Clinical Significance of the Inferomedial Orbital Strut in Orbital Blowout Fractures: Incidence of Symptomatic Diplopia in a Fractured vs. Intact Strut

Abstract

Background/Objectives: This study aims to compare the clinical findings, particularly symptomatic diplopia, associated with an inferomedial orbital strut fracture versus intact strut and to determine the clinical significance of the inferomedial orbital strut in patients with orbital floor and medial orbital wall fractures. Methods: A 10-year retrospective observational study involving orbital blowout fracture cases was conducted in our institution. Patients with fractures of the orbital floor medial to the infraorbital groove and medial orbital wall, as seen on computed tomography (CT) scans, were included in this study. Patients with concomitant orbital rim fracture and those with old orbital fractures were excluded. Fracture of the inferomedial orbital strut was diagnosed via coronal CT images and patients were classified into those with an inferomedial orbital strut fracture and those without. Results: A total of 231 orbits from 230 patients was included in the study (fractured strut on 78 sides and intact strut on 153 sides). Approximately 2/3 of patients in both groups had the field of binocular single vision in primary position upon first examination (p = 0.717). Patients with strut fractures demonstrated only comminuted or open fractures, while those without strut fractures showed diverse fracture patterns (p < 0.001). Conclusions: Inferomedial orbital strut fracture does not automatically result in diplopia in patients with orbital blowout fractures. The integrity of the orbital periosteum plays a more essential role in hampering extraocular muscle displacement, thereby preventing symptomatic diplopia in these patients.