A thesis submitted to the Faculty of Medicine, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy. Johannesburg, 1994. / Dislocation of the hip is a common deformity in cerebral palsied (CP) patients who are not walking. Surgery of the hip is performed to prevent or correct the deformity. This surgery is based on the assumption that a dislocated hip contributes towards patient management problems, in that it compromises nursing care, interferes with sitting, snd may be painful. Reports on the outcome of surgery vary, and there is a controversy as to whether an established hip dislocation should be reduced. This study was undertaken to investigate the above assumptions, and to assess the long term outcome of hip surgery, both in terms of stability, and patient management, In the background to the study, abnormal development of the CP hip, causation theory, rationale of treatment (both conservative and surgical) and the evolution of hip surgery are described. This comparative study involves two groups of patients. Surgically treated patients are compared to a random sample of untreated patients matched for age and nonambulatory status. The treated patients (Group A) had undergone surgery at the Johannesburg Hospital between 1980 and 1987, and the minimum follow-up period