Modified Salter osteotomy for the treatment of developmental dysplasia of the hip: description of a new technique that eliminated the use of pins for internal fixation.

The Salter innominate osteotomy has been used successfully for many years in the treatment of developmental dysplasia of the hip. One of its main drawbacks is the need for internal fixation with pins and their subsequent removal. We describe a modification of this osteotomy that does not require pin fixation and secondary removal. We retrospectively reviewed 114 hips in 94 patients who had been operated on by a single surgeon. An oblique rather than the original horizontal osteotomy was used without internal fixation. There were 80 female and 14 male patients. The mean age at operation was 25 months (18 to 84) and the mean follow-up was 30 months (12 to 88). Most patients required additional open reduction and capsuloplasty. The mean pre-operative acetabular index was 37.9 degrees (24 degrees to 54 degrees ), which decreased to 19.9 degrees (7 degrees to 29 degrees ) in the immediate post-operative period, and improved to 14.6 degrees (5 degrees to 25 degrees ) at the final follow-up (student's t-test, p < 0.0001). We believe that by changing the direction of the osteotomy line, it is possible to avoid pin fixation. The radiological outcomes are comparable to those of the original technique, but longer follow-up will be necessary.