Diagnosis and Treatment of Midface Fractures
The midface is important functionally and cosmetically. It serves an important role in vocal resonance within the sinuses of the facial bones as well as in the function of the ocular, olfactory, respiratory, and digestive systems. The face is also fundamental to interpersonal recognition and the perception of self-image.
The midfacial complex is constructed of a series of vertical pillars that primarily provide protection from vertically directed forces. These include the nasomaxillary (nasofrontal), zygomaticomaxillary, and pterygomaxillary buttress.1 These vertical pillars are further supported by the horizontal buttresses—the supraorbital or frontal bar, infraorbital rims, and zygomatic arches.2,3 Contrary to claims of a lack of sagittal buttresses, the midface does have support, however weak, from the maxillary walls, lateral nasal wall, and nasal septum. Clearly, these weaker buttresses of the midface tolerate frontal or laterally directed forces poorly.4 Behind this buttress system sits the medial and lateral pterygoid plates inferiorly and the skull base superiorly. This framework results in a few anatomic sites of weakness, resulting in fairly predictable patterns of fracture.
Rene Le Fort’s cadaver studies in the early twentieth century defined the three weakest levels of the midfacial complex when assaulted from a frontal direction. He defined the three most common “linea minoros resistentiae,” which are classified as the Le Fort I, Le Fort II, and Le Fort III fractures. These fracture patterns are characteristic of a unidirectional, low-energy injury rather than the multivector, high-energy mechanisms commonly observed today. However, this system is popular because it provides a simple, anatomically differentiated system for the general classification of midfacial injuries.5
The Le Fort type I fracture pattern results from a force directed above the maxillary teeth, resulting in a floating palate (Fig. 17-1). The Le Fort type II fracture pattern results from a force delivered at the level of the nasal bone, resulting in mobility of the midface through the orbits and midfacial region (Fig. 17-2). The Le Fort type III fracture pattern results from a force directed at the orbital level, resulting in a craniofacial dysjunction or separation of the entire middle third of the craniomaxillofacial skeleton from the skull base (Fig. 17-3).
FIGURE 17-1 Le Fort I fracture.
FIGURE 17-2 Le Fort II fracture.
FIGURE 17-3 Le Fort III fracture.
Initial evaluation of the severely injured midface can be an intimidating experience (Fig. 17-4). Emergency care should be immediately initiated, applying the principles of Advanced Trauma Life Support (ATLS). When dealing with midfacial injuries in the emergency setting, certain components of the examination and treatment deserve special attention (Fig. 17-5).
FIGURE 17-4 Compound comminuted midfacial fractures.
The airway is immediately evaluated for obstruction. The oral cavity may be full of secretions or debris, which may contribute to supraglottic obstruction and aspiration. The oropharynx must be manually cleared of any fractured teeth, dentures, and/or blood clots. If stable, the patient may be placed in a lateral decubitus position and mild Trendelenburg position to allow optimal drainage. If oral or nasal bleeding is encountered, these sites should be packed.6 If bleeding is uncontrollable, a definitive airway should be established immediately.
Any patient with facial trauma is presumed to have a cervical spine injury and should be stabilized with a rigid collar until ruled out by appropriate examination. Any motion of the head can be lethal because of bone fragment impingement or laceration of the spinal cord. The presence of cervical spine injuries have been reported as 1.0% to 1.8% to as many as 9.6% of patients with facial fractures.7–9
The safety of orotracheal intubation by various techniques in patients with cervical spine injuries has been shown to be safe if precise in-line immobilization is provided.10 A cricothyroidotomy is also an appropriate option for establishing an emergency definitive airway in this setting.11 If nonurgent airway control is needed in the setting of cervical spine fracture, an awake fiberoptic intubation is likely the safest option because no atlanto-occipital extension is required with this technique.12
A lower airway obstruction, such as laryngeal or tracheal fracture, requires an emergency tracheostomy. Also, if reconstructive procedures of the midfacial injuries will be limited by the presence of an endotracheal tube, a tracheotomy is also indicated.
