Clinical outcomes of 90 isolated unilateral facet fractures, subluxations, and dislocations treated surgically and nonoperatively

Delayed Unilateral Facet Interlocking After a Stable Superior Articular Process Fracture of the Cervical Spine: A Case Report

A 42-year-old man presented with neck pain after a fall from a tree. Spine computed tomography (CT) illustrated the right C5 superior articular process fracture without displacement. Magnetic resonance imaging (MRI) confirmed the fracture and injury of the posterior ligament complex. Initially he was managed conservatively with a neck brace as there were no signs of instability or vertebral body misalignment. However, three days after discharge, right shoulder weakness and numbness of the right upper arm became prominent. X-rays and CT showed anterior slippage of the C4 vertebral body and locked C4/5 facet ??a fractured bony fragment of the C5 superior articular process was pushed forward by the locked inferior articular process of C4 and invaded the neural foramen. Anterior cervical discectomy and fusion (ACDF) was performed using allograft and plate/screws fixation. Although initial imaging showed no evidence of subluxation, surgeons should be aware of occult instability and the possibility of delayed dislocation associated with the unilateral cervical facet fracture.

Assessing Treatment of Floating Lateral Mass (FLM) Fractures of the Subaxial Cervical Spine

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

The purpose of the study was to evaluate differences across surgical approaches (anterior, posterior, or combined anterior-posterior) in terms of outcomes following treatment for floating lateral mass (FLM) fractures. Furthermore, we sought to determine whether operative approach to FLM fracture treatment remains superior to nonoperative treatment in terms of clinical outcomes.

BACKGROUND DATA

FLM fractures of the subaxial cervical spine involves separation of the lateral mass from the vertebrae via a disruption of both the lamina and pedicle, resulting in a disconnection of the superior and inferior articular processes. This subset of cervical spine fractures is highly unstable, making proper treatment selection of great importance.

METHODS

In this single-center, retrospective study, we identified patients meeting the definition of an FLM fracture. Radiological imaging from the date of injury was reviewed to ensure presence this injury pattern. Treatment course was assessed to determine nonoperative versus operative treatment. Operative treatment was divided into patients who underwent anterior, posterior, or combined anterior-posterior spinal fusion. We then reviewed postoperative complications among each of the subgroups.

RESULTS

Forty-five patients were determined to have a FLM fracture over a 10-year span. The nonoperative group had n=25, and evidently, there were no patients that crossed over to surgery due to subluxation of the cervical spine after nonoperative treatment. The operative treatment group had n=20, and consisted of 6 anterior, 12 posterior, and 2 combined approaches. Complications appeared in posterior and combined groups. Two hardware failures were noted in the posterior group, along with two postoperative respiratory complications in the combined group. No complications were observed for the anterior group.

CONCLUSIONS

None of the nonoperative patients in this study required further operation or management of their injury, indicating nonoperative treatment as a potentially satisfactory management for appropriately selected FLM fractures.

Reduction of Lower Cervical Facet Dislocation: A Review of All Techniques

Objective: The surgical treatment of lower cervical facet dislocation is controversial. Great advancements on reduction techniques for lower cervical facet dislocation have been made in the past decades. However, there is no article reviewing all the reduction techniques yet. The aim is to review the evolution and advancements of the reduction techniques for lower cervical facet dislocation.Methods: The application of all reduction techniques for lower cervical facet dislocation, including closed reduction, anterior-only, posterior-only, and combined approach reduction, is reviewed and discussed. Recent advancements on the novel techniques of reduction are also described. The principles of various techniques for reduction of cervical facet dislocation are described in detail.Results: All reduction techniques are useful. The anterior-only surgical approach appears to be the most popular approach. Moreover, many novel or modified reduction and fixation methods have been introduced in recent years.Conclusion: The selection of surgical approach depends on a combination of factors, including surgeon preference, patient factors, injury morphology, and inherent advantages and disadvantages of any given approach.

Unilateral Cervical Facet Fractures: Relevance of Acute Disc Injury in Conservative Treatment Failure

STUDY DESIGN

Case-control study.

PURPOSE

Analyze association between imaging factors related to the failure of conservative treatment in isolated subaxial cervical facet fractures.

OVERVIEW OF LITERATURE

Facet fracture (F1, F2, and F3 AOSpine) may be stable or unstable depending on clinical and imaging variables, which are not well established. As a result, differences in fracture management lead to differences in surgical or conservative indications, and there is no evidence to predict conservative treatment failure.

METHODS

Patients were categorized into two groups: six patients (16.2%) with conservative treatment failure (defined as the appearance of neurological symptoms, listhesis >3.5 mm, kyphotic deformation >11°, and/or non-union), and 31 patients (83.7%) with successful conservative management (defined as complete consolidation confirmed by computed tomography [CT] at the 6-month followup). All participants were fitted with rigid collars of the Miami type, and standardized follow-up was performed until consolidation or failure. CT and magnetic resonance imaging (MRI) was used to examine imaging characteristics. Sagittal balance parameters were assessed using CT, and signs of acute disc injury, prevertebral edema, facet synovitis, and interspinous hyperintense signal were assessed using MRI.

RESULTS

Thirty-seven patients were diagnosed with unilateral cervical facet fractures between 2009 and 2020. In this sample, acute disc injury had a significative association to failure of conservative treatment in F2 and F3 AOSpine facet fractures, 100% of the failure group presented with traumatic disc injury compared to 9.7% of the successful group, for the other variables: prevertebral edema, 83.7% vs. 41.9%; facet synovitis, 100% vs. 77.4%; and interspinous hyperintensity, 71.4% vs. 38.7%, respectively. With conservative management, all F1 fractures healed successfully. Conservative treatment failed in 20% of F2 fractures and 50% of F3 fractures, respectively. In terms of cervical sagittal balance parameters, there were no significant differences between groups.

CONCLUSIONS

Conservative management was successful in all F1 fractures. In F2 and F3 types, there was a significant association between acute disc injury and conservative treatment failure.

Contiguous-Level Unilateral Cervical Spine Facet Dislocation—A Report of a Less Discussed Subtype

Unilateral facet dislocation of subaxial cervical spine trauma is characterized by dislocation of inferior facet of superior vertebra over the superior facet of inferior vertebra. The injury is due to high-velocity trauma and associated with instability of spinal column. Such unilateral facet dislocations occurring at multiple adjacent levels for some reason are not reported or studied frequently. We have reported two cases of multiple-level dislocation of unilateral facets managed in our hospital with a review of available literature. The injury occurs as one side of the motion segment translates and rotates around an intact facet on the contralateral side. The major mechanism of injury is distractive flexion injury with axial rotation component. The injury is associated with instability secondary to loss of the discoligamentous complex. In cases with multiple-level dislocations of unilateral cervical facets, there are multiple mechanisms associated with significant neurological injury and most of them succumb at the site of injury. Only three other cases are available in English language literature. The neurological outcome is invariably poor. Multiple-level facet dislocations of subaxial cervical spine are reported sparsely in literature. We suspect that due to high-velocity nature of these injuries, most of them succumb soon after injury and not often reported. This article reports two cases of contiguous-level unilateral facet dislocation of subaxial cervical spine with associated injuries and the outcomes with review of literature.

