Abstract:

BACKGROUND: Finite element method has been used in studies regarding orthopedics-related biomechanics under static loading, evaluation of stress peak and stress distribution. However, due to fatigue calculation and complex in vivo mechanical environment, clinic-related biomechanics is difficult to identify.
OBJECTIVE: To investigate the biomechanical basis of breakage of pubic connection plate after reconstruction of periacetabular defect by finite element method.
METHODS: The three-dimensional pelvic ring finite element model was reconstructed, and type Ⅱ+Ⅲ resection was simulated. The three-dimensional modular hemipelvic endoprosthesis was reconstructed with CAD software. Finite element model of the reconstructed pelvis was established. The stress distribution of the pubic connection plate was analyzed in simple standing and gait cycle. The position and value of peak stress was analyzed.
RESULTS AND CONCLUSION: The results of finite element analysis showed the peak von Mises stress was 3.5 MPa in the middle of the plate, and the peak stress during the gait cycle was 273.0 MPa located at the junction of plate and artificial acetabulum. The stress concentration position was the same as that of breakage during follow-up. The reason for breakage of the pubic connection plate was attributed to the fatigue fracture during high cycle of gait load.