After definitive airway control is obtained, the ATLS protocol may continue. In regard to midfacial fractures, it is uncommon for hemorrhage from this region alone to result in hemodynamic instability. However, it is important to be cognizant of blood loss, especially if multiple large vessels are violated, large grossly open wounds are present, or continuous blood loss continues from this highly vascular region. As noted, packing of the cavities or wounds with selected clamping of blood vessels is usually effective immediately.
After initial stabilization, a complete facial examination is performed. This requires clinical and radiographic components;, however, the radiographic examination may be delayed until the patient’s condition is fully stabilized.
The face is systematically evaluated for the presence of any lacerations or obvious deformities of the skull and asymmetries are noted. Otorrhea or rhinorrhea is assumed to be cerebrospinal fluid (CSF) until proved otherwise. No packing of the ear or nose should be performed if a CSF leak is suspected. This practice is potentially helpful for initially preventing a retrograde infection that might result in meningitis.
The craniomaxillofacial skeleton is palpated bimanually in a systematic manner and any discontinuity or irregularity is noted. The frontal area and supraorbital rim is examined first, with a logical progression downward, including the lateral and infraorbital rims, although extensive edema in this area may make the examination difficult.
Periorbital edema and ecchymosis are often initial signs of orbital trauma (Fig. 17-6). The globe may protrude because of gross edema, making a complete examination difficult. Visual acuity is grossly examined and extraocular muscle function evaluated. The presence and direction of diplopia or strabismus are noted. Pupil size, shape, and reaction to light are recorded. The location and extent of subconjunctival hemorrhage are also recorded. A fundoscopic examination is carried out to evaluate for intraocular hemorrhage. If lid lacerations are present, they should be closed promptly to prevent contracture. A through and through laceration requires a three-layer closure. A 6-0 plain absorbing suture may be used on the conjunctiva, with care to prevent protruding knots that may injure the cornea. The orbicularis oculi muscle is closed with 5-0 resorbable suture; the skin is closed with a 6-0 nonresorbable suture. Exact approximation of the gray line of the lid margins is obtained with 6-0 resorbable suture (Fig. 17-7).
Ocular injury is present in most midfacial fractures and is common in midfacial trauma. Al-Qurainy et al, in a prospective study on orbital injury with midfacial fractures of any type, have reported that 90% of patients had an ocular injury to some degree, 16% had moderate ocular injuries, and 12% had severe injuries. Almost 15% of patients had a decrease in vision.13 In patients with naso-orbital-ethmoid fractures, ocular injury and subsequent loss of vision were reported in 30% of patients.14 Isolated orbital wall fractures have also been reported to present with an almost 30% incidence of ophthalmic complications.15 Current evidence supports the practice that facial fractures involving the orbit should be referred for ophthalmologic evaluation.13–18
Crepitation to palpation is indicative of orbital emphysema. This examination finding is most commonly observed when injuries result in communication with the ethmoidal or maxillary sinuses and requires no treatment. The patient should, however, be instructed to not blow his or her nose to prevent expanding subcutaneous emphysema. The attachment of the medial canthal ligament is evaluated by palpating the insertion of the medial canthal ligament for crepitus or instability and by lateral traction on the lateral canthus. Bimanual examination may also be performed by application of a Kelly clamp intranasally and a finger on the central fragment; this is followed by an attempt at lateral displacement of the central fragment.19 Physical findings of medial canthal ligament disruption include rounding of the lacrimal lake, epiphora, and increased intercanthal distance.
The zygomatic arches, nasal bones, maxilla, and mandible are then sequentially evaluated. Mobility of the maxilla is assessed by firmly grasping the premaxilla and attempting to displace it in three dimensions. Ecchymotic areas, especially of the palate, are common findings with fractures of the maxilla. The pharynx is examined for lacerations or retropharyngeal bleeding. If responsive, the patient should also be questioned about any salty, metallic-tasting discharge, which is an indication of CSF drainage.
The mandibular opening is evaluated for fracture or displacement of the zygoma, which may obstruct the forward movement of the coronoid process. The buccal vestibule is palpated with the index finger and crepitation or displacement of the lateral antral wall; zygoma can be easily appreciated by this maneuver. The occlusion and quality of the dentition are recorded, because these factors may significantly influence in the method of treatment.
