Michael A. Finn, Paul A. Anderson
Cervical facet dislocations, also known as jumped facets, are the result of a hyper- flexion or flexion distraction injury, often associated with a component of rota- tion. In cases of unilateral dislocation, patients most often escape neurologic injury, whereas bilateral facet dislocations are frequently associated with significant neuro- logic deficit.1 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 irrevers- ible, 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.2-6 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.7-9
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 fash- ion to meet this goal. Closed reduction of the cervical fracture dislocations via traction provides the most rapid means of reducing the traumatic deformity and decompress- ing the neural elements, and its safe use has been well reported.10-14 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 precipi- tating a neurologic decline through the displacement of extruded disk material.15-18 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.
CASE PRESENTATIONS Case 1
A 35-year-old woman came for treatment after a high-velocity fall over the han- dlebars in a mountain biking accident. She experienced a brief loss of conscious- ness and was transported for medical evaluation using full spinal precautions. She complained of numbness in bilateral C7 distributions.
• PMH: Unremarkable • PSH: Unremarkable
• 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 frac- tured 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.
Case 2
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.
A
C
B
FIGURE 14-1 Sagittal CT reconstructions demonstrating C6-7 fracture dislocation with C5-6 and C6-7 dis- located facets on the left (A) and a fractured C7 facet on the right (C). Approximately 50% anterolisthesis of C6 on C7 can be seen (B).
A
C
B
FIGURE 14-3 Sagittal reconstructions from CT scanning performed during traction. Note continued facet dislocation on left (A).
FIGURE 14-2 Lateral radiograph taken with the patient in 30 lb of traction. Note widening of the C6-7 interspace.
• PMH: Unremarkable • PSH: Unremarkable
• 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
A B
FIGURE 14-4 Radiographs obtained after anterior and posterior fixation via C6 corpectomy, anterior plat- ing, and posterior lateral mass instrumentation.
6
7
FIGURE 14-5 Lateral radiograph demonstrating C6-7 facet dislocation with approximately 50% anterolisthesis.
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.
TREATMENT OPTIONS
Reduction of facet dislocations may be accomplished using cranial tong traction, and surgically using either an anterior or posterior approach.