Subaxial cervical articular process subluxation and dislocation: Cervical locked facet injuries in dogs

OBJECTIVE

To describe neurologic signs, diagnostic imaging findings, potential treatments, and outcomes in dogs with subaxial cervical articular process subluxation and dislocation, or a "locked facet."

STUDY DESIGN

Retrospective case series.

ANIMALS

Ten client-owned dogs.

METHODS

Dogs with a diagnosis of cervical locked facets were identified through medical records and imaging reports searches. Data on presenting signs, diagnostic findings, treatment, and outcome were recorded.

RESULTS

All cases were small or toy-breed dogs with preceding trauma. Four dogs were tetraplegic with intact pain perception, five were nonambulatory tetraparetic, and one was ambulatory tetraparetic, with half of the tetraparetic dogs having worse motor function in the thoracic limbs. The only sites affected were C5/6 (n = 6) and C6/7 (n = 4). All dogs had unilateral dorsal displacement of the cranial articular process of the caudal vertebra relative to the caudal articular process of the cranial vertebra at the luxation site. Five dogs were treated surgically, three by external coaptation, one by restriction, and one was euthanized the day after diagnosis. All dogs with outcome data (n = 8) became ambulatory. Nonambulatory dogs returned to ambulation in a median of 4 weeks (IQR 1-12; range 1-28).

CONCLUSION

In these dogs, locked facet injuries affected the caudal cervical vertebrae in small breeds and could be identified on imaging through the presence of dorsal displacement of a cranial articular process. Our small cohort had a functional recovery regardless of treatment.

CLINICAL SIGNIICANCE

Locked facet injuries should be a differential for small or toy-breed dogs with a cervical myelopathy secondary to trauma.

Estimating Facet Joint Apposition with Specimen-Specific Computer Models of Subaxial Cervical Spine Kinematics

Computational models of experimental data can provide a noninvasive method to estimate spinal facet joint biomechanics. Existing models typically consider each vertebra as one rigid-body and assume uniform facet cartilage thickness. However, facet deflection occurs during motion, and cervical facet cartilage is nonuniform. Multi rigid-body computational models were used to investigate the effect of specimen-specific cartilage profiles on facet contact area estimates. Twelve C6/C7 segments underwent non-destructive intervertebral motions. Kinematics and facet deflections were measured. Three-dimensional models of the vertebra and cartilage thickness estimates were obtained from pre-test CT data. Motion-capture data was applied to two model types (2RB: C6, C7 vertebrae each one rigid body; 3RB: left and right C6 posterior elements, and C7 vertebrae, each one rigid body) and maximum facet mesh penetration was compared. Constant thickness cartilage (CTC) and spatially-varying thickness cartilage (SVTC) profiles were applied to the facet surfaces of the 3RB model. Cartilage apposition area (CAA) was compared. Linear mixed-effects models were used for all quantitative comparisons. The 3RB model significantly reduced penetrating mesh elements by accounting for facet deflections (p = 0.001). The CTC profile resulted in incongruent facet articulation, whereas realistic congruence was observed for the SVTC profile. The SVTC profile demonstrated significantly larger CAA than the CTC model (p < 0.001).

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.

Accuracy and reliability of the AO Spine subaxial cervical spine classification system grading subaxial cervical facet injury morphology

PURPOSE

A classification system was recently developed by the international association AO Spine for assessing subaxial cervical spine fractures. Significant variability exists between users of the facet component, which consists of four morphological types (F1-F4). The primary aims of this study were to assess the diagnostic accuracy and reliability of this new system's facet injury morphological classifications.

METHODS

A survey consisting of 16 computed tomography (CT) scans of patients with cervical facet fractures was distributed to spine surgeon members of AO Spine Latin America. To provide a gold standard diagnosis for comparison, all 16 injuries had been classified previously by six co-authors and only were included after total consensus was achieved. Demographic and surgical practice characteristics of all respondents were analyzed, and diagnostic accuracy calculated. Inter- and intra-observer agreement rates were calculated across two survey rounds, conducted one month apart.

RESULTS

A total of 135 surgeons completed both surveys, among whom the mean age was 41.6 years (range 26-71), 130 (96.3%) were men, and 83 (61.5%) were orthopedic surgeons. The mean time in practice as a spine surgeon was 9.7 years (1-30). The overall diagnostic accuracy of all responses was 65.4%. Inter-observer and intra-observer agreement rates for F1/F2/F3/F4 were 55.4%/47.6%/64.0%/94.7% and 60.0%/49.1%/58.0%/93.0%, respectively.

CONCLUSION

This study evaluates the AO Spine Classification System specifically for facet injuries involving the subaxial cervical spine in a large sample of spine surgeons. There was significant variability in diagnostic accuracy for F1 through F3-type fractures, whereas almost universal agreement was achieved for F4-type injuries.

Management of Unilateral Cervical Facet Joint Dislocation in Neurologically Intact Patients: Results of an Ao Spine latin American Survey

BACKGROUND

The treatment of unilateral CFD in patients without neurologic deficits remains controversial, especially in the choice of the best surgical approach. Our objective is to determine the way spine surgeons from Latin America manage this condition.

METHODS

A survey regarding management and surgical strategies was conducted by the AO Spine Latin American Trauma Study Group considering the treatment of unilateral CFD.

RESULTS

All AO Spine Latin American Trauma Study Group members were sent a link to the survey, among whom 285 replied, with 197 respondents answering all the questions. Nonsurgical management was considered by 25% of the surgeons. The majority stated that magnetic resonance imaging is necessary (65%) to treat this type of patient. A posterior approach was preferred by 44%, an anterior approach by 29%, and a combined approach by 25%, while 2.2% did not answer. Traction was not used by the majority of respondents (62%). In the setting of an anterior disk herniation, the majority of surgeons preferred to employ an anterior (45%) or combined (44%) approach versus an isolated posterior approach (only 0.5%). Comparing early versus late cervical trauma, fewer surgeons adopted an isolated anterior approach with the latter (29% vs. 15%).

CONCLUSIONS

Wide variations exist in the management of unilateral CFD by Latin American surgeons, with early injuries generally treated using either an anterior or posterior approach and treated early but after an MRI, while a combined approach is used more commonly with late injuries. Either an anterior or combined approach is used when disk herniation is present.

The influence of timing of surgery in the outcome of spinal cord injury without radiographic abnormality (SCIWORA)

Background

Spinal cord injury without radiographic abnormality (SCIWORA) is a rare traumatic myelopathy. Although surgery is one of the most important treatments, the surgery for SCIWORA is controversial, especially the time of surgery is a topic of controversy. Here, we investigate the effects of difference in duration from injury to surgery on the outcome of SCIWORA.

