Twelve-month prospective analysis of biomechanical and pigmentary remodeling in split-thickness skin graft donor sites.

Abstract

Donor site scarring is a common concern for patients undergoing split-thickness skin grafting. The aim of this prospective study was to evaluate the remodeling of STSG donor sites with regard to elasticity, pliability, erythema, and melanin content, and to compare the maturation process at the center and the margin of the donor site to support accurate patient education. Twenty-two thin split-thickness skin graft donor sites on the thigh were evaluated 1, 3, 6 and 12 months after harvesting. The donor sites were assessed using the Vancouver, Hamilton, and Manchester Scar Scales as well as a subjective visual analog scale. Cutometer® parameters R0, R2, R3, and R5 were measured to assess skin elasticity and pliability, while erythema and melanin indices were recorded using the Mexameter®. Total scores of the Hamilton Scar Scale and the subjective rating scale improved significantly over the 12-month follow-up period (3.46 ± 1.22 vs. 1.18 ± 0.80, p < 0.0001; and 8.8 ± 6.9 vs. 3.5 ± 5.5, p = 0.021). Skin pliability (Cutometer® parameter R0) gradually increased from 0.77 ± 0.20 to 1.20 ± 0.23 (p < 0.0001), whereas skin elasticity (R5) decreased from 0.92 ± 0.24 to 0.69 ± 0.17 (p = 0.0019). Both parameters showed no significant differences between the center and the margin. The erythema index decreased steadily but remained elevated after 12 months, whereas the melanin index normalized after 3 months. Both the erythema and melanin indices were slightly higher at the margin compared to the center. The maturation of split-thickness skin graft donor site skin properties is heterogeneous. While pliability, elasticity, and melanin content normalize relatively quickly, erythema persists for at least 12 months. Comparison between the center and margin of the scar showed no significant differences in mechanical skin properties; however, erythema and melanin levels were slightly higher at the margin. This indicates that the majority of the skin's regenerative processes are initiated from the wound bed.