Orientation of collagen in wound healing.

Skin incisions were made in each of adult female white Yorkshire pigs. One set of 3 incisions was made on the back and one on the side of the animal. In each site one incision was longitudinal, another transverse to the length of the animal, and a third was longitudinal but at an angle of about 45° to the surface. Disposition of fibroblasts, new reticulin and collagen fibres was studied at 5, 15 and 30 days after the operations. No significant differences in fibre alignment were seen between the longitudinal and the transverse, and the back and the flank wounds. In the oblique wounds the cells and fibres ran in the direction of the incision and perpendicular to it rather than in relation to the direction of the pre-existing collagen. The data indicate that the orientation of cells and fibres might be due to chemotactic influence of the traumatized area rather than to mechanical factors or to pre-existing structural arrangement.