Zygomatic Complex Fractures 

Updated: Dec 03, 2018
Author: Stuart Seiff, MD, FACS; Chief Editor: Hampton Roy, Sr, MD 

Overview

Background

The zygomatic bone occupies a prominent and important position in the facial skeleton. The zygoma forms a significant portion of the floor and lateral wall of the orbit and forms a portion of the zygomatic arch, otherwise known as the malar eminence, which plays a key role in the determination of facial morphology. Fractures of the zygomatic complex occur because of the rotation of the zygoma associated with the disarticulation of the zygomatic bone at the zygomaticofrontal suture (along the lateral orbital rim), the zygomaticomaxillary suture (medially), and along the zygomatic arch to the temporal bone (see below).[1, 2]

The zygoma forms a firm buttress for the orbit and The zygoma forms a firm buttress for the orbit and typically fractures at its sutures.

Anatomically, the zygomatic bone contains foramina that allow for the passage of the zygomaticofacial and zygomaticotemporal arteries and corresponding nerves of the second division of the trigeminal nerve that supply sensation to cheek and anterior temple. Similarly, the infraorbital nerve courses the floor of the orbit and exits the infraorbital foramen or notch. Consequently, fractures of the zygomatic arch can lead to hypoesthesia in the corresponding dermatome. Muscle attachments along the zygomatic arch include the origin of the masseter, the zygomaticus major, and some fibers of the temporalis fascia. The Whitnall tubercle, which serves a critical role in the maintenance of eyelid contour as the attachment site for the lateral canthal tendon, is located on the zygomatic bone 2 mm behind the lateral orbital rim.[3]

Pathophysiology

The zygoma is the main buttress between the maxilla and the skull, but, in spite of its sturdiness, its prominent location makes it prone to fracture. The mechanism of injury usually involves a blow to the side of the face from a fist, from an object, or secondary to motor vehicle accidents. Moderate force may result in minimally or nondisplaced fractures at the suture lines. More severe blows frequently result in inferior, medial, and posterior displacement of the zygoma. Comminuted fractures of the body with separation at the suture lines are most often the result of high-velocity motor vehicle accidents.

In general, displaced fractures involve the inferior orbital rim and orbital floor, the zygomaticofrontal suture, the zygomaticomaxillary buttress, and the zygomatic arch. However, occasionally, a direct blow to the arch results in an isolated depressed fracture of the arch only.[3]

Epidemiology

Frequency

In the United States, zygomatic fractures are the second most common fracture of the facial bones following nasal bone fractures.[4] Studies from countries outside the United States found zygomatic complex fractures to be the most common fracture site in patients with maxillofacial trauma.[5]

Mortality/Morbidity

Patients with zygomatic fractures frequently have associated ophthalmic injuries, especially in the setting of combined zygomatic and orbital floor fractures.[6]

Sex

Males experience zygomatic fractures more commonly than females, and a higher proportion of male patients requires surgical intervention.[7]

Age

Most cases of zygomatic complex fractures occur in young patients in their second to third decades of life, with the exception of fractures due to accidental falls, which are mainly seen in older patients.[7, 8]

Prognosis

Displaced fractures can lead to changes in globe position and facial contour if not properly realigned. Associated ophthalmic and intracranial injuries may occur and may carry separate prognostic considerations.

Postoperative complications include ectropion, epiphora,[9] plate exposure, and wound infections, potentially requiring removal of implanted material.[10] Case reports have also described postoperative orbital hemorrhage, which can lead to permanent blindness in the affected eye.[11]

Indicators of favorable outcome include bony union, absence of skeletal or soft tissue deformity, and a normal range of mandibular movement.

Patient Education

It is essential to instruct patients to avoid forceful nose blowing. The disrupted orbital walls can allow air to be forced into the retrobulbar space, causing orbital emphysema, which may lead to pain and visual loss. Advise patients to call the surgeon at any time if orbital bleeding is suspected.

Intermittent application of ice packs to the area of the fracture in the first 3-4 days after injury may aid in alleviating pain and edema.

