Management of irreducible unilateral facet joint dislocations in subaxial cervical spine: two case reports and a review of the literature

Classification of unilateral cervical locked facet with or without lateral mass-facet fractures and a retrospective observational study of 55 cases

This study describes a morphology-based unilateral cervical facet interlocking classification in an attempt to clarify the injury mechanism, instability, neurological deficits, radiological features, and determine optimum management strategies for these injuries. A total of 55 patients with unilateral cervical locked facet (UCLF) involving C3 to C7 were identified between January 1, 2012 and December 1, 2019. The injuries were classified into three types, and they were further divided into six subtypes using three-dimensional computed tomography. The injury mechanism, clinical features, neurological deficits, and imaging characteristics were analyzed, and the appropriate treatment strategies for UCLF were discussed. UCLFs were divided into the following six subtypes: UCLF without lateral mass-facet fracture (type I) in nine cases, with superior articular process fracture (type II A) in 22, with inferior articular process fracture (type II B) in seven, both superior and inferior articular process fractures (type II C) in four, with lateral mass splitting fracture (type III A) in three, and with lateral mass comminution fractures (type III B) in ten. A total of 22 (40.0%) of the 55 patients presented with radiculopathy, and 23 patients (41.8%) had spinal cord injuries. The subtype analyses showed high rates of radiculopathy in types II A (68.2%) and II C (75.0%), as well as significant spinal cord injury in types I (77.8%) and III (61.5%). Destruction of the facet capsule was observed in all patients, but the injury of disc, ligamentous complex, and vertebra had a significant difference among the types or subtypes. The instability parameters of the axial rotation angle, segmental kyphosis, and sagittal displacement showed significant differences in various types of UCLF. Closed reduction by preoperative and intraoperative general anesthesia traction was achieved in 27 patients (49.1%), and successful rate of closed reduction in type I (22.2%) was significantly lower than that in type II (51.5%) and type III (61.5%). A total of 35 of 55 patients underwent a single anterior fixation and fusion, 10 patients were treated with posterior pedicle and (or) lateral mass fixation, and combined surgery was performed in ten patients. Ten patients (18.2%) with a poor outcome were observed after first surgery. Among them, 3 patients treated with a single anterior surgery had persistent or aggravated radiculopathy and posterior approach surgery with ipsilateral facet resection, foramen enlargement, and pedicle and (or) lateral mass screw fixation was performed immediately, 5 patients treated with a short-segment posterior surgery showed mild late kyphosis deformity, and 2 patients with vertebral malalignment were encountered after anterior single-level fusion during the follow-up. This retrospective study indicated that UCLF is a rotationally unstable cervical spine injury. The classification proposed in this study will contribute to understanding the injury mechanism, radiological characteristics, and neurological deficits in various types of UCLF, which will help the surgeons to evaluate the preoperative closed reduction and guide the selection of surgical approach and fusion segment.

Regional and experiential differences in surgeon preference for the treatment of cervical facet injuries: a case study survey with the AO Spine Cervical Classification Validation Group

PURPOSE

The management of cervical facet dislocation injuries remains controversial. The main purpose of this investigation was to identify whether a surgeon's geographic location or years in practice influences their preferred management of traumatic cervical facet dislocation injuries.

METHODS

A survey was sent to 272 AO Spine members across all geographic regions and with a variety of practice experience. The survey included clinical case scenarios of cervical facet dislocation injuries and asked responders to select preferences among various diagnostic and management options.

RESULTS

A total of 189 complete responses were received. Over 50% of responding surgeons in each region elected to initiate management of cervical facet dislocation injuries with an MRI, with 6 case exceptions. Overall, there was considerable agreement between American and European responders regarding management of these injuries, with only 3 cases exhibiting a significant difference. Additionally, results also exhibited considerable management agreement between those with ≤ 10 and > 10 years of practice experience, with only 2 case exceptions noted.

CONCLUSION

More than half of responders, regardless of geographical location or practice experience, identified MRI as a screening imaging modality when managing cervical facet dislocation injuries, regardless of the status of the spinal cord and prior to any additional intervention. Additionally, a majority of surgeons would elect an anterior approach for the surgical management of these injuries. The study found overall agreement in management preferences of cervical facet dislocation injuries around the globe.

Differential Diagnosis of Facet Joint Disorders

Spinal pain due to facet joint disease is difficult to diagnose since the clinical history and physical examination findings are usually nonspecific. Facet joint disorders have a wide range of causes and, because of the potential for chronic back pain and disability, an accurate diagnosis is essential. The most frequent cause of pain in facet joints is osteoarthritis, which can be assessed at radiography, CT, or MRI. Ganglion and synovial cysts of the facet joints can cause compressive symptoms of adjacent structures, especially radiculopathy, lower back pain, and sensory or motor deficits. In ankylosing spondylitis, imaging findings of the facet joints are useful not only for diagnosis but also for monitoring structural changes. In septic arthritis of the facet joints, an early diagnosis at MRI is essential. Gout and metabolic diseases are best evaluated at dual-energy CT, which allows the depiction of crystals. Traumatic dislocations of facet joints are usually unstable injuries that require internal reduction, fixation, and fusion and can be well assessed at CT with three-dimensional reconstructions. Facet joint neoplasms like osteoid osteoma, plasmacytoma, tenosynovial giant cell tumor, and osteochondroma are best evaluated at CT or MRI. The authors provide an overview of key imaging features of the most common facet joint disorders along with anatomic tips and illustrative cases. Acknowledging key imaging findings for the differential diagnosis of facet joint disorders plays a crucial role in the diagnostic accuracy and proper treatment approach for such entities. Online supplemental material is available for this article. ^©RSNA, 2021.

