Is Screw-Fracture Proximity or Residual Fracture Displacement Correlated to Outcomes After Open Reduction and Internal Fixation of Mandibular Angle Fractures?

Abstract

Computed tomography (CT) imaging is commonly obtained following open reduction and internal fixation (ORIF) of mandibular fractures but the significance of common findings is unknown. The purpose of this study is to examine the relationship of screw-to-fracture proximity and residual fracture displacement to post-operative complications following ORIF of mandibular angle fractures treated with monocortical fixation techniques. The authors conducted a retrospective cohort study consisting of all patients with mandibular angle fractures treated with ORIF using monocortical fixation at the lateral surface of the mandible from the dates August 1, 2015 to May 31, 2020. The predictor variables were the distance measurements between the 2 closest screws to the fracture and the fracture line and the amount of residual fracture displacement, both measured on postoperative CT. The primary outcome variable was the presence of postoperative inflammatory complications (POICs). Statistical analysis was performed using logistic regression and Bayesian variable selection to calculate posterior probability of importance for the variables of interest. Of the 285 patients included in the study, 84.6% were men and the average age was 30.8 years. POICs occurred in 22.1% of the patients. Age, smoking, homelessness, noncompliance and drug use were associated with POICs. However, none of the screw-to-fracture distances were associated with POICs, including linear, dichotomous or polynomial transformations of these variables. Additionally, the residual fracture displacement distances and transformations of these distances were also not associated with POICs. The present study did not find any evidence to suggest that a closer screw-fracture distance or increased residual fracture displacement on postoperative CT imaging increased the risk of POICs for mandibular angle fractures treated with ORIF using monocortical fixation at the lateral border.