Traumatic subxial cervical facet dislocation(TSCFD) is one of the most devastating injuries involving the axial skeleton. Several approaches to reduction and stabilization have been proposed with all demonstrating advantages and disadvantages16. The objective of this paper is to evaluate the manual close reduction in emergency room in the initial management of TSCFD. The secondary aim is to analyze the different surgical choices in TSCFDs.
The impairment to the spinal cord and nerve root injury is the most critical event in TSCFD. The nerve root injury may lead to different degrees of upper limb dysfunction. The cervical spinal cord injury(SCI) could lead to spinal shock and complete/incomplete paraplegia, which affect not only the patient but also their family and even the society6-8. Generally speaking, injury to the cervical spinal cord typically leads to a combination of symptoms and signs resulting from immediate and delayed injuries17,18. The initial mechanical trauma tends to primarily damage the central grey matter because of its high metabolic requirement. It is thought that the grey matter is irreversibly damaged within the first hour after injury, whereas the white matter is irreversibly damaged within 72 h after injury17.
It is known that the degree of the recovery and the severity of the pathological changes are directly related to the duration of the acute compression. And this is demonstrated by experiment studies in which longer compression time produces less demonstrable clinical recovery19-21. Thus, relieve the acute compression to the cervical spinal cord and nerve roots is very critical for the TSCFD patients, no matter whether there is spinal cord injury(SCI). Early reduction can restore the volume of the spinal canal, not only relieve the acute compression to the cervical spinal cord and nerve roots, but also provide a loose space for them, and this could produce demonstrable clinical recovery (Fig. 3, case 6).
Cranial traction is thought to be an effective and fast way to achieve close reduction of TSCFD14,15. It is less invasive, and allows for the decompression of the spinal cord compression due to the dislocation, and realigns the spine to an anatomic position16,22. If we perform the longitudinal traction manually in emergency room, just like cranial traction, then make flexion and extension, lateral buckling and slight rotation movements, it is possible to get close reduction of the TSCFD. In this study, 5 of the 10 TSCFD patients achieved successful manual close reduction in emergency room by this way, and this procedure started as soon as the dislocation diagnosis was made. This obviously reduced the duration of acute compression to the cervical spinal cord and nerve roots.
For the patients with complete paralysis, when the close reduction is achieved, but without significant improvement in neurological status, it is difficult to make a choice about whether to proceed with the next surgery. Although we strongly recommend a surgical treatment even if it is just for the sake of early sitting up and standing with assistance in rehabilitation therapy post the surgery (Case1,10), there are still some complete paralysis patients refuse a surgery with a hopeless neurological improvement, and choose conservative treatment (Fig. 1, Case 2).
For case 8, the patient’s syndrome was only neck pain, with a normal limb function, manual close reduction was achieved successfully in emergency room. The post-reduction MRI showed the disc and the posterior ligamentous complex (PLC) were not seriously teared, or in other words, the stable structure of the cervical spine was not severely damaged, so we choose a conservative treatment. The patient sit up and walked 7 days later with a philadelphia neck brace. And returned to a normal life gradually 1 months later. As been followed-up for 6 months, there was no obvious discomfort in this patient.
The optimal treatment of TSCFD has been controversial 23,24. The surgeon’s experience is a decisive factor, such as skull traction under general or local anesthesia, open reduction and internal fixation (anterior approach; anterior first and posterior second; anterior first and posterior second and then anterior approach; posterior approach; and posterior first and anterior second), and no uniform standards of treatment strategy are available yet.
Many scholars advocate a single anterior approach to finish the decompression, reduction and stabilization25,26, especially in cases with unilateral dislocation. For the close reduction successful patients, anterior procedure is a good choice because it’s less invasive. For the close reduction fail patients, there is also a high success rate of reduction and good clinical results25,26. However, there are reports about the anterior approach alone may be technically challenging when intraoperative reduction is required 27, especially in patients with bilateral dislocation, and forcible reduction may increase the risk of secondary cervical spinal cord injury in patients. In a biomechanical study, Bozkus 28 found that posterior fixation system provides a batter stability than anterior fusion with a locking plate and bone graft or cage.
