Residency · Residency · Ophthalmology

Orbital Fractures and Surgical Repair

Introduction

Orbital fractures are common sequelae of facial trauma and can result in functional and cosmetic deformity. The orbit is composed of seven bones, with the floor (maxillary bone) and medial wall (lamina papyracea) being the thinnest and most frequently fractured. Timely evaluation and appropriate surgical intervention are essential to prevent permanent diplopia and enophthalmos.

Anatomy of the Orbital Walls

Roof: frontal bone (thick anteriorly, thins at orbital plate) Floor: maxillary bone (0.5 mm thick); contains the infraorbital nerve and canal. Medial wall: lamina papyracea of the ethmoid (0.2-0.4 mm, thinnest wall) Lateral wall: greater wing of sphenoid and zygoma (thickest wall) Orbital rim: dense cortical bone providing structural support.

Classification of Orbital Fractures

Blowout Fractures

Pure blowout: fracture of an orbital wall without rim involvement. Most common locations: floor > medial wall > combined floor and medial wall. Mechanism: hydraulic theory (globe transmits force to walls) and buckling theory (direct force on orbital rim causes wall buckling)

Other Fracture Types

Blow-in fractures: wall fragments displaced into the orbit (associated with roof fractures) Tripod (zygomaticomaxillary complex) fractures: involve lateral wall, floor, and infraorbital rim. Le Fort fractures: types II and III involve the orbit. Trapdoor fractures: linear fracture with periosteal hinge; common in children (white-eyed blowout); tissue entrapment with minimal radiographic findings. Naso-orbito-ethmoidal (NOE) fractures: involve medial wall, nasal bones, and medial canthal tendon.

Clinical Evaluation

History

Mechanism and timing of injury. Diplopia (especially in upgaze), pain, numbness, visual change. History of epistaxis (do not blow nose -- risk of orbital emphysema)

Examination

Visual acuity and pupillary exam -- rule out associated globe injury. Forced duction testing -- differentiate entrapment from muscle edema/hemorrhage. Hertel exophthalmometry -- document enophthalmos (may be masked initially by edema) Infraorbital nerve sensation -- hypesthesia in V2 distribution. Extraocular motility -- restriction (especially upgaze in floor fractures, lateral gaze in medial wall fractures) Oculocardiac reflex -- bradycardia, nausea, and syncope suggest tissue entrapment (especially in pediatric trapdoor fractures)

Imaging

CT orbit and face (thin-cut axial and coronal): gold standard. Evaluate fracture location, size, degree of herniation, muscle position. Look for associated injuries: globe rupture, retrobulbar hemorrhage, intracranial injury.

Indications for Surgical Repair

Urgent (Within 24-48 Hours)

Pediatric trapdoor fracture with muscle entrapment and oculocardiac reflex. Non-resolving oculocardiac reflex with tissue incarceration. Early enophthalmos with large fracture.

Semi-Urgent (Within 1-2 Weeks)

Persistent diplopia in functional gaze positions with positive forced ductions. CT evidence of muscle or periorbital tissue entrapment. Large floor fracture (>50% of floor or defect >2 cm) predicting late enophthalmos. Significant enophthalmos (>2 mm)

Observation

Minimal diplopia resolving with conservative management. Small fractures without entrapment or significant herniation. Isolated medial wall fractures with minimal symptoms.

Surgical Techniques

Approaches

Transconjunctival (preseptal or retroseptal) -- preferred; lower rate of lid retraction and ectropion. Subciliary -- good exposure but higher risk of lower lid malposition. Transantral (Caldwell-Luc) -- rarely used; endoscopic-assisted approach gaining popularity. Transcaruncular -- for medial wall fractures.

Implant Materials

Titanium mesh -- strong, thin, easily contoured; risk of implant palpability. Porous polyethylene (Medpor) -- tissue integration; difficult to remove if infected. Resorbable plates (PDS, PLLA) -- avoid permanent implant; limited structural support. Autologous bone (split calvarial, iliac crest) -- gold standard for large defects but donor site morbidity. Nylon foil (Supramid) -- thin, flexible; used for small defects.

