Wound contraction. Correlations between the tension generated by granulation tissue, cellular content and rate of contraction.

The tension generated in vitro by samples of granulation tissue taken from wounds at various times after wounding has been measured. Throughout the period when in vivo contraction was occurring with a constant linear rate of movement of the wound margins the in vitro tension produced by samples of the granulation tissue remained constant at approximately 80 mg/mm2. With cessation of contraction in vivo, the tension generated by the granulation tissue fell to 40 mg/mm2. Morphometric studies demonstrated that total cellularity paralleled the tension developed. However, the decrease in cellularity preceded by approximately 4 d the decrease in the tension developed. Strong correlation between the rate of contraction and the maximum thickness of the granulation tissue was demonstrated.