Kinetic analysis and stability evaluation of femoral neck fracture with internal fixation based on gait rehabilitation training.

To explore the biomechanical effects of different internal fixation methods on femoral neck fractures under various postoperative conditions, mechanical analyses were conducted, including static and dynamic assessments. Ultimately, a mechanical stability evaluation system was established to determine the weights of each mechanical index and the evaluation scores for each sample. In static analysis, it was found that the mechanical stability of each model met the fixation requirements post-fracture. During the healing process, the maximum stress on the hollow nail slightly increased, and stress distribution shifted from multi-point to a more uniform single-point distribution, which contributes to fracture healing and reduces the risk of stress concentration. In dynamic analysis, resonance points frequently occurred at low frequencies. With increasing walking speed, the maximum stress increased significantly. At slow speeds, the maximum stress approached the material's yield limit. Under cyclic dynamic loading, the number of cycles barely met the requirements of the healing period, and increasing walking speed may lead to fatigue fractures. The evaluation model established in this study comprehensively considers different mechanical performances in static and dynamic analyses. Based on various mechanical analyses and evaluation systems, the applicability of internal fixation treatment plans can be assessed from multiple dimensions, providing the optimal simulated mechanical solution for each case of femoral neck fracture treatment.