Wound healing.

The response of living tissue to trauma—chemical, thermal, or mechanical—is of prime concern to the physician . This is particularly true in surgery . The body, not the surgeon, repairs wounds . The surgeon is responsible for providng optimum environmental circumstances for wound healing consistent with the surgical problems he faces . Gentleness in the handling of tissues is the first surgical axiom. The knife destroys; nature heals. The process of tissue repair encompasses a most complex, interrelated group of biochemical, electrical, and genetic phenomena. Cellular reproduction is the very essence of life. The amputation is an excellent clinical laboratory for the study of wound healing . Since the surgical trauma is terminal, there are no tissues distal to the operative site which require body support for viability . Physical modalities such as pressure, temperature, and immobilization can be controlled and measured without concern for a more distal uninvolved body segment. The Prosthetics Research Study (PRS) accepted the assignment to investigate immediate postsurgical prosthetic amputee fitting on the basis of a wound-healing study . Ongoing investigations continue to emphasize wound healing as a primary concern. Our study of the complex and little understood mechanism of wound healing has been confined to the application of certain physical influences on the immediate postsurgical amputation wound . Tissue rest (immobilization) early in the process of wound repair is important. Animals involuntarily splint an injured limb . For centuries this simple fact has been carried over into management of injured body tissue . The degree and duration of immobilization has been the subject of considerable study . The term arthrofibrosis is used to designate the ill effects of prolonged immobilization for joint injuries . The graduated transition from rest to function will depend on the nature of the tissue injury and the type of tissues involved. The chemical and vascular phenomena involved in injury cause intracellular and extracellular fluid accumulation . Control of this posttraumatic edema has also been incorporated into wound management for hundreds of years . Elevation of the injured part, the application of