Management of Depressed Anterior Frontal Sinus Fracture
For isolated depressed anterior table frontal sinus fractures with an intact nasofrontal duct and no posterior table involvement, surgical reduction and fixation is the definitive treatment, with minimally invasive approaches (endoscopic or subbrow incision) preferred over traditional coronal incisions to minimize morbidity while achieving anatomic restoration. 1, 2, 3
Initial Assessment and Imaging
Obtain CT maxillofacial without contrast as the gold standard imaging modality to evaluate the fracture pattern, degree of displacement, and involvement of critical structures 1, 4. This provides superior delineation of osseous structures and can detect subtle nondisplaced fractures 1.
Always obtain complementary CT head without contrast since 56-87% of frontal bone fractures have associated intracranial injuries, with 8-10% requiring surgical intervention for subdural or epidural hematoma 1. This is critical as frontal sinus fractures result from high-energy trauma 5.
Request 3D reconstructions for surgical planning, as these significantly improve surgeon confidence and better characterize complex fractures 1, 4.
Key Imaging Evaluation Points:
- Assess posterior table integrity: Displaced posterior table fractures indicate potential dural disruption and require different management 1
- Evaluate nasofrontal duct patency: Duct obstruction mandates surgical intervention to prevent mucocele formation and osteomyelitis 1
- Check for cribriform plate involvement: This requires surgical exploration due to CSF leak risk 1
- Look for orbital roof extension: Requires evaluation for globe injury and extraocular muscle entrapment 1
Treatment Algorithm Based on Fracture Pattern
Isolated Anterior Table Fracture (Intact Nasofrontal Duct, No Posterior Table Involvement)
Surgical reduction and fixation is indicated for depressed anterior table fractures to restore forehead contour and prevent late complications 2, 3, 5.
Surgical Approach Options (in order of preference for minimizing morbidity):
1. Endoscopically-Assisted Reduction (preferred for appropriate candidates):
- Performed through two small slit incisions in the hair-bearing area 2
- Uses 4-mm 30-degree endoscope with subperiosteal dissection 2
- Depressed segments reduced and fixed with microplates 2
- Advantages: Avoids complications of traditional bicoronal incision (paresthesia, scarring, alopecia), improved convalescence, superior aesthetic results 2
- Helps diagnose unsuspected CSF leaks 2
2. Subbrow Incision Approach:
- Single 2-3 cm incision at lower margin of brow for inconspicuous scar 6, 3
- Periosteal incision made 3 mm above superior orbital rim 3
- Provides direct visualization for accurate reduction and rigid fixation 3
- Advantages: Minimal invasiveness, barely visible scars long-term, complete contour restoration 3
3. Percutaneous Screw Reduction (very limited indications):
- Reserved for noncomminuted anterior wall fractures only 7
- Reduction achieved by traction of two percutaneously applied screws 7
- Caveat: Not suitable for complex or comminuted fractures 7
4. Traditional Coronal Approach:
- Reserved for complex fractures requiring extensive access 7, 5
- Higher morbidity with paresthesia, scarring, and alopecia risk 2
Combined Anterior and Posterior Table Fractures
Surgical exploration via bifrontal craniotomy with sinus cranialization or obliteration is the standard approach when there is CSF leak or nasofrontal duct obstruction 1. This prevents long-term complications including chronic sinusitis, mucocele formation, and osteomyelitis 5.
Fractures with Nasofrontal Duct Involvement
Surgical intervention is mandatory to prevent mucocele formation and osteomyelitis, regardless of anterior table displacement 1.
Fractures with Cribriform Plate Involvement
Surgical exploration is required due to high risk of CSF leak and chronic sinusitis 1.
Surgical Timing
Perform definitive treatment as early as safely possible once life-threatening injuries are stabilized 1. Management of ongoing hemorrhage or intracranial hypertension takes precedence over frontal bone fracture repair 1.
Critical Pitfalls to Avoid
Do not underestimate posterior table injury: The posterior table is thin and delicate, easily fractured despite the anterior table's ability to withstand up to 1,000 kg of force 1. Always carefully evaluate CT imaging for posterior table involvement.
Do not miss nasofrontal duct obstruction: This requires surgical intervention even if the fracture appears minor, as duct obstruction leads to mucocele formation 1.
Do not overlook cervical spine injury: Present in 6-19% of significant maxillofacial trauma cases 1.
Do not use minimally invasive techniques for complex fractures: Percutaneous and endoscopic approaches are only appropriate for isolated, noncomminuted anterior table fractures 7, 2.
Postoperative Monitoring
Monitor for delayed complications including mucocele formation, osteomyelitis, and chronic sinusitis during follow-up 1, 5. These can develop months to years after injury if the fracture was inadequately managed.