Once the patient is sufficiently stabilized, radiographic evaluation may proceed. The preferred radiologic modality for midfacial injuries is a maxillofacial computed tomography scan (CT).20–22 A maxillofacial CT scan will provide 2- to 3-mm axial cuts with coronal reformatting. If desired, sagittal or three-dimensional formatting may also be provided. The CT scan allows evaluation of bone, providing detailed information about fracture patterns. CT scans also provide characterization of soft tissues, including the extent of edema, presence of foreign bodies, formation of a retrobulbar hematoma, or entrapment of the extraocular musculature. Plain films, although necessary in the absence of CT scanning, provide little diagnostic information. The plain films obtained in the history include the Water’s, submentovertex, anteroposterior, and lateral skull views.
As a general principle, early management of these fractures is preferable following stabilization of the patient’s condition and diagnosis of midfacial fractures. After 7 to 10 days, it may become more difficult to mobilize the maxilla and achieve an ideal reduction, particularly in patients in whom there is impaction of the fractured segment. In our opinion, in the patient with substantial midface injury, earlier rather than later repair significantly enhances outcome.
The maxilla, palatine bone, and nasal bones form the bulk of the midface. The maxillary bones are integral in the formation of the three major cavities of the face—the upper part of the oral cavity and the nasal and orbital fossa. The maxillary sinus, which is small at birth, expands inferiorly within the maxilla with maturity until it forms the major bulk of the midface. This factor adds to the distinct weakness of the region. Because of the many articulations between the surrounding bones, it is difficult at times to categorize fractures patterns. However, the classic Le Fort I and II classifications of midfacial fractures will be discussed here and the Le Fort type III and naso-orbital-ethmoid (NOE) fracture patterns will be discussed separately (Fig. 17-8).
Le Fort type I fractures are caused by a force delivered above the apices of the teeth. The fracture occurs at the level of the piriform aperture and involves the anterior and lateral walls of the maxillary sinus, lateral nasal walls and, by definition, pterygoid plates. The nasal septum may also be fractured and the nasal cartilage may be buckled. Sagittal fracture(s) of the palate may also be present. The pull of the medial and lateral pterygoid muscles may contribute to displacement of the fractured segment in a posterior and inferior direction, resulting in an open bite deformity. This fracture may present as an impacted, immovable, or free-floating maxillary segment.
Le Fort I injuries, on initial examination, may not be clearly evident. Examination should include firmly grasping the maxillary arch with the finger and thumb facially and palatally and attempting displacement of the maxilla in three dimensions, as well as compression and expansion of the maxillary arch. Malocclusion and mobility may be noted. Hypoesthesia of the infraorbital nerve may be caused by the rapid development of edema. A unilateral maxillary fracture may also occur, with the fracture coursing through the palatal suture line or adjacent to it. Palatal ecchymosis is usually noted and may present in conjunction with a malocclusion or displacement of the fractured fragment.
The internal and external pterygoid muscles together have been suspected as being responsible for the posterior and inferior pull seen in fractures of the maxilla. However, unlike the mandible, the midface is more subject to traumatic rather than muscular displacement.
The blood supply to the maxilla is via the internal maxillary arteries. Together with the superior and posterior alveolar arteries, they supply the hard and soft palates. Anteriorly, the nasopalatine artery reaches the incisive foramen and supplies the mucoperiosteum of the anterior palate.
Neurosensory supply is via the second division of the trigeminal nerve. This nerve exits the infraorbital foramen and supplies the lateral nasal, superior labial, and inferior palpebral regions, as well as the labial mucosa and anterior teeth.
The fractured segment is reduced by digital pressure and a maxillary arch bar is applied loosely to the teeth in the mobile segment and firmly to the stable dentition in the unfractured maxillary segment. MMF is then applied between the maxillary and mandibular arch bars and the reestablished pretraumatic occlusion is used to reduce the mobile maxillary segment. Open reduction and internal fixation by miniplates are completed through a vestibular incision and MMF is removed. The patient is kept on a soft diet for 2 to 3 weeks while the fractures heal. MMF may also be left in place if there is concern for patient compliance.
