2017-18 HSC Section 4 Green Book

S.W. Delaney

subsequently be treated in a delayed fashion, which will be discussed later on in this review.

Simple depressed fracture

The conventional surgical approach to the anterior table of the frontal sinus is an open approach through a coronal incision. 16 A preexisting laceration or direct brow incision may also be used to access the anterior table. Recently, closed and endoscopic reduction of anterior table frontal sinus fractures has been suggested as a less morbid alter- native to open approaches ( Figure 6 ). The coronal approach permits unparalleled exposure and direct access to manipulate frontal bony fragments for optimal reduction and fixation. This approach is particu- larly well suited for reconstructing large, severely commi- nuted anterior table fractures. The coronal incision extends from helical root to helical root, traversing the vertex. A subperiosteal or subgaleal dissection is performed anteri- orly to the fracture site. If a subgaleal plane is selected, the dissection is then transitioned to a subperiosteal plane as the fracture is encountered. Care is taken to avoid injury to the supraorbital neurovasculature and frontal branch of the facial nerve. The coronal approach is associated with risk of developing unsightly scars, paresthesias, alopecia, intra- operative blood loss, and facial nerve injury. 17 e 19 Particular attention must be paid to camouflage a coronal incision in patients with male-pattern baldness. 3 The coronal incision may be placed at the upper occiput with no compromise of surgical access to the frontal region. A preexisting laceration in the frontal region may be used for access to the bony fragments. However, lacerations often do not provide adequate exposure for reduction and fixation, and extending these lacerations should be avoided. A transcutaneous direct brow approach permits direct access to the fracture site with less operative time and blood loss than a coronal approach. This approach has largely fallen out of favor and been replaced by other methods due to the risk of unacceptable forehead scars and hypoesthesia secondary to supraorbital and supratrochlear nerve injury. However, the direct brow approach may still be considered as an alternative to the coronal approach in (1) men with male-pattern baldness or women with alope- cia and (2) favorable deep horizontal frontal creases in which the incisions can be hidden. 18 As the transection of cutaneous sensory nerves is inherent with this approach, incisions should be placed in a higher forehead crease when possible to minimize loss of sensation. 18 To circumvent the problem of unsightly scarring associ- ated with coronal and direct brow approaches, a number of closed reduction techniques have been described. Hwang and Song 20 were one of the earliest to describe closed reduction of an anterior table fracture through the intro- duction of a periosteal elevation via a single medial brow stab incision. Kim et al. 21 reported a similar approach to the frontal sinus using peri-brow stab incisions for 17 patients, with favorable outcomes. When necessary, a burr can be used to create a small opening near the fracture line, to permit insertion of an instrument or inflatable balloon for reduction. Spinelli et al. 9 reduced simple depressed ante- rior table sinus fractures in 15 patients with the placement

Figure 4 Displaced anterior table frontal sinus fractures. A) Simple depressed fracture. B) Comminuted depressed fracture.

Because anterior table fractures rarely result in func- tional problems, the decision to repair an anterior table fracture, therefore, is contingent upon reestablishing pre- morbid contours and achieving satisfactory aesthetics. Anterior table fractures with depressions of 4 mm result in delayed contour irregularities, regardless of the fracture area, 2 particularly in patients with thin skin.

Acute anterior table fractures

The repair of anterior table frontal sinus fractures can transpire in the acute ( < 2-week) or delayed ( > 8-week) setting. 15 In the acute phase, the goal of anterior table fracture repair is the accurate reduction of displaced bony fragments to their premorbid position, with or without rigid fixation. Alternatively, the purpose of delayed repair is to camouflage frontal contour deformities once over- lying soft tissue injuries and edema have resolved, rather than bony reduction and fixation. Repair between 2 and 8 weeks may be considerably more challenging, as the neo- osteogenesis will render bony reduction more difficult, and persistent soft tissue swelling may prohibit satisfac- tory recontouring. As mentioned earlier, isolated anterior table frontal sinus fractures confer low complication risks, and surgical repair of such fractures is for cosmetic pur- poses. Therefore, the decision of when to correct such a contour deformity depends on concomitant injuries that need to be addressed, the nature of the fracture, as well as the patient’s wishes. The surgical approach for acute frontal sinus fractures depends on the extent of comminution. Simple depressed fractures can be managed with less invasive surgical tech- niques, whereas severely comminuted fractures will require more invasive approaches ( Figure 5 ). Non-displaced anterior table frontal sinus fractures pose minimal risk of mucocele formation or contour deformity. As such, these fractures are best managed expectantly. Should contour deformities become apparent once over- lying soft tissue edema subside, the deformity may

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