SOFT TISSUE HEALING

Soft tissues are those tissues that connect and support the body, these include muscles, tendons, ligaments, fascia, nerves, fibrous tissues, fat, blood vessels.This classification is based on a treatment protocol. But some time phases overlap and dependable on the individual response to healing and the type of injury.

Inflammatory phase:

The acute inflammatory response is of relatively quite long  duration and involves activities that generate exudates- plasma like fluid that exudes out of tissue or its capillaries and is composed of protein and granular leukocytes (white blood cells).In the Chronic inflammatory response is of prolonged duration and involves the presence of nongranular leukocytes and the production of scar tissue.

Proliferative phase:

Formation of granulation tissue is a central event during the proliferative phase. Its formation occurs 3-5 days following injury and overlaps with the preceding inflammatory phase. Granulation tissue includes inflammatory cells, fibroblasts, and neovasculature in a matrix of fibronectin, collagen, glycosaminoglycans, and proteoglycans.

Epithelialization:

Epithelialization is the formation of epithelium over a denuded surface. It involves the migration of cells at the wound edges from one side of the incision to the other. Incisional wounds are epithelialized within 24-48 hours after injury. This epithelial layer provides a seal between the underlying wound. The processes begin within hours of tissue injury. Epidermal cells at the wound edges undergo structural changes, allowing them to detach from their connections to other epidermal cells and to their basement membrane. Intracellular actin microfilaments are formed, allowing the epidermal cells to creep across the wound surface.

Fibroplasia:

The fibroblast is a critical component of granulation tissue. Fibroblasts are responsible for the production of collagen, elastin, fibronectin, glycosaminoglycans, and proteases.Fibroblasts grow in the wound as the number of inflammation cells decrease.Fibroplasia begins 3-5 days after injury and may last as long as 14 days. Skin fibroblasts and mesenchymal cells differentiate to perform migratory and contractile capabilities. Fibroblasts migrate and proliferate in response to fibronectin, platelet-derived growth factor (PDGF), fibroblast growth factor, transforming growth factor. Fibronectin serves as an anchor for the myofibroblast as it migrates within the wound.

Angiogenesis:

A rich blood supply is vital to sustain newly formed tissue and is appreciated in the erythema of a newly formed scar. The macrophage is essential to the stimulation of angiogenesis and produces macrophage-derived angiogenic factor in response to low tissue oxygenation.Angiogenesis results in greater blood flow to the wound and, consequently, increased perfusion of healing factors.