An occlusal splint is an excellent option for accurate reduction of the fractured maxillary segment. Alginate impressions are taken of the maxillary and mandibular arches and the correct occlusal relationships are reestablished on study models. An interocclusal splint is then constructed. Arch bars may be placed before or after placement of the interocclusal splint, depending on the mobility of the maxillary segments. The maxillary arch bar is secured by interdental fixation and the interocclusal splint is secured to the maxillary arch bar. The mandible is then passively guided into the interocclusal splint. MMF may be used to stabilize the maxillary fragments during open reduction and internal fixation (ORIF), or may be used as a method of fixation if ORIF is not desired, but will require a 3- to 4-week period of MMF.
Impacted maxillary fractures may be impossible to mobilize with digital manipulation alone. A disimpaction forceps may be used in this situation for reduction of the impacted maxillary segment. Teeth in the line of fracture should be left in place unless excessively mobile or hopelessly nonrestorable.
Early reduction of Le Fort type I injuries presents minimal difficulty but, beyond 7 to 10 days, increasing amounts of force are required because of the natural healing process. ORIF with restoration of facial contour is the preferred method of treatment. MMF is also an acceptable, although less optimal, method of treatment. This requires a treatment period of approximately 6 weeks, depending on the level of comminution.
Incisions for the open reduction are made in the buccal vestibule in a circumvestibular fashion, from the first premolar to the first premolar on the opposite side. Wide buccal pedicles of the U-shaped incision are retained for maintenance of the vascular supply. This approach allows visualization of the lateral antral wall and zygomatic buttresses. A Rowe or Hayton-Williams forceps can then be used to complete the reduction, if necessary (Figs. 17-9 and 17-10).
The advent of plate and screw fixation has transformed craniomaxillofacial fracture repair from obligatory long-term MMF and craniofacial suspension to rigid stabilization. Rigid stabilization provides an opportunity for primary bone healing and allows earlier function and optimized nutrition.
The patient is first placed in MMF to reestablish the pretraumatic occlusal relationship. The maxillomandibular complex can then be oriented in three dimensions as a unit, with special attention to the position of the condyles. Ensuring that the condyles are seated properly in the glenoid fossa will limit subsequent development of an open bite. Stabilization of a fracture must prevent translational and rotational motions in the x, y, and z axes.23 Four-point fixation along the pyriform and zygomaticomaxillary buttresses is routinely provided for stability of this fracture pattern. Occlusion should be immediately rechecked following release of MMF (Fig. 17-11).
The Le Fort type II fracture pattern is also referred to as a pyramidal fracture; the apex of the pyramid is the nasofrontal suture (Fig. 17-12). This fracture pattern involves the nasofrontal suture, nasal and lacrimal bones, infraorbital rim in the region of the zygomaticomaxillary suture, maxilla, and pterygoid plates. This fracture is typically higher than the Le Fort type I fracture posteriorly. As with the Le Fort type I pattern, the nasal septum may also be involved.
FIGURE 17-12 Le Fort II fracture.
The physical examination is likely to reveal noticeable signs of injury. Edema is often present overlying the fracture sites. The classic raccoon sign caused by bilateral periorbital edema and ecchymosis may be noted. CSF rhinorrhea may be encountered as the result of a dural tear. Epistaxis is common. Hypoesthesia of the infraorbital nerve is also common because of direct trauma or rapid edema formation. Malocclusion is often present in the form of an anterior open bite. Grasping the anterior maxilla and attempting anteroposterior displacement facilitates evaluation of the nasofrontal suture and inferior orbital rims.
ORIF is advantageous for treatment of these fractures. If the nasofrontal suture area is intact and continuous with the maxillary segment, bilateral intraoral exposure allows appropriate four-point fixation. However, the orbital floor, inferior orbital rim, or nasofrontal region often requires exploration and repair. In these situations, additional access is required. The basic incisions are the infraorbital, subciliary, middle to lower lid, and transconjunctival incisions. These methods of access will be briefly discussed.
The infraorbital incision, first described by Converse et al in 1944,24,25 is made transcutaneously over the infraorbital rim in the natural crease, 4.5 mm inferior to the gray line. Advantages include excellent access to the floor and surrounding areas and ease of use. Disadvantages are potential poor healing, cicatricial distortion of the lower lid, and potential for development of lymphedema. More than 90% of the lymphatic drainage from the scalp, forehead, and upper lid passes lateral to the orbit.
