The case histories and investigations for five adolescent girls with a presumed diagnosis of either primary acetabular protrusio or acute idiopathic chondrolysis are presented. The follow-up ranged from three to nine years. All were treated by extensive soft-tissue release but in no case did this improve movement of the affected hip and permanent stiffness was the inevitable result. The literature is reviewed and methods of treatment are discussed in the light of the CT findings.

We report a case of malignant fibrous histiocytoma of the hip which occurred 30 years after the insertion of a single chrome-cobalt alloy screw for a slipped femoral epiphysis. The possible aetiological association between malignant tumours and metallic implants is discussed.

In 1957 Somerville and Scott described their "direct approach" to the management of established congenital dislocation of the hip; arthrography after a period of traction served to distinguish the dislocated from the subluxated hip. We review the long-term outcome of hips which, using their criteria, were subluxated; 72 hips have been reviewed at periods ranging from 15 to 37 years after treatment by traction, closed reduction and femoral osteotomy. The results have been classified clinically and radiologically according to Severin's criteria. There was progressive deterioration with age in both clinical function and radiographic appearance: 48.5% of hips showed evidence of dysplasia or subluxation at review. The results are similar to those found in a series treated by open reduction and limbectomy, differing only in the much lower incidence of degenerative changes after closed reduction.