Cervical facet dislocations, also known as jumped facets, are the result of a hyperflexion or flexion distraction injury, often associated with a component of rotation. In cases of unilateral dislocation, patients most often escape neurologic injury, whereas bilateral facet dislocations are frequently associated with significant neurologic deficit. Neurologic deficits in the setting of cervical dislocation with jumped facets are attributable to both the primary injury, or the initial trauma and disruption of neural tissue, and to the secondary injury, or injury attributable to the ongoing compression of neural elements. Although the primary neurologic injury is irreversible, the secondary injury represents a treatable source of neurologic dysfunction and is thought to occur in proportion to the length of time and the magnitude of physical compression. One cause of this secondary injury is spinal cord ischemia due to compression of the anterior spinal artery and radicular feeders. Simple spinal realignment may at a minimum reestablish blood flow to partially damaged tissue, thereby reducing the severity of secondary injury. Timely decompression of neural elements has been shown to be critical in minimizing secondary neurologic injury and maximizing the chances of neurologic recovery in animal studies, although proof of this in humans is lacking except in anecdotal case reports.
Patients with either unilateral or bilateral jumped facets and incomplete neurologic injury present a situation in which the primary neurologic injury is subtotal; thus the goal of initial treatment is to minimize secondary injury, that is, to lessen the chances of neurologic decline from further spinal cord necrosis and to maximize the chances of recovery. Neurologic decompression should be carried out in an expeditious fashion to meet this goal. Closed reduction of the cervical fracture dislocations via traction provides the most rapid means of reducing the traumatic deformity and decompressing the neural elements, and its safe use has been well reported. Despite its well-documented efficacy, however, the closed reduction of cervical fracture dislocations has been the focus of much debate in the literature because of the fear of precipitating a neurologic decline through the displacement of extruded disk material. Although this risk may be real, it is relatively small and should not delay the prompt closed reduction of a traumatic deformity in the awake, examinable patient.
A 35-year-old woman came for treatment after a high-velocity fall over the handlebars in a mountain biking accident. She experienced a brief loss of consciousness and was transported for medical evaluation using full spinal precautions. She complained of numbness in bilateral C7 distributions.
Exam: Strength in the triceps was 4/5 bilaterally with full strength in all other muscle groups and decreased sensation to light touch from C7 down. Rectal tone was normal, and reflexes were symmetric and nonpathologic.
Imaging: Computed tomography (CT) revealed a fracture dislocation at C6-7 with 50% anterolisthesis of C6 on C7, a dislocated facet on the left, a fractured dislocated facet on the right, and a complex fracture of C5 with fracture through the pedicle and posterior elements resulting in a floating lateral mass ( Figure 14-1 ).
The patient was placed in Garner-Wells tongs and 10 lb of traction was applied. Traction was increased in 10-lb increments, with radiography and a thorough physical examination performed at each interval increase in weight, until 30 lb was reached, at which point there was some concern for overdistraction at the C6-7 interspace ( Figure 14-2 ). CT with the patient in traction demonstrated a 25% reduction in dislocation, but persisting facet dislocation of C6-7 ( Figure 14-3 ).
The patient was then taken to the operating room for a C6 corpectomy with C5-C7 anterior fusion followed by posterior fixation from C5 to C7 on the right ( Figure 14-4 ). Reduction was obtained with distraction using distraction posts during the anterior portion of the procedure. Left-sided posterior instrumentation was precluded by the fracture pattern. The patient’s sensory and motor deficits had resolved completely by 1-month follow-up.
A 16-year-old gymnast fell from parallel bars onto a hyperflexed neck. She was immediately quadriplegic and was brought to the emergency department within 45 minutes of injury.
Exam: Neurologic examination revealed a complete C6 cord-level injury except for patchy sensation on her chest. The bulbocavernosus reflex was absent.
Imaging: A lateral radiograph revealed bilateral facet dislocations at C6-7 ( Figure 14-5 ).
