A torsional strength comparison of vascularized and nonvascularized bone grafts.

Comparisons of torsional strength are made on the ulnae from the forelegs of short haired hounds where a nonvascularized graft was performed on one leg and a vascularized graft performed on the other. By using the forelegs of a dog as the experimental model and microsurgical techniques, a vascularized bone segment was used to graft a five centimeter nonunion in one leg and at the same time a conventional bone graft was performed on a similar nonunion in the other leg. Similar segments of rib bone were used for each graft. Torsional strength data are shown for nine experimental animals. A successful method for mounting the bones for testing of torsional strength in a torsion machine is given. In each case for which the bones healed properly, the vascularized bone graft proved to be significantly stronger in torsion.