Le Fort I and Le Fort Ii Fractures
Jacob O. Boeckmann
Fractures of the midface account for up to 20% of facial fractures presenting to the emergency department. When fractures of the midface occur, significant functional problems and aesthetic deformities can result. Much of the understanding of midface trauma is attributed to Rene Le Fort’s work published in 1901. Le Fort studied the impact of low-velocity blunt force to cadaver facial skeletons and noted three distinct fracture patterns based upon inherent lines of weakness (Fig. 51.1). The original descriptions were represented as symmetric and occurring in isolation. In today’s society, Le Fort fractures are rarely seen in their pure form and can present as a unilateral fractures, combined fracture patterns, or comminuted fractures. Timely diagnosis and treatment of these injuries is important in order to optimize patient outcomes and minimize long-term sequela. The goals of management are directed toward the reestablishment of preinjury structure and function. Advances in implant technology have allowed the reconstructive surgeon the ability to perform a single-stage repair with rigid internal fixation. This provides the patient more rapid bone healing, improved cosmesis, enhanced nutrition, and earlier return of preinjury function.
In the United States, Le Fort fractures typically are sustained as a result of motor vehicle accidents, physical assault, and occupation-related, sport-related, or gunshot injuries. The majority of these injuries occur in males during their 3rd and 4th decade of life. However, the elderly remain an at-risk group due to a higher incidence of falls in this population. Rarely do children sustain these injuries due to their developing craniofacial anatomy.
The mechanism of injury, including the velocity, direction, and location of the force, can help the physician anticipate the fracture pattern. Le Fort I fractures typically occur following blunt force directed in an anterior to posterior direction to the midface. Le Fort II injuries can result either from a horizontal force directed across the midface or from a transmitted force from the mandible following forces directed to the chin. Due to the amount of force needed to fracture the midface, it is not uncommon for patients to present with coexistent complex fractures to the surrounding facial skeleton, cervical spine, central nervous system, and/or orbit.
The treating physician must have a high index of suspicion for associated injuries. Critical components of the history should focus on the status of the dentition, cranial nerve defects, vision changes, and rhinorrhea. Malocclusion is common following fractures of the craniofacial skeleton and, in some instances, may be the only clue in a patient without obvious signs of injury. Cranial nerve defects may accompany these fractures, particularly the second branch of the trigeminal nerve (V2). Any change in vision reported by the patient raises the possibility of an orbital fracture or orbital trauma. Finally, anosmia, rhinorrhea, or otorrhea may be indicative of a skull base injury with potential cerebrospinal fluid (CSF) leak.
Frequently, the evaluation of these patients occurs in an emergency room setting. As in all trauma situations, initial assessment and resuscitation using the ABCDE primary survey and immediate treatment of life-threatening injuries take precedence. Airway assessment takes priority, as the potential for obstruction exists secondary to posterior dislocation of the fractured segment into the airway. Bleeding can also result in obstruction if the patient is unable to control his or her airway secretions.
When airway compromise exists, the preferred method for airway management is orotracheal intubation by a skilled responder. This may not always be possible due to impaired visualization from blood and secretions, coexistent cervical spine trauma, or altered anatomy. One must therefore always anticipate the need for an alternate airway. If coexistent cervical spine injury is suspected or present, the airway can be obtained via fiberoptic or nasotracheal intubation. When these options are unsuccessful, a surgical airway can be established in an emergent or planned situation via a cricothyroidotomy or tracheostomy.
It is not uncommon to encounter epistaxis following midface trauma due to disruption to the delicate nasal and sinus mucosa. Bleeding of this nature is typically self-limited but occasionally requires control with nasal packing, a 30-mL Foley balloon, or temporary fracture reduction. Epistaxis can also be the source of life-threatening hemorrhage from disruption of the distant branches of the external carotid artery (e.g., internal maxillary artery) or the skull base. When this occurs, timely awareness and intervention is warranted to minimize significant morbidity and mortality from hypovolemic shock. This scenario requires advanced techniques for control, which may include ligation of the external carotid artery, or intravascular control with coils and/or embolization.
Once the patient is stabilized, a detailed physical examination is possible. Examination of facial symmetry is an important first step in evaluating trauma patients. Unfortunately, this can be challenging to identify in the acutely injured patient due to soft tissue edema and ecchymosis overlying the facial skeleton. Once the acute edema subsides, the surgeon can easily note the facial asymmetry.
