Surgical approaches for cervical bifacetal dislocations: anterior, posterior, or circumferential?

Cervical facet dislocation (AO Spine cervical Type C injury) is a common spinal trauma caused by flexion-distraction force that usually results in damage to both the spinal columns. Typically, there is injury to all the stabilizing structures – the intervertebral disc, the facet joints and the posterior ligamentous complex (Figure 1). 

During the disruption, the intervertebral disc often prolapses into the spinal canal, and posteriorly the facet joints are fractured, subluxated or dislocated, causing a global instability. It is a high magnitude injury and associated with neurological deficit in more than 60% cases.  

In these patients, treatment is usually not about deciding whether to operate, but how. Reduction, decompression, fixation, and fusion are all on the table. Early reduction can potentially help relieve spinal cord compression and may improve outcomes, especially in those with spinal cord injury.

Surgical approach for cervical type C injury

Despite the ubiquity of the injury, the surgical approach for reduction of cervical dislocation is a matter of debate (Figure 2). Since both the columns are injured, there are strong proponents for a combined anterior and posterior approach.  

However, since these patients are physiologically unstable, several surgeons prefer the direct anterior approach, wherein anterior discectomy, distraction and posterior translation measures are used to reduce the subluxation. Others believe that the main culprit that impedes a successful reduction are the posterior facets, which are better addressed through a posterior approach.  

In this blog post, we walk through how we think about these options in daily practice and highlight the main principles, advantages, and disadvantages of anterior-only, posterior-only, and circumferential approaches in cervical bifacetal dislocation. 

Anterior approach to cervical bifacetal dislocation

Anterior-only approach surgery uses the anterior Smith Robinson approach for accessing the injured spine. It is especially useful for the patients with traumatic disc herniation causing ventral cord compression and neurological deficit.  

Technique

Through a vertical or horizontal incision and Smith Robinson approach, the anterior column of the spine is accessed. Caspar pins are placed in the two adjacent vertebral bodies. After pin distraction, thorough discectomy is performed under loupe or microscopic magnification. After discectomy, several techniques have been described to enable reduction. Kanna et al used distraction, either manually or through inter-body laminar spreaders, and used the Caspar pins as joy sticks to reduce the dislocation. They reported 100% success with this technique. Other authors have used the Caspar pins alone to reduce the subluxation in a convergent manner (Ordonez et al). The use of laminar spreader (Reindl et al), periosteal detacher (Ren et al) and trial model device (Du et al) into the disc space to distract and lever the dislocated vertebral body has also been successfully reported.  

Advantages of the anterior approach

In suitable patients, the anterior approach offers several practical advantages. It is a familiar approach and allows ease of positioning on the operating table, especially in patients with spinal cord injury. It is surgically less traumatic owing to its blunt inter-plane dissections and is associated with a low infection rate (<2% vs. 16% in posterior approaches).

The anterior approach provides direct access to the injured intervertebral disc and allows mono-segment fixation, whereas posterior approaches often rely on long segment fixation. It is biomechanically stronger through the compression side of the spine and is associated with higher fusion rates. 

Limitations of the anterior approach

At the same time, anterior-only surgery is not the right answer for every bifacetal dislocation. It requires expertise, as it is difficult to reduce the facet joints through anterior access and is not applicable in delayed dislocations. In order to release the facet joints, the distraction required is often too much, which may cause secondary iatrogenic injury to the spinal cord.

In patients with co-existent vertebral body fractures or osteoporosis, it is not possible to distract adequately. Even if reduction is achieved, many of these patients have extensive posterior injury, which will require supplemental posterior fixation. At lower levels and in short-necked patients, it is difficult to assess the adequacy of posterior facet reduction in lateral images intra-operatively. 

Posterior approach to cervical bifacetal dislocation

The posterior approach provides direct access to the dislocated facets, consequently helping in reduction and stabilization.  

Compared to the anterior approach where the reduction is indirect and requires manipulation, the reduction in the posterior approach is under direct visualization without any forceful manipulation. The posterior approach is especially preferred in delayed or neglected dislocations where callus formation has begun to form which prevents anterior reduction. 

Technique

Under general anesthesia and prone position, a midline posterior incision provides access to the dislocated cervical facets.  

