Prediction of tissue deformation based on mechanical and physiological factors in the prone position during surgery

Aim: This study aimed to predict tissue deformation based on the pressure applied while lying in the prone position and physiological factors. Methods: Healthy volunteers were instructed to lie on mattresses of four different hardness levels (50, 87.5, 175, and 262.5 N). The order in which the mattresses were used was randomized per participant. Pressure at the iliac crests was measured using a pressure mapping sensor sheet. Participants were placed in the prone position for 10 min, with pressure data used from the latter 5 min. For the tissue deformation at the iliac crests, our previous study data were used. Multiple regression analysis was used to identify predictive mechanical and physiological factors. Results: The distance between the left and right greater trochanters, maximum interface pressure and age were significant predictors for compression of the skin and soft tissue. Significant predictors of internal soft tissue displacement were the distances between the left and right anterior superior iliac spines and greater trochanters. No factors predicted skin surface displacement. Conclusions: Our study provided predictive factors that may be measured easily in a clinical setting to reduce the risk of pressure ulcers during surgery in the prone position.