hook model than in the without-hook model, especially with increased bone graft volumes, and the stiffness of the bone graft material was decreased. Relative micromotions in the without-hook model were higher than in the with-hook models. The highest relative micromotion was observed in the model with increased bone graft volume and lower stiffness of bone graft material. Conclusions In biomechanical analyses, the hook effectively dispersed stress and improved the initial fixation strength of the acetabular reinforcement ring.