[Results of Salter's innominate osteotomy in residual hip dysplasia in children. Apropos of 60 cases].

Sixty Salter innominate osteotomies were analysed retrospectively with a mean post-operative follow-up of five years. The 53 children, suffering from congenital dislocation of the hip discovered at walking age, had initially been treated by Somerville-Petit conservative management. The results were assessed using the Severin classification and showed 80 per cent of good results (Severin groups Ia, Ib and IIa). The bad results were all due to errors of operative indications (failure to respect the Salter pre-requisites) or technical faults. Complications were uncommon. There were 11 pin extrusions, which led to the use of threaded pins to so as to gain sounder fixation of the osteotomy. An analysis of the characteristics of each hip allowed an assessment to be made of the effects of Salter osteotomy using several angular parameters, including Hilgenreiner's and Wiberg's angles. The description of a new parameter, the angle between the acetabulum and the epiphyseal line (acetabulo-epiphyseal line) and its normal values provides a new approach to the lower limit for the indications for operation on dysplastic hips. This parameter seems to be more discriminatory than Wiberg's angle in relation to dysplasia and makes it possible to determine a threshold of uncovering of the head that justifies surgical correction.