Cranial tong traction was immediately applied, and reduction was achieved at 40 lb of traction weight within 20 minutes after the patient entered the emergency department ( Figure 14-6 ). She noted an instantaneous return of sensation to her arms and legs when reduction occurred. Within 6 hours she began to regain motor function, and by the next day had normal motor strength but residual spasticity. Five days later she underwent a posterior C6-7 fusion and maintained normal motor and sensory function.
Reduction of facet dislocations may be accomplished using cranial tong traction, and surgically using either an anterior or posterior approach.
The closed cranial tong traction technique is faster and is preferred in patients with severe neurologic injury. Disadvantages include a failure rate of between 5% and 25% and a small risk of neurologic deterioration.
Surgical reduction via a posterior approach was traditionally used, which allowed open reduction by manual means or with removal of small amounts of the facet to allow unlocking and then fusion. More recently with the development of rigid anterior cervical plates the anterior approach has been advocated and safely performed. This allows diskectomy and theoretically prevents neurologic deterioration from retained disk fragments that may compress the cord after reduction. It also allows reduction using anterior distraction pins and manual leverage. Disadvantages are lack of familiarity with techniques of open anterior reduction and failure of the construct in the presence of vertebral body fractures, which occur frequently.
Reduction with Tong Traction
Before traction is initiated, images of the cervical spine should be scrutinized closely for the presence of injuries cephalad to the dislocated level, with specific attention directed to the occipitocervical junction ( Tips from the Masters 14-1 ). The presence of skull fractures underlying the site of application of the tongs should also be ruled out if clinically suspected ( Tips from the Masters 14-2 ). Finally, the presence of an ankylosed cervical spine, as in the case of ankylosing spondylitis, is a relative contraindication to the use of traction. In these cases, attempts at reduction should be performed using fluoroscopy and a slow escalation of traction weights.
Carefully assess the cervical spine for rostral injuries. Odontoid and hangman fractures and atlantooccipital dislocation are contraindications to closed reduction.
Patients who are neurologically intact should, if possible, undergo magnetic resonance imaging (MRI) before reduction to evaluate the location of the intervertebral disk. If there is a herniated disk behind the body of the dislocated vertebrae, an anterior diskectomy should be performed before reduction.
The patient is positioned supine on a hospital bed that accepts a traction apparatus. The skin overlying the pin insertion site is prepared in the normal fashion. Hair shaving is not necessary. Local anesthesia is injected into the skin and down to the periosteum in awake patients. For Gardner-Wells or similar tongs, the standard site of pin placement is approximately 1 cm superior to the pinna and 1 cm anterior to the external auditory canal, a location which places the tongs below the equator of the skull and thereby reduces the risk of pullout. More anterior placement can lead to penetration of the superficial temporal artery. Of note, stainless steel tongs are less susceptible to deformation and should be used if high traction weights (more than 50 lb) are anticipated rather than graphite and titanium MRI-compatible tongs. Alternatively, a standard halo ring can be used with traction if halo immobilization is likely to be required after reduction. When Gardner-Wells tongs are used, the pins are tightened until the spring indicator protrudes 1 mm. Care should be taken to ensure that pins are placed symmetrically.
Before traction is initiated, a thorough neurologic examination is performed ( Tips from the Masters 14-3 ). Traction is typically started at 10 lb and increased in 5- to 10-lb increments until reduction is achieved. A neurologic examination is performed and a lateral cervical radiograph is scrutinized after each increase in weight. Fluoroscopy can also be useful to obtain real-time evaluation of traction maneuvers. Specific attention should again be paid to more cephalad levels to ensure that there is no distraction, defined as widening of the disk space to more than 1.5 times that of the adjacent levels, or an occult injury. Although many authors report using weight of approximately 10 lb per level of injury in addition to the initial 10 lb (e.g., 60 lb total for a C5-6 injury), weights of up to 140 lb have been reported to be used safely and successfully. Placing the bed in reverse Trendelenburg position is useful with the application of higher weights to counteract the tendency to pull the patient cephalad in the bed. For bilateral facet dislocations it can also be helpful to place the Gardner-Wells pins slightly posterior to the angle of the vector of traction and allow for the creation of a greater flexion moment.