Methods

This retrospective study was performed in all patients with spinal cord injury admitted to the Third Affiliated Hospital of Hebei Medical University from January 2013 to April 2017. Fifty-seven patients who met the study requirements were divided into 3 groups according to the duration from injury to surgery. Group A (surgery within 3 days of injury) had 18 patients, group B (surgery within 3–7 days) had 18 patients, and group C (surgery later than 7 days) had 21 patients. All the groups were compared with Mann–Whitney U test; the functional improvement of spinal cord was compared and analyzed using the ASIA sports score and ASIA Impairment Scale (AIS).

Results

There was a significant improvement in the long-term AIS (final follow-up) in all the 3 groups compared to before surgery. The final follow-up recovery rate of group C was worse than group A and group B. The curative effect of operation within 7 days was significantly better than the surgery done 7 days later. The recovery rate of group C was worse than group A and B. The ASIA sports score showed that recovery was quicker in the early stage and slow in the later stage.

Conclusions

The optimal schedule of surgical treatment was 3–7 days after injury, which can significantly improve the short-term and long-term follow-up effects. Longer the time to surgery from the time of injury, the worse was the prognosis.

Clinical Outcomes of Cervical Facet Fractures Treated Nonoperatively With Hard Collar or Halo Immobilization

STUDY DESIGN

Retrospective review.

OBJECTIVES

To evaluate the rate of nonoperative treatment failure for cervical facet fractures while secondarily validating computed tomography-based criteria proposed by Spector et al for identifying risk of failure of nonoperative management.

METHODS

Single-level or multilevel unilateral cervical facet fractures from 2007 to 2014 were included. Exclusion criteria included spondylolisthesis, dislocated or perched facets, bilateral facet fractures at the same level, floating lateral mass, thoracic or lumbar spine injuries, or spinal cord injury. Patients were placed into 3 groups for evaluation: immediate operative management, successful nonoperative management, and failed nonoperative treatment requiring surgical intervention.

RESULTS

Eighty-eight patients (106 facets) were included. Twenty-one patients underwent operative treatment with anterior cervical discectomy and fusion or posterior spinal instrumentation and fusion without any failures. Sixty-seven of these patients were treated nonoperatively with either a hard collar (n = 62) or halo vest (n = 5). Eleven patients failed nonoperative treatment (16.4%), all with an absolute fracture height of at least 1 cm and 40% involvement of the absolute height of the lateral mass. Of the 56 patients successfully treated through nonoperative measures, 8 (14.3%) had fracture measurements exceeding both operative parameters.

CONCLUSION

We conclude that it is safe and appropriate for patients with unilateral cervical facet fractures to receive a trial period of nonoperative management. However, patients who weigh over 100 kg, have comminuted fractures, or have radiographic measurements outside of the proposed computed tomography criteria for nonoperative treatment should be educated on the risks of treatment failure.

The effect of axial compression and distraction on cervical facet mechanics during anterior shear, flexion, axial rotation, and lateral bending motions

The subaxial cervical facets are important load-bearing structures, yet little is known about their mechanical response during physiological or traumatic intervertebral motion. Facet loading likely increases when intervertebral motions are superimposed with axial compression forces, increasing the risk of facet fracture. The aim of this study was to measure the mechanical response of the facets when intervertebral axial compression or distraction is superimposed on constrained, non-destructive shear, bending and rotation motions. Twelve C6/C7 motion segments (70 ± 13 yr, nine male) were subjected to constrained quasi-static anterior shear (1 mm), axial rotation (4°), flexion (10°), and lateral bending (5°) motions. Each motion was superimposed with three axial conditions: (1) 50 N compression; (2) 300 N compression (simulating neck muscle contraction); and, (3) 2.5 mm distraction. Angular deflections, and principal and shear surface strains, of the bilateral C6 inferior facets were calculated from motion-capture data and rosette strain gauges, respectively. Linear mixed-effects models (α = 0.05) assessed the effect of axial condition. Minimum principal and maximum shear strains were largest in the compressed condition for all motions except for maximum principal strains during axial rotation. For right axial rotation, maximum principal strains were larger for the contralateral facets, and minimum principal strains were larger for the left facets, regardless of axial condition. Sagittal deflections were largest in the compressed conditions during anterior shear and lateral bending motions, when adjusted for facet side.

Preinjury Patient Characteristics and Postinjury Neurological Status Are Associated With Mortality Following Spinal Cord Injury

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

This study investigates the association between spinal cord injuries (SCI) and post-injury mortality.

SUMMARY OF BACKGROUND DATA

SCIs) are severe conditions treated in the acute trauma setting. Owing to neurological deficits, unstable spinal columns, and associated injuries, these patients often have complex inpatient hospitalizations with significant morbidity and mortality. It is assumed that a high rate of postinjury mortality would follow such severe injuries; however, the effect of SCI and its treatment on predictors of longevity remain largely unknown.

METHODS

Patients seen at a regional referral center for SCI were reviewed from a prospectively maintained database. Four hundred and twenty-six patients with SCI and varying degrees of injury between 2004 and 2009 were collected. Injury characteristics, including injury severity score, level of SCI, and type of SCI were retrieved. To determine independent predictors of 5-year mortality, a logistic regression using patient and injury characteristics at the time of presentation was performed.

RESULTS

Average age was 47.4 years (range: 14-95), and 74.5% (318/426) were male. Half of the cohort sustained low-energy mechanisms of injury (220/426; 52.4%). The 30-day, 90-day, 1-year, 2-year, and 5-year mortality rates in the SCI cohort were 6.6% (28/426), 9.2% (39/426), 12.0% (51/426), 15.0% (64/426), and 17.8%, respectively (76/426). Logistic regression demonstrated that increasing age (B = 1.06, P < 0.001), increasing ICU length-of-stay (B = 1.06; P = 0.002), decreased motor score at presentation (B = 0.98; P = 0.004), and lack of surgical intervention (B = 0.38; P < 0.001) were independent predictors of mortality at 5 years.

CONCLUSION

There is substantial mortality associated with SCI. A significant proportion of the mortalities occurred acutely after injury. Mortality was associated with neurological deficit and severity of injury, as well as with preinjury patient characteristics. To combat this high rate of death, efforts are needed to address the concomitant disease processes associated with neurological deficits.

LEVEL OF EVIDENCE

3.

Facet Joints of the Spine: Structure–Function Relationships, Problems and Treatments, and the Potential for Regeneration

The zygapophysial joint, a diarthrodial joint commonly referred to as the facet joint, plays a pivotal role in back pain, a condition that has been a leading cause of global disability since 1990. Along with the intervertebral disc, the facet joint supports spinal motion and aids in spinal stability. Highly susceptible to early development of osteoarthritis, the facet is responsible for a significant amount of pain in the low-back, mid-back, and neck regions. Current noninvasive treatments cannot offer long-term pain relief, while invasive treatments can relieve pain but fail to preserve joint functionality. This review presents an overview of the facet in terms of its anatomy, functional properties, problems, and current management strategies. Furthermore, this review introduces the potential for regeneration of the facet and particular engineering strategies that could be employed as a long-term treatment.

