External fixation of the pelvic girdle with a trapezoid compression frame.

The compression obtained with external anchorage in the anterior and posterior part of the pelvic girdle has been studied with a measuring device in the sacroiliac joint and and the symphysis of a specimen pelvis. Two models of external frames were tested, in both of which anchorage to the pelvic bone was brought about with 3 pins inserted in the iliac crests. The results were best with a trapezoid frame and bar exerting a compressive force on the pelvic girdle. When mounted with an inclination of 70 degrees to the long axis of the body, the frame exerted considerable compression on the posterior part of the pelvic girdle. This mounting afforded good stability of the detached hemipelvis. The trapezoid compression frame is recommended as an alternative to conventional methods of treating unstable fractures and dislocations of the pelvic girdle.