Are Age and Trauma Mechanism Associated with Volume Change in the Fractures of the Bony Orbit?

Abstract

Blowout fractures are common midfacial fractures in which one or several of the bones of orbital vault break. This is usually caused by a direct trauma to the eye with a blunt object such as a fist. Fracturing of the fragile orbital bones can lead to changes in the orbital volume, which may cause enophthalmos, diplopia, and impaired facial aesthetics. Objectives: The aim of this study is to investigate whether there is an association between volume change of the bony orbit and age, gender, or trauma mechanism. Methods: A retrospective study of patients with unilateral blowout or blow-in fractures treated and examined in Päijät-Häme Central Hospital, Lahti, Finland was conducted. Altogether, 127 patients met the inclusion criteria. Their computed tomographs (CT) were measured with an orbit-specific automated segmentation-based volume measurement tool, and the relative orbital volume change between fractured and intact orbital vault was calculated. Thereafter, a statistical analysis was performed. A p-value less than 0.05 was considered significant. Results: We found that relative increase in orbital volume and age have a statistically significant association (p = 0.022). Trauma mechanism and gender showed no significant role. Conclusions: Patient's age is associated with increased volume change in fractures of the bony orbit.

Keywords: automated segmentation; blow-out fracture; blowout fracture; facial trauma; orbit; orbital volume.

Figure 1

Orbital volume is measured from CT scans with an automated segmentation tool in which a virtual triangle mesh expands from a starting point in the bony orbit to another on the other side. The volume of the fractured orbit (red) is compared to the intact (blue) one to obtain the relative orbital volume change.

Figure 2

Relative volume change increased along with patient’s age. Each blue dot represents individual patient, and red line shows average relative (%) volume change compared to age.

Figure 3

Relative volume change and trauma mechanism have no correlation. Blue box represents 50% of the patients and median; whiskers represent highest and lowest 25 percentages; stars and dots demonstrate the measurement outliers.

Figure 4

Trauma mechanisms’ association with age: 1. fall, 2. assault, 3. sports, 4. traffic, 5. others. Blue box represents 50% of the patients and median; whiskers represent highest and lowest 25 percentages.

Figure 5

Females and males have distinct age profiles. Females more frequently suffer orbital traumas as young adults and in older age, whereas male are more susceptible to trauma in middle age.