The subciliary or lower blepharoplasty incision is made 2 to 3 mm inferior to the gray line of the lower eyelid. The incision runs parallel to and along the length of the lower eyelid margin. The traditional method of pre–orbicularis oculi incision has fallen out of favor because of high rates of ectropion development, 38% to 42% temporary and 8% permanent.26 The post–orbicularis oculi dissection, or skin-muscle flap, is when the incision is made through both skin and muscle and dissection occurs superficial to septum. This modification has become popular because of ease of use and has been shown to have a lower rate of early ectropion, 6% in one study, with resolution typically within weeks.27
The transconjunctival approach was popularized by Tessier in 1973.28 This approach is made through the conjunctiva parallel to the gray line and can be made anterior or posterior to the septum.29 The incision can also be extended laterally by lateral canthotomy and inferior cantholysis and medially by a transcaruncular incision to allow excellent access to the orbit (Fig. 17-13).
Access should be carefully planned on an individualized basis. Depending on the situation, various approaches are available and lacerations may be used. When multiple sites are affected, a coronal incision provides excellent exposure as well as access to cranial bone for bone grafting.
Isolated fractures of the palate are rare, but up to 8% to 13% of Le Fort fractures are complicated by concomitant palatal fractures.30,31 Most patients will also have notable signs and symptoms of palatal fracture. Indications of palatal fracture on clinical examination include laceration of the lip and concurrent gingival and palatal lacerations. Often, a change in occlusion is also noted with the maxillary segment displaced anterolaterally.3 Diagnosis is confirmed by a maxillofacial CT with axial and coronal cuts.
Several classification systems have been suggested30,31 for palatal fractures. Hendrickson et al30 have described six patterns based on the anatomic location of fracture (Fig. 17-14; Box 17-1).
Surgical treatment planning depends on the type of fracture, presence or quality of the dentition, and concomitant facial fractures. Treatment incorporates the possible application of rigid internal fixation, arch bars, and palatal acrylic splints, depending on the clinical situation.3,30–33
Although there has been much discussion on the use of rigid fixation in palatal vault fractures, it is seldom clinically indicated. The first problem with this technique originates with the placement of transoral plates and screws to the palatal vault. This practice requires the mouth to be open and thereby excludes the application of ORIF and occlusal stabilization. This lack of occlusal control leads almost inescapably to error in the appropriate reduction of maxillary width and height. The second consideration is vascularization of the maxilla. Although techniques for making longitudinal palatal incisions are often described, vascular studies of the Le Fort I segment following osteotomy have shown that the blood flow in the severely fractured or osteotomized maxilla is dependent on the ascending pharyngeal and palatal mucosal blood supply.34 Because management of midfacial injury often require an anterior vestibular incision, if treated open, any palatal flap raised under these circumstances must be approached with caution.
Treatment of the palatal fracture in dentate patients should center on occlusal reduction with MMF and a facial vestibular approach. Incorporation of occlusal splints can be extremely helpful in the comminuted palatal fracture and requires preoperative dental models to fabricate. The use of a palatal splint should be approached with caution. As noted, care must be taken to ensure that the palatal vascular supply is not compromised. In addition, postoperative surveillance of the palate for healing, fistula development, or necrosis of segments becomes more difficult because direct inspection of the palatal vault is obscured by the splint. If a concomitant mandibular fracture exists, open reduction and anatomic fixation of this injury first will allow the treatment of the palatal fracture to proceed with the appropriate occlusal template.
An indication for the use of rigid fixation for sagittal palatal fractures in the edentulous or near-edentulous patient exists if the patient does not have preexisting dentures or no preoperative Gunning-type splint was fabricated. In these rare patients, special care must be taken to reduce the fractures as anatomically as possible from the facial vestibular approach. Additional stabilization of the palate can then be gained from transmucosal locking plate and screw fixation, as described by Pollock, which attempts to preserve the critical vascular supply.35
The naso-orbital-ethmoid (NOE) injury, often referred to as an NOE fracture, represents a significant diagnostic and reconstructive challenge.36,37 This region houses the lacrimal apparatus, medial canthal ligament, and anterior ethmoidal artery. CSF rhinorrhea is common following NOE fractures.38 In one series, Cruse et al have reported that central nervous injuries are present in 51% of cases and 42% have CSF drainage14 (Fig. 17-15).
