Frontal Sinus Fractures Treatment & Management

The most appropriate treatment of frontal sinus (FS) fractures can be complex and, at times, controversial. The treating physician should have a clear algorithm in mind for management of different fracture patterns.

The author proposes a conservative algorithm for the treatment of most FS injuries. Treatment options include observation, open reduction and internal fixation (ORIF), sinus obliteration, sinus exenteration (ie, removal of anterior table, Reidel procedure), and sinus cranialization. The algorithm is based on 5 anatomic parameters that need to be evaluated before deciding on the most appropriate treatment option. These parameters include NFR fractures, anterior table fractures, posterior table fractures, dural tears (CSF leak), and degree of fracture comminution. Fascial planes of the forehead and temple are depicted below.

Nondisplaced or minimally displaced (< 1-2 mm) isolated anterior table fractures can be managed conservatively with local wound care and analgesics. Patients should be closely observed for signs of frontal sinusitis, which may indicate fracture involvement in the nasofrontal duct.

A study by Dennis et al indicated that nonsurgical treatment is a viable means of addressing nonobstructed fractures of the FS ostium or NFR. The reaeration rates of the study cohort’s sinuses following conservative management of such injuries were 91% (ostia) and 98% (NFRs). For obstructed fracture patterns, the reaeration rates were 50% and 77%, respectively. ^[6]

General goals of surgical therapy include protection of intracranial contents, prevention of early and late complications (eg, meningitis, mucocele), restoration of aesthetic forehead contour, and return of normal frontal sinus (FS) function. Although accomplishing all these goals may not be possible, the intracranial contents must be protected, and a "safe" sinus must be reconstructed. Repair of aesthetic and functional deformities can be addressed secondarily. ^{[7, 8, 9]}

A study by Choi et al in which the investigators surveyed facial plastic surgeons with otolaryngology training, general otolaryngologists, plastic surgeons, and oral and maxillofacial surgeons found that 61.7% of respondents believed that endoscopic sinus surgery had altered their way of managing frontal sinus fractures. The study also found that when it came to uncomplicated, nondisplaced frontal sinus outflow tract fractures, 91.8% of the physicians surveyed favored observation. In terms of uncomplicated, displaced frontal sinus outflow tract fractures, 36.4% of respondents favored observation and 35.9% favored endoscopic sinus surgery. Plastic surgeons and oral and maxillofacial surgeons had a greater tendency to favor obliteration in complicated, displaced frontal sinus outflow tract fractures than did the physicians with otolaryngology training. ^[10]

A review by Dedhia et al of current trends and literature in the management of frontal sinus fractures remarks on the evolving conservative management of select cases and the expansion of such treatment due to the role of minimally invasive endoscopic sinus surgery techniques. The authors outline a new algorithm for treatment decisions and emphasize the need for follow-up of at least a year to monitor for possible complications. ^[11]

Nasofrontal recess fractures

Nondisplaced fractures involving the floor of the FS or anterior ethmoid region should raise suspicion for nasofrontal recess (NFR) injury.

In the absence of associated FS injuries, close observation and repeat CT at 4-6 weeks may reveal sinus opacification, indicating outflow obstruction.

If NFR injury is highly suspected, but it cannot be confirmed on the CT scan, a frontal sinusotomy and endoscopic evaluation is indicated (see Intraoperative Details).

Displaced fractures usually require FS obliteration. Some authors have advocated more conservative approaches, such as NFR reconstruction with mucoperiosteal flaps (eg, Sewell-Boyden flaps) or intersinus septectomy, which theoretically allows the injured sinus cavity to drain into the uninjured NFR. These techniques have not gained significant popularity.

Anterior table fractures

Nondisplaced fractures can generally be managed nonoperatively. Nondisplaced anterior table fractures rarely result in mucocele formation, functional deficit, or aesthetic deformity. Advise patients of a small risk of external deformity, which can often be repaired endoscopically. ^[12]

Displaced fractures greater than 1-2 mm have an increased risk of aesthetic deformity and mucocele formation. ORIF of the fracture is indicated within 7-10 days.

• Consider endoscopic NFR evaluation through the fracture site or via trephination.

• Anterior table fractures with only mild comminution can be repaired with preservation of FS function; however, injuries with severe comminution and marked mucosal injury may require bone grafting and FS obliteration.

