IN THE NAME OF GOD

Frontal Sinus Fractures

Cummings Otolaryngology 2015

CHAPTER 23 – Maxillofacial Trauma

Dr .Akhtar Kavan

Introduction

• The term maxillofacial trauma is generally used to refer to the injuries of the facial skeleton

• Craniomaxillofacial trauma might be a better term because the anterior wall and floor of the anterior cranial fossa are included in these injuries

• management of these injuries is sometimes thought of as “facial orthopedics.”

Embryology

• Absent at birth

• Doesn’t begin development until about 2 years

• Radiographically evident at about 8 years

• Adults size at about 12 years ; but pneumatization continues slowly until 40 years

• Consists of one or more compartments

• Irregular shapes & asymmetric

Embryology

• Lined by respiratory epithelium

• Intimate relation with cranial fossa

• Volume approx 5 - 15 mls

• Ant. wall thickers / stronger than post. wall

• Dura adheres to deep surface of post. table

• Mucosal lining continous with ethmoidal air cells & Nasofrontal ducts

Embryology

• Foramina of Breschet = venous drainage of mucosa are site of potential intracranial spread of infection

• Mucosa deeply invaginates foramina

Anatomical Variation

• 10 % unilateral

• 5 % rudimentary

• 4 % absent

• 20 % of people “abnormal frontal sinus anatomy

Nasofrontal Duct

• Drains frontal sinus

• Located posteromedial floor of sinus

• Very variable course

• True duct is absent in 85% people

• - FS drains indirectly via ethmoidal air cells to middle meatus

Anatomy

• The face can be divided into 3 sections

• the frontal bones are generally considered the upper third of the face

• The maxillae, zygomas, and orbits comprise the middle third, or midface, which may include the nose

• The mandible is considered the lower third

Physiology

• Upper Third

• Displaced fractures of Frontal bone can create various deformities, the most common of which is a central forehead depression (Fig. 1).

Pathophysiology

• Frontal bone fractures may involve only the anterior sinus walls, in which case the fractures are significant only for sinus function and cosmesis

• or they may involve the posterior wall of the sinus or extend beyond the sinus, in which case they are true skull fractures and become neurosurgical concerns as well

Pathophysiology

• The supraorbital rims and roofs are also part of the frontal bones, which are therefore also related to the orbits, and fractures can thus affect orbital and ocular functions.

• This thick glabellar bone protects the underlying frontal outflow tracts and the cribriform plates, which house the branches of the olfactory nerves

Pathophysiology

• The supraorbital and supratrochlear nerves pass through notches or foramina in the supraorbital rims and can be injured from trauma or, more commonly, from surgical manipulation.

Evaluation and Diagnosis

• Physical Examination

• performing a good physical examination.

• the initial assessment must address the ABCs and any other potentially life-threatening injuries

Evaluation and Diagnosis

• In the upper third of the face, the forehead is evaluated for sensation and motor function.

• In some cases, fractures may be visible as depressions (see Fig.1) or palpable as step-offs, although typically these fractures are more readily seen on CT scans.

Radiographic Evaluation

• With some exceptions, the CT scan has replaced other forms of radiographic imaging for the assessment of craniomaxillofacial injuries.

• The exception here is for simple nasal fractures (simple meaning without evidence of involvement of other facial bones)

Radiographic Evaluation

• For frontal fractures, a high-resolution axial CT gives good information about the anterior and posterior walls

• When the posterior wall is displaced (regardless of the degree of displacement), and there is soft tissue density within the sinus, the inside of the sinus be visualized

Associated injuries

• Neurological

• Closed head injury

• Pneumocephalus

• Cerebral contusions

• Hematomas

• Open brain

Associated injuries

• Ophthalmological

• - Up to 25 %

• Full ophthalmological examination mandatory

Associated injuries

• Maxillofacial injuries

• - NOE

• - ZMC

• - Le Fort fractures

• - Panfacial fractures

Classification Schema

• Many classification system

• Can get very detailed classification ;

• However not useful clinically

• most useful classification, which predicts the likelihood of disruption of the frontal sinus drainage passages, was presented by Stanley and Becker.