For excellent patient education resources, visit eMedicineHealth's First Aid and Injuries Center. Also, see eMedicineHealth's patient education article Facial Fracture.

 

Presentation

History

Vision can be threatened as a result of direct ocular injury or intraorbital hemorrhage.

Binocular diplopia is noted in as many as 30% of zygomatic fractures. This can be secondary to muscle entrapment, neuromuscular injury, or intramuscular hematoma.

Difficulty with mastication, otherwise known as trismus, can occur because of masseter spasm or bony impingement of the coronoid process.

In some patients, ipsilateral epistaxis also is noted as a result of lacerated maxillary sinus mucosa.

Physical Examination

Since most of these patients are involved in multisystem trauma, involvement by a trauma team for airway, breathing, and circulatory status is essential.

Ophthalmic evaluation, including globe integrity, should be performed promptly. Inferior displacement of the lateral canthal tendon is common. Proptosis may be present due to orbital edema or hemorrhage. Acute orbital hematoma may cause vision compromise and should be managed appropriately.[6]

Periorbital and/or subconjunctival ecchymosis are seen in as many as 50% of patients.

Significant malar depression can be seen with step defects at the infraorbital rim, frontozygomatic suture, and zygomatic buttress of the maxilla intraorally.

Fractures of the zygomatic bone evoke pain on palpation in 70% of patients.

Paresthesias in the distribution of the infraorbital, zygomaticofacial, or zygomaticotemporal nerves can occur.

Posterior displacement of the fracture fragment may impinge on movement of the mandible causing difficulty with mastication. Inferior displacement of the lateral canthal angle may indicate inferior migration of the fractured zygomatic bone. Although these are not true orbital blowout fractures, entrapment of orbital contents, enophthalmos, and diplopia with restriction of motility may occur because of the contributions of the zygomatic bone to the orbital floor. Use of the Hertel exophthalmometer in the assessment of relative enophthalmos or exophthalmos may be complicated because the lateral orbital rim, which is displaced in most zygomatic complex fractures, serves as a reference point for this instrument. Consideration should be given to the use of the Naugle exophthalmometer in these cases, which uses the frontal bone as a reference.[12]

Crepitus from subcutaneous emphysema or proptosis and visual loss from orbital emphysema may occur with forceful nose blowing. Patients should be cautioned against this.

Zygomatic fractures may be associated with skull base fractures, which may present with rhinorrhea or otorrhea.[13]

Complications

In patients with a zygomatic complex fracture, the injury itself can be complicated by associated ophthalmic or intracranial trauma. The necessary components of a thorough physical examination to assess for associated injuries are listed in Physical Examination.

Rare postoperative complications include hemorrhage, which can lead to permanent blindness in the affected eye,[11] ; plate exposure; and wound infections, potentially requiring removal of implanted material.[10] However, routine administration of a postoperative course of oral antibiotics has not been found to decrease the incidence of wound infections.[14]

The complications of an inadequately or unreduced zygomatic fracture are very difficult to correct secondarily. Malunion is the most common complication of zygomatic fractures and is the result of improper reduction and fixation, resulting in malocclusion, facial asymmetry, and enophthalmos.

Extraocular muscle entrapment, although usually attributable to the initial fractures, also can occur secondary to fracture repair. The rare complication of sudden onset blindness resulting from retrobulbar hemorrhage following reduction of even simple zygomatic fractures means that, in some instances, this procedure may be unsuitable for outpatient surgery. This serious complication, although rare (0.3% in the largest case series of surgically treated zygomatic fractures[15] ), is potentially reversible upon early recognition of the symptoms and signs of retrobulbar hemorrhage (eg, pain, proptosis, loss of vision, decreased motility). If the surgeon suspects a retrobulbar hemorrhage, a lateral canthotomy and cantholysis should be performed without delay. This should be completed at the bedside if the patient has visual compromise and is not near the operating suite.

