A Review of Structure and Mechanisms of Tendon Injury and Repair in Small Animals

Tendons are soft connective tissues composed of parallel collagen fibers embedded in an extracellular matrix. This organized structure allows the tendons to bear and transfer large forces between the muscle and the bone. Tendons contain 86% collagen, 1-5% proteoglycan ,and 2% elastin, which are calculated as dry weight, and water is responsible for 60-80% of the wet weight of the whole tendon. Tendon healing can be generally divided into 3 phases; the repair, inflammation, and remodeling phases. Although the tensile strength of the healed tendon improves over time, it does not reach the level of uninjured tissue.