The Paradoxical Predominance of Medial Wall Injuries in Blowout Fracture.

PURPOSE: To evaluate the type and cause of orbital blowout fractures in Korea.

DESIGN

Retrospective, observational case series.

METHODS

Patients who underwent reconstruction for blowout fracture from March 2004 to April 2013 at Korea University Guro and Ansan Hospitals were included in this study. Patient demographics and orbital computed tomography (CT) scans were reviewed. On CT, ethmoid air cell septa, blowout fracture type, and other combined fractures were analyzed. Blowout fracture was classified as affecting up to 4 areas: the floor lateral to the infraorbital canal, the floor medial to the canal, the maxilla-ethmoidal strut ("inferomedial" strut), and the medial wall. Furthermore, trauma type and associated injury were reviewed. The results of adolescent patients and adult patients were compared, as were those of males and females.

RESULTS

The study included 659 eyes of 659 patients; mean patient age was 31.01 ± 14.27 years. In total, 513 (77.85%) patients were male and 146 (22.15%) were female. The most common blowout fracture type was medial wall fracture, followed by floor wall, floor and medial wall without inferomedial strut, and floor and medial wall fracture with inferomedial strut, in that order. Interestingly, patients with floor wall blowout fracture were younger (26.87 ± 12.90 y) than other groups: medial wall fracture (32.35 ± 14.64 y, P < 0.0001), floor and medial wall fracture (35.22 ± 14.49 y, P < 0.0001), and floor and medial wall fracture involving the maxillaethmoidal strut (32.62 ± 13.75 y, P = 0.002). The number of ethmoidal air cell septa was lowest in the medial wall fracture group (3.62 ± 0.67): floor wall fracture (4.07 ± 0.69, P < 0.0001), floor and medial wall fracture (3.90 ± 0.78, P < 0.0001), and floor and medial wall fracture involving the maxilla-ethmoidal strut (4.05 ± 0.72, P = 0.001).

CONCLUSIONS

Our study demonstrated that the blowout fracture type distribution in Korea varied from the results of many other studies. Medial wall fracture is the most common among the 4 types, and anatomic variance, such as number of ethmoid air cell septa, could influence blowout fracture type, especially in medial wall fracture.