Superior segmental deficiency. A, Multiple previous revisions had been done for sequelae of congenital hip dysplasia. Socket previously was placed in false acetabulum with high hip center. Large superior segmental defect is above true acetabulum. B, Five years after revision with structural bone grafting of superior segmental deficit and cementless acetabular component, no migration is seen but bone ingrowth is unlikely. SEE TECHNIQUE 3.24.