The Fate of Free, Pedicled and Free Vascularized Cancellous Iliac Bone Grafts and the Effect on the Healing of Femoral Osteotomy: An Experimental Study

ABSTRACT

A new model for vascularized and nonvascularized iliac bone autograft transfer to a femoral shaft osteotomy site is presented in this experimental study. As demonstrated on roentgenograms taken at 4 to 6 weeks postoperatively, callus formation between vascularized grafts and recipient sites was 1.5 to 2 times faster than in the nonvascularized graft transfer. According to densitometric analysis, conventional free grafts lost more hydroxyapatite and restored their mineral structure at a slower rate than vascularized grafts. There was no difference between free vascularized and pedicled grafts in the rate of mineral deposition changes, but the pedicle grafts had more significant loss of bone density. Formation and mineralization of periosteal callus between the femoral-shaft fragments took place more rapidly in the first 12 weeks after pedicled bone transplantation. The correlation between the densitometric results and morphologic behavior of transplanted bones was examined. It was demonstrated that all of the grafts at the recipient site underwent remodeling into cortical bone. However, vascularized, and especially pedicled, grafts maintained their cancellous structure relatively longer.