INFLUENCE OF PELVIC OSTEOTOMY ON BIRTH CANAL SIZE

Six pelvic osteotomies (Salter, Sutherland, Steel, Tonnis, Chiari, and periacetabular) were performed on the right hemipelvis of adult femal e pelvic plastic models. Each pelvis underwent conventional X-ray and computed tomographic digital pelvimetry before and after osteotomy. Th e change in the anteroposterior and transverse dimensions at the inlet , midpelvis, and outlet were calculated. None of the osteotomies signi ficantly decreased the inlet. The Salter and Sutherland osteotomies de creased the midpelvis to borderline low. The Salter, Sutherland, and S teel osteotomies significantly decreased the pelvic outlet. These chan ges correlated closely with those in living patients. Much of this dec rease is nullified when the osteotomy is performed prior to the pubert al growth spurt.