Modelling of Scarring Resulting from Primary Closure of High Tension, Large, Deep Tissue Pressure Injuries

Introduction: Suture primary closures of deep tissue pressure injuries (DTPIs) are seldom recommended due to the high-tension closure, inflicting ischemia, necrosis and dehiscence of the wound. Wound closure by secondary healing using negative pressure systems typically results in a wide round scar. Following excision of the necrotic and scar tissues, immediate primary closure can now be achieved using the tension relief system (TRS) which results in a longitudinal scar.

Methods: Our aim was to investigate the biomechanical effects of the dimensions and quality of a scar following closure of a DTPI on surrounding tissues in a supine position. For this purpose, we incorporated each of the two types of scars in a previously validated three-dimensional anatomically-realistic finite element (FE) model of the female buttocks. Outcome measures included distribution of effective stress and cumulative percentage of muscle tissue exposure to effective stresses for both scar simulations. These outcome measures were compared between the wide and longitudinal scar simulations.

Results and conclusions: Effective stresses in muscle tissues surrounding the wide scar were greater than the ones calculated for the longitudinal narrow scar in the buttocks. These elevated stresses associated with the wide scar increase the risk of recurrence of DTPIs in its vicinity.