Tendons and ligaments are tough, strong bands of soft connective tissue—collagen-rich materials that hold various body structures together. Tendons and ligaments, like other connective tissues, consist of three elements: cells, fibers (primarily collagen and elastin), and “ground substance,” also known as extracellular matrix. Tendons usually connect muscles to bones, whereas ligaments typically connect bones to other bones.

Tendon and ligament injuries are important causes of lameness and contribute to decreased performance, lost training days, and sometimes loss of the horse. Rehabilitating injured tendons is an expensive and time-consuming endeavor associated with variable success rates largely due to the propensity for injury recurrence.