COLLAGEN IN TENDON, LIGAMENT, AND BONE HEALING - A CURRENT REVIEW

Cells that produce a particular type of collagen under normal physiolo gic circumstances can be induced by certain local triggers to change t he amount and type of collagen synthesized, This has become most appar ent during bone, tendon, and ligament healing, where cells that once p roduced the collagen of normal intact tissue are induced to synthesize different types of collagen at the repair site of injured tissue, For example, Type III collagen, not a major component of the extracellula r matrix in normal tendons, is believed to be of great advantage durin g the healing process because of its ability to form rapid crosslinks and precariously stabilize the repair site, Although much is known abo ut the gross histologic changes occurring during tissue healing, littl e is known about the specific role of the individual collagen types or what influences their development, This review addresses the role of collagen in normal and healing bone, tendon, and ligament, Much experi mental effort is needed to uncover the distribution and function of th e collagen types within connective tissue elements and the effect of g rowth factors on the phenotype of collagen produced in these tissue, w ith the ultimate goal of developing clinical manipulations that take a dvantage of the unique properties of each type of collagen.