ROTATIONAL ACETABULAR OSTEOTOMY FOR SEVERE DYSPLASIA OF THE HIP WITH A FALSE ACETABULUM

We have divided Severin group-V severely dysplastic hips with a false acetabulum into three subtypes, based on the height and shape of the s ocket. We performed rotational acetabular osteotomy (RAO) in 19 hips i n 17 young adults,vith a type-1 'low' false acetabulum which had direc t contact with the true acetabulum, This is a periacetabular osteotomy which gives acetabular coverage with articular cartilage and produces a nearly normal position of the head, Concomitant osteotomies of the proximal femur were carried out in 11 hips. We reviewed the patients c linically and radiologically at a mean of ten years (6 to 18) after op eration, Of the 19 hips, 15 showed very good or good results, This ope ration is indicated in young adults with a dysplastic hip and a type-1 low false acetabulum, Subclassification of Severin group V is a conve nient way of defining those patients who would benefit from the proced ure.