Volumetric Analysis of Orbital Volume Discrepancy as a Marker of Change in Globe Position After Three-Point Fixation of Zygomatic Complex Fractures.

Abstract

Background: Many researchers have proposed incorporating orbital volume (OV) discrepancies between the affected and unaffected orbits into routine diagnostic processes as an indicator for early surgical repair of zygomatic complex fractures (ZMCFxs) to avoid postoperative ocular complications.

Purpose: The study aimed to determine the correlation between the preoperative OV discrepancy and postoperative globe position.

Study design, setting, sample: A retrospective cohort study was performed on patients with unilateral ZMCFxs associated with orbital floor fractures, treated at Al-Zahraa Hospital, Al-Azhar University, from January 2020 to July 2023. Patients with comminuted ZMCFxs, medial or superior orbital wall fractures, or corrective surgeries were excluded.

Predictor variable: The predictor variable was the preoperative OV discrepancy between the affected and unaffected orbits.

Outcome variables: The outcome variables were the 3-month postoperative globe position, which was classified as normal, enophthalmos, or exophthalmos, and the orbital repair quality, that was categorized as well-corrected, under-corrected, or over-corrected.

Covariates: They included age, sex, ethnicity, side, etiology, type of orbital floor fractures, timing, and indication for surgery.

Statistical analysis: χ², Pearson's correlation, and linear regression analyses were used; the statistical significance was set at P < .05.

Results: The study included 111 patients, with an average age of 30.3 ± 6.6 years and male predominance. The preoperative OV discrepancy between both orbits was 5.1± 1 cc³, associated with enophthalmos in the patients. Postoperatively, the OV discrepancy became 0.9 ± 0.7 cc³, but the globe position was heterogenic. Thirty-seven patients (33.3%) had normal globe position. Sixty-three (56.8%) subjects had enophthalmos. Eleven (9.9%) individuals had exophthalmos. The preoperative OV discrepancy and postoperative globe position had a significant weak positive linear correlation. For every one-cubic-centimeter change in OV, the globe moved 0.1 mm (P < .05). The majority of the patients had under-corrected orbits, followed by over-corrected and well-corrected orbits. Every category of globe position was recorded with every category of orbital repair, and the findings showed no correlation between globe position and orbital repair quality (P = .08).

Conclusion: Preoperative OV discrepancies between both orbits should not be employed as the sole predictor of globe position because a one-cubic-centimeter change in OV affects globe position by only 0.1 mm.