Preoperative Planning of Acetabular Arc Osteotomy Using Finite Element Method / 医用生物力学

ABSTRACT

Objective In order to simulate different angles of acetabular blocks that need to be adjusted during operation, the optimal angle was determined through analyzing the contact stress and contact area of cartilage around the hip joint, so as to provide an individual scheme for acetabular osteotomy. Methods The finite element models for development dysplasia of hip (DDH) and normal pelvis were established to investigate morphological characteristics of the acetabulum and the causes of stress concentration. To simulate osteotomy for the DDH model, a total of 20 postoperative osteotomy models were obtained through the combination of different angles for anterior rotation and lateral rotation of acetabular blocks, and the differences in optimal results of the models during simulated one legged-standing were compared and analyzed. Results The maximum contact pressure of acetabular cartilage in normal model was 7.85 MPa. The maximum contact pressure of acetabular cartilage in DDH model was 13.42 MPa. The optimal contact pressure after simulated osteotomy decreased to 8.49 MPa, and the contact distribution was improved more significantly. Conclusions Changing the anterior rotation angle can significantly improve the contact pressure distribution and size, as well as stay away from the preoperative lesion area, which has a positive impact on postoperative outcomes. Personalized osteotomy plan based on actual situation of each patient before the operation is crucial for the surgical effect.