2023, Vol. 27 ›› Issue (27): 4265-4270

Finite element analysis of hip stress distribution at different hip abduction angles in patients with developmental dysplasia of the hip

Guo Sutong, Guo Yu, Wang Ling, Ding Yujian, Ren Tianhao, Xu Haitao, Wang Yulin, Feng Dehong   

Abstract: BACKGROUND: There are relatively few finite element studies on hip dysplasia, and the influence of the size of hip abduction angle on the biomechanical distribution of the hip joint is not clear.  
OBJECTIVE: To apply the finite element method to analyze the hip joint stress distribution on the healthy side and the affected side of patients with hip dysplasia under different abduction angles, and to provide solutions for the prevention, treatment and rehabilitation of hip dysplasia.
METHODS: A patient with left-sided hip dysplasia was selected from the CT scan data of bilateral hip joints, and the hip joint model was established by Mimics software, solidified by Geomagic Wrap software and assembled with cortical bone and cancellous bone by Solidworks software. The Ansys Workbench software was used to load the joint load, and the stress distribution of the hip joint under the condition of single foot landing under different abduction angles was analyzed.  
RESULTS AND CONCLUSION: (1) The model constructed in this study was consistent with the actual situation. As the hip abduction angle increased, the maximum stress value of the femoral neck in the normal hip part gradually increased and was always located on the medial side of the femoral neck, and the maximum stress value of the femoral head was the smallest when the hip abduction on the healthy side was 15°, and the maximum stress value above the acetabulum was the smallest when the hip abduction was 20°. (2) The maximum stress value in the affected hip of developmental dysplasia of the hip patients was always located above the acetabulum, and the maximum stress value in the acetabulum was minimal when the abduction of the hip was 25°; the maximum stress value in the femoral head was minimal when the hip was abducted at 20°, and the maximum stress value in the femoral neck was minimal when the hip was abducted at 0° and was located posterior to the femoral neck. As the hip abduction angle increased, the maximum stress point in the femoral neck gradually moved towards the medial inferior aspect of the femoral neck.

Key words: developmental dysplasia of the hip, hip joint, hip abduction, finite element, femoral head necrosis, hip arthropathy