Three-Dimensional Analysis of Zygomatic-Maxillary Complex Fracture Patterns

Abstract

Zygomatic-maxillary (ZMC) complex fractures are a common consequence of facial trauma. In this retrospective study, we present a novel method of ZMC fracture pattern analysis, utilizing three-dimensional visualization of computed tomography (CT) images to record displacement of the malar eminence in a three-dimensional coordinate plane. The pattern of fracture was then correlated with treatment outcome. Facial CT scans were obtained from 29 patients with unilateral ZMC fractures and 30 subjects without fractures and analyzed. Briefly, displacement of the malar eminence (ME) on the fractured side was measured in medial-lateral (x), superior-inferior (y), and anterior-posterior (z) dimensions, as well as Euclidean distance, by comparison to ME location on the unfractured side. Baseline natural variance in asymmetry was accounted for by comparing ME location on the left and right sides in subjects without fractures. Patients who required open reduction and internal fixation (ORIF) to repair the ZMC fracture alone had significantly greater cumulative ME displacements than patients who did not require ORIF ( p = 0.02). Additionally, patients with a high fracture score of 3, 4, or 5 (assigned based on severity displacement in each dimension) had significantly higher rates of ORIF than patients with a low fracture score of 0, 1, or 2 ( p = 0.05). Severe displacement in one or more dimensions was associated with higher rates of ORIF than seen in patients with only neutral or mild displacements in all dimensions ( p = 0.05). Severe x displacement was most strongly correlated with surgical intervention ( p = 0.02). Overall, orbital floor repair was less strongly associated with most displacement measures than ZMC repair alone; however, patients requiring orbital floor repair had greater Euclidean ME displacements than patients who did not require orbital floor repair ( p = 0.02). Fracture severity, as determined by multiple parameters in this novel evaluation system, is associated with higher rates of ORIF in patients with unilateral ZMC fractures. Determination of ZMC fracture pattern may thus be informative when considering treatment options.