We typically perform a bilateral facetectomy to release the locked joints and gain enough mobility for reduction. Lateral mass screws are placed into the involved and adjacent vertebrae. Contoured rods are seated into the screw tulips.

We then apply gradual compression between screws over the rods under direct vision and fluoroscopic control. As we close the construct, the facets reduce and alignment is restored. Bone grafts or substitutes are placed over the decorticated posterior elements to promote fusion.  

Advantages of the posterior approach

Advantages of the posterior approach include its familiarity and the direct access it provides to the dislocated facets, allowing reduction under direct visualization. It also avoids the need for forceful, indirect manipulation to achieve reduction.

Cervical pedicle screws used with this approach provide a stiffer construct with better stability. The posterior approach is the approach of choice in delayed or neglected dislocations and locked facets.

It is also utilized when there is a lamina fracture compressing the cord and should be preferred when a closed reduction with skull traction fails. 

Limitations of the posterior approach

Disadvantages of the posterior approach include its unsuitability in polytrauma patients and the risk of neurological worsening in patients with associated traumatic disc herniation. This approach may also require long segment fixation.

Additional limitations are increased operative time and risk of infection, postoperative axial neck pain, and decreased fusion rates when compared to the anterior approach. 

Circumferential approach to cervical bifacetal dislocation

Although anterior-only and posterior-only techniques may be effective in selected cases of BFD, circumferential stabilization remains an important strategy for highly unstable or complex injuries. This is particularly relevant in bilateral facet dislocations with extensive ligamentous injury, associated facet fractures, severe kyphosis, osteoporosis, or involvement of the cervico-thoracic junction.  

An anterior approach allows direct decompression of traumatic disc herniation or bone fragment, restoration of disc height, and reconstruction of the anterior column through interbody fusion while the posterior approach permits direct visualization of locked facets, facilitates reduction in irreducible injuries, and restores the posterior tension band using lateral mass or pedicle screw fixation. This approach typically starts with a posterior approach to reduce the facetal subluxation and fixation, followed by an anterior discectomy and fusion. 

Advantages of circumferential surgery

When indicated, circumferential surgery offers several advantages. Combined fixation provides superior stability compared with isolated constructs.

This approach also allows flexibility in reduction strategy. In patients with large traumatic disc extrusions, anterior decompression before reduction may theoretically reduce the risk of neurological deterioration during manipulation. Conversely, chronic or irreducible facet dislocations often require posterior release before successful reduction can be achieved. The combined approach, therefore, allows surgical sequencing to be individualized based on injury morphology and the localization of neural compression.

Circumferential constructs offer greater resistance to rotational and flexion-extension forces than anterior-only fixation. This added stability could lower the likelihood of postoperative kyphosis, pseudarthrosis, or fixation failure, especially in patients with significant posterior ligamentous disruption. 

Limitations of circumferential surgery

These benefits need to be weighed against real drawbacks. Combined procedures are associated with longer surgical time, greater blood loss, prolonged anesthesia exposure, and higher overall surgical morbidity. They can also increase surgical and implant costs. In polytrauma patients or those with medical frailty, this increased physiological burden may be clinically significant. Furthermore, the need for intraoperative repositioning may heighten logistical complexity and perioperative risks.

Approach-related complications are also cumulative. The anterior approach carries risks such as dysphagia, recurrent laryngeal nerve injury, airway edema, and esophageal injury, whereas posterior surgery may result in increased postoperative pain, bleeding, muscle devascularization, and wound complications. Circumferential procedures may prolong recovery and hospitalization compared with single-approach strategies.

Another controversy concerns whether all bilateral facet dislocations truly require combined fixation. Several authors have reported satisfactory outcomes with anterior-only stabilization in carefully selected patients, particularly when reduction is achieved without over-distraction and posterior bony injury is limited. 

Choosing the optimal approach for bilateral cervical facet dislocations: anterior, posterior, or circumferential?

Ultimately, surgical decision-making should be tailored to the individual, taking into account injury type, neurological status, reducibility, disc pathology, bone quality, and surgeon expertise.  

For those without severe systemic injuries, good bone quality, and a low risk of implant failure, an anterior or posterior approach may be sufficient in most cases, with close clinical and radiological follow-up. The circumferential approach is a valuable and flexible option for treating severely unstable bilateral cervical facet dislocations, particularly when optimal stability and deformity correction are required.