Assessment of occlusion is essential for all patients with facial fractures because malocclusion sometimes may be the only evidence of a fracture. Frequently, the disrupted premaxilla leads to premature contact with the molars and a resultant anterior open bite deformity. A palate or alveolar fracture can also complicate the occlusive relationship by widening the dentoalveolar arch resulting in a posterior cross-bite deformity. Any dental gaps and avulsed teeth must be accounted for to ensure that the airway is clear. A patient with avulsed teeth should have a chest radiograph to rule out aspiration of dental fragments.
Palpation of the bony skeleton often reveals step-off deformities and tenderness overlying the fracture lines. Crepitus involving the soft tissue or gingivobuccal sulcus may be present if an associated fracture of the paranasal sinus is present. Mobility should be assessed with bimanual palpation from the thumb and index finger. With Le Fort I injuries, mobility of the palate will be present while those with Le Fort II injuries will have movement of the maxilla and nasal complex. Absence of mobility does not always exclude a Le Fort injury as impaction can impair mobility of the fractured segment. Any lacerations should be noted as these can be associated with underlying bony defects and may be used as potential routes of exposure for reduction.
A complete ocular examination is important when any concern exists for periocular trauma. Periorbital edema, ecchymosis, chemosis, and subconjuctival hemorrhage frequently are present when an orbital fracture is present. Ocular motility should be assessed as impingement of bony fragments may restrict extraocular motility. When a disturbance is present, forced duction testing should be performed to distinguish between entrapment and neurologic impairment. Epiphora can result from a disruption of the nasolacrimal duct drainage system.
Finally, a complete head and neck neurologic evaluation should be performed, with particular emphasis on the level of consciousness, cranial nerve examination, and cervical spine status. Frequently, patients have paresthesia of the midface along the second branch of the trigeminal nerve due to direct injury, bony impingement, or neural edema. If a CSF leak is suspected, it can be confirmed with collection of a fluid sample for beta-2 transferrin testing or further imaging.
These injuries are not life threatening, but left unrepaired, they can result in significant cosmetic and functional sequela. The vertical buttress system is composed of paired zygomaticomaxillary (lateral), nasomaxillary (medial), and pterygomaxillary (posterior) buttresses and functions to resist the forces of mastication and establishes midface height. The horizontal buttress system is composed of the frontal bone and supraorbital rims, the infraorbital rims and zygoma, and the alveolus and palate. The horizontal buttress establishes facial width and projection and further supports the vertical buttresses. Le Fort injuries often disrupt one or both buttress systems, resulting in a vertical shortening of the face and a flattened appearance.
For Le Fort injuries, the goals of treatment are threefold:
1. Restoration of preinjury occlusion
2. Restoration of facial height and width
3. Restoration of soft tissue integrity
Not all patients require open reduction and internal fixation. If the patient is reliable and has a nondis-placed Le Fort I with easily restorable occlusion, closed reduction with MMF for 4 to 6 weeks can be considered. For all other patients, repair with open reduction and internal fixation is indicated.
The proper timing of repair remains debatable with few studies available to provide definitive evidence supporting early versus late repair. Advocates for early repair report improved outcomes in function, cosmesis, and decreased rates of infection. However, not all patients are candidates for early repair due to coexistent injuries and medical instability from other life-threatening injuries. Any patient with periorbital trauma should undergo preoperative examination by an ophthalmologist to rule out an orbital injury or other condition that may preclude repair. A ruptured globe, retrobulbar hematoma, or extraocular muscle entrapment may require urgent intervention while findings of a hyphema or traumatic optic neuropathy may delay or alter the treatment strategy. Those patients with closed head injuries, significant frontal or skull base fractures, or CSF leak should be evaluated by a neurosurgeon and cleared for surgery prior to intervention. These patients must await medical stability prior to fixation.
When delayed repair is indicated, most surgeons agree it is best to address these fractures within 2 weeks of injury to avoid the potential need for bone grafting or osteotomies. Ultimately, the reconstructive surgeon must exercise judgment as to the optimal timing of repair for each individual patient.
Contraindications for surgical repair of midface fractures generally are related to coexistent life-threatening injuries that have not been stabilized from the initial trauma or those at high risk of general anesthesia due to coexistent medical comorbidities and instability.
High-resolution computer tomography (CT) of the facial skeleton with axial and coronal thin cut (1.5-mm) imaging has become the standard imaging modality in the evaluation of a patient with facial trauma. CT provides superior characterization of the facial fracture segments and overlying soft tissue compared to traditional plain film radiography. It also allows the reconstructive surgeon the opportunity to evaluate the degree of injury and the potentially involved adjacent structures such as the optic canal, skull base, carotid canal, and integrity of the globe.