What is the management approach for a fracture of the temporal part of the zygomatic bone?

Management of Temporal Part of Zygomatic Bone Fractures

Fractures involving the temporal portion of the zygomatic bone (zygomatic arch) require surgical repair when there is displacement of bony fragments, with open reduction and internal fixation (ORIF) being the treatment of choice for cases with comminution or instability. 1

Initial Diagnostic Approach

CT maxillofacial without contrast is the essential diagnostic modality, providing high-resolution imaging of osseous structures with multiplanar reconstructions and 3-D reformations critical for surgical planning 2. This imaging is superior to plain radiography, which misses approximately 12% of maxillofacial fractures 2.

Key Imaging Features to Evaluate

• Zygomaticomaxillary complex involvement: Direct blows to the zygoma transmit force to adjacent weaker areas, potentially causing fractures of the zygomatic arch, inferior orbital rim, anterior and posterior maxillary sinus walls, and lateral orbital rim 3
• Degree of displacement and comminution to determine surgical approach 2
• Infraorbital nerve involvement for prognostic assessment 2
• Associated injuries: Cervical spine injury occurs in 6-19% of significant maxillofacial trauma, and intracranial injury is present in 9% of patients with orbital wall fractures 2

Clinical Assessment Priorities

Immediate Life-Threatening Concerns

• Monitor for bradycardia or heart block indicating oculocardiac reflex from potential orbital muscle entrapment—this is a potentially life-threatening condition requiring urgent intervention 4, 5
• Assess for globe subluxation into the maxillary sinus, which requires immediate surgical repair 4
• Evaluate for "white-eyed blow-out fracture" with muscle entrapment, particularly in children, requiring immediate surgical repair 4

Functional Assessment

• Perform detailed sensorimotor examination assessing versions, ductions, saccades, pursuit, and alignment in multiple gaze positions 4
• Conduct forced duction and forced generation testing to distinguish restriction from paresis of extraocular muscles 4
• Evaluate for mandibular impingement: Zygomatic arch fractures may impinge on the mandible's coronoid process, causing restricted mandibular function and malocclusion 3

Surgical Indications and Timing

Immediate Surgical Repair (Emergency)

• CT evidence of entrapped muscle or periorbital tissue with nonresolving oculocardiac reflex 4
• Globe subluxation into the maxillary sinus 4
• White-eyed blow-out fracture with muscle entrapment and oculocardiac reflex 4

Early Surgical Repair (Within 2 Weeks)

• Symptomatic diplopia with positive forced ductions or entrapment on CT with minimal improvement 4
• Large floor fractures, hypoglobus, and progressive infraorbital hypoesthesia 4
• Early enophthalmos or hypoglobus causing facial asymmetry 4
• Displaced zygomatic arch fractures causing cosmetic deformity 3

Observation Only

• Minimal diplopia not affecting primary or downgaze 4
• Good ocular motility without significant enophthalmos or hypoglobus 4
• Non-displaced fractures without functional impairment 1

Surgical Technique

Fixation Strategy

Three-point fixation using miniplates is superior to two-point fixation, with significantly fewer postoperative complications including decreased malar height and vertical dystopia 6. The three points typically include:

• Frontozygomatic suture
• Infraorbital rim
• Zygomaticomaxillary buttress 1, 6

Surgical Approaches

Multiple incisions are available depending on fracture pattern 7:

• Lateral brow or lateral upper blepharoplasty for frontozygomatic access 8
• Transconjunctival or subciliary for infraorbital rim access 8
• Intraoral for zygomaticomaxillary buttress access 8

Reduction Technique

The Carroll-Girard T-bar screw is highly effective for reduction, as it can rotate in any direction and vector, allowing more accurate and safe correction of displaced zygomatic bone without leaving facial scars 8, 9. This instrument provides stable fixation after adequate exposure for three-dimensional anatomic reduction 8.

Important Clinical Pitfalls

• Isolated bilateral zygomatic arch fractures are associated with skull base fractures in 76% of cases—always evaluate for this 3
• Even with proper repair, strabismus and diplopia can persist in up to 37% of patients postoperatively 4
• Serious ocular injury occurs in up to 24% of blowout fractures—all vision-threatening conditions must be treated before addressing strabismus 4
• In cases without muscle entrapment, waiting 4-6 months after orbital trauma is advised as strabismus may resolve spontaneously 4

Conservative Management Options

For less severe cases without surgical indications:

• Short burst of oral steroids can hasten recovery and help identify strabismus that will persist despite resolution of orbital edema/hematoma 4
• Occlusion, filters, Fresnel prisms, and prism glasses may provide temporary or permanent relief of diplopia 4