- 大阪体育大学紀要 (ISSN:02891190)
- vol.32, pp.149-157, 2001-07-01
The structure of the human tendon and ligament is dense organized connective tissue, which includes two basic elements: fibroblast, a fixed cell of connective tissue, and extracellular matrices. The tendon, for instance, has been suggested to consist of 20% collagen, 78% water, and 2% glycosaminoglycans. The fibroblast synthesizes three polypeptide chains, which develop into a triple helix, called a procollagen molecule inside the cell. The procollagen molecules enzymatically secreted from intracellular to extracellular form a tropocollagen. The tropocollagen molecule consists of two amino acids: hydroxyproline and hydroxylysin. The hydroxylysin is the essential component of crosslinks. The cross-links form intra- and intermolecule bounding from one collagen filament to another in order to organize the tropocollogen molecules. They also play a critical role in the mechanical tensile strength within collagenous tissue and function as energy absorber. Therefore, whether the cross-links in collagen fibers are reorganized is an important factor to understand the healing process in the tendon or ligament damaged. The healing process first shows vascular, chemical and cellular reaction to injury. This reaction facilitates the fibroblast to synthesize fibrous protein and collagen. Developing the extracellular matrix, tissue regeneration or scar formation takes place in time. Since the tendon and ligament have relatively poor blood supply, their healing process is slow. Nevertheless, it can be the same as general tissue trauma, which is divided into three phases: 1) inflammatory, 2) proliferative, and 3) remodeling. The purpose of this paper is to review each phase of the healing process.