Pressure reducing skin pie-crusting in extremity trauma: An in-vitro biomechanical study and human case series

Multiple small relaxing skin incisions oriented parallel to the longitudinal axis (so-called "pie-crusting") near traumatic lacerations or surgical incisions in edematous tissue beds have been utilized to achieve primary closure when edema or skin loss would otherwise have made this difficult. Our study hopes to demonstrate (1) biomechanical evidence that pie-crusting decreases wound closure tension and (2) provide a case series with data showing clinical results.

This study is a biomechanical cadaveric study and retrospective small series cohort using 16 porcine limbs and 7 patients with 8 wounds in which pie-crusting was performed. An elliptical incision was made on the porcine limbs and the wound closure tension was measured with a hydraulic test machine before and after pie-crusting. The retrospective patient cohort had pie-crusting performed on traumatic wounds that were difficult to primarily close. The patient cohort was assessed by retrospective chart review examining wound dimensions before and after pie-crusting, and wound healing at final follow-up.

The biomechanical data showed that pie-crusting the wound with both a single and double row of incisions significantly decreased the closing tension. A single row decreased wound tension by an average of 34%. Using an average of 3.5 parallel layers of pie-crusting at the time of definitive closure all wounds in the patient cohort closed and healed well with no complications at average follow-up (average 18 months).

Pie-crusting may allow for easier wound closure and decrease the need for skin-grafting in edematous extremity wounds, with minimal patient morbidity.