Assessment of these injuries requires close attention to the soft tissue and osseous structures and an accompanying CT scan, with both coronal and axial views.39 Physical examination is likely to demonstrate a severely fractured nose, often with comminution and posterior displacement. The nasal bridge is widened and the nasal complex splayed. Epistaxis is common. Traumatic telecanthus (see Fig. 17-15) may occur because of disruption of the medial canthal ligament. The average intercanthal distance for a white adult is 28 to 35 mm, which is approximately half of the interpupillary distance. Halving the interpupillary distance is a useful tool on the preliminary physical examination because severe periorbital edema is preset in most cases. Traumatic telecanthus is suspected when the intercanthal distance is greater than 35 mm; a measurement more that 40 mm is diagnostic for this type of injury.40 Epiphora following trauma to this area is likely the result of damage to the lacrimal apparatus. Narrowing of the palpebral fissure, obliteration of the caruncle, and flatting of the base of the naso-orbital valley are more likely to be noted following the resolution of edema.
NOE fracture repair requires a broad knowledge of anatomy and should be based on anatomic reconstruction; the repair should be done early, when possible. Inadequate reconstruction or delay in treatment may result in a multitude of suboptimal results, generally including midface retrusion, blunted palpebral fissures, ocular complications, nasal deformities, and cerebrospinal fistula formation.14,41–44
These injuries may occur with other midfacial fractures, may be isolated or bilateral, and may have different patterns on either side of the midline, depending on the mechanism and velocity of impact.40,44–49 Repair of these fractures requires surgical approaches that provide wide exposure and allow an anatomic repair. Attention to the anatomy of this region, in particular the intercanthal distance, is essential to a satisfactory outcome.
The NOE region is made up of the cranium, nose, orbit, and maxilla (Fig. 17-16). The frontomaxillary buttress provides structural support to this region and serves as the stabilization point for reconstruction. The associated lateral buttresses are the frontal bar superiorly and the zygoma and inferior orbital rims inferiorly. The medial portion of the buttress contains the perpendicular plate of the ethmoid, lacrimal ones, and lamina papyracea. These bones are thin, fragile, and form a so-called crumple zone that is predisposed to medially displaced comminuted fractures46 Reconstruction of the bony architecture is necessary in this area to control orbital volume.
The nasal bones are anterior to the medial orbit and connect to the frontal bone superolaterally and the lacrimal bone and frontal process of the maxilla medially. The ethmoid sinuses, located centrally and posterior to the nasal complex, are also vulnerable to injury. Because of the proximity of the ethmoid sinuses to the cribriform plate, the collapse and posterior displacement of these structures may result in intracranial involvement and potential for CSF rhinorrhea, pneumocephalus, and olfactory dysfunction. Fractures of the frontal sinus are also common because the floor of the frontal sinus is a component of the medial orbital roof. Ductal drainage leaves the frontal sinus inferoposteriorly, travels through the ethmoid bone, and exits at the middle meatus of the nose. Complications because of disruption of this system may be noted following NOE fractures.
The medial canthal tendon is a fibrous extension of the tarsal plates. It divides into two limbs, anterior and posterior. The anterior limb is larger and stronger, attaches to the frontal process of the maxilla, and functionally pulls the medial commissure of the eyelid forward and down.50 The posterior or deep limb is comparatively thinner, inserts into the posterior lacrimal crest of the lacrimal bone, and functions to maintain the eyelid’s position in relation to the globe. The posterior limb is also intimately associated with Horner’s muscle, which is responsible for the flow of tears through the lacrimal sac. A superior limb develops from an extension of fibers from the anterior and posterior limbs, which serves to encompass the lacrimal sac and functions to add the posterior and superior vector of the medial canthal tendon. The normal anatomic position of the medial canthal tendon is responsible for medial eyelid function, position, appearance, and lacrimal drainage. The degree of displacement varies significantly; the method of repair depends on whether an injury results in complete avulsion or continued attachment to variously sized bony fragments. In any situation, precise reconstruction of the osseous components and medial reattachment or stabilization of the medial canthal tendon are required to prevent telecanthus, enophthalmos, and dysfunction of the lacrimal system. When this condition is improperly managed on initial reconstruction, the ensuing deformity can be debilitating and extremely difficult to manage secondarily.
