Introduction: The donor site wound of a split-thickness skin graft (STSG) is seen as the ideal test bed for wound dressing trials, as these wounds are assumed to be uniform. Variability in thickness of STSG has never been statistically assessed. If there is significant variability, then this introduces a potential confounder into all studies of wound healing using STSG donor sites. No such study has ever accounted for this.

Methods: Central biopsy of STSG taken from the thigh of paediatric burns patients, subsequently examined for thickness after preparation and sectioning. All STSGs were taken at 7/1000 inch using an air-powered dermatome.

Results: There were 140 STSG from 91 patients examined. There were no predictable significant differences in STSG central biopsy mean thickness by age or sex of patient (p>0.05). There were no predictable significant differences in STSG thickness when comparing surgeons (4), or the age of the dermatome blade in use (first swipe, second swipe, etc). There was variability of STSG thickness across all surgeons, with 50% of STSG falling between 5-9/1000 of an inch.

Conclusions: This study demonstrates variability of STSG thickness, but provides no evidence of differences that may be predicted and/or corrected for pre-operatively. STSG thickness should be accounted for in studies of donor site wound healing.

Variability in split-thickness skin graft depth when using an air-powered dermatome: a paediatric cohort study.