Molded vascularized osteoneogenesis: a preliminary study in rabbits

The clinical application of free vascularized bone grafting techniques in reconstructive surgery has limitations with respect to available donor sites and configuration of the graft. In this study, we were able to produce a vascularized bone graft with a predetermined size and shape by the use of titanium chambers implanted into the groins of rabbits. Forty adult New Zealand white rabbits were included in this study. In all animals, bone fragments were harvested from the iliac crests and placed within a titanium chamber. The chamber was positioned in the groin with the saphenous vessels passing through the chamber longitudinally in contact with the bony fragments. In half the animals, a segment of periosteum was harvested from the tibia and sutured around the vessels with the cambium layer facing the bone fragments. Sacrifices were performed at 4, 8, 12, and 16 weeks to examine the chamber contents. At all time periods, the contents completely filled the chamber, and the saphenous vessels remained patent. Histologic evaluation showed remodeling of the bone fragments as early as 4 weeks concomitant with a sprouting vascular network demonstrable with microangiography. Fluorochrome bone labels documented new bone formation within the chamber. These changes were progressive to week 12, but the 16-week specimens appeared to be undergoing resorption.