ABSTRACT
To help patients avoid unnecessary injuries and to achieve better outcome following treatment, it is important for us to understand the basic science behind ligament and tendon function, injury mechanisms, and the healing process. Numerous laboratory studies have shown that ligaments and tendons exhibit complex and nonlinear load-elongation behavior under uniaxial tensile loads. They also display viscoelastic and temperaturedependent properties. Various factors such as skeletal maturity, aging, homeostatic responses to immobilization or mobilization of the joint, and exercise can greatly alter these properties. After injury, the composition and microstructure of ligaments and tendons will be largely altered. As a result, their biomechanical properties will also be dramatically impaired. The treatment options vary depending on their intrinsic ability to heal. Various approaches attempting to return the injured ligaments and tendons to their original status have been tried. However, it has been shown that all current treatment strategies cannot restore the tissue quality and normal joint function (Frank, Woo et al. 1983; Woo, Inoue et al. 1987). Recently, novel technology including functional tissue engineering methods, i.e., the application of bioscaffolds, growth factor, gene therapy, cell therapy, etc. have been investigated, some of which have shown particular promises (Batten, Hansen et al. 1996; Badylak, Arnoczky et al. 1999; Awad, Boivin et al. 2003; Musahl, Abramowitch et al. 2004; Liang, Woo et al. 2006).
