The effect of periosteal preservation on osteogenesis in a canine rib autograft model: tetracycline fluorescence incident photometry.

In the first portion of this study, we describe a new technique, tetracycline fluorescence incident photometry (TFIP) for quantifying new bone formation. In this portion, we use routine histology, Microfil vascular injection, and tetracycline incidence fluorescence (TFIP) to determine the effect of periosteal preservation on bone formation in canine rib autografts. We found that periosteal preservation significantly enhanced new bone formation in both cortical and trabecular bone (83-70% of control) when compared with autografts without the periosteum (76-60% of control) (p < 0.05). In addition, periosteal preservation favorably influenced graft revascularization. We found that the periosteum of the transferred rib autografts was made up of 3 distinct layers: (1) the inner (cambial) layer of osteogenic cells, (2) the middle (fibrous) layer of osteogenic reserve cells, and (3) the outer vascular network of arterioles and venules, which communicate with the trabecular vessels internally. This outer vascular network has not been previously described in transferred bone grafts and is responsible for early graft revascularization.