Therefore, the question then becomes, is anterior fusion and stabilization adequate? For the complete paraplegia patients, the answer may be yes, because the patient could only sit or stand up with assistance in the rehabilitation therapy after surgery. The anterior stabilization with a locking plate and cage, and the philadelphia neck brace, could provide enough stability for the cervical spine (Table 1. Case1,10). The posterior stabilization may be unnecessary for the complete paraplegia patients, but may increase surgery trauma, surgery time and treatment costs. Of course, this is under the precursor of successful close reduction or successful open reduction through anterior approach. For the patients with a good neurological status, only anterior fusion and stabilization may be not strong enough for the patients in early walking after surgery, in this situation, because the stable structure post cervical spine has been disrupted, neck flexion is dangerous as the fixation screws may be pulled out. Thus, a posterior fixation may be necessary. For the case 6 (Fig. 3) and case 4 (Fig. 4), pedicle/lateral mass screws and rod system was used on one side (there were fractures on the other side, which made it difficult to put the screws accuratly), the torn supraspinous ligament was sutured before the wound closure, added with the ACDF, a 270° fusion was achieved through all these procedures, and it was strong enough for early walking after surgery.
Although there are reports that most of the dislocations can be reset through anterior approach25,26, there is report that 25% dislocations could not be reduced using a single anterior approach26. In this situation, the surgeons have to close the anterior wound temporarily, turn the patient over, reset and fix the facet through posterior approach, then turn over the patient again to finish the anterior surgery. This anterior-posterior-anterior procedure is too complicated, and may be dangerous for the cervical spinal cord. So if we expect there will be a failed reduction through anterior approach, a posterior-anterior procedure may be a good choice. For case 4(Fig. 4), the right articular process of C6 fractured seriously, the fracture line extended to the entire cervical vertebral plate, this made the longitudinal traction power can’t conduct to the dislocated right facet, thus it may be impossible to achieve close reduction of the dislocated right facet, or achieve open reduction through anterior surgery, and the dislocated right facet may also hinder the left facet reduction. Both the manual close reduction in emergency room and the close reduction under cranial traction in operation room were all failed. In the posterior surgery, we saw the fractured right articular process exactly, which was keeping still under traction power, and the longitudinal traction power can’t conduct to the dislocated and fracture right facet. Until after the unnecessary fracture fragments of the right facet was removed and the right facet was roughly reset (Fig. 4C, H), the left facet reduction was achieved finally by being pried and reset using a large curette. Then the left lateral mass/pedicle screws and rod were used while the right facet was left without fixation, the torn supraspinous ligament was sutured, the wound was closed, and the patient was turned over for ACDF. This posterior-anterior procedure seems better than a possible anterior-posterior-anterior procedure.
Although there is a report that a stand-alone posterior approach is adopt to treat TSCFD 29. It needs multi segments fixation to prevent screws being pulled out during multidimensional cervical spine movement, and this comes often at the cost of sacrifice stability of multiple segments. At the same time, we believe that it is inappropriate to leave the ruptured disc untreated, in which a possible disc herniation could make a continuous compression to the cervical spinal cord.
We must watch out for the incidence of neurological deterioration related to closed reduction. The ruptured disc fragments may be enrolled into the cervical spinal canal during the close reduction maneuver, which may bring new acute compression, or aggravate the existing compression to the cervical spinal cord. However, it has been reported that the risk of neurologic deterioration from early closed reduction may be lower than previously thought 30. There is report about the incidence of neurological deterioration related to closed reduction remains low. with reported rates of transient deficits of 2–4% and permanent deficits of < 1% 31.
So MRI may be necessary for TSCFD patients, which could detect whether there is a disc herniation or a ruptured disc fragment, which may be enrolled into cervical spinal canal during close reduction, aggravating the compression to the cervical spinal cord. In this series of 10 TSCFD cases, 7 patients undertook MRI examination before manual close reduction. If there is definitely a free body in the cervical spinal canal (Fig. 3D, Fig. 4D), close reduction may be dangerous to the cervical spinal cord. An anterior approach to perform disc discectomy may be more important than close reduction in this situation. Obviously, reduction after decompression through an anterior approach is much more safe. If the reduction is failed, we should close the anterior wound temporarily, turn the patient over, perform the posterior reduction and fixation, then turn the patient over again to finish the anterior fusion and stabilization finally. Although this anterior-posterior-anterior procedure is complicated, it may be more safe to the cervical spinal cord than the posterior-anterior procedure.
However, it seems that the analysis above is only a theoretical possibility. There is an obvious disc herniation in case 6 (Fig. 3D), which is not enrolled into the cervical spinal canal during the close reduction maneuver (Fig. 3H), and it doesn’t bring new acute compression, or aggravate the existing compression to the cervical spinal cord (Fig. 3H). The patient’s neurological symptom is relieved after manual close reduction. For the case 4, there is also an obvious disc herniation (Fig. 4D), after multiple attempts but failed close reduction, open reduction posteriorly is performed, before the disc discectomy anteriorly, and the neurological status is not only not aggravated but also improved significantly. These two cases indicate that neurological symptom aggravation after close reduction may be only a low probability event, and it is consistent with previous reports31.
The obvious weakness of this study lies in its retrospective nature and the heterogeneous methods that were used to treat TSCFD.