Late complications usually result from scar formation, which can lead to lid retraction, ectropion, and epiphora.[9]

Etiology

The mechanism of injury usually involves a blow to the side of the face. While most zygomatic fractures are caused by motor vehicle accidents, more recent studies show an increasing incidence of assault, followed by accidental falls.[4, 7, 5]

 

DDx

 

Workup

Laboratory Studies

The only laboratory tests needed are those for preoperative evaluation as required by the surgery facility.

Imaging Studies

Orbital imaging is appropriate.

Radiographic evaluation of the fracture is mandatory and may include both plain films and a CT scan. Typically, CT scan is the study of choice. There is little role for MRI in the management of these injuries.[16]

A Waters view radiograph may show evidence of the zygomatic fracture and subsequent displacement, as shown below.

Waters view demonstrating a zygomatic complex frac Waters view demonstrating a zygomatic complex fracture involving the zygomaticofrontal suture, inferior orbital rim, and opacification of the maxillary sinus.

CT scans (orbit and sinuses) have now essentially replaced plain films as the standard imaging study in both evaluation and treatment planning. CT scans are generally easier to read than plain films and give more helpful information. See the images below.

CT scan of the orbit demonstrating disruption of t CT scan of the orbit demonstrating disruption of the zygomatic arch.
CT scan demonstrating disruption of the lateral wa CT scan demonstrating disruption of the lateral wall of the orbit and medial inferior orbital rim.

An axial CT scan with 1-mm sections and a coronal CT scan with 3-mm cuts (facial series) should be obtained to best delineate the anatomy. The CT scan accurately reveals the extent of orbital involvement and the degree of displacement of the fractures. The integrity of the mandible as well as of the temporomandibular joint should be evaluated.

CT scans are vital in planning the operative approach. The CT scans should be available for review in the operating room. Furthermore, evaluation with CT scans is helpful for the approximately 50% of patients who have concomitant intracranial injury.

Ultrasonography could be useful as a screening tool to aid in the detection of zygoma and orbital rim fractures. With experience, ultrasonography could also be used for intraoperative evaluation after a closed reduction where direct visualization of alignment is not possible.[17]

Staging

Several classifications of zygomatic fractures have been described in the literature, but none seem to be universally accepted. Most classifications are based on the degree of comminution, whether the fracture is simple or compound, and the site of the fractures. In 75% of cases, these fractures are displaced inferiorly, medially, and posteriorly.[3]

 

Treatment

Medical Care

The aims of treatment of zygomatic complex fractures include the restoration of normal facial contour, normal sensory nerve function, normal globe position, and normal masticatory function. Indications for repair of zygomatic complex fractures include displacement or instability of the fracture, mechanical restriction of mandibular movement (chewing), alteration in facial contour, globe dystopia, enophthalmos, diplopia, or sensory nerve deficit.[18]

The literature indicates that 10-50% of all zygomaticomaxillary complex fractures require no surgical intervention.[7] This is suitable for fractures that are nondisplaced or minimally displaced or where systemic status precludes operative intervention.

Stable, nondisplaced fractures may be observed weekly for healing.

Avoidance of nose blowing is mandatory in the medical care of these patients. The disrupted orbital walls can allow air to be forced into the retrobulbar space and cause pain and visual loss.

The routine use of systemic antibiotics for isolated zygomatic arch fractures generally is not recommended.

Surgical Care

Generally, it is suggested to avoid surgery during times of maximum edema but prior to the adhesion of displaced bony fragments and scarring of soft tissues into bony defects. Most surgeons advise surgical intervention prior to the formation of dense scar tissue. As a general guideline, surgery should be undertaken within 3 weeks from the time of injury.[4, 19, 20]

Traditionally, closed-reduction techniques were the method of choice for nearly all zygomatic fractures. In the past, simple techniques, such as exerting pressure under the zygomatic arch and resetting the bones in their anatomic position (eg, Gilles approach), were hindered by unsatisfactory cosmetic results and persistent diplopia. Although open techniques currently are favored, closed-reduction techniques may be suitable for isolated arch fractures and minimally displaced noncomminuted fractures.[21]

A more aggressive approach using open-reduction techniques and rigid stabilization with plating systems (eg, Synthes or Leibinger) is the standard of care today, particularly for unstable or potentially unstable fractures.[22]

This approach provides direct access to the frontozygomatic suture, orbital floor, and infraorbital rims.

