The treatment of frontal sinus fractures depends on the extent of the fracture. Fractures of the frontonasal recess and the posterior table of the frontal sinus often require operative intervention. Displaced fractures typically require open reduction. The primary goals of treatment in frontal sinus fractures include preventing complications and restoring normal forehead contour.
Surgical developments within the last few decades have reduced marked cosmetic deformities and a high incidence of long-term complications. Modern techniques of evaluation and treatment allow better triage of patients with frontal sinus fractures to surgical intervention or observation. Fine-cut CT scanning as well as office and intraoperative endoscopy have allowed surgeons to improve patient selection for ablative surgery. In the past, the ablative procedures of a frontal osteoplastic flap and the cranialization procedure were the two primary procedures used to repair complex frontal sinus fractures. Fractures thought in the past to require these interventions, particularly posterior table fractures, have more recently been shown in case series and animal models to be amenable to more conservative treatment. The choice of when to operate and which procedure to perform depends on the extent of the fracture and functional evaluation of the frontonasal recess.
In addition to improved methods of patient selection, more recent advances in instrumentation and technique have also allowed less invasive methods including endoscopy to be used to repair and/or camouflage fractures. Endoscopic techniques are performed through small incisions behind the hairline similar to the approach used for an endoscopic brow lift.
Open Reduction and Internal Fixation
This method exposes fractured bone and replaces the fragments as close to their original configuration as possible. Fixation is typically accomplished with a combination of plates and screws contoured to the bony fragments. Approaches principally include direct approaches through lacerations, a mid brow incision, and the coronal approach (Figures 16–3 and 16–4).
(A) Intraoperative photograph demonstrating displaced fractures. Coronal incision was used with reflected skin flap visible to the left. (Photo contributed by Andrew N. Goldberg, MD.) (B) Intraoperative photograph demonstrating fracture reduction and plating. Coronal incision was used with reflected skin flap visible to the left. (Courtesy of Andrew N. Goldberg, MD.)
(A) Preoperative photograph demonstrating depression of forehead (arrows). (Photo contributed by Andrew N. Goldberg, MD.) (B) Postoperative photograph demonstrating restoration of contour of forehead 2 months after surgery. (Photo contributed by Andrew N. Goldberg, MD.)
The concept of removing the frontal sinus as a functioning unit was introduced in 1958 by Goodale and Montgomery with the osteoplastic flap. This flap or hinged opening of the frontal sinus is created through either a midforehead or a coronal incision and sinus obliteration; this approach may also be used through an existing forehead laceration. The procedure, which remains one of the principal means for treating frontal sinus fractures today, involves raising a subperiosteal flap from a coronal or midforehead incision down to the superior border of the frontal sinus. The anterior table of the frontal sinus is then opened at its superior and lateral margins, creating an inferiorly based bone flap. All mucosa is then stripped from the sinus, and all the bony walls of the sinus are burred down with a drill to ensure complete mucosal removal. The frontonasal recess mucosa is stripped or turned down into the ostium, and the ostium is obliterated using a muscle or fascia plug. The sinus is then obliterated, most commonly using a free fat graft. Finally, the anterior wall of the frontal sinus and the coronal or midforehead flap is replaced.
The Cranialization Procedure
In the cranialization procedure, the posterior wall of the frontal sinus is removed and the frontal dura is allowed to rest against the anterior table of the frontal sinus. This procedure also involves complete stripping of the mucosa, burring any mucosal remnants from the remaining anterior sinus wall, and plugging the frontonasal recess.
Using endoscopic techniques, incisions can be made smaller and morbidity from extensive dissection minimized. At this point, endoscopic techniques are used to repair and/or camouflage frontal sinus fractures involving the anterior table only, although technique development is ongoing. Small incisions behind the hairline are used to reduce and fixate fractures and camouflage contour defects through onlay grafts and other techniques for improved cosmesis. Endoscopic transnasal reduction of anterior table frontal sinus fracture has also been reported. The endoscope can be very useful, however, in examining the frontonasal recess and other areas during surgery.
There has been significant debate over which material is best for obliterating the frontal sinus. One option is to remove all mucosa, plug the frontonasal recess, and allow ingrowth of fibrous tissue without obliteration. Other options involve the use of various grafts.
Free-fat grafts have been both studied and used most extensively. Overall autologous fat provides a safe obliterative material with few infectious complications. Over time fat tends to be reabsorbed and replaced with fibrous material. Serial MRI scans in patients with fat-obliterated frontal sinuses show the median half-life of the obliterated adipose tissue to be 15.4 months. In addition, the incidence of seroma in fat harvests is approximately 5%.
Other Autologous Tissue Grafts
Other autologous tissues for obliteration include cancellous bone, muscle, and pericranial flaps. Autologous grafts typically involve some donor site morbidity, such as pain, infection, or the formation of sarcomas, hematomas, or both. Pericranial flaps with an inferior or lateral base offer a living tissue option for both obliteration and recreation of the anterior table with minimal donor site morbidity.
