Evaluation of congenital hip dysplasia and tibial torsion by computed tomography.

We have performed over 200 examinations in children with congenital dislocation of the hip during a 3-year period. From this experience, we conclude that computed tomography is useful in the evaluation of: (a) concentricity of closed reduction; (b) obstacles to closed reduction, such as infolding of the capsule, secondary to a tight iliopsoas tendon; (c) femoral torsion; (d) intraarticular obstacles contributing to persistent subluxation, such as (1) hypertrophy of the pulvinar, (2) intraarticular soft-tissue interposition, and (3) iatrogenic obstacles, such as metallic pins penetrating into the joint space; and (e) acetabular configuration, specifically (1) anterior or posterior lip of the acetabulum, (2) capacity of the acetabulum, and (3) acetabular torsion.