Observation
The decision on when to intervene is mostly dictated by the associated injuries and clinical signs.
With an isolated medial wall fracture, ecchymosis in the medial rectus muscle, rather than entrapment, is the more common cause of diplopia, and it can cause horizontal diplopia in either adduction or abduction, therefore observation is appropriate for a minimum of 7–14 days because spontaneous resolution is likely to occur.
- There is little published data on outcomes and management of horizontal motility deficits with pure medial blowout fracture.
- It is reasonable to treat with antibiotics (because soft tissues have prolapsed into the sinus) and corticosteroids (to unmask entrapment once the edema is reduced), but there are no published data to support the efficacy.
An isolated medial wall fracture can cause enophthalmos in the presence of substantial bony displacement.
- A period of observation allows for resolution of periorbital edema and more accurate assessment of possible enophthalmos.
- There are no specific criteria for predicting enophthalmos based on the radiographic appearance, both for a pure medial blowout fracture and for the contribution of a medial wall fracture in association with other injuries.
Observation might be necessary because of an associated ocular injury such as hyphema or a ruptured globe.
During the period of observation, it is appropriate to prescribe nasal decongestants and to have the patient to avoid nose blowing.
Surgery
Indications for repair
Vagal symptoms of nausea, vomiting, and bradycardia indicate incarceration and potentially ischemic tissues that require urgent surgical release to prevent permanent damage.
- This is a rare situation compared to that seen with an orbital floor fracture.
Entrapment of the medical rectus muscle in an isolated medial wall fracture can cause an abduction deficit and a "white eye injury," so called because there can be relatively little associated soft tissue edema and ecchymosis.
Even without absolute entrapment, there might be unresolved diplopia in useful fields of gaze suspected to be restrictive in nature, or secondary to globe malposition, and therefore appropriately managed with exploration and restoration of orbital anatomy.
- The need to explore and restore anatomy is less with medial wall than orbital floor fractures, but it is not precisely characterized in large clinical studies.
The associated fractures usually dictate the need for surgical repair, but rarely the isolated medial wall fracture.
Open fracture with overlying facial laceration can be an indication for repair of the medial wall, but this can also extend the management from local to general anesthesia.
Most clinicians would agree that surgical repair does not need to be delayed for a large fracture likely to cause enophthalmos, particularly when associated with an orbital floor fracture that is independently a risk factor for enophthalmos.
When delayed for up to 4 weeks when indicated for patient stabilization of other ophthalmic or systemic injuries, surgical outcomes with repair of enophthalmos should be comparable to early repair.
Approach
Transcaruncular: Visualization should be adequate for exploration of the defect, repositioning orbital contents, and placement of an implant across the defect.
- In a recent study, a secondary supporting implant was inserted in 29 patients who underwent transcaruncular repair of large medial wall fractures, as a means of stabilizing the primary implant placed along the bony defect.
- The supporting implant was bent into a U-shape and inserted into the ethmoid sinus as support for the implant that lies over the defect (Kim, OPRS 2013).
Direct endoscopy through the transcaruncular incision can be helpful.
- In a study of 93 large, isolated, medial-wall fractures near the orbital apex approached by an endoscopic transcaruncular incision and repaired with 1.0‑mm thick porous polyethylene implants placed over the edges of the fractures, which ranged in size from 16–30 mm vertically and 25–34 mm horizontally, reconstruction of the bony defect was demonstrated by CT scan 6 months after surgery in 98.9% of patients (n = 92).
- There were 3 cases of residual diplopia on medial gaze from presumed paralysis of the medial rectus muscle and 1 case of postoperative orbital hemorrhage (Wu, Ophthalmology 2013).
Transantral or transnasal endoscopy can help visualize the posterior edge of the fracture, when dissecting soft tissue and inserting the implant, combined with the transorbital approach (Woog, Arch Ophthalmol 1998 & Shi, J Craniofac Surg 2012).
Incisions:
- Transcutaneous medial canthal tendon incision (Timoney, Ophthal Plast Reconstr Surg 2012)
- Medial eyelid crease incision can be adequate for access to superior medial wall fractures.
- Lynch incision or use of overlying traumatic facial laceration
- Transconjunctival with lateral canthotomy/cantholysis is often used when there is associated orbital floor fracture and more inferior medial wall fracture.
- Bicoronal incision is often used when other associated facial fractures are present (nasoethmoid or Lefort III).
Endoscopic endonasal approach alone has been described, but a rigid reconstruction of the medial wall defect is not performed, so late enophthalmos has been noted for larger fractures (Kim, Ann Plast Surg 2012).
The anterior and posterior ethmoid arteries are frequently visualized and require cauterization or ligation.
The posterior edge of the implant should be shaved and tapered to protect against compressive optic neuropathy should there be posterior migration of the implant.
Biomedical glue can be used to fixate the implant against the bony edges.
Systemic corticosteroids and antibiotics should be prescribed postoperatively for 3–5 days to minimize the morbidity from postoperative edema.
Surgical goals
Careful release of entrapped tissue:
- Forced ductions at the start, during, and after placement of the implant with comparison to the opposite orbit to achieve equivalent globe motility by the end of the case
- Might require removal of bony fragments to fully release adherent or entrapped tissues
Placement of implant to reproduce the anatomic position of the medial orbital wall:
- The implant margins should rest on secure bony ledges surrounding the defect tapering posteriorly to avoid abutting the optic nerve.
- Endoscopic endonasal visualization can be useful to ensure correct placement.
- Anterior implant fixation to the orbital rim with one screw is usually sufficient to avoid posterior implant migration.
- Many surgeons will not fixate a medial orbital wall implant due to difficulty in finding thick, stable bone anteriorly that will support a screw.
- Maintaining the correct alignment with respect to the orbital floor is critical to restoring normal orbital volume.
- Intraoperative CT is becoming more readily available to assess for proper implant placement and contour.