title: Adult orbital trapdoor fracture.
abstract: Trapdoor fractures occur almost exclusively in the pediatric population. The authors describe an adult with an entrapped inferior rectus muscle sheath in a trapdoor fracture. A 37-year-old man presented with persistent diplopia 3 weeks after blunt right orbital trauma. The only abnormal findings on clinical examination were limited vertical ductions. No bony defect or displacement was evident on CT. However, several small pockets of air were visible adjacent to the inferior rectus muscle. On surgical exploration, a linear nondisplaced orbital floor fracture was confirmed, and the entrapped inferior rectus muscle was released. One month postoperatively, extraocular motility had improved with no diplopia in primary or reading positions. This case demonstrates that trapdoor fractures can occur in adults and should be considered when suggestive findings are encountered. Clinicians should be aware of this because timely diagnosis and treatment might achieve more favorable outcomes.
authors.affiliation: Department of Ophthalmology, University of California San Francisco, San Francisco, California 94143, USA.
authors.forename: Clarissa
authors.initials: C
authors.lastname: Kum
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: McCulley
authors.forename: Michael K
authors.initials: MK
authors.lastname: Yoon
authors.forename: Thomas N
authors.initials: TN
authors.lastname: Hwang
mesh_terms: D000328:Adult; D000818:Animals; D004172:Diplopia / Q000209:etiology; D005131:Eye Injuries / Q000209:etiology*; D006733:Horns / Q000293:injuries*; D006801:Humans; D008297:Male; D015835:Ocular Motility Disorders / Q000000981:diagnostic imaging / Q000209:etiology* / Q000601:surgery; D009801:Oculomotor Muscles / Q000000981:diagnostic imaging / Q000293:injuries* / Q000601:surgery; D013508:Ophthalmologic Surgical Procedures; D009917:Orbital Fractures / Q000000981:diagnostic imaging / Q000209:etiology* / Q000601:surgery; D012756:Sheep; D014057:Tomography, X-Ray Computed; D014949:Wounds, Nonpenetrating / Q000209:etiology*