ABSTRACT
The bone constitutes an internal support system for all higher vertebrates. It is a highly specialized connective tissue that consists of a structural framework of mineralized matrix and a heterogeneous cell population. It is characterized by its marked rigidity and hardness and is a complex living tissue that continuously undergoes rebuilding, which is critical to maintaining its function. The main functions of the bone are as follows: 1) to provide mechanical support for the body and serve as levers for muscle action; 2) to provide protection of internal vital organs; 3) to provide an environment for marrow (blood cell production); and 4) to maintain calcium homeostasis and act as an ion reservoir for phosphate, magnesium, potassium, and bicarbonate (Bilezikian et al. 1996). In addition, the bone matrix maintains the storage of growth factors and fatty acids, buffers against excessive pH changes in the blood, and is involved in endocrine signaling. The bone is a very dynamic organ that constantly undergoes self-remodeling and has within itself the unique ability to repair/regenerate to a certain extent after injury. Each year, more than 6.5 million
15.1 Introduction .................................................................................................. 345 15.2 Bone Grafts ...................................................................................................346