The inferior orbital rim and floor can be exposed via an infraciliary approach or a transconjunctival approach. The transconjunctival incision gives excellent exposure and saves the patient a visible scar on the face.

The floor of the orbit is routinely explored and reconstructed, if needed, to restore orbital volume. At this point, the zygomatic arch and orbital rims should be aligned.[23]

Typically, the inferior rim defects are visible through the orbital incision. The lateral rim fracture frequently occurs at the frontozygomatic suture line. This sometimes can be reached via the lateral lid crease or canthal incision. Rarely, a second incision may be needed under the lateral brow. This can be used to approach the lateral fracture and to provide access to elevate that bony fragment.

Once proper access to the lateral rim has been achieved, an elevator is passed along the lateral rim and under the zygomatic arch at its anterior origin. Firm anterior pressure, not prying, is applied to the elevator to align the lateral and inferior fragments.

Once these are positioned, they are fixated with miniplates.

Precise reconstruction with rigid internal fixation of the zygoma at 2 or 3 points (across the frontozygomatic suture, the inferior orbital rim, and the lateral midfacial buttress) is needed to counter the force of the masseter muscle. The orbital contents can be supported as for simple orbital floor fractures.

Consultations

When zygomatic complex fractures are primarily managed by the oculoplastic surgeon, consultations with other services such as otolaryngology, the oral maxillofacial service, facial plastic surgery, and neurosurgery may be needed if significant concomitant nasal, oral, and/or cranial fractures are present.

Diet

Patients commonly are placed on a soft diet for several days to weeks. A dietary consultation may be warranted.

Activity

Advise patients to avoid nose blowing for several weeks after the surgery. All contact sports and most strenuous activity also should be avoided for several weeks.

Complications

Postoperative complications include ectropion, epiphora,[9] plate exposure, and wound infections, potentially requiring removal of implanted material.[10] However, routine administration of a postoperative course of oral antibiotics has not been found to decrease the incidence of wound infections.[14] Case reports have also described postoperative orbital hemorrhage, which can lead to permanent blindness in the affected eye.[11]

Prevention

With the widespread use of seatbelts and improvements in safety mechanisms such as airbags, the contribution of motor vehicle accidents to the overall incidence of maxillofacial fractures has been decreasing. However, motorcycle- and bicycle-related injuries remain a frequent cause of zygomatic complex fractures.[9, 7]

Further Outpatient Care

Follow-up care is essential for the evaluation of surgical success. Masticatory function, globe position, and restoration of normal facial anatomy are all important elements that need to be critically addressed in the postoperative period.[9]

Inpatient & Outpatient Medications

Most surgeons place patients on oral pain medications and administer perioperative intravenous corticosteroids to limit postoperative inflammation and edema. While oral antibiotics are frequently prescribed, no evidence supports their routine use.[14]

 

Guidelines

Guidelines Summary

Stable nondisplaced fractures may be observed weekly for healing. Indications for surgical repair of zygomatic complex fractures include displacement or instability of the fracture, mechanical restriction of mandibular movement (chewing), alteration in facial contour, globe dystopia, enophthalmos, diplopia, or sensory nerve deficit.[18]

While general guidelines for surgical management are lacking and preferred techniques vary by individual surgeon and specialty, a recent survey regarding the management of zygomatic fractures, including by plastic surgeons, oral and maxillofacial surgeons (OMFS), and otorhinolaryngologists (ENT), found that open reduction and rigid internal fixation is the preferred approach.[24]

 

Medication

Medication Summary

The treatment of zygomatic complex fractures is primarily surgical. Supportive treatment may include analgesics and nasal decongestants. Data regarding the efficacy and safety of perioperative intravenous corticosteroids are sparse and inconclusive, with some studies suggesting increased rates of delayed wound healing while others found no adverse effects.[25, 26]