[Contribution of x-ray computed tomography to the diagnosis and treatment of fractures of the acetabulum. Apropos of 88 cases].

Eighty-eight recent fractures of the acetabulum have been investigated by standard antero-posterior and oblique radiographs and by CT scanning. The results of the two examinations have been compared. Whilst the type of fracture is well defined by radiography, CT scanning frequently reveals associated lesions, not seen on standard radiographs, which may have an effect on the relationship between the femoral head and the acetabulum. Thus, out of 28 cases with intra-articular fragments, 18 were not visible on standard radiographs and were discovered by CT scan. Similarly, out of 25 peripheral impactions of the acetabulum, 16 were not visible on standard radiographs, of 12 notching lesions of the femoral head, nine were not visible and six out of 23 sacro-iliac displacements were not recognised. CT scanning improved the appreciation of congruence between the femoral head and the acetabular roof in 15 cases and between the femoral head and the acetabulum in 24 cases. Only in 17 patients was there complete agreement between standard radiographs and CT scans. In particular, there is no doubt about the value of CT scanning in comminuted fractures and in fractures of the posterior wall or posterior column. It is a useful adjunct in the choice between conservative and operative treatment.