Grafts of Synthetic Materials
One difficult situation in which synthetic materials may play a role is in fractures with a loss or a severe comminution of the anterior table. In these scenarios, bone grafts (iliac, rib, or split calvarial) or methyl methacrylate have been used to recreate the anterior table. Titanium mesh offers a synthetic alternative for severely comminuted fractures, but its use is limited in cases with significant loss of anterior table bone. Hydroxyapatite cement is another synthetic material that has been used both to obliterate the sinus and recreate the anterior table but experience is limited. Reoperation on patients obliterated with hydroxyapatite and some other synthetic materials is challenging.
Anterior Table Fractures and Frontonasal Recess Injuries
To treat fractures of the anterior wall appropriately, a couple of key issues need to be resolved. The first is the degree of the displacement of the fracture; this question can be answered easily with a combination of physical exam and CT scan. If a displaced fracture is present, exploration of the fracture with open reduction and internal fixation is required (Figure 16–1).
The second key issue in treating fractures of the anterior wall is whether there is significant injury to the frontonasal recess. Figure 16–2 depicts a CT scan in a patient who has a frontonasal recess injury. The frontonasal recess is more difficult to evaluate accurately on a CT scan because the functional capability of the frontal sinus drainage pathway is not clearly elucidated on CT. A 70–90% rate of frontonasal recess injury has been reported for patients who have associated fractures of the floor of the frontal sinus, the nasoethmoid complex, or the supraorbital rim. It is thus reasonable to surgically evaluate the frontonasal recess in such patients.
Traditional management of fractures involving the frontonasal recess is operative exploration and either obliteration or cranialization if injury to the frontonasal recess is noted intraoperatively. However, some studies suggest that fractures with frontonasal recess involvement do not always require obliteration or cranialization. Some physicians have managed these patients expectantly, following this approach with serial CT scans. Patients who failed to re-aerate their sinuses were treated with endoscopic frontal sinus procedures; in limited trials, favorable results were obtained. The trend in modern management of these fractures in patients for whom follow-up is feasible is toward more expectant management of frontonasal recess injury and follow-up CT scanning to assess functional patency.
For unilateral frontonasal recess injuries in which the contralateral duct has been demonstrated to work, some clinicians advocate the Lothrop procedure: removal of the intersinus septum and the use of mucosal flaps to allow drainage through the contralateral frontal sinus. This procedure can be performed endoscopically.
Posterior Table Fractures
Fractures of the posterior table may require surgical intervention. This is an area where treatment recommendations are in evolution secondary to improved methods of imaging and improved understanding of the role of the frontonasal recess in mucocele formation.
In general, posterior table fractures are suspicious for dural disruption and CSF leak. Dural tears with persistent CSF leak should be repaired in consultation with a neurosurgeon. In the absence of persistent CSF leak, some clinicians advocate the use of serial CT scanning and close follow-up of nondisplaced or minimally displaced posterior table fractures. The treatment of displaced posterior table fractures is controversial and may require obliteration or cranialization based on the surgeon's judgment. These fractures have a high incidence of frontonasal recess injury and, untreated, have a theoretical risk for mucocele formation. The modern trend, however, is toward expectant management and serial CT scanning in reliable patients who have posterior table injuries with good aeration of the sinuses.
Comminuted and displaced posterior table fractures are best treated with cranialization. “Through and through” injuries involve significant injury to the skin, anterior table, posterior table, and dura. These injuries can often be diagnosed by viewing the brain through the wound and are best managed with cranialization if sufficient bone remains to recreate the anterior table. In cases of severe anterior and posterior table bone loss, ablation may be the only viable alternative.
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. (Favorable results using titanium mesh for repair of comminuted frontal sinus fractures is discussed.)
Maturo SC, Weitzel EK, Cowhart J, Brennan J. Isolated posterior table frontal sinus fractures do not form mucoceles in a goat model. Otolaryngol Head Neck Surg
. (A goat model was used to demonstrate that mucocele formation in posterior table frontal sinus fractures was dependent on frontonasal recess obstruction and not extent of injury.)
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. (Favorable results using pericranial flap for frontal sinus obliteration is discussed.)
Petruzelli GJ, Stankiewicz JA. Frontal sinus obliteration with hydroxyapatite cement. Laryngoscope
. (Favorable results using hydroxyapatite cement to obliterate the frontal sinus and recreate the anterior wall of the frontal sinus is discussed, although the authors of this chapter do not recommend this method.)
Rontal ML. State of the art in craniomaxillofacial trauma: frontal sinus. Curr Opin Otolaryngol Head Neck Surg
. (Description of the paradigm shift in management of frontal sinus fractures integrating modern techniques of examination and treatment.)
Smith T. Endoscopic management of the frontal recess in frontal sinus fractures: a shift in the paradigm? Laryngoscope
. (A limited series of expectant management of frontal outflow tract injuries with endoscopic surgery for failed ventilation yields good results.)
Strong EB, Kellman RM. Endoscopic repair of anterior table frontal sinus fractures. Facial Plast Surg Clin North Am 2006;14(1);25.
Weber R. Osteoplastic frontal sinus surgery with fat obliteration: technique and long-term results using MRI in 82 operations. Laryngoscope
. (An osteoplastic flap with fat obliteration is highly effective.)