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.
- Can cause horizontal diplopia in either adduction or abduction
- Observation is appropriate for a minimum of 7–14 days, awaiting spontaneous resolution.
- 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.
Indications for repair
Vagal symptoms of nausea, vomiting, and bradycardia indicate incarceration and potentially ischemia.
- Requires urgent surgical release to prevent permanent damage
- Rare situation compared to that seen with orbital floor fracture
- Entrapment and abduction deficit as "white eye injury" is less common in the medial wall because the bone does not snap back and catch the soft tissues.
There may be restrictive abduction deficit due to soft tissue edema and/or scarring, even without absolute entrapment.
- Appropriately managed with exploration
- May need muscle surgery
The associated fractures usually dictate the need for surgical repair, but rarely the isolated medial wall fracture.
- Surgical repair does not need to be delayed.
- Large fracture likely to cause enophthalmos should be repaired before scarring potentially interferes with restoration
Transcaruncular: Visualization should be adequate for exploration of the defect, repositioning orbital contents, and placement of an implant across the defect.
- A secondary supporting implant can be inserted as a means of stabilizing the primary implant placed along the bony defect.
- The supporting implant is 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, 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).
- 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 may 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.
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.