Healing Of Full-thickness Defects Research Articles

Effect of oxygen treatment and dressing oxygen permeability on wound healing

Although it has been shown that both the level of tissue oxygen and its gradient are critical factors in the healing process, optimal conditions for oxygen therapy have not been determined. In this study, both the oxygen level and oxygen gradient for a full-thickness defect were modified on the basis of preceding in vitro studies to determine the effect on the healing process. The goal of this study was to help determine the optimal clinical oxygen treatment protocol. Specifically, the healing of full-thickness defects in a rabbit model as determined by histomorphometric analyses (cell and tissue volume fraction, epithelialization, and contraction) under two types of dressings with or without oxygen treatment (70% O(2)) was investigated. One of the dressings was more oxygen permeable than the other. No significant differences were found in the histomorphometric response between the wounds covered with the oxygen-permeable and oxygen-impermeable dressings in the group without supplemental oxygen. Oxygen treatment, however, seemed to enhance the healing response significantly. According to the histomorphometric response, the wounds covered with the oxygen-impermeable dressings were significantly better than those with the oxygen-permeable dressing in the oxygen-treated group after 1 week, but the wounds covered by the oxygen-permeable dressings were better healed at 3 weeks. Therefore, oxygen-impermeable dressings may be useful only in the early stages of healing, before granulation tissue formation.

Dermal regeneration in native non‐cross‐linked collagen sponges with different extracellular matrix molecules

Collagenous dermal templates can prevent scarring and wound contraction in the healing of full-thickness defects. In a porcine wound model, full-thickness wounds were substituted by reconstituted and native collagen sponges in combination with autologous split-skin mesh grafts and covered with a semipermeable wound membrane. Native collagen sponges were also linked with either hyaluronic acid, elastin, or fibronectin. Reconstituted collagen matrixes, composed of cross-linked small collagen fibrils, disintegrated within a week and did not contribute to dermal regeneration, whereas native collagen matrixes, composed of intact collagen fibers, disintegrated within 2 weeks and did contribute to dermal regeneration. Addition of extracellular matrix proteins retarded the disintegration to 4 weeks. However, fibronectin-treated matrixes caused aberrant epithelization. When hyaluronic acid was added, matrixes were invaded by more fibroblasts and myofibroblasts. This process correlated with fibrosis and wound contraction. In contrast, the native collagen/elastin matrix reduced the amount of fibroblasts and myofibroblasts. This latter matrix resulted in optimal dermal regeneration and little wound contraction.

Motion, not immobility, advocated for healing synovial joints

Orthopedic surgeons who "make a fetish out of applying plaster casts" should instead look to the use of motion to heal injured or diseased synovial joints. They should also realize, says Robert B. Salter, MD, professor and head of orthopaedic surgery at the University of Toronto Faculty of Medicine, that it is possible to regenerate articular cartilage with relative comfort and little inconvenience to the patient if one is willing to set aside plaster of Paris. Speaking to the 50th annual meeting of the Royal College of Physicians and Surgeons of Canada in Toronto, Salter said that the traditional concept that tissue, including cartilage, must be rested in order to heal "really is not valid" and the concept itself "must be put to rest." Salter was reporting not only on his long-term experimental investigations on the healing of fullthickness defects in articular cartilage in animals, but also on his subsequent

The biological effect of continuous passive motion on the healing of full-thickness defects in articular cartilage

The biological effect of continuous passive motion on the healing of full-thickness defects in articular cartilage

The biological effect of continuous passive motion on the healing of full-thickness defects in articular cartilage. An experimental investigation in the rabbit.

The biological effect of continuous passive motion on the healing of full-thickness defects in articular cartilage. An experimental investigation in the rabbit.