Anterior Fixation of Floating Facet Fractures in the Cervical Spine: A Prospective Case Series and Biomechanical Analysis

Background

Unilateral fractures involving complete separation of the lateral mass from the vertebra and lamina (floating lateral mass fractures) are a unique subset of cervical spine fractures. These injuries are at significant risk for displacement without operative fixation. Posterior fixation has proven to facilitate adequate fusion. However, there are few data supporting the clinical success of single-level anterior fixation.

Methods

Biomechanical evaluation of floating lateral mass fractures and a consecutive case series of patients with rotationally unstable floating lateral mass fractures treated with anterior fixation using an integrated cage-screw device with anterior plating (ICSD) was performed. The study comprised 7 fresh human cadaver cervical spines (C2-C7), and 11 patients with floating lateral mass fractures. Segmental flexibility testing evaluating axial rotation, flexion/extension, and lateral bending was performed in a cadaveric model after 2 types of single-level anterior fixation and 1 type of 2-level posterior fixation. Eleven patients with a floating lateral mass fracture of the cervical spine underwent anterior fixation with an ICSD. Radiographs and clinical outcomes were retrospectively reviewed.

Results

Compared with the intact condition, posterior instrumentation significantly (P < .05) reduced range of motion (ROM) in all 3 planes; anterior fixation with cervical plate and interbody spacer significantly reduced ROM in lateral bending only; and the ICSD significantly reduced ROM in flexion/extension and lateral bending. In the clinical arm, there were no long-term complications, subsidence >2 mm, failure of fixation, reoperation, pseudoarthrosis, or listhesis at final follow-up.

Conclusions

The addition of 2 screws placed through a cervical cage can improve anterior fixation in a human cadaveric model of floating lateral mass fractures. Early clinical results demonstrate a low complication rate and a high rate of healing with single-level anterior fixation using this technique.

Management of Severe Lower Cervical Facet Dislocation without Vertebral Body Fracture Using Skull Traction and an Anterior Approach

BACKGROUND Cervical facet dislocation is the anterior displacement of one cervical vertebral body on another. The aim of this study was to evaluate the clinical efficacy of skull traction through an anterior cervical approach in the treatment of severe lower cervical facet dislocation without vertebral body fracture. MATERIAL AND METHODS Forty subjects with severe lower cervical facet dislocation, without vertebral body fracture, were treated between February 2010 and December 2013. Road traffic accident was the primary cause of injury. Patients presented with dislocated segments in C3-C4 (n=4), C4-C5 (n=4), C5-C6 (n=12), and C6-C7 (n=20). Twenty-six patients had unilateral facet dislocation, and 14 patients had bilateral facet dislocation. Spinal injuries were graded according to the American Spinal Injury Association (ASIA) impairment scale and included grade A (eight cases), grade B (six cases), grade C (six cases), grade D (12 cases), and grade E (eight cases). The mean follow-up time was 4.2 years. RESULTS All procedures were completed successfully, with no major complications. Postoperative X-rays showed satisfactory height for the cervical intervertebral space and recovery of the vertebral sequence. Bone fusion was completed within four to six months after surgery. Surgery significantly improved neurological function in all patients. CONCLUSIONS Skull traction and an anterior approach can be used to successfully treat severe lower cervical facet dislocation, obtaining complete decompression, good reduction, and maintenance of intervertebral height with retention of the physiological curvature of the cervical spine.

Traumatic subaxial cervical facet subluxation and dislocation: epidemiology, radiographic analyses, and risk factors for spinal cord injury

BACKGROUND CONTEXT

Distractive flexion injuries (DFIs) of the subaxial cervical spine are major contributors to spinal cord injury (SCI). Prompt assessment and early intervention of DFIs associated with SCI are crucial to optimize patient outcome; however, neurologic examination of patients with subaxial cervical injury is often difficult, as patients commonly present with reduced levels of consciousness. Therefore, it is important to establish potential associations between injury epidemiology and radiographic features, and neurologic involvement.

PURPOSE

The aims of this study were to describe the epidemiology and radiographic features of DFIs presenting to a major Australian tertiary hospital and to identify those factors predictive of SCI. The agreement and repeatability of radiographic measures of DFI severity were also investigated.

STUDY DESIGN/SETTING

This is a combined retrospective case-control and reliability-agreement study.

PATIENT SAMPLE

Two hundred twenty-six patients (median age 40 years [interquartile range = 34]; 72.1% male) who presented with a DFI of the subaxial cervical spine between 2003 and 2013 were reviewed.

OUTCOME MEASURES

The epidemiology and radiographic features of DFI, and risk factors for SCI were identified. Inter- and intraobserver agreement of radiographic measurements was evaluated.

METHODS

Medical records, radiographs, and computed tomography and magnetic resonance imaging scans were examined, and the presence of SCI was evaluated. Radiographic images were analyzed by two consultant spinal surgeons, and the degree of vertebral translation, facet apposition, spinal canal occlusion, and spinal cord compression were documented. Multivariable logistic regression models identified epidemiology and radiographic features predictive of SCI. Intraclass correlation coefficients (ICCs) examined inter- and intraobserver agreement of radiographic measurements.

RESULTS

The majority of patients (56.2%) sustained a unilateral (51.2%) or a bilateral facet (48.8%) dislocation. The C6-C7 vertebral level was most commonly involved (38.5%). Younger adults were over-represented among motor-vehicle accidents, whereas falls contributed to a majority of DFIs sustained by older adults. Greater vertebral translation, together with lower facet apposition, distinguished facet dislocation from subluxation. Dislocation, bilateral facet injury, reduced Glasgow Coma Scale, spinal canal occlusion, and spinal cord compression were predictive of neurologic deficit. Radiographic measurements demonstrated at least a "moderate" agreement (ICC>0.4), with most demonstrating an "almost perfect" reproducibility.

CONCLUSIONS

This large-scale cohort investigation of DFIs in the cervical spine describes radiographic features that distinguish facet dislocation from subluxation, and associates highly reproducible anatomical and clinical indices to the occurrence of concomitant SCI.

Kinematics of the Cervical Spine After Unilateral Facet Fracture: An In Vitro Cadaver Study

STUDY DESIGN

Biomechanical study utilizing human cadaveric cervical spines.

OBJECTIVE

To quantitatively assess the effects on intervertebral motion of isolated unilateral cervical facet fracture, and after disruption of the intervertebral disc at the same level.

SUMMARY OF BACKGROUND DATA

Clinical evidence has indirectly suggested that cervical facet fractures involving 40% of the height of the lateral mass can cause instability of the involved segment. No study to date has demonstrated the kinematic effects of such an injury in a cadaveric model of the cervical spine.

