MRI evaluation of femoral and acetabular anteversion in developmental dysplasia of the hip. A study in an early walking age group.

MRI assessment of acetabular and femoral anteversion was done in 45 children with developmental dysplasia of the hip in an early walking age group of 12 to 48 months. Femoral anteversion, acetabular anteversion, acetabular anteversion of the cartilage anlage and acetabular index were measured by MRI in 45 dislocated hips and in a control group of 37 normal contralateral hips of index cases. We found that there was no statistically significant difference between these two groups for femoral anteversion. The acetabular anteversion was found to be significantly increased in the dislocated group compared to the normal group. Similar results were obtained for the cartilage anlage of the acetabulum. There was a positive correlation between acetabular anteversion and acetabular index, while there was no correlation between femoral anteversion and other parameters. We conclude that femoral anteversion is not increased, while the acetabulum is excessively anteverted on the dislocated side in developmental dysplasia of the hip in an early walking age group. Analysis of femoral and acetabular anteversion is an essential part of pre operative planning in developmental dysplasia of hip, and for this MRI is a good modality as it is radiation free.