Certain deformities of the hip joint seem to predispose the hip to the development of osteoarthrosis. Successful surgical correction of these deformities before the onset of osteoarthrosis requires accurate characterization of the anatomic deviations from normal as the first step in planning corrective osteotomy. Three-dimensional computed tomography (CT) reconstruction in planning reconstructive hip osteotomy has most often been employed in developmental dysplasia of the hip. Computed tomography scanning with three-dimensional reconstruction can characterize the often complex deviations from normal in shape and attitude of acetabulum and femoral head in cases with residual hip dysplasia. Three-dimensional reconstruction also allows simulation of redirectional femoral or pelvic osteotomies to facilitate precise application of newer powerful surgical techniques for reorienting the acetabulum.