METHODS

Nine six-segment cervical spines were defrosted and fixated to a spine motion simulator capable to apply unconstrained bending moments in the three anatomical planes. The spines were subjected to a maximum torque of 2 N · m in flexion, extension, left and right lateral bending, and of 4 N · m in left and right axial rotation. Each spine was tested in the intact configuration (INTACT), and following two increasing degrees of injury at C4-C5: fracture of the facet (CF1), and CF1 with disruption of the intervertebral disc at the same level (CF2). Intervertebral kinematics was tracked via clusters of active markers fixated on each vertebra. Differences in kinematics between INTACT and the two injured configurations were assessed via one-way Analysis of Variance (P < 0.05).

RESULTS

No significant differences were detected between INTACT and CF1 across all kinematic parameters (P > 0.05) at C4-C5. CF2, however, resulted in significant increase of flexion, left axial rotation, and left lateral bending with respect to INTACT (flexion at C4-C5: INTACT = 8.7° ± 3.5°; CF2 = 14.3 ± 5.7; P < 0.05).

CONCLUSION

Our findings suggest that superior articular facet fractures alone involving 40% of the lateral mass may not necessarily result in intervertebral instability under physiologic loading conditions. The addition of partial injury to the intervertebral disc, however, resulted in statistically significant increase in angular displacement.

LEVEL OF EVIDENCE

N /A.

Risk Factors for Failure of Nonoperative Treatment for Unilateral Cervical Facet Fractures

Study Design

Retrospective clinical study.

Purpose

The purpose of this study was to determine what percentage of patients who underwent nonoperative management of unilateral non-displaced or minimally displaced facet fractures progressed radiographically and to determine what percentage of patients required surgical intervention and to identify risk factors for failure of conservative management.

Overview of Literature

According to most commonly used classification systems, unilateral, non-and minimally displaced facet fractures are be amendable to nonoperative management.

Methods

A retrospective review of the Trauma Registry of a Level I trauma center was performed to identify all patients diagnosed with a non- or minimally displaced unilateral facet fracture which was managed nonoperatively. Several demographic variables and clinical outcomes were recorded. Using computed tomography scanning and plain radiographs, fracture pattern, listhesis, displacement, angle and percentage of the facet that included the fracture were determined. Radiographic progression was defined as the occurrence of listhesis of more than 10% of the anterior-posterior dimensions of the inferior vertebral body during radiographic follow-up. Failure of conservative management was defined as a patient requiring surgical intervention after initially being managed nonoperatively.

Results

Seventy-four patients were included. Fifteen patients (20%) progressed radiographically. However, only 2 developed radicular symptoms and none developed myelopathy or other catastrophic cord related symptoms. Seven patients (9%) underwent surgery. Indications for surgery included significant radiographic progression and/or radicular symptoms. Risk factors for failure of conservative management included presence of radiculopathy at the time of presentation, a higher body mass index, increased Injury Severity Score, greater initial fracture displacement and more than 2 mm of listhesis.

Conclusions

Patients with non-displaced or minimally displaced facet fractures who do not have neurological symptoms at the time of presentation can safely be managed conservatively with careful observation and follow-up.

Management of Acute Unilateral Nondisplaced Subaxial Cervical Facet Fractures

BACKGROUND

Few studies have focused on the management of patients with nondisplaced cervical facet fractures.

OBJECTIVE

To determine the rate of successful nonoperative management and risk factors for instability in patients with acute traumatic, unilateral, nondisplaced cervical facet fractures.

METHODS

We reviewed patients with single or multilevel unilateral nondisplaced or minimally displaced subaxial cervical facet fractures between 2008 and 2014. Facet fractures were classified as type A1 fractures: superior facet fracture of caudal vertebra; type A2: inferior facet fracture of rostral vertebral; and type A3: floating lateral mass (fracture of pedicle and vertical laminar fracture). All patients were given a trial of nonoperative management with external immobilization using a hard cervical collar. Follow-up clinical data and cervical spine radiographs were analyzed to determine factors associated with instability.

RESULTS

Thirty-five patients (34 males, mean age 40.2 ± 2.4 yr) were reviewed. The mean follow-up duration was 2.7 ± 0.4 mo. The distribution of fracture types was type A1 (n = 15), type A2 (n = 4), type A3 (n = 5), type A1 and A2 fractures (n = 10), and type A1 and A3 fractures (n = 1). Nonoperative management was successful in 29 patients (82.9%), and 6 patients developed instability requiring surgery. All patients who failed nonoperative management had associated injuries suggesting a more severe mechanism of injury. No significant association was found between the type of facet fracture and outcome (Fisher's exact test, P = .18).

CONCLUSION

In our series, more than 80% of the patients with unilateral, nondisplaced cervical facet fractures underwent successful nonoperative management in the short term.

Anterior Surgical Fixation for Cervical Spine Flexion-Distraction Injuries

BACKGROUND

Optimal surgical management for flexion-distraction cervical spine injuries remains controversial with current guidelines recommending anterior, posterior, and circumferential approaches. Here, we determined the incidence of and examined risk factors for clinical and radiographic failure in patients with 1-segment cervical distraction injuries having undergone anterior surgical fixation.

METHODS

A retrospective review of 57 consecutive patients undergoing anterior fixation for subaxial flexion-distraction cervical injuries between 2008 and 2012 at our institution was performed. The primary outcome was the number of patients requiring additional surgical stabilization and/or radiographic failure. Data collected included age, gender, mechanism and level of injury, facet pattern injury, and vertebral end plate fracture.

RESULTS

A total of 6 patients failed clinically and/or radiographically (11%). Four patients (7%) required additional posterior fixation. Although 2 other patients identified met radiographic failure criteria, at follow-up they had fused radiographically, were stable clinically, and no further treatment was pursued. Progressive kyphosis and translation were found to be significantly correlated with need for revision (P < 0.05 and P = 0.02, respectively). No differences were identified for all other clinical and radiologic factors assessed, including unilateral or bilateral facet injury, facet fracture, and end plate fracture.

CONCLUSION

This study contributes to the growing body of evidence supporting anterior fixation alone for flexion-distraction injuries. Findings suggest that current measurements of radiographic failure including segmental translation and kyphosis may predict radiographic failure and need for further surgical stabilization in some patients. Future follow-up studies assessing for independent risk factors for anterior approach failure with a validated predictive scoring model should be considered.

Traumatic cervical spine fractures in the adult

This article reviews fractures of the cervical spine, highlighting the pertinent goals of initial management, the indications for different imaging modalities and the different fracture patterns. Basic principles of management of these different fracture patterns are outlined.

