Role of the limbus in femoral-head deformation in developmental dislocation of the hip: findings of two-directional hip arthrography.

Two-directional arthrographic findings made during conservative treatment of developmental dislocation of the hip were compared with the femoral-head configurations and radiological results obtained from long-term follow-up examinations in this retrospective study. Sixty hips were followed until at least age 14. Arthrography was carried out according to Terazawa's method. The shape of the superior, anterior, and posterior limbus was evaluated based on a modified Fujii's classification. The femoral-head configuration was classified into 4 groups, and the radiological results were evaluated using Severin's classification at the final observation. There was a statistically significant relationship between the shape of the anterior limbus, the number of portions of deformed limbus (superior, anterior, posterior), and the femoral-head configuration. Also, a statistically significant relationship between the shape of the limbus and Severin's classification was observed. These results suggest that the deformed limbus seems to play an important role in triggering femoral-head deformities, possibly via mechanical compression, and negatively affects development of the hip joint.