A study by Spinelli et al indicated that percutaneous screw placement can effectively be used for closed reduction of isolated fractures of the anterior frontal sinus. In the report, 15 patients with such fractures were treated with this technique. ^[13]

Posterior table fractures

Treatment of posterior table fractures remains controversial. A review of the literature reveals that some authors advocate exploration of all posterior table fractures, no matter how slight. Others recommend observation even when the posterior table is significantly displaced. No prospective randomized studies are reported to corroborate the different approaches.

Nondisplaced fractures have a reduced risk of complications (eg, dural tears, CSF leak, meningitis, mucocele formation) when compared with displaced posterior table fractures. The need for exploration often depends on the presence or absence of a CSF leak.

• CSF leak absent: When possible, patients should undergo frontal sinusotomy and endoscopic evaluation of the posterior table integrity. Sinus endoscopy is helpful to rule out mucosal injury, dural tear, CSF leak, or NFR injury. If the examination results are negative, the patient can be observed.

• CSF leak present: Patients with active CSF leaks may be observed for 5-7 days while undergoing treatment with IV antibiotics. Approximately half of these patients have spontaneous resolution of the CSF leak. FS obliteration is indicated if the CSF leak is persistent.

Displaced fractures have an increased risk of complications and require a more aggressive approach.

• CSF leak absent: Categorize cases by the severity of posterior table comminution. If no comminution is present, frontal sinusotomy and endoscopic evaluation for medial fractures is indicated. Obtain patient consent for an osteoplastic flap with possible obliteration or cranialization in case the injury is more severe than anticipated. Mild comminution requires osteoplastic flap and sinus obliteration. Moderate-to-severe comminution (ie, >30% of the posterior table) requires cranialization. Use a pericranial flap for dural repair as necessary. Consult a neurosurgeon for assistance with brain debridement and dural closure.

• CSF leak present: Patients should undergo open exploration with an osteoplastic flap. If minimal-to-mild comminution is present, sinus obliteration is indicated. Moderate-to-severe comminution requires sinus cranialization.

All patients undergoing open FS procedures should be counseled regarding potential risks, including the following:

• External scar, particularly in patients with male pattern baldness

• Bleeding

• Infection

• Forehead paraesthesias

• External deformity

• Diplopia

• CSF leak

• Meningitis

• Sinusitis

• Mucocele formation

• Death

Frontal sinusotomy and endoscopy

Make a 1- to 1.5-cm skin incision placed midway between the medial canthus and the glabella, approximately 1 cm inferior to the brow. The incision is well hidden when placed inferior and deep to the curve of the brow.

• The incision can be placed laterally and above the brow to access lateral portions of the FS.

• The surgeon should use a FS template (see FS obliteration, below).

• The surgeon should also attempt to avoid the supratrochlear neurovascular pedicle.

A guarded needle-point monopolar electrocautery is used to incise the periosteum. Use a cutting burr to open a 4- to 5-mm frontal sinusotomy approximately 1 cm medial and inferior to the medial brow. Incise FS mucosa; instill oxymetazoline for decongestion, if necessary.

Direct visualization of the NFR is obtained with a nasal endoscope to document any mucosal laceration or CSF leak.

• Methylene blue or fluorescein can also be instilled into the FS to confirm patency.

• Intranasal endoscopy will reveal the presence of dye if the NFR is patent.

Avoid NFR instrumentation because it may result in NFR stenosis. The procedure can be repeated on the contralateral side if necessary. The FS trephine procedure is limited by FS anatomy. Lateral fractures and intersinus septations may limit visualization.

ORIF

Position patient 180° away from anesthesia. Explore all forehead lacerations. Although lacerations alone are usually inadequate for exposure, diagnosis, and repair of FS fractures, they should be used to assist with fracture repair.

For coronal flap dissection, part the hair in a widow's peak pattern 4-6 cm behind the anterior hairline. A 1- to 2-cm strip of hair can be shaved along the incision line, but this is not necessary. The scalp is incised and elevated in a subgaleal plane. Avoid brow incisions to prevent prominent scars and forehead anesthesia.

Lateral flap dissection is performed between the temporoparietal fascia (superficial temporal fascia) and the temporalis muscle fascia (deep temporal fascia). The temporoparietal fascia and frontal branch of the facial nerve are elevated with the flap. The temporalis muscle fascia can also be incised and elevated with the flap to provide an extra layer of protection for the facial nerve.

Identify and protect the supraorbital and supratrochlear neurovascular pedicles.