Management of Sub-axial Cervical Spine Injuries

Sub-axial cervical spine injuries are commonly seen in patients with blunt trauma. They may be associated with spinal cord injury resulting in tetraplegia and severe permanent disability. Immobilization of the neck, maintenance of blood pressure and oxygenation, rapid clinical and radiological assessment of all injuries, and realignment of the spinal column are the key steps in the emergency management of these injuries. The role of intravenous methylprednisolone administration in acute spinal cord injuries remains controversial. The definitive management of these injuries is based upon recognition of the fracture pattern, assessment of the degree of instability, the presence or absence of neurologic deficit, and other patient related factors that may influence the outcome. Nonoperative treatment comprises of some form of external immobilization for 8 to 12 weeks, followed by imaging to assess fracture healing, and to rule out instability. The goals of surgery are realignment of the vertebral column, decompression of the neural elements and instrumented stabilization.

Pedicolaminar Fracture-Dislocation

A 28-year-old man presented to a level 1 trauma center with significant cervical spine pain after sliding into third base during a softball game. He struck his head on the thigh of the defensive player and had immediate pain in his neck and arm. He reported no loss of consciousness, no transient tetraplegia/paraplegia, and no loss of bowel and bladder control. After initial imaging, enhanced computed tomography scans were obtained.

Outcome Instruments in Spinal Trauma Surgery: A Bibliometric Analysis

Study Design Literature review. Objective To identify outcomes instruments used in spinal trauma surgery over the past decade, their frequency of use, and usage trends. Methods Five top orthopedic journals were reviewed from 2004 to 2013 for clinical studies of surgical intervention in spinal trauma that reported patient-reported outcome instruments use or neurologic function scale use. Publication year, level of evidence (LOE), and outcome instruments were collected for each article and analyzed. Results A total of 58 studies were identified. Among them, 26 named outcome instruments and 7 improvised questionnaires were utilized. The visual analog scale (VAS) for pain was used most frequently (43.1%), followed by the Short Form 36 (34.5%), Frankel grade scale (25.9%), Oswestry Disability Index (20.7%) and American Spinal Injury Association Impairment Scale (15.5%). LOE 4 was most common (37.9%), and eight LOE 1 studies were identified (10.3%). Conclusions The VAS pain scale is the most common outcome instrument used in spinal trauma. The scope of this outcome instrument is limited, and it may not be sufficient for discriminating between more and less effective treatments. A wide variety of functional measures are used, reflecting the need for a disease-specific instrument that accurately measures functional limitation in spinal trauma.

Floating Lateral Mass Fractures of the Cervical Spine

STUDY DESIGN

Level I trauma center case series.

OBJECTIVE

The purpose of this study was (i) to characterize the floating lateral mass (FLM) fracture with the mechanism of injury, anatomical injury pattern, associated vascular injuries, neurological deficits, and key radiographic features; and (ii) to better understand the most effective method of treatment.

SUMMARY OF BACKGROUND DATA

An uncommon and poorly described subset of unilateral lateral mass fractures is FLM with fractures of the adjacent pedicle and lamina.

METHODS

Prospectively collected trauma registries were assessed to identify all patients with FLM fractures involving C3 to C7 between January 1, 2007 and December 31, 2012.

RESULTS

After institutional review board approval, 60 consecutive cases were identified from the trauma registries. The mean follow-up was 9 months (range 0-42 months). The most common level was C6. The most common mechanism of injury was a high speed motor vehicle accident (45%). Radiographic rotational displacement manifested as an anterolisthesis. CT showed facet joint widening at the level above and below in 63%. Vertebral artery injuries occurred in 22%. Neurological deficits occurred as radiculopathy in 38% and spinal cord injury in 18%. All eight patients, who were treated nonoperatively, developed subluxation despite external immobilization and six patients required surgery. Of the 58 patients treated operatively, 31 (53%) patients underwent a 2 level Anterior Cervical Discectomy and Fusion (ACDF) alone. Nine (15%) patients had one level ACDF, with 83% demonstrating radiographic failure. Posterior fusion alone or combined with ACDF/corpectomy was performed in 6 patients (10%) and 7 patients (12%), respectively.

CONCLUSION

A FLM fracture results from a high energy injury and involves two motion segments. Vertebral artery injuries and neurological deficits frequently occur. Magnetic Resonance demonstrates a significant disc injury in 81% of patients, usually at the lower level. Two level ACDF or Posterior Spinal Instrumented Fusion are effective means of treatment.

LEVEL OF EVIDENCE

3.

Influence of graft size on spinal instability with anterior cervical plate fixation following in vitro flexion-distraction injuries

BACKGROUND CONTEXT

Anterior cervical discectomy and fusion with plating (ACDFP) is commonly used for the treatment of distractive-flexion cervical spine injuries. Despite the prevalence of ACDFP, there is little biomechanical evidence for graft height selection in the unstable trauma scenario.

PURPOSE

This study aimed to investigate whether changes in graft height affect the kinematics of instrumented ACDFP C5-C6 motion segments in the context of varying degrees of simulated facet injuries.

STUDY DESIGN

In vitro cadaveric biomechanical study was used as study design.

METHODS

Seven C5-C6 motion segments were mounted in a custom spine simulator and taken through flexibility testing in axial rotation, lateral flexion, and flexion-extension. Specimens were first tested intact, followed by a standardized injury model (SIM) for a unilateral facet perch at C5-C6. The stability of the ACDFP approach was then examined with three graft heights (computed tomography-measured disc space height, disc space height undersized by 2.5 mm, and disc space height oversized by 2.5 mm) within three increasing unstable injuries (SIM, an added unilateral facet fracture, and a simulated bilateral facet dislocation injury).

RESULTS

In all motions, regardless of graft size, ACDFP reduced range of motion (ROM) from the SIM state. For flexion-extension, the oversized graft had a larger decrease in ROM compared with the other graft sizes (p<.05). Between graft sizes and injury states, there were a number of interactions in axial rotation and lateral flexion, where specifically in the most severe injury, the undersized graft had a larger decrease in ROM than the other two sizes (p<.05).

CONCLUSIONS

This study found that graft size did affect the kinematic stability of ACDFP in a series of distractive-flexion injuries; the undersized graft resulted in both facet overlap and locking of the uncovertebral joints leading to decreased ROM in lateral bending and axial rotation, whereas an oversized graft provided larger ROM decreases in flexion-extension. As such, a graft that engages the uncovertebral joint may be more advantageous in providing a rigid environment for fusion with ACDFP.

Treatment of isolated cervical facet fractures: a systematic review

OBJECT

In this clinically based systematic review of cervical facet fractures, the authors’ aim was to determine the optimal clinical care for patients with isolated fractures of the cervical facets through a systematic review.

METHODS

A systematic review of nonoperative and operative treatment methods of cervical facet fractures was performed. Reduction and stabilization treatments were compared, and analysis of postoperative outcomes was performed. MEDLINE and Scopus databases were used. This work was supported through support received from the Association for Collaborative Spine Research and AOSpine North America.

