Wound healing depends on many factors, including its cause, extent, the occurrence of contamination or an infection and on wound treatment. Before thinking about techniques that can help wounds to heal its important to understand the different phases because despite differences in etiology and pathophysiology, all wounds heal in a dynamic process that has four main phases:

1 Hemostasis

2 Inflammatory

3 Proliferative

4 Remodeling

Knowledge on these phases is important for adequate wound care.

As a basic rule we can state that most wounds will eventually heal if the person injured remains alive.

In complex wounds with tissue loss, especially in severe open fractures, this may happen after a very long time of waiting / conservative wound management, and with loss of function of the limb. That's why health care workers can interfere and improve the conditions for the wound to heal quickly and with good limb function preserved. Multiple factors influence the remodeling phase and should be taken into account in wound management, including:

Systemic factors – the nutritional status of the patient, comorbidities and medications influencing mobility and perfusion and immune status.

Local factors – wound location, tissue loss, infection, mechanical stress on the wound and the presence of foreign bodies.

During all four phases wound healing can be supported:

1 Hemostasis phase (time of injury)

The main goal of the hemostasis phase¹ is to stop bleeding. Blood vessels constrict to stop bleeding and form blood clots. We can assist in this phase to help to stop bleeding by compression (preferably on the wound with a gauze + bandage, or a temporary tourniquet when local compression is not enough (this is rarely the case).

2 Inflammatory phase (time of injury to day 3)

The main goals of the inflammatory phase¹are to prevent infection during healing, degrade necrotic tissue and activate signals required for wound repair. This phase is characterized by swelling and redness. Increased vasodilatation and fluid extravasation are key components of this phase. Neutrophils and monocytes infiltrate the site of injury, initiating an immune response. This immune response is sustained by the recruitment of macrophages by cytokines. In chronic wounds, normal healing progression usually becomes arrested in the inflammatory stage. The presence of necrotic tissue, foreign material and bacteria result in the abnormal production of matrix metalloproteinases, which alter the balance of inflammation and impair the function of the cytokines. Timely antibiotic treatment can help to prevent deep infection.

3 Proliferative phase (day 4 to week 2-6)

In the proliferative phase¹, the wound is rebuilt with connective tissue to promote granulation. Keratinocytes and fibroblasts are activated by cytokines and growth factors. Keratinocytes migrate over the wound to restore the vascular network and assist closure. Fibroblasts produce collagen that deposits in the wound¹. In small wounds and wounds that have been closed by primary closure this may leed to a closed wound with scar tissue. In bigger wounds vascularized soft tissue flaps or skin grafts are needed to achieve adequate wound healing.

4 Remodeling phase (up to 18 months after wound closure)

In the remodeling phase¹, collagen in the wound matures and strengthens. The scar becomes softer, stronger and less visible. Scar therapy may be considered to reduce pain, itching and to improve appearance.