32 Medial Orbital Blowout Fracture Repair


32 Medial Orbital Blowout Fracture Repair

Seanna Grob, Emily Charlson, and Jeremiah P. Tao


Medial orbital blowout fractures are a common sequela of blunt trauma and can be isolated or in combination with other fractures—namely, the orbital floor. Composed in part of the very thin lamina papyracea, the medial wall is most susceptible to fracture. Emergent repair is indicated for muscle entrapment which is rare along the medial wall. For all other cases, surgical invention or not is based on clinical exam findings once the acute soft-tissue swelling has subsided. Repair should be considered for persistent double vision/strabismus or to forestall disfiguring enophthalmos. Transcaruncular or transcutaneous approaches can be used to access the medial orbital wall. When an orbital floor fracture is also present, an additional swinging eyelid transconjunctival approach to the orbital floor can be performed. Combined medial wall and floor fractures can often be repaired with a single implant in a “wraparound” fashion. Complications of medial wall repair include lacrimal system damage, lower eyelid malposition, optic nerve compression, and globe restriction. With adequate planning and good surgical technique, outcomes after medial orbital wall blowout fracture repair are generally favorable with minimal visible scars.

32.1 Goals

Medial orbital wall fractures are common after facial trauma. While not all medial wall orbit fractures require surgical intervention, ones that cause enophthalmos or eye movement abnormalities require repair. Surgery is generally performed within weeks of injury to successfully treat enophthalmos, globe malposition, strabismus, and large fractures. Rarely, if acute muscle entrapment is present, urgent surgical intervention in less than 24 hours is necessary. 1 Direct exposure of the entire fracture site, freeing of prolapsed orbital tissue from the fracture site, and reconstruction of the orbital wall with an orbital implant achieve the reconstructive goals of restoring extraocular muscle function, eye alignment, and globe projection.

32.2 Advantages

Repair of a medial orbital wall fracture is aimed at restoring the normal anatomy of the orbit, which in turn can normalize globe position and eye movement. Following fracture, repair is not always indicated if the examination is normal, the fracture is small, or if there is no displacement of the fractured segment. If the examination is normal, the fracture is small, or there is minimal displacement of bone, fracture may not be indicated. Surgery can treat and prevent subsequent abnormalities. For example, should strabismus result from the trauma, strabismus surgery may improve diplopia, although single binocular vision in all fields of gaze is less likely than prevention with proper reduction of the fracture.

32.3 Expectations

Orbital appearance and globe function restored to the preinjury state can be expected in many cases with medial orbital wall fracture. Apart from soft-tissue edema, ecchymosis, and possibly some nasal congestion, many medial orbital wall fracture patients have minimal symptoms. Many medial wall fractures are incidentally discovered on facial imaging. Expansion of orbital volume causing enophthalmos (Fig. 32‑1) or restriction of orbital tissues with resulting strabismus are occasional sequelae of isolated medial wall fractures. When indicated, proper repair of medial wall fractures usually results in good outcomes with few complications and long-term stability. Importantly, many isolated medial wall fractures are associated with no morbidity and can be managed expectantly.

Fig. 32.1 Axial (a) and coronal (b) CT image showing a large medial orbital wall fracture with herniation of the medial rectus and orbital soft tissues into the fracture site.

32.4 Key Principles

  • Medial wall orbital fractures are common after trauma and often occur concomitant to ipsilateral orbital floor fractures. 2 Isolated medial wall fractures are often inconsequential clinically.

  • Extraocular muscle entrapment is an indication for immediate repair. 1 ,​ 3 ,​ 2 ,​ 3 ,​ 4 ,​ 5 ,​ 6 Nausea, dizziness, or bradycardia with attempted eye ductions is suggestive of entrapment. Urgent repair is indicated to control the oculocardiac reflex as well as forestalling muscle necrosis. In other cases, fractures may be observed for 1 to 2 weeks to allow soft tissue swelling to decrease. The primary indications for repair are nonresolving strabismus or enophthalmos, usually of 2 mm or greater.

  • Medial fracture repair is most successful with direct exposure of the entire fracture perimeter, complete release of prolapsed orbital contents from the fracture site, and secure placement of a well-fitted orbital implant that re-creates the natural bony orbital wall contour and does not adhere or restrict the adjacent orbit.

32.5 Indications

Urgent repair (<24 hours) is indicated for medial wall fractures with medial rectus entrapment. Entrapment often manifests as impaired horizontal eye movements, especially with abduction. 3 ,​ 4 ,​ 5 Other findings include bradycardia due to the oculocardiac reflex, nausea, or dizziness with attempted eye movements. Immediate repair is associated with an improved prognosis. 7

In the absence of muscle incarceration, fractures can be observed for 1 to 2 weeks while spontaneous resolution of edema occurs, allowing for a more accurate assessment of extraocular movements and globe position.

Indications for repair of nonentrapped fractures include

  • Enophthalmos >2 mm or globe malposition, especially when inferior or posterior (however, formal exophthalmometry may be unreliable in the early injury phase due to edema).

  • Persistent double vision, especially horizontal strabismus from medial rectus restriction in the setting of a medial wall fracture. 7

  • Large fracture (>50% of the medial wall evidenced on neuroimaging) that is likely to result in globe malposition if left untreated.

  • Concomitant orbital floor fracture needing repair. 2

32.6 Contraindications

The major contraindication to medial wall fracture repair is concurrent severe ocular trauma such as corneoscleral laceration, rebleeding hyphema, compressive optic neuropathy from orbit compartment syndrome, or retinal detachment. As always, patients with an unstable general medical condition are not immediate candidates for surgery. Other concomitant injuries may be more urgent to address surgically prior to orbital fracture repair.

32.7 Preoperative Preparation

Informed patient consent should include possibilities of visual loss, infection, bleeding, implant extrusion, persistent diplopia, eyelid malposition, persistent or recurrent enophthalmos, and need for more surgery. CT imaging should be carefully reviewed. This provides information regarding the extent of the fracture site and concurrent orbital floor or other orbital or facial fractures that should be repaired simultaneously if possible (Fig. 32‑1). Importantly, muscle entrapment is a clinical diagnosis that can be missed on neuroimaging. If there is active sinusitis or other risk factors for infection, then antibiotics or nasal decongestants or both should be considered.

If clinical assessment indicates entrapment of a rectus muscle, surgery should be expedited to prevent ischemia to the muscle and permanent muscle damage. Otherwise surgical intervention may be deferred until soft-tissue edema has improved—approximately 1 to 3 weeks after injury.

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May 7, 2020 | Posted by in OPHTHALMOLOGY | Comments Off on 32 Medial Orbital Blowout Fracture Repair

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