There has been a recent trend towards more conservative management of frontal sinus fractures. In 2002, Smith etal. demonstrated good results with observation, followed by staged endoscopic frontal sinusotomy when indicated. This is applied to patients with anterior table fractures with extension into the frontal recess [29]. In a small study by Jafari etal., resolution of frontal recess obstruction on interval imaging was noted in 87% of patients with observation alone [30].

obstruction was identied [32]. Cranialization, however, still carries a risk of sec­ondary mucocele formation even decades after the initial injury.

Similar to the management of the frontal outow tract, advances in endoscopic sinus surgery and improved intraoperative navigation have allowed surgeons to employ endoscopic techniques to repair traumatic CSF leaks. Grayson etal. demon­strated success in repairing both anterior and posterior table fractures with or with­out CSF leaks in carefully selected patients [3]. However, the authors note that patients requiring a craniotomy are not ideal candidates for an endoscopic proce­dure and will likely need cranialization. They also echo the utility of endoscopic techniques in managing the frontal outow tract. A 10-year review of 59 patients by Choi etal. showed that even in cases with signicant comminuted fracture patterns and a high rate of CSF leak, only a single patient required cranialization [25]. Recently, Miller etal. describe their preliminary result of open repair with frontal sinus preservation [33]. In their series of 23 patients who required major open surgi­cal intervention due to trauma or tumor resection, the frontal sinuses were pre­served, and an allograft and pericranial ap was used to “compartmentalize” the extracranial and intracranial contents. This allowed the repair of any dural defects and CSF leaks while maintaining the function of the frontal sinus as long as the outow tract was intact. The authors note that having an intact pericranium is vital to the success of this technique and if not available, then traditional obliteration or cranialization should be employed.

Despite the trend towards endoscopic and conservative management, there is still a place for the open approach with cranialization, as Dedhia etal. noted in their review of patients with severely depressed and comminuted posterior table fractures with refractory CSF leak [8]. Additionally, Chegini etal. reported a lower complica­tion rate in patients treated with cranialization compared to patients who would have otherwise been cranialized but were observed due to comorbidities [34].

While cranialization now plays a more limited role in the contemporary manage­ment of frontal sinus fractures, in our current practice, the open approach with or without cranialization is appropriate for severely displaced and/or comminuted fractures that require rigid xation, management of refractory CSF leak, and the need for craniotomy to simultaneously address neurosurgical issues. Frontal sinus obliteration for severely compromised frontal sinus outow is more controversial.

Hydroxyapatite is a calcium phosphate compound and is one of the primary mineral components of bone. Hydroxyapatite cement (HAC) is a compound that hardens via isothermic chemical reaction to form a paste in-vivo; thus, there is no surrounding thermal injury, and it has been used to repair bony defects in craniofacial recon­struction [71, 72]. It is also used in otologic surgeries for temporal bone reconstruc­tion, cranioplasty for translabyrinthine approaches, and for jugular bulb dehiscence [73–75]. Histologic studies have shown good biocompatibility of HAC with mini­mal inammation, osseointegration, and osteo conversion, leading to decreased risk of extrusion [76, 77]. HAC benets from ease of application and ability to contour well especially when compared to preformed hydroxyapatite ceramic [71]. The most common complications were edema (10%), tenderness (6%), sinusitis (4%), and surgical site infections (3%) [76]. Risk factors associated with increased risk of infection or implant removal include placing the implant underneath the bicoronal incision, postoperative radiation, secondary pediatric craniofacial reconstruction, or exposure to the sinus mucosa [78–81]. Data, however, is limited by mixtures of pediatric and adult populations, small sample sizes, and varied pathologies ,includ­ing trauma, neoplasms, and congenital defects.

made about 1–1.5cm posterior to the hairline. A common mistake is designing the incision directly over the vertex, necessitating additional elevation. The supercial temporal vessels should preserved if the ap is to be based laterally, especially the posterior branch.

Cranialization requires the removal of the posterior table. Typically, this may be performed by the neurosurgical team while they are repairing any dural defects. Anterior skull base reconstruction, which is addressed in another chapter, is also accomplished at this time by creating a barrier between the cranial and sinonasal compartments. This is typically done by placing vascularized tissue beneath the dura, such as a pericranial ap.