Differentiation of the osteochondrogenic cells of the periosteum in chondrotrophic environment.

The behaviour of the cells in free periosteal graft was studied in growing rabbits in three chondrotrophic recipient milieus: costal cartilage, ear cartilage and synovial fluid of the knee joint. The periosteal grafts first formed cartilage, which was then quite rapidly transformed into bone on the costal cartilage, quite slowly and in smaller amounts in the ear cartilage, whereas no bone was found in the cartilaginous loose bodies formed in the knee joint. In bone formation vascularization plays a major role, but other factors are also involved.