Damage to the acetabular labrum has been associated with cartilage degeneration. Because conventional pressure measurement devices were not able to measure the articular cartilage contact patterns in porcine hips, we applied an image-based deformation to finite element analysis. In a CT scanner, the bone position of the femur and acetabulum were continuously tracked every three minutes by scanning the whole joint. Using the bone position from the CT images, displacement-controlled finite element analysis was performed to estimate contact area and nominal strain or articular cartilage at different time points. There were no changes in cartilage contact area after labrectomy. Compared to the intact state of the acetabular labrum, the mean nominal strain in labrectomized hips was increased early after loading. The areas of “high” strain in labrectomized hips were found to be increased by approximately seven percent after 30 minutes of cyclic loading, while the changes in the areas of “low” strain were small. Our results showed that changes in articular cartilage strain following labrectomy were concentrated on locally overloaded areas where the degenerative process of articular cartilage may be initiated.
Acetabular labrum; Articular cartilage; Biomechanics; Medical imaging; Hips; Osteoarthritis; Material Properties