A thorough visual inspection is followed by manual palpation of the supraorbital rims, nasofrontal junctions, lateral nasal complex, inferior orbital rims, and nasal complex as a unit. Mobilization of the nasal complex and its relationship to the nasofrontal junction are examined. Mobilization of the nasal complex in three dimensions is attempted to determine mobility, possible osseous impaction, and the extent of the fracture.
The attachment of the medial canthal ligament is evaluated by palpating the insertion of the medial canthal ligament for crepitus or instability and by lateral traction on the lateral canthus, with evaluation of the medial canthal attachment. Bimanual examination may also be performed by application of a Kelly clamp intranasally and a finger placed externally on the central fragment; lateral displacement is then attempted.19 Indications of medial canthal ligament disruption include rounding of the lacrimal lake, epiphora, and increased intercanthal distance.
Measurement of the intercanthal and interpupillary distance is also completed at this time and compared with normal individuals of white, black, and Asian ethnicity to determine whether displacement is present and if it is unilateral or bilateral. Another excellent method of determining pretraumatic intercanthal width is to obtain preinjury photographs.51 Periorbital edema and ecchymosis will be present and must be taken into consideration when completing this examination.
Nasal tip position and telescoping of the nasal cartilage under the osseous segments of the nasal complex must also be determined. This is important for later reconstruction. A complete intranasal examination may be assisted by applying cocaine or oxymetazoline to shrink soft tissue and performing a careful visual examination of the nasal septum, concha, nasal mucosa, and intranasal position of osseous structures. The presence of CSF rhinorrhea can be determined with this examination; this is an indication of the extent of the injury into the ethmoidal sinuses and to the cranial base by way of the cribriform plate.
Axial and coronal CT scanning are required in any patient suspected of having NOE injuries; 1.5- to 2-mm cuts are usually satisfactory for determining the extent of this injury. Correlation of the clinical and radiographic examination facilitates a proper diagnosis. Attention to anatomic structures in regard to location, displacement, size, and comminution is critical. Treatment outcome is based largely on proper identification of the bony segment and the status of the attachment of the medial canthal tissue.
A commonly used classification system developed by Markowitz et al identified NOE fractures based on their relationship to the central fragment at the site of medial canthal tendon attachment.52 The fractures are typically noted to be unilateral, bilateral, simple, or comminuted and are likely to have with different fracture presentations bilaterally. They may occur as an isolated injury or in conjunction with other major facial fractures.
The simplest form of NOE fracture involves only one portion of the medial orbital rim, with its attached medial canthal tendon. It may occur in a bilateral or unilateral form. When the bilateral complete type I fracture occurs, there is no medial canthal tendon displacement and transnasal wiring is not required. Stabilization of the osseous segment is all that is usually necessary (Fig. 17-17A).
Type II NOE fractures may occur in a bilateral or unilateral form and may be large segments or comminuted. Most commonly the canthus remains attached to a large central segment. Reduction is usually best accomplished by control of the specific segment of bone that is associated with the canthal tendon (see Fig. 17-17B).
This fracture includes comminution involving the central fragment of bone where the medial canthal tendon attaches. The canthus is rarely avulsed completely but, on occasion, the fragments of bone are so small that reconstruction is not possible. In this circumstance, transnasal wiring of the canthus is required, as is osseous reconstruction (see Fig. 17-17C).
Treatment of the NOE fracture begins with a specific diagnosis and careful treatment planning. The fundamentals of surgical repair are early surgical intervention, wide exposure, careful anatomic osseous reduction, and internal rigid fixation. Special attention to the medial canthal tendon and its attachment is necessary to obtain optimal aesthetic results.
