Orbital Trapdoor Fracture With Extraocular Muscle Entrapment in Adults: A Case Series.

PURPOSE: To report adult patients with an orbital trapdoor fracture with extraocular muscle entrapment.

METHODS: We retrospectively reviewed 566 adult patients (>18 years) with a pure orbital fracture who were referred to us from January 2016 to May 2023. The following data were collected: age, sex, affected side, causes of injury, concomitant ocular injury and nasal bone fracture, presence or absence of oculocardiac reflex and infraorbital nerve hypesthesia, period from injury to surgery, follow-up period, and pre- and postoperative limitation of extraocular muscle motility and fields of a binocular single vision.

RESULTS: We found 5 patients (0.9%) with an orbital trapdoor fracture with extraocular muscle entrapment (age range, 19-47 years; all males; 2 right and 3 left). Causes of injury included performing a bench press, fall, assault, boxing, and bicycle accident. Entrapment of the inferior and medial recti muscles was seen in 2 and 3 patients, respectively. None of the patients had any sign of oculocardiac reflex. After surgical reduction, the field of binocular single vision became normal in 3 patients and was incompletely recovered in 2 patients, in whom consultation with us was delayed.

CONCLUSION: Adults with extraocular muscle entrapment may not present with an oculocardiac reflex. Urgent release of an entrapped muscle is, however, still recommended to avoid permanent limitation of extraocular muscle motility.