Isolated trapdoor-type medial blowout fracture in an adult presenting horizontal diplopia treated by endoscopic endonasal approach
A 38-year-old woman presented diplopia with left lateral gaze after sustaining trauma to the left orbit. There was mild periorbital edema and ecchymosis at presentation. Ophthalmologic examination results were within normal except of ocular motility revealed an abduction deficit in the left eye (Fig. A). Computed tomography (CT) demonstrated a trapdoor-type left medial orbital wall fracture with entrapment of the medial rectus muscle (Fig. A). She was immediately taken to the operating room and underwent surgery under general anesthesia. Endoscopic endonasal reduction surgery for medial blowout fracture, first introduced by Yamaguchi [] was used to expose the fractured medial orbital wall. The entrapped medial rectus muscle and herniated orbital tissue were gently released from the fracture after ethmoidectomy. The herniated orbital tissue and fractured bone were reduced to the original position, and then supported with a suitably sized Silastic sheet placed in the ethmoid sinus in an inverse U shape. A piece of Merocel® was packed between the Silastic sheets to provide support and prevent orbital tissue herniation, which were removed 4 weeks later at out-patients clinic (Fig. ). The patient's ocular symptoms completely resolved 3 days postoperatively (Fig. B). Computed tomography scans demonstrated that the medial rectus muscle was reduced after surgery (Fig. B).