Biomechanical analysis of internal fixation system stability for tibial plateau fractures

Guoqiang Wei; Xiaofen Niu; Yuan Li; Tingjie Chang; Jianfang Zhang; Haiyan Wang; Xiaohe Li; Yujie He; Ruijiang Wang; Fei Tian; Yangyang Xu

doi:10.3389/fbioe.2023.1199944

Biomechanical analysis of internal fixation system stability for tibial plateau fractures

Front Bioeng Biotechnol. 2023 Jun 14:11:1199944. doi: 10.3389/fbioe.2023.1199944. eCollection 2023.

Authors

Guoqiang Wei¹, Xiaofen Niu¹, Yuan Li², Tingjie Chang², Jianfang Zhang¹, Haiyan Wang³, Xiaohe Li³, Yujie He³, Ruijiang Wang⁴, Fei Tian^{5

6}, Yangyang Xu⁷

Affiliations

¹ Department of Rehabilitation Medicine, Changzhi Medical College Affiliated Changzhi People's Hospital, Changzhi, China.
² Department of Orthopedics, Changzhi Medical College Affiliated Peace Hospital, Changzhi, China.
³ Department of Anatomy, School of Basic Medical Sciences, Inner Mongolia Medical University, Hohhot, China.
⁴ Department of Orthopedics, Changzhi Second People's Hospital, Changzhi, China.
⁵ Department of Health Management, Changzhi Medical College, Changzhi, China.
⁶ Department of Rehabilitation Medicine, Changzhi Medical College Affiliated Peace Hospital, Changzhi, China.
⁷ Beijing Key Laboratory for Design and Evaluation Technology of Advanced Implantable and Interventional Medical Devices, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, China.

Abstract

Background: Complex bone plateau fractures have been treated with bilateral plate fixation, but previous research has overemphasized evaluating the effects of internal fixation design, plate position, and screw orientation on fracture fixation stability, neglecting the internal fixation system's biomechanical properties in postoperative rehabilitation exercises. This study aimed to investigate the mechanical properties of tibial plateau fractures after internal fixation, explore the biomechanical mechanism of the interaction between internal fixation and bone, and make suggestions for early postoperative rehabilitation and postoperative weight-bearing rehabilitation. Methods: By establishing the postoperative tibia model, the standing, walking and running conditions were simulated under three axial loads of 500 N, 1000 N, and 1500 N. Accordingly, finite element analysis (FEA) was performed to analyze the model stiffness, displacement of fractured bone fragments, titanium alloy plate, screw stress distribution, and fatigue properties of the tibia and the internal fixation system under various conditions. Results: The stiffness of the model increased significantly after internal fixation. The anteromedial plate was the most stressed, followed by the posteromedial plate. The screws at the distal end of the lateral plate, the screws at the anteromedial plate platform and the screws at the distal end of the posteromedial plate are under greater stress, but at a safe stress level. The relative displacement of the two medial condylar fracture fragments varied from 0.002-0.072 mm. Fatigue damage does not occur in the internal fixation system. Fatigue injuries develop in the tibia when subjected to cyclic loading, especially when running. Conclusion: The results of this study indicate that the internal fixation system tolerates some of the body's typical actions and may sustain all or part of the weight early in the postoperative period. In other words, early rehabilitative exercise is recommended, but avoid strenuous exercise such as running.

Keywords: biomechanical study; finite element analysis; interfragmentary motion; internal fixation; tibial plateau fracture; weight bearing.

Grants and funding

This research was funded by the National Natural Science Foundation of China (No. 11972065), Teaching Reform Innovation Project of Higher Education Institutions in Shanxi Province (No. J20220847).