RESULTS

Eleven studies with 368 patients met the inclusion criteria. Forty-six patients had bilateral isolated cervical facet fractures and 322 had unilateral isolated cervical facet fractures. Closed reduction was successful in 56.4% (39 patients) and 63.8% (94 patients) of patients using a halo vest and Gardner-Wells tongs, respectively. Comparatively, open reduction was successful in 94.9% of patients (successful reduction of open to closed reduction OR 12.8 [95% CI 6.1–26.9], p < 0.0001); 183 patients underwent internal fixation, with an 87.2% success rate in maintaining anatomical alignment. When comparing the success of patients who underwent anterior versus posterior procedures, anterior approaches showed a 90.5% rate of maintenance of reduction, compared with a 75.6% rate for the posterior approach (anterior vs posterior OR 3.1 [95% CI 1.0–9.4], p = 0.05).

CONCLUSIONS

In comparison with nonoperative treatments, operative treatments provided a more successful outcome in terms of failure of treatment to maintain reduction for patients with cervical facet fractures. Operative treatment appears to provide superior results to the nonoperative treatments assessed.

Detecting Facet Joint and Lateral Mass Injuries of the Subaxial Cervical Spine in Major Trauma Patients

STUDY DESIGN

Radiologic imaging measurement study.

PURPOSE

To assess the accuracy of detecting lateral mass and facet joint injuries of the subaxial cervical spine on plain radiographs using computed tomography (CT) scan images as a reference standard; and the integrity of morphological landmarks of the lateral mass and facet joints of the subaxial cervical spine.

OVERVIEW OF LITERATURE

Injuries of lateral mass and facet joints potentially lead to an unstable subaxial cervical spine and concomitant neurological sequelae. However, no study has evaluated the accuracy of detecting specific facet joint injuries.

METHODS

Eight spinal surgeons scored four sets of the same, randomly re-ordered, 30 cases with and without facet joint injuries of the subaxial cervical spine. Two surveys included conventional plain radiographs series (test) and another two surveys included CT scan images (reference). Facet joint injury characteristics were assessed for accuracy and reliability. Raw agreement, Fleiss kappa, Cohen's kappa and intraclass correlation coefficient statistics were used for reliability analysis. Majority rules were used for accuracy analysis.

RESULTS

Of the 21 facet joint injuries discerned on CT scan images, 10 were detected in both plain radiograph surveys (sensitivity, 0.48; 95% confidence interval [CI], 0.26-0.70). There were no false positive facet joint injuries in either of the first two X-ray surveys (specificity, 1.0; 95% CI, 0.63-1.0). Five of the 11 cases with missed injuries had an injury below the lowest visible articulating level on radiographs. CT scan images resulted in superior inter- and intra-rater agreement values for assessing morphologic injury characteristics of facet joint injuries.

CONCLUSIONS

Plain radiographs are not accurate, nor reliable for the assessment of facet joint injuries of the subaxial cervical spine. CT scans offer reliable diagnostic information required for the detection and treatment planning of facet joint injuries.

Surgical treatment of cervical unilateral locked facet in a 9-year-old boy: A case report

Most of the cervical spine injuries in the pediatric population are typically seen in the upper cervical region. Unilateral cervical facet dislocation (UFD) in subaxial region is a rare injury in pediatric population. In this paper, a rare case of delayed locked UFD in a 9-year-old boy with rare injury mechanism treated surgically is reported. Clinical and radiological findings were described. The patient with C6-7 UFD without neurologic deficit was underwent open reduction and internal fixation via anterior and posterior combined approaches. Significant improvement of pain and free motion in cervical spine was obtained. There was no complication during the follow up. Only three case reports presented about the lower cervical spine injury with UFD under the age of 10 were found in the literature.

Health-related quality-of-life outcomes after thoracic (T1-T10) fractures

BACKGROUND CONTEXT

The thoracic spine exhibits a unique response to trauma as the result of recognized anatomical and biomechanical differences. Despite this response, clinical studies often group thoracic fractures (T1-T10) with more caudal thoracolumbar injuries. Subsequently, there is a paucity of literature on the functional outcomes of this distinct group of injuries.

PURPOSE

To describe and identify predictors of health-related quality-of-life outcomes and re-employment status in patients with thoracic fractures who present to a spine injury tertiary referral center.

STUDY DESIGN

An ambispective cohort study with cross-sectional outcome assessment.

PATIENT SAMPLE

A prospectively collected fully relational spine database was searched to identify all adult (>16 years) patients treated with traumatic thoracic (T1-T10) fractures with and without neurologic deficits, treated between 1995 and 2008.

OUTCOME MEASURES

The Short-Form-36, Oswestry Disability Index, and Prolo Economic Scale outcome instruments were completed at a minimum follow-up of 12 months. Preoperative and minimum 1-year postinjury X-rays were evaluated.

METHOD

Univariate and multivariate regression analysis was used to identify predictors of outcomes from a range of demographic, injury, treatment, and radiographic variables.

RESULTS

One hundred twenty-six patients, age 36±15 years (mean±SD), with 135 fractures were assessed at a mean follow-up of 6 years (range 1-15.5 years). Traffic accidents (45%) and translational injuries (54%) were the most common mechanism and dominant fracture pattern, respectively. Neurologic deficits were frequent-53% had complete (American Spinal Injury Association impairment scale [AIS] A) spinal cord deficits on admission. Operative management was performed in 78%. Patients who sustain thoracic fractures, but escaped significant neurologic injury (AIS D or E on admission) had SF-36 scores that did not differ significantly from population norms at a mean follow-up of 6 years. Eighty-eight percent of this cohort was re-employed. Interestingly, Oswestry Disability Index scores remained inferior to healthy subjects. In contrast, SF-36 scores in those with more profound neurologic deficits at presentation (AIS A, B, or C) remained inferior to normative data. Fifty-seven percent were re-employed, 25% in their previous job type. Using multiple regression analysis, we found that comorbidity status (measured by the Charlson Comorbidity index) was the only independent predictor of SF-36 scores. Neurologic impairment (AIS) and adverse events were independent predictors of the SF-36 physical functioning subscale. Sagittal alignment and number of fused levels were not independent predictors.

CONCLUSIONS

At a mean follow-up of 6 years, patients who presented with thoracic fractures and AIS D or E neurologic status recovered a general health status not significantly inferior to population norms. Compared with other neurologic intact spinal injuries, patients with thoracic injuries have a favorable generic health-related quality-of-life prognosis. Inferior outcomes and re-employment prospects were noted in those with more significant neurologic deficits.

Clinical outcomes of the surgical treatment of isolated unilateral facet fractures, subluxations, and dislocations in the pediatric cervical spine: report of eight cases and review of the literature

PURPOSE

We present a small series consisting of eight children with unilateral facet injury of the cervical spine treated surgically.

METHODS

A retrospective review was performed. Injury data, radiographs, surgical data, and outcomes (Neck Disability Index (NDI), Short Form 36 (SF-36), and Visual Analog Scale for Neck Pain (VAS-NP)) were collected from seven patients. A literature review was performed for one additional case.

