Wound shape geometry measurements correlate to eventual wound healing

Wound geometry measurements have long been associated with wound-healing outcomes but there is little published evidence to support this. We studied serial wound tracings of 338 venous leg ulcers (VLUs) that had been followed during a controlled, prospective, randomized pivotal trial of two topical wound treatments, to determine whether the relationship between wound surface area and wound perimeter planimetry measurements, as well as the qualitative assessment of wound shape, could be correlated to wound-healing outcomes. VLUs that transitioned to a more convex wound shape, and maintained a linear relationship between their wound margin size and wound surface area size, had faster healing rates and were more likely to completely heal by 12 weeks (odds ratio=4.84, p=0.001). VLUs that initially presented with isolated areas of epithelium within the wound margins, large concavities, or were segmented into multiple ulcers typically had a poorer linear correlation between their margins and their surface area. Only 18 out of 134 (13%) VLUs with a linear r ²<0.80 eventually reached full wound closure, vs. 43% (102 of 270) of the remaining wounds with an r ²≥0.80 (Fisher's exact p<0.001). We believe our results show that the proportional relationship between one-dimensional perimeter and area measurements accurately correlates to the healing progress of the wound. Wounds that do not correlate to this linear relationship (concave geometries or multiple islands of healing) may be physiologically different than wounds that have good linear correlation, which we concluded through the analysis of wound acetate tracings.