In the current study, using the arthrogram, we developed two-dimensional finite element (FE) models of the human hip joint. To clarify the relationship between the stress distribution and the degree of acetabular dysplasia, three FE models were established and analyzed. The models varied only in the degree of the bony covering of the femoral head; i.e. the center-edge (CE) angle = 20, 10, 0 degrees. An edge load (x = 0 N, y = 600 N) was then applied on the distal border of the femur to simulate the bearing of the body weight. In the CE = 20 degree model, no definite stress concentration was seen at the site of the labrum. On the other hand, the stress concentration was seen from the attachment of the labrum to the superior aspect of the acetabulum in the CE = 0 degree model. The site of stress concentration clearly corresponded to the lesions where the acetabular rim pathologies were seen in the clinical practice. Moreover, we found that the Von Mises stress increases dramatically with decreasing the CE angle at the attachment of the labrum. In the dysplastic hip, the mechanical stress increases significantly at the supero-lateral aspect of the acetabulum, which eventually leads to the tearing or detachment of the labrum.
- Finite element analysis
- Von Mises stress
ASJC Scopus subject areas
- Orthopedics and Sports Medicine