You are in: eMedicine Specialties >
Ophthalmology > ORBIT
Orbital Fracture, Zygomatic
Article Last Updated: Jun 18, 2006
AUTHOR AND EDITOR INFORMATION
Section 1 of 10  
Author: Stuart R Seiff, MD, FACS, Chief, Emeritus Professor of Ophthalmology, Department of Ophthalmology, San Francisco General Hospital
Stuart Seiff is a member of the following medical societies: American Academy of Ophthalmology, American Society of Ophthalmic Plastic and Reconstructive Surgery, and California Medical Association
Coauthor(s):
Jesus Torres, MD, Fellow, Section of Oculoplastic Surgery, Hospital de Viladecans, Spain;
Dan D DeAngelis, MD, FRCS(C), Ophthalmic Plastic and Reconstructive Surgery, Assistant Professor, Department of Ophthalmology and Vision Sciences, University of Toronto;
Susan Carter, MD, Co-Director of Ophthalmic Plastic and Reconstructive Surgery, Assistant Professor, Department of Ophthalmology, University of California at San Francisco
Editors: Ron W Pelton, MD, PhD, Private Practice, Colorado Springs, Colorado; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Mark T Duffy, MD, PhD, Consulting Staff, Division of Oculoplastic, Orbito-facial, Lacrimal, and Reconstructive Surgery, Green Bay Eye Clinic, BayCare Clinic; Lance L Brown, OD, MD, Ophthalmologist, Affiliated With Freeman Hospital and St John's Hospital, Regional Eye Center, Joplin, Missouri; Hampton Roy Sr, MD, Associate Clinical Professor, Department of Ophthalmology, University of Arkansas for Medical Sciences
Author and Editor Disclosure
Synonyms and related keywords:
zygomatic fractures, tripod fracture, facial fracture, facial bone fracture, orbit, orbital rim, ophthalmic injury, eye injury, trimalar fracture
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 Image 1). Anatomically, the zygomatic bone contains foramina that allow for the passage of 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 also 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 tendons, is located on the zygomatic bone 2 mm behind the lateral orbital rim.
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, 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.
Frequency
United States
Zygomatic fractures are the second most common fracture of the facial bones behind nasal bone fractures.
Mortality/Morbidity
As many as 5% of these patients have associated ophthalmic injuries.
Sex
Males are afflicted more commonly than females by a 4:1 ratio.
Age
Most cases occur in young patients in their second to third decades of life.
History
- 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
- Since most of these patients are involved in multisystem trauma, involvement by a trauma team for airway, breathing, and circulatory status are 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.
- 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.
- Crepitation from subcutaneous emphysema or proptosis and visual loss from orbital emphysema may occur with forceful nose blowing. Patients should be cautioned against this.
Causes
The mechanism of injury usually involves a blow to the side of the face from a fist, object, or secondary to motor vehicle accidents. Studies show that 80% of these injuries are due to motor vehicle accidents.
Enophthalmos
Globe Retraction
Orbital Fracture, Floor
Orbital Fracture, Medial Wall
Other Problems to be Considered
Midface fractures
Lab Studies
- The only 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 computed tomographic (CT) scan. Typically, CT scan is the study of choice. There is little role for MRI in the management of these injuries.
- A Waters view radiograph may show evidence of the zygomatic fracture and subsequent displacement (see Image 2).
- 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 Images 3-4).
- 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 degree of displacement of the fractures. The integrity of the mandible as well as of the temporomandibular joint should be evaluated.
- CT scan is vital for planning the operative approach. The films should be available for review in the operating room. Furthermore, CT evaluation is helpful for the approximately 50% of patients that have concomitant intracranial injury.
- Ultrasonography could be useful as a screening tool for 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 (Friederich et al, 2003).
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.
Medical Care
The aims of treatment of zygomatic complex fractures include the restoration of normal facial form, 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.
- The literature indicates that 10-50% of all zygomaticomaxillary complex fractures require no surgical intervention. 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 prior to 3 weeks postinjury.
- 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.
- 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.
- 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 or 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.
- 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 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
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.
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.
In/Out Patient Meds
- Most surgeons place patients on oral antibiotics, oral pain medications, and often order a short course of oral steroids as well.
Complications
- 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% of treated zygomatic fractures), 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 as soon as possible. This should be completed at the bedside if the patient has visual compromise and is not near the operating suite.
Prognosis
- Indicators of favorable outcome include bony union, absence of skeletal or soft tissue deformity, and a normal range of mandibular movement.
Patient Education
- Advise patients to avoid nose blowing for fear of orbital emphysema and potential blindness. Also, warn them of the signs and symptoms of orbital/retrobulbar hemorrhage. Advise patients to call the surgeon at any time if orbital bleeding is suspected.
- For excellent patient education resources, visit eMedicine's Breaks, Fractures, and Dislocations Center. Also, see eMedicine's patient education article Facial Fracture.
Medical/Legal Pitfalls
- Physicians need to be reminded to perform a complete examination prior to embarking on surgical repair. Complete ophthalmic evaluation should include assessment for a ruptured globe and retinal detachment. These are a few of many pathologies that need to be ruled out. Adequate consultation for ancillary problems, such as malocclusion, should be obtained.
| Media file 1:
The zygoma forms a firm buttress for the orbit and typically fractures at its sutures. |
 |  View Full Size Image | |
Media type: Photo
|
| Media file 2:
Waters view demonstrating a zygomatic complex fracture involving the zygomaticofrontal suture, inferior orbital rim, and opacification of the maxillary sinus. |
 | View Full Size Image | |
Media type: X-RAY
|
| Media file 3:
CT scan of the orbit demonstrating disruption of the zygomatic arch. |
 | View Full Size Image | |
Media type: CT
|
| Media file 4:
CT scan demonstrating disruption of the lateral wall of the orbit and medial inferior orbital rim. |
 | View Full Size Image | |
Media type: CT
|
- Covington DS, Wainwright DJ, Teichgraeber JF, Parks DH. Changing patterns in the epidemiology and treatment of zygoma fractures: 10-year review. J Trauma. Aug 1994;37(2):243-8. [Medline].
- Friedrich RE, Heiland M, Bartel-Friedrich S. Potential of ultrasound in the diagnosis of midface fractures. Clinical Oral Investigations. 2003;7:226-229. [Full Text].
- Gruss JS, Van Wyck L, Phillips JH, Antonyshyn O. The importance of the zygomatic arch in complex midfacial fracture repair and correction of posttraumatic orbitozygomatic deformities. Plast Reconstr Surg. Jun 1990;85(6):878-90. [Medline].
- Laine FJ, Conway WF, Laskin DM. Radiology of maxillofacial trauma. Curr Probl Diagn Radiol. Jul-Aug 1993;22(4):145-88. [Medline].
- McLoughlin P, Gilhooly M, Wood G. The management of zygomatic complex fractures--results of a survey. Br J Oral Maxillofac Surg. Oct 1994;32(5):284-8. [Medline].
- Randall DA, Bernstein PE. Epistaxis balloon catheter stabilization of zygomatic arch fractures. Ann Otol Rhinol Laryngol. Jan 1996;105(1):68-9. [Medline].
- Smyth AG. A modified miniplate for use in malar complex fractures. Br J Oral Maxillofac Surg. Jun 1995;33(3):169-70. [Medline].
- Zingg M, Laedrach K, Chen J, et al. Classification and treatment of zygomatic fractures: a review of 1,025 cases. J Oral Maxillofac Surg. Aug 1992;50(8):778-90. [Medline].
Orbital Fracture, Zygomatic excerpt Article Last Updated: Jun 18, 2006
|
