The effect of abaxial retraction on pelvic geometry after pelvic symphysiotomy

Abstract

To describe the effect abaxial retraction after pelvic symphysiotomy has on the geometry of the sacroiliac joints (SIs) in dogs. Experimental study. Canine cadavers (n = 9). Canine cadavers free of sacroiliac disease had pelvic symphysiotomy and retraction to 25%, 50%, 75%, and 100% of transverse sacral width, followed by axial reduction of the symphysis. Before symphysiotomy, after each abaxial retraction value, and after reduction of the symphysis each SI joint had a computed tomographic scan to evaluate the effect on the SI joints. There was no luxation at 25% abaxial retraction, unilateral SI luxation in three cadavers after 50% abaxial retraction and in all cadavers after 75% abaxial retraction. Axial reduction of the symphysis resolved all luxations. Pelvic symphysiotomy and abaxial retraction between 50% and 75% of transverse sacral width leads to unilateral SI luxation, which is resolved by axial reduction. While not likely requiring ancillary stabilization, SI joint luxation may be a cause for additional postoperative pain, reluctance to ambulate, and prolonged hospitalization/recovery.