The pericranium is incised 1-2 cm above the sinus and elevated below the fracture. If any concern about a posterior table injury or dural tear exists, elevate the entire pericranial flap from the coronal incision line. The vascularized pericranial flap may then be used for a dural repair.

Reduce the concave fracture segments. If the fracture segments overlap, a bone hook can be insinuated between the fragments and pulled forward.

• If the bone fragments do not overlap, fracture reduction can be difficult. The traumatic force applied to the FS results in horizontal compression of the bone. As the frontal bone fractures, it releases into a concave shape, as shown below.

  The compressive force of frontal bone as the bone is deformed from a convex shape to a concave shape.

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• In this case, fracture reduction can be accomplished by placing a 1.7-mm screw in the depressed segment, grasping the screw with a hemostat, and pulling the segment anteriorly).

• Careful removal of a fragment may need to occur to reduce the tension along the fracture line. Attempt to keep most of the fragments in place because this allows for a more accurate final reduction.

• After the fracture is reduced, remove any torn mucosa from fracture lines to avoid entrapment and evaluate the sinus and NFR endoscopically.

• Reconstruct gaps larger than 5 mm with split calvarial bone grafts and bone pate harvested from the frontal bone with a cutting burr. Other techniques for anterior table reconstruction include combinations of titanium mesh, resorbable mesh, and hydroxyapatite cement. ^[14]

• After fracture reduction, plate the reduced fragments with 1- to 1.2-mm microplates.

• Close the pericranium, galea aponeurosis, and skin in a layered fashion. Insert two Penrose drains and a pressure dressing. Take care to assure that the ears are not rolled forward under the pressure dressing.

FS obliteration

Preoperatively, obtain an anterior-posterior plain radiograph (ie, Caldwell projection) of the skull. Alternatively, a surgical navigation system can be used intraoperatively to localize the sinus.

Prepare the patient for a coronal flap and abdominal fat graft.

Confirm the orientation of the Caldwell radiograph by comparison with a CT scan. Cut out a FS template from the Caldwell radiograph. Lateral "wings" paralleling the orbital rims should be left in place, as in the image below. To assist with accurate intraoperative placement of the template, an "R" should be scratched into the right side of the template.

Perform a coronal incision and elevate a scalp flap (see ORIF). If the anterior table of the FS is not comminuted, the FS template is applied over the pericranium. Tattoo an outline of the FS on the bone with an 18-gauge needle and methylene blue. Incise the pericranium in the coronal plane. Make parallel lateral cuts along the temporal line and raise a large inferiorly based pericranial flap. Take care to maintain a wide pedicle and avoid perforation of the flap.

The midline elevation should continue to approximately 1 cm below the outline of the FS.

A drill can be used to perforate the outline of the flap. Angle the drill toward the sinus cavity to avoid intracranial penetration and injury. The perforations can then be joined with an oscillating saw. A high-speed Midas Rex drill with a B-1 bit is efficient and obviates the need for an oscillating saw.

A 4-mm osteotome is used to fracture the superior orbital rims and glabella at the periphery of the sinus. Avoid injuring the supraorbital/supratrochlear neurovascular pedicles.

A curved osteotome is then placed through the saw kerf, and the intersinus septum is fractured. Repeat this step around the periphery of the sinus with multiple osteotomes until the anterior table of the sinus is hinged open inferiorly. The use of several osteotomes allows the surgeon to repeatedly place a new osteotome without losing the purchase from the previous one.

Assess the posterior table comminution and make a decision regarding sinus obliteration or cranialization. If the sinus is to be obliterated, meticulously debride all mucosa from the sinus with cutting and diamond burrs. Loop magnification can assist with the debridement. Pay particular attention to the periphery of the sinus and the NFR. Treat free bone fragments in a similar fashion. The FS infundibulum mucosa is elevated inferiorly, and a temporalis muscle plug is placed to occlude each ostia. Small sinus cavities can be obliterated with the pericranial flap. A small amount of bone is first removed from the inferior portion of the bone flap. The vascularized pericranial flap is then passed through the bony defect into the sinus cavity.

If fat is to be used to obliterate the sinus, obtain a fat graft through a periumbilical incision using sterile instruments. After fat graft placement and closure of the osteoplastic flap, the fat should approximate but not extrude from the saw kerf. Other materials used for FS obliteration include cancellous bone and muscle. The use of hydroxyapatite cements is not recommended until further studies are complete.

