Development of the acetabulum and hip: computed tomography analysis of the axial plane.

Acetabular growth and development in the axial plane was evaluated by computed tomography (CT) scan. One hundred seventy normal hips of children ranging in age from 6 months to 17 years were evaluated for axial acetabular index, anterior and posterior center-edge angles (CEA), and acetabular anteversion. The acetabulum deepens and becomes increasingly spherical with time until the age of 13 years. Little further change in acetabular shape occurs once the triradiate cartilage closes. Closure ensues between the ages of 11 and 13 years, occurring slightly earlier in girls. Posterior bony coverage of the femoral head is greater than anterior coverage at all times. Acetabular anteversion showed little change as the acetabulum developed. Establishing normal values for axial development of the hip and acetabulum allows a better three-dimensional concept of the different pathologic conditions and aids in treatment planning.