Bone Remodeling After Surgical and Non-Surgical Management of Isolated Zygomatic Arch Fractures

Purpose: The healing process of isolated zygomatic arch (ZA) fractures is not well understood. This study sought to investigate and compare bony remodeling outcomes following surgical and nonsurgical management of isolated ZA fractures. Through analysis of pre- and post-treatment computed tomography (CT) scans, we aimed to quantify the degree of fracture reduction over time. Methods: A retrospective cohort study identified subjects presenting to the emergency room with acute isolated ZA fractures between 2011 and 2021 who had both initial post injury and subsequent CT scans of the face. Inclusion criteria required follow-up CT at least 6 months post-injury for nonsurgical patients and at least 1 month for surgical patients. Patients with no measurerable initial fracture displacement or any concurrent facial fractures were excluded. The independent variable was treatment approach (operative vs. nonoperative). The outcome variable was degree of fracture reduction between initial and follow-up CT imaging. Covariates collected included patient age, treatment (operative vs nonoperative) and time to follow-up CT. Bivariate statistical analysis conducted to compare fracture measurements between initial and follow-up, surgical and nonsurgical groups at a significance level of 0.05. Results: Of 27 patients met study inclusion criteria, 11 (40.7%) underwent surgical reduction and 16 (59.3%) were treated conservatively. The median age at presentation was 48 (IQR 35–64) years old with an average fracture displacement of 0.43 ± 0.2 cm. Both surgical and nonsurgical patients demonstrated significant fracture reduction on follow-up CT ( P < 0.001). In the nonsurgical cohort, the average initial fracture displacement was 0.30 ± 0.16 cm, and fracture reduction averaged 19.9% on follow-up (range 0%–41.7%). For the surgical cohort, the average initial fracture displacement was 0.60 ± 0.09 cm and fracture reduction averaged 63.6% (range 11.6%–100%) on follow-up. While the surgical group had a significantly greater degree of fracture reduction compared with the nonsurgical group ( P < 0.001), there was no significant difference in final fracture displacement between surgical and nonsurgical groups ( P = 0.4). Conclusion: Bony remodeling occurs following both surgical and nonsurgical management, where comparable outcomes highlight the importance of thoughtful patient selection.