The coronal incision is used most frequently in the management of fractures of the NOE region. This incision provides wide exposure of the superior and medial orbital compartments. The nasal bones are also evaluated and fractured segments removed for later use in reconstruction. Care should be taken to limit disruption of the nasal lacrimal duct and lacrimal sac and the inferior extent of this incision. Determination of nasal lacrimal duct patency will be discussed later in this chapter. A lower eyelid incision may also be necessary to gain access to the inferomedial orbital components. Further stabilization may be necessary by an internal approach to gain access to the nasomaxillary buttress for stabilization of the inferior portion of the NOE complex.
Systematic treatment of NOE fractures is necessary for a predictable outcome. A systematic approach of eight key steps in the sequencing of NOE fractures was described by Ellis.37 These steps include surgical exposure, identification of the medial canthal tendon and tendon-bearing bone fragment, reduction and reconstruction of the medial orbital rim, reconstruction of the medial orbital wall, transnasal canthopexy, reduction of septal fractures, nasal dorsum reconstruction and augmentation, and soft tissue adaptation.
The type I fracture is best managed by three-point rigid fixation—reestablishing the relationships of the nasofrontal junction to the nasal complex, the nasal complex to the maxillary buttress, and the nasal complex to the infraorbital rim (Figs. 17-18 and 17-19). As noted, in this type of injury, medial canthal tendon detachment is rare.
FIGURE 17-18 A, Basic fixation treatment of unilateral fracture requiring three-point fixation. B, Rigid plate fixation of unilateral fracture requiring three-point stabilization. C, Bilateral single-segment injuries with superior and inferior rigid fixation approaches.
Type II fractures require a more extensive superoinferior approach because a degree of comminution is present by definition. Access through the coronal flap and infraorbital and intraoral incisions are often necessary. The small bony fragments must first be anatomically reduced with 28- to 30-gauge intraosseous wiring or with microplates. Rigid internal fixation then proceeds as for a type I fracture to reestablish the bony buttresses. Reattachment of the medial canthal tendon is then completed de facto by appropriate reduction of the large central fragment(s) to which the tendon is attached.
The type III NOE fracture involves extensive comminution and displacement of the osseous structures, with apparent avulsion of the medial canthal tendon unilaterally or bilaterally from its osseous attachment. The principles of access and repair follow the same principles as for type I and II fractures, although establishing pretraumatic osseous and soft tissue contour is more challenging because of the level of comminution. Severe comminution of the nasal region may require a dorsal nasal cantilever-type bone graft to reestablish dorsal nasal support and nasal tip projection. This bone graft can be placed through the coronal incision and stabilized with intraosseous screws into the nasal process of the frontal bone (Fig. 17-20). Cranial bone grafts can be used for this technique and may also be needed for reconstruction of the facial buttresses. Other autogenous sites recommended for the procedure include the rib, ilium, and mandible.53 Canthoplasty, unilateral or bilateral, may be required. Direct transnasal wiring of the medial canthal tendon in a position slightly posterior and superior to the normal anatomic position will help overcome the forces of migration, relapse, and telecanthus (Fig. 17-21).
Transnasal wiring or transnasal medial canthopexy is performed when necessary. This step follows surgical exposure, identification of the medial canthal tendon or tendon-bearing bone fragment, reconstruction of the medial orbital rim, and reconstruction of the medial orbital wall. This sequence of repair is important because reconstruction of the medial orbital rim is key to reestablishing the pretraumatic intercanthal distance,52 and reconstruction of the medial orbital wall is required to maintain an appropriate orbital volume.54–56
A small incision is made approximately 3 mm medial to the medial canthus and blunt dissection is used to identify the fibers of the medial canthal tendon. Once the tendon is identified, a hole is made through the unstable central fragment and through bone on the contralateral side, one hole just posterior and superior to the lacrimal crest and the other superior to the lacrimal fossa. A double 26-, 28-, or 30-gauge wire is then threaded through the two holes transnasally with a curved needle or awl. The wire is secured to a screw or small plate on the contralateral supraorbital rim. This orientation provides the posteriorly and superiorly directed pull typically exerted by the medial canthal tendon. The same procedure may be used when the medial canthal tendon is completely detach/>