Computed tomography usually can provide accurate documentation of the
adequacy of a reduction in congenital dislocation of the hip. It should
supplement other radiographic examinations when the status of a reduction
is in question because the patient is wearing a plaster cast. The computed
tomography scan provides a clear image of the reduction in the transverse
plane, so that anterior or posterior subluxation of the femoral head can be
easily detected. In addition it allows direct measurement of acetabular
anteversion which previously had not been possible with non-invasive
studies in the living patient. Radiation exposure is less than that for
conventional tomography. We used computed tomography in five patients with
congenital dislocation of the hip and our study provided new evidence
concerning the role of acetabular anteversion in this condition. Acetabular
anteversion was increased on the dislocated side in each patient, and
returned to normal as treatment progressed.