Plastic Surgery Case Review (eBook)

Case 2 Zygomatic Fractures

Vinay Rao and Albert S. Woo

2.1 Description

• Right mid-facial and periorbital edema with malar depression and mild right hypoglobus, with presumed enophthalmos

• Computed tomography (CT) demonstrates comminuted, displaced right zygomaticomaxillary complex (ZMC) fracture, and fracture of coronoid process of mandible

• By definition, the right orbital floor is fractured in a displaced zygomatic injury

2.2 Work-Up

2.2.1 History

• Mechanism of injury: Helpful in determining angle of force and severity of injury

• Change in vision, loss of vision, or diplopia

– Must rule out orbital injury prior to operative intervention

• Trismus can occur with medial displacement of the zygomatic arch impinging on the temporalis muscle

• Relevant medical history (previous facial injuries or fractures), surgical history (previous facial surgeries), and social history (alcohol, smoking, drug use)

2.2.2 Physical Examination

• Signs of ZMC fractures are malar depression (masked by soft tissue swelling early on), periorbital ecchymoses, enophthalmos, and/or hypoglobus (usually masked by orbital swelling), inferior slant of the palpebral fissure, and tenderness at infraorbital rim and along zygomaticofrontal (ZF) suture

• Numbness of the cheek, nose, upper lip, and teeth: Typical of V2 distribution

• Associated eye examination: Look for visual changes, diplopia, or extra-ocular muscle entrapment

2.2.3 Pertinent Imaging or Diagnostic Studies

• High resolution maxillofacial CT scan

– Evaluate the five articulations of the zygoma: (1) lateral orbital rim (zygomaticofrontal), (2) inferior orbital rim, (3) zygomaticomaxillary buttress, (4) zygomatic arch, and (5) lateral orbital wall (zygomaticosphenoid)

– Evaluate orbital floor defect on coronal cut images

2.3 Patient Counseling

• Older patients, in particular, may consider nonoperative management despite displaced fractures. Surgeons must help weigh risks against benefits of surgery.

• Patients must be informed of possible development of enophthalmos/hypoglobus, malar asymmetry/depression, or appreciable bony step-offs. These clinical examination findings may become more prominent as facial swelling subsides.

• With operative management, adverse events/complications must be discussed, including asymmetric malar positioning, development of possible entropion/ectropion and a remote possibility of vision loss.

2.4 Treatment

2.4.1 Initial Management (in the Emergency Department)

• Always start with ABCs of trauma. All emergent injuries must be managed first.

• Ophthalmology consultation in all orbital fractures to rule out injury of globe must be performed prior to operative interventions as manipulation may exacerbate eye injury.

• Definitive treatment of facial fractures may be delayed for up to 2 weeks without compromising results.

2.4.2 Nondisplaced Fractures

• Simple, nondisplaced fractures do not need surgery and may be managed conservatively

• Recommend soft diet to minimize activation of the masseter

2.4.3 Isolated Zygomatic Arch Fracture

• Temporal (Gillies) approach (▶ Fig. 2.1)

– A 2-cm transverse incision is made in the hairline. Dissect through the superficial and deep temporal fascia layers until temporalis muscle is visible. An elevator is advanced behind the displaced arch.

• Intra-oral approach (Keen) may also be used for reduction.

2.4.4 Displaced Fractures

• Timing of repair: 1 to 2 weeks for adults and within 1 week for pediatric patients

– Addressing fractures at a later time may require osteotomies to allow for adequate reduction. Coronal access may be needed to osteotomize the zygomatic arch.

• Fractures that are significantly displaced or comminuted require open reduction/internal fixation. Plates should be positioned at facial buttresses (▶ Fig. 2.2).

– Critical points of fixation include: (1) Zygomaticofrontal region or lateral orbital rim, (2) infraorbital rim, and (3) zygomaticomaxillary buttress. At least three points of fixation are necessary to guarantee three-dimensional stability. When indicated, the zygomatic arch may be stabilized as a fourth point of fixation (▶ Fig. 2.3).

• The operative approach is determined by the status of the zygomatic arch. If the arch is comminuted or otherwise irreducible, a coronal incision will be needed for reduction and fixation of the arch. Otherwise, the zygomatic fracture can be addressed with an anterior approach.

• The standard anterior approach consists of three incisions:

– Lateral part of upper blepharoplasty (or lateral brow) incision for access to the lateral orbital rim and wall. Note that the best means of confirming three-dimensional reduction of the ZMC fracture is at the lateral orbital wall, which is accessed through this approach.

– Lower eyelid incision (transconjunctival, subciliary, or subtarsal) for inferior orbital rim and orbital floor

– Upper buccal sulcus incision for access to maxillary buttresses

• Orbital floor evaluation

– Zygomatic reduction may cause orbital floor blowouts to become more prominent.

– If a sizeable defect is present, the floor should be reconstructed with an implant (e.g., porous polyethylene or titanium) or bone graft after the zygoma has been reduced.

2.5 Complications

• Retrobulbar hematoma

– It can occur at time of injury or postoperatively.

– Signs are severe eye pain, proptosis, afferent pupillary defect, change in visual acuity, and ultimately blindness.

– Surgical emergency: Requires immediate lateral canthotomy with inferior cantholysis for drainage of the hematoma.

– Mannitol, acetazolamide, and ophthalmology consult are supplementary measures.

• Diplopia

– Commonly seen after surgery due to edema

– Differential diagnosis following zygomatic repair includes extraocular muscle entrapment, muscle contusion, periorbital edema, enophthalmos, or motor nerve palsies

– Muscle entrapment is ruled out if forced duction procedure was performed

– If no structural abnormality is suspected, the patient can follow-up for monitoring

• Inadequate reduction resulting in malposition or enophthalmos

• V2 distribution (infraorbital nerve) anesthesia/paresthesias

– Most commonly due to nerve contusion and generally resolves within 6 months

• Lower lid ectropion (external incision) or entropion (transconjunctival incision)

– This usually responds to eyelid massage but may require surgical correction.

– The subciliary incision has the highest risk of ectropion when compared to transconjunctival or subtarsal approaches.

• Infection requires antibiotics and possible hardware removal

2.6 Critical Errors

• Failure to assess ABCs in acute trauma

• Missing other facial injuries on examination or CT. Watch out for naso-orbito-ethmoid (NOE) fractures, which may occur concomitantly.

• Failure to identify orbital injury, which can be worsened with surgery

• Inadequately addressing the orbital floor at the time of zygomatic reduction

• Inability to...