Fracture healing perspectives.

This paper reviews the sequence of histomorphologic changes that occur in and around a fracture site, and discusses recent concepts about the roles of the cells and bone matrical moieties in promoting specific cell transformations during the phases of callus tissue formation and consolidation of the bony cortex. Current knowledge about the roles of autocrine, paracrine, and endocrine polypeptide growth and transforming factors lends new perspectives about this classic problem in bone physiology.