Classification
Frontal sinus fractures are relatively complex injuries, often occurring alongside nasoethmoidal-orbital complex fractures. They can be categorized into three types: fractures of the anterior wall, posterior wall, and nasofrontal duct. Each type can further be divided into linear fractures, depressed fractures, and comminuted fractures.
Clinical Manifestations
Frontal sinus fractures are frequently accompanied by cranio-cerebral injuries, and their clinical manifestations can be divided into two major categories: neurological symptoms and local frontal sinus symptoms. Local symptoms include epistaxis, swelling or depression in the frontal region, retraction of the supraorbital margin, and downward displacement of the eyeball. Frontal sinus fractures, especially nasoethmoidal-orbital complex fractures, are often associated with nasofrontal duct fractures, lacrimal system damage, and vision impairment. Linear fractures of the anterior wall typically present with milder symptoms, such as epistaxis, soft tissue swelling, and localized tenderness. Acute-phase depressed fractures result in frontal swelling, which may reveal a depression in the forehead after the swelling subsides. Comminuted fractures may present with swelling in the supraorbital region, subcutaneous emphysema, retraction of the supraorbital margin, and downward displacement of the eyeball. Posterior wall fractures accompanied by meningeal tears can result in cerebrospinal fluid rhinorrhea, intracranial hemorrhage, and pneumocephalus in the anterior cranial fossa, potentially leading to severe intracranial infections.
Diagnosis
Diagnosis is typically based on the patient's history, symptoms, signs, local examination, and auxiliary investigations. Due to the unique anatomical location of the frontal sinus, deep probing with instruments is generally avoided in open fractures. Anteroposterior and lateral X-rays of the frontal sinus are useful in determining the location of the fracture. CT imaging can also be utilized.
Treatment
Frontal sinus fractures often require emergency management due to their frequent association with cranio-cerebral injuries. Linear fractures of the anterior wall are treated by decongesting the nasal mucosa, maintaining the patency of the nasofrontal duct, and performing debridement and suturing. For depressed or comminuted fractures of the anterior wall, an incision along the supraorbital margin allows the repositioning of depressed bone fragments.
For isolated linear fractures of the posterior wall, treatment principles are similar to those for anterior wall fractures. Depressed or comminuted fractures of the posterior wall often require removal of the fractured posterior wall of the sinus and prompt management of associated neurosurgical conditions, such as epidural hematoma.
A common complication of frontal sinus fractures is impaired drainage of the frontal recess, which can lead to the gradual development of mucoceles if left untreated. The management principle involves reconstructing the drainage pathway of the frontal sinus and restoring its function. Depending on the clinical situation, different types of incisions can be selected, and if necessary, a T-shaped expansion tube may be placed from the base of the frontal sinus into the nasal cavity.
When handling the frontal sinus cavity, the preservation of the sinus mucosa should be prioritized whenever possible. Silicone expansion tubes can be implanted at the sinus ostium for fixation and drainage until complete healing occurs, thereby preventing closure of the sinus ostium.