Complications

Persistent or new-onset diplopia. Lower lid retraction or ectropion (especially with subciliary approach) Infraorbital nerve injury. Implant infection, extrusion, or migration. Retrobulbar hemorrhage (rare, vision-threatening) Residual enophthalmos.

Key Clinical Pearls

Pediatric trapdoor fractures are surgical emergencies -- muscle necrosis occurs within hours. The "white-eyed blowout" in children can have minimal external signs but severe entrapment. Never instruct a patient with orbital fracture to blow their nose. Enophthalmos may be masked by acute edema; reassess at 1-2 weeks. Forced duction testing under anesthesia is essential to confirm entrapment before repair.

References

1. Burnstine MA. Clinical recommendations for repair of orbital facial fractures. Curr Opin Ophthalmol. 2003;14(5):236-240.
2. Jordan DR, et al. Intervention within days for some orbital floor fractures: the white-eyed blowout. Ophthalmic Plast Reconstr Surg. 1998;14(6):379-390.
3. Boyette JR, et al. Management of orbital fractures: challenges and solutions. Clin Ophthalmol. 2015;9:2127-2137.
4. American Academy of Ophthalmology. Orbit, Eyelids, and Lacrimal System. BCSC Section 7. 2023-2024.

For the intern

At 3am, your job is to rule out emergencies: check visual acuity, pupils, and extraocular movements. If a child has bradycardia, nausea, or pain with eye movement (oculocardiac reflex), call your senior immediately—this is a trapdoor fracture requiring urgent surgery within 24 hours to prevent muscle necrosis. Order a CT orbit/face with thin cuts if not already done. Document infraorbital nerve sensation and perform Hertel exophthalmometry if available. Admit for observation if there's concern for retrobulbar hemorrhage or globe rupture. Otherwise, instruct the patient never to blow their nose (risk of orbital emphysema), apply ice, elevate the head, and arrange ophthalmology or oculoplastics follow-up within one week. Most surgical decisions—whether to operate on diplopia, enophthalmos, or large floor fractures—can wait until daylight when your attending can assess forced ductions and review imaging properly.

Common pitfalls

• Missing the white-eyed blowout: Pediatric trapdoor fractures often have minimal external trauma but severe muscle entrapment. Don't be falsed by the benign appearance—bradycardia is your clue.
• Delaying imaging: Always get thin-cut coronal CT. Axial cuts alone miss floor fractures, and clinical exam underestimates herniation when orbital edema masks enophthalmos.
• Forgetting the nose-blowing warning: Patients instinctively want to clear their sinuses. Emphasize this creates dangerous orbital emphysema that can compromise vision.
• Operating too early on adults: Most blowout fractures need 1-2 weeks to declare themselves. Edema resolves, and many diplopia cases improve without surgery.

Make it stick

You're a new intern, and it's your first night float. A 7-year-old boy comes in with a swollen eye after falling off his bike. He denies double vision, and his vision is 20/20. You notice he’s a bit pale and seems nauseous, but the ophthalmology resident is tied up in the OR. You carefully check his extraocular movements and notice he has pain and restricted upgaze, but more strikingly, his heart rate drops to 50 bpm every time you try to check his eye movements. You remember the lecture's emphasis on the oculocardiac reflex in pediatric trapdoor fractures. You immediately page the senior resident, explaining your findings and the concern for muscle entrapment. This prompt action leads to an urgent surgical repair, saving the child's extraocular muscle function.

If you remember one thing

A pediatric patient with restricted eye movement, pain, and oculocardiac reflex (bradycardia, nausea) after orbital trauma needs urgent surgical evaluation for a trapdoor fracture. Always advise orbital fracture patients not to blow their nose due to the risk of orbital emphysema.

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