Spontaneous osteoneogenesis and auto-obliteration have also been advocated.

• Anterior table stabilization is achieved with 1- to 1.2-mm plates.

• Harvest bone pate from the frontal bone to fill the osteotomy kerf and any bony defects in the anterior table. Cover the bone pate with Gelfoam.

• Close the pericranium and scalp as described above.

A study by Lee et al reported that in frontal sinus obliteration for traumatic anterior table frontal sinus fractures accompanied by nasofrontal duct injury, the use of computed tomography (CT)-scan guidance permits more accurate osteotomy procedures than does the employment of plain radiographic templates or the “cut-as-you-go” technique. The study, which included 29 patients, found no perioperative complications in those whose surgery involved CT-scan guidance. In contrast, complications, including inadvertent dural exposure and the need for exposure-related hardware removal, occurred in the radiographic template and cut-as-you-go groups. ^[15]

FS cranialization

The surgical approach for cranialization is identical to that described for FS obliteration. Exposure of the sinus rarely requires osteotomies because of the severity of the anterior table injury.

Remove posterior table bone by using elevators and rongeurs. Large pieces of posterior table bone should be divested of mucosa and preserved for reconstruction of the anterior table during closure. Cleanse grossly contaminated bone fragments and soak the fragments in Betadine until needed for reconstruction. The posterior sinus margin is then drilled flush with the anterior cranial fossa. Each FS infundibulum is drilled out, the mucosa is inverted, and the ostium is occluded with a temporalis muscle plug.

Simple lacerations of the dura can be repaired with interrupted 5-0 nylon sutures. More complex injuries may require neurosurgical debridement and dural closure with a pericranial flap. A small bony defect must be fashioned in the anterior table to allow the pericranial flap to pass intracranially without cutting off the blood supply.

Cleanse the preserved bone fragments with saline and reconstruct the anterior table using 1- to 1.2-mm microplates. Outer table calvarial bone grafts should be used as necessary to supplement native bone. Close the scalp in layers. Place drains and a pressure dressing as described above.

Penrose drains are removed after 24 hours. Pressure dressing is discontinued after 3 days. Skin sutures and staples are removed after 10-14 days.

The need for long-term follow-up of patients with FS fractures cannot be overemphasized. The risk of late mucocele formation is significant.

Perform repeat CT or MRI if the patient has symptoms of recurrent infection. Trephination may be necessary in rare cases because radiographic identification of an infected fat graft is difficult.

Improper management of FS and NFR injuries can result in significant complications, including aesthetic deformity, forehead paresthesia or anesthesia, chronic sinusitis, mucopyocele, diplopia, visual loss, meningitis, brain abscess, and death.

Management of postoperative mucoceles usually involves a revision obliteration procedure or sinus exenteration (ie, Reidel procedure) with subsequent cranioplasty.

Patients with mildly displaced anterior table fractures do extremely well after surgical repair, and significant long-term sequelae are uncommon.

Displaced FS fractures generally result from more extreme forces. Consequently, most patients who undergo surgical treatment of these injuries have some long-term sequelae. The most common sequelae are mild and include frontal headache (20%), sinus infections (12%), sinus fullness (11%), sinus drainage (10%), and forehead depression (10%). Less common but more severe long-term sequelae include diplopia (4%), seizures (4%), mucocele formation (exact incidence uncertain [0-10%]), and brain abscess (1%).

For excellent patient education resources, see eMedicineHealth's Headache and Migraine Center and First Aid and Injuries Center. Also, visit eMedicineHealth's patient education articles, Sinus Infection and Facial Fracture.

The most common controversies associated with FS trauma are the aggressiveness of surgical repair for a given fracture type and the optimum material used for FS obliteration. Unfortunately, long-term follow-up in patients with FS fractures is extremely difficult. Definitive studies on the most efficacious management do not exist.

The author(s) has proposed a conservative treatment algorithm to guide the surgical repair of given fracture types. When obliteration is indicated, the author prefers autologous fat. Other materials that have been used include muscle, bone, fascia, osteoneogenesis (auto-obliteration), hydroxyapatite cement, and bioactive glass. Although autologous fat does have donor site morbidity, it is readily available, easy to handle, and cost-effective. Most importantly, it has long-term proven efficacy.

A similar algorithm that advocates observation of nondisplaced anterior table fractures that do not demonstrate radiographic evidence of nasofrontal recess obstruction has recently been suggested after reviewing 857 patients. ^[5]