Classification Schema

• They separated frontal sinus fractures into linear horizontal and linear vertical and comminuted anterior and posterior walls, with and without NEC or supraorbital rim fractures

Clincal Classification

• Anterior Table

• - Displassed

• - un -displaced

• Posterior Table

• - Displaced

• - Un- displaced

• Anterior & Posterior Table

• - Displaced

• - Un - displaced

• Nasofrontal duct

• - Involved

• - Un involved

Clincal Classification

Simplified Clinical Classification

• 1- Fracture of anterior table

• 2- Fracture with disruption of posterior wall

• 3- Fracture involving floor of sinus

Management

• General

• Antibiotic treatment should be initiated at the time the patient initially presents

• Typically, antibiotics that cover oral organisms such as penicillins, cephalosporins, or clindamycin are selected

Management

• Many surgeons have suggested that surgery should be delayed until swelling resolves

• Certainly, logic seems to suggest that early intervention to restore the hard and soft tissues to their normal anatomic positions would be beneficial

Surgical Access

• There is also an additional challenge in craniomaxillofacial surgery, which is the inability to make incisions directly over most fractures,

• because unacceptable scars and facial nerve injuries would result

Surgical Access

• Coronal flap preferable

• Generally avoid using laceration or local incisions

• Avoid “ Gull Wing “ & “ Open Sky “ approaches

• In the patient with hair, irregularizing the incision with a running W or a wavy line

Surgical Access

• Shaving the hair is not required

• When full exposure of the zygomas is required, the incision begins in the preauricular crease

• When zygomatic exposure is not needed, the incision starts above the auricle

• When a long pericranial flap is needed , the incision should not violate the pericranium

Surgical Access

• As the flap is elevated anteriorly, care must be used to avoid injury to the temporal (frontalis) branches of the facial nerve

• The supraorbital and supratrochlear nerves are encountered as the flap is elevated to the supraorbital rims.

Biomechanics of the Facial Skeleton

• In the upper third, the anterior wall of the frontal sinus is thin and there are no significant forces acting on this area.

• The supraorbital rims and the frontal bones lateral and superior to the frontal sinuses are thicker , It requires more force to fracture these bones

Surgical Management

• Cranialization

• Vs

• Oblitration

Oblitration

• Frontonasal ducts oblitrated ,

• Mucosal lining removed And sinus “ packed “

• Various materials advocated :

• -Fat

• -Muscle

• -Bone

• -Hydroxyapatite

Fracture Repair

• Most repairs are performed using titanium plates and screws

• a variety of absorbable plates and screws are used as well

• there is no contraindication to the use of stainless steel wires when needed

Fracture Repair

• A number of algorithms have been published

• The key issues in frontal sinus trauma relate to two fundamental questions:

• (1) Is exploration necessary?

• (2) Is obliteration necessary?

Fracture Repair

• Keep in mind the purposes of the bone being repaired

• The sinus outflow tracts must function to drain the sinuses

• Thus pure anterior wall fractures that do not extend into the nasofrontal ducts are repaired for cosmetic purposes only.

Fracture Repair

• These should be explored if they are significantly depressed, because even in the absence of acute deformity, they are likely to lead to deformities when the swelling resolves.

• The smallest plates available are generally used, because there are little or no force

• Use of the endoscope may allow repair of selected anterior wall fractures with minimal incisions

Fracture Repair

• When the ducts are involved but the posterior wall is intact, judgment allows more than one option

• 1- Frontal sinus obliteration is always acceptable

• 2-Allow the sinus to function to see what happens

Fracture Repair

• A nondisplaced posterior wall fracture can be observed

• if the posterior wall is displaced, it is difficult to determine the status of the dura and underlying brain

• In the absence of apparent ductal injury, it is still wise to consider trephination and transcutaneous endoscopy

Fracture Repair

• In the absence of posterior wall displacement and with no soft tissue abnormalities associated with such a nondisplaced fracture, it is unclear that obliteration is mandatory

• Careful follow-up including interval CT scans will demonstrate whether or not aeration of the sinus ensues

Fracture Repair

• Numerous complications have been encountered using hydroxyapatite cements

• but in one series using it in combination with live pericranial flaps, no complications were seen

• they can be used to repair the frontal contour in the presence of severe comminution and/or bone loss of the anterior wall

Cranialization

• Frontal craniotomy

• Dural repair

• Removal of posterior wall

• Removal of mucosal lining

• Plugging of nasofrontal ducts

• Galeal flap placed

CSF Rhinorrhea

• CSF rhinorrhea is not rare and may occur via the frontal sinuses, or through the cribriform plate, ethmoid sinuses, and/or sphenoid sinuses

• Large defects should be repaired at the time of facial fracture repair.

• Small defects should be identified endoscopically and can usually be repaired using this approach

Skull Base Disruption

• Prophylactic Antibiotics

• Incidence of meningitis between 3-50%

• Mortality about 10%

• Usually pneumococcus spp.

• Prophylactic Antibiotics not recommended

CSF leak

• Fracture reduction often stops leak

• Most traumatic leaks close spontaneously

• Leak more than 72 h.= lumbar drain

• Surgical repair

• -Endoscopic

• -Intracranial

Skull Base Disruption

• The use of the Transglabellar Subcranial Approach may allow for earlier intervention

• It also allows direct visualization of the cribriform area without disarticulating it completely