A roentgen stereophotogrammetric investigation of innominate osteotomy (Salter).

The effect of the innominate osteotomy according to Salter was investigated by a roentgen stereophotogrammetric method in a 17-year-old girl with hip dysplasia as a part of the tricho-rhino-phalangeal (Giedion) syndrome. The osteotomy resulted in a total rotation of 32 degrees about an axis passing cranially to the pubic symphysis and the osteotomy. The acetabulum rotated 22 degrees forwards about a transverse axis, 9 degrees laterally about a longitudinal axis and 24 degrees laterally about a sagittal axis. The acetabulum was translated 2 mm laterally along a transverse axis, 21 mm caudally along a longitudinal axis and 19 mm dorsally along a sagittal axis. The position of the screw axis indicates that some motion also took place in one or both of the sacroiliac joints. The correction as measured with the CE-angle was 25 degrees which was almost the same as the correction about the sagittal axis. It is, however, noted that the CE-angle was also dependent upon the rotations about the transverse and longitudinal axes.