Studies on the osteogenic potential of vascularized periosteum: behavior of periosteal flaps transferred onto soft tissues.

We investigated the basic properties of vascularized periosteal autografts. A pleuro-periosteal flap based on the intercostal vessels was developed in a canine model. Fourteen animals had vascularized periosteal flaps rotated onto the soft tissues of the chest wall. These animals were killed at intervals of 7 to 90 days and the flaps were studied by tetracycline labeling and light microscopy. Four other animals had similar flaps transplanted onto the soft tissues of the neck by microvascular techniques. All harvested flaps showed periosteal bone production, leading to the following observations: Osteogenesis begins as early as 7 days after grafting; the rate and extent of periosteal osteogenesis is proportional to the vascular supply; bone formation starts in small foci of active osteoblasts that grow and become confluent; and intimate bony periosteal contact is not necessary for periosteal osteogenesis to take place, but it appears to influence the rate and amount of bone formation.