Debunking the myth of the periosteum.

The foundations of Orthopaedics are a great deal better supported with evidence today than previously. Nonetheless, superstitions and myths have not completely disappeared. One of them is the role of the periosteum in fracture healing. The anatomy and physiology of the periosteum under normal circumstances have been studied for many a decades, and its role in the growth and development of tubular bones well defined. The evidence regarding its participation in fracture healing in non-rigidly immobilized fractures cannot be questioned at this time. However, extrapolations on its participation in rigidly immobilized fractures are open to question. I submit that under rigid immobilization conditions the periosteum plays a minimal role and that rather than assisting in expediting healing, it retards it (1, 2, 3, 4). (Fig. 1). coverage of bone with thick muscles being important for osteogenesis suggesting that the myoblast is capable of undergone osteoblastic metaplasia, which is not the case. The theory loses further value as one observes that fractures with minimal or no muscle coverage heal as readily as fractures in other bones with large muscle coverage as exemplified by fractures of the metacarpals, metatarsals, phalanges, the clavicle, the fibula as well as the ribs. It has become an almost sacred obsession to accept the importance the periosteum has in fracture healing. This is true only if rigid immobilization of the fragments is not created. In the nonimmobilized fracture of a long bone, peripheral callus forms as a result of the intervention of capillaries from the periosteum and the surrounding tissues. Studies that we and others have conducted have demonstrated that in the nonimmobilized diaphyseal fracture this massive invasion of capillaries begins to take almost immediately after the initial insult (Fig. 2).