Reduced pre-operative skin oxygen saturation predicts revision after open reduction and internal fixation in calcaneal fractures : A reduced pre-operative oxygen saturation as measured by laser-Doppler spectrophotometry in 8 mm depth is associated with revision surgery after open reduction and internal fixation of calcaneal fractures through an extended lateral approach

Abstract

Abstract Purpose To assess which pre-operative parameters correlate with wound revisions after an extended lateral approach to the calcaneus. Methods Pre-operative laser-Doppler spectrophotometry was applied in patients undergoing open reduction and internal fxation. The number of wound revisions was recorded during pos-toperative follow-up. Spearman rho analysis was used to identify factors associated with wound revision and receiver operator characteristics curves were calculated for the identifed factors. Results Thirty-four patients (29 men, 5 women; 37 calcanei) with a mean patient age of 43±14 years were analyzed. The minimal oxygen saturation value at the fve measurement locations as well as the minimal value for fow correlated negatively with wound revisions (p value=0.025 and 0.038, respectively). The area under the curve for the pre-operative minimal value of oxygen saturation was 0.841 (95%CI 0.64–1.00, p=0.028), indicating a good accuracy as a test to predict wound revision. Conclusion A pre-operative oxygen saturation of at least 20.5% across fve measurement points along the anticipated incision identifed all patients not needing a wound revision (negative predictive value 100%). On the other hand, patients with at least one measurement below 20.5% were at risk for wound revision surgery (sensitivity 100%, specifcity 48.5%).