Sub-Axial Cervical Facet Dislocation: A Review of Current Concepts

Cervical facet dislocation is a serious injury that carries risks of short- and long-term morbidity. The optimal management of these injuries remains controversial with the ongoing debate regarding indications and requirements for closed reduction, timing, type of surgical approach and method of fixation. This review gives an update on the relevant anatomy, classification systems for sub-axial cervical facet dislocation and an overview of the current concepts regarding their management, including surgical approaches and the choice of implants.

Early Management of Cervical Spine Trauma: WFNS Spine Committee Recommendations

Epidemiology, prevention, early management of cervical spine trauma and it's reduction are the objectives of this review paper. A PubMed and MEDLINE search between 2009 and 2019 were conducted using keywords. Case reports, experimental studies, papers other than English language and and unrelated studies were excluded. Up-to-date information on epidemiology of spine trauma, prevention, early emergency management, transportation, and closed reduction were reviewed and statements were produced to reach a consensus in 2 separate consensus meeting of World Federation of Neurosurgical Societies (WFNS) Spine Committee. The statements were voted and reached a positive or negative consensus using Delphi method. Global incidence of traumatic spinal injury is higher in low- and middle-income countries. The most frequent reasons are road traffic accidents and falls. The incidence from low falls in the elderly are increasing in high-income countries due to ageing populations. Prevention needs legislative, engineering, educational, and social efforts that need common efforts of all society. Emergency care of the trauma patient, transportation, and in-hospital acute management should be planned by implementing detailed protocols to prevent further damage to the spinal cord. This review summarizes the WFNS Spine Committee recommendations on epidemiology, prevention, and early management of cervical spine injuries.

Anterior reduction and fusion for acute unilateral cervical facet dislocation without severe spinal cord injuries

PURPOSE

This study aimed to evaluate safety and effectiveness of simple anterior reduction and fusion for acute lower cervical unilateral facet dislocation without severe spinal cord injuries.

MATERIALS AND METHODS

One hundred and two patients with unilateral cervical facet dislocations without severe spinal cord injuries who were surgically treated by the only anterior approach were analyzed. The treatment effects were evaluated based on the Visual Analogue Scale (VAS) scores, the Cobb angle of kyphosis, the Neck Disability Index (NDI) and Odom's criteria. Neurological recovery of patients was assessed by the Frankel grading.

RESULTS

The mean duration of follow-up was 12.4 ± 4.2 years (range, 10 to 17 years). VAS scores, Kyphosis angle and NDI scores were significantly changed from preoperative values of 7.4 ± 0.8, 11.3° ± 6.8° and 29.3 ± 5.1 to last follow-up values of 1.3 ± 0.8, -6.1° ± 7.5° and 8.8 ± 3.6 (P = 0.000). Of patients, 92 (90.2%) had good to excellent outcomes, 9 (8.8%) had satisfactory outcomes, and 1 (1.0%) had poor outcomes. Patients have obtained satisfactory neurological recovery. Three patients needed additional posterior reduction.

CONCLUSION

The anterior reduction and fusion is effective and safe for acute unilateral cervical facet dislocation, and can achieve good long-term clinical effects.

C2-C3 spinal fracture subluxation with ligamentous and vascular injury: a case report and review of management

Introduction

Spinal cord injury is one of the leading causes of paralysis and permanent morbidity. High cervical spine injuries, in particular, have the potential to be fatal and debilitating due to injury to multiple components, including but not limited to, discoligamentous disruption, vascular insult and spinal cord injury. To date, no unifying algorithm exists making it challenging to guide treatment decisions.

Case presentation

We present the case of a 29-year-old polytrauma patient with an unstable C2-C3 fracture subluxation secondary to hyperextension and rotation injury with complete ligamentous dissociation and vertebral artery dissection after a high-velocity injury. We review the literature on injury patterns, associated complications and neurological outcomes in subaxial cervical spine injuries.

Discussion

Our patient's injuries had several components including fracture subluxation, ligamentous disruption, central cord syndrome, and vascular insult. The lack of a unifying algorithm to guide treatment decisions highlights the variations in pathology and subsequent limitations in generalizability of current literature. Our patient underwent an open anterior C2-C3 reduction and discectomy with fusion and plating and a subsequent C2-C4 posterior instrumented fusion. The patient regained some motor function postoperatively and through rehabilitation. Careful consideration of multiple components is crucial when treating subaxial spine injuries.