RESULTS

Motor vehicle accidents (62 %, n = 5) and falls (38 %, n = 3) accounted for all injuries. The C6-7 level accounted for most of the injuries (37.5 %, n = 3). The mean NDI score with at least 3 months follow-up was 5.3 (n = 6, range, 1-12; standard deviation, 4.5), corresponding to mild disability. Of the norm-based SF-36 scale scores available (n = 6), the mean physical functioning (PF), role-physical (RP), and role-emotional (RE) scores were significantly less than the adult, age 18-24, norm-based means, with a mean difference of -6.4, -9.13, and -11.3, respectively (p value = 0.03, 0.001, and 0.01, respectively). The mean general health (GH) and vitality (VT) scores, however, were significantly greater than the adult, age 18-24, norm-based mean, with a mean difference of 7.82 and 10.3 (p = 0.04 and 0.02, respectively). VAS-NP showed a return to the "no pain" level at 3 months or more follow-up in all patients.

CONCLUSIONS

We suggest that surgical treatment of these injuries in the pediatric age group may lead to satisfactory clinical and radiographic outcomes, but HRQoL analysis suggests that patients remain physically and emotionally disabled to some degree after surgery.

Comparative effectiveness of surgical versus nonoperative management of unilateral, nondisplaced, subaxial cervical spine facet fractures without evidence of spinal cord injury

Object

Facet joints are major stabilizers of cervical motion allowing for effortless and pain-free multidimensional cervical spine movements without significant linear or rotational translation, thus minimizing any chance for spinal cord or nerve root impingement. Unilateral, nondisplaced subaxial facet fractures do not meet the conventional criteria for spinal instability under physiological loads. Limited evidence indicates that even with no or minimal displacement, 20%–80% of these fractures fail nonoperative management. The risk factors for instability in isolated nondisplaced subaxial facet fractures remain uncertain. In this retrospective study of prospectively collected data, the authors attempted to identify the predictors of failure in the management of isolated, nondisplaced subaxial facet fractures admitted to their Level I trauma center over a 10-year period.

Methods

Demographic, clinical, imaging, and follow-up data for 25 patients with unilateral nondisplaced subaxial facet fractures who were managed surgically (n = 10) or nonoperatively (n = 15) were statistically analyzed.

Results

The mean age of the patients was 38 years, 19 were male, and 21 of the fractures were the result of either motor vehicle accidents or falls. The mean motor score on the American Spinal Injury Association scale was 99.2, and the mean Subaxial Injury Classification (SLIC) severity score was 3 (operated 3.5, nonoperated 2.3). Allen mechanistic classification included 22 compressive-extension Stage 1 and 2 distractive-extension Stage 1 fractures. Subaxial facet fractures involved C-7 in 17 patients (68%), C-6 in 7 (28%), and C-3 in 1 (4%). The anatomical plane of fracture through the lateral mass was sagittal in 12 patients, axial in 8, and coronal in 3 patients. Nondisplaced floating lateral mass injuries were noted in 2 patients. The mean instability score, considering 7 components of the discoligamentous complex on MRI, was 3.2 (operated 3.6, nonoperated 3.0). Ten (40%) of 25 patients in this investigation did not have successful management, 9 in the nonoperated and 1 in the operated group (p = 0.018). Unsuccessful management was significantly greater in younger patients (p = 0.0008), possibly indicating selection bias (p = 0.07, Wilcoxon ranksum test). Fracture plane, instability, and SLIC scores did not play a significant role in treatment failure in this study.

Conclusions

In this study, surgery was superior to nonoperative management of isolated, nondisplaced, or minimally displaced subaxial cervical spine facet fractures.

Comparison of perioperative outcomes and cost of spinal fusion for cervical trauma: weekday versus weekend admissions

STUDY DESIGN

Retrospective database analysis.

OBJECTIVE

To characterize the impact of the admission day (weekday vs. weekend) on the length of stay, costs, complications, and mortality in patients undergoing cervical spine surgery for spinal trauma.

SUMMARY OF BACKGROUND DATA

The effect of the admission day on the hospital outcomes for patients undergoing anterior cervical fusion (ACF), posterior cervical fusion (PCF), or anterior and posterior cervical fusion (APCF) to manage cervical spine trauma remains unknown.

METHODS

The Nationwide Inpatient Sample was queried from 2002 to 2011. Patients undergoing an ACF, PCF, or APCF for the treatment of cervical spine trauma were identified. Patients were separated into cohorts based on the day of admission (weekday vs. weekend). Patient demographics, comorbidities, admission status, length of stay, costs, mortality, and outcomes were assessed. A value of P ≤ 0.001 denoted statistical significance due to the large sample size.

RESULTS

A total of 34,122 patients underwent cervical fusion for cervical spine trauma between 2002 and 2011. Weekend admits accounted for 11.5% (n = 3126), 19.9% (n = 1048), and 17.2% (n = 301) of the ACF, PCF, and APCF procedures, respectively. On average, the weekend admits in all surgical approaches were younger, had a predilection toward more males, and demonstrated fewer comorbidities than the weekday cohort. ACF-treated weekend admits were hospitalized 4.4 days longer (P = 0.00001) and incurred $10,045 more in total hospital costs than the ACF-treated weekday admits (P = 0.0003). PCF-treated weekend admits were hospitalized 2.6 days longer (P = 0.0003) and incurred $10,227 more in total hospital costs (P = 0.0005). Finally, the APCF-treated weekend admits were hospitalized 4.2 days longer (P = 0.0004) and incurred $11,301 more in total hospital costs (P = 0.0001). The mortality rates were not significantly different among the admission-day cohorts. The ACF-treated weekend cohort demonstrated significantly greater incidences of postoperative infection (P = 0.0003), cardiac complications (P = 0.0004), and urinary tract infection (P = 0.0001) than their weekday admit counterparts.

CONCLUSION

The weekend cohorts in all surgical approaches incurred a greater length of stay and total hospital costs than their weekday counterparts. The ACF-treated weekend cohort demonstrated significantly greater incidences of postoperative infection, cardiac complications, and urinary tract infection. There were no significant differences in mortality based on the admission day for any surgical approach. Further research is warranted to further evaluate hospital utilization, costs, and patient outcomes based on the admission day.

The impact of facet dislocation on clinical outcomes after cervical spinal cord injury: results of a multicenter North American prospective cohort study

STUDY DESIGN

A multicenter prospective cohort study.

OBJECTIVE

To define differences in baseline characteristics and long-term clinical outcomes in patients with cervical spinal cord injury (SCI) with and without facet dislocation (FD).

SUMMARY OF BACKGROUND DATA

Reports of dramatic neurological improvement in patients with FD and cervical SCI, treated with rapid reduction have led to the hypothesis that this represents a subgroup of patients with significant recovery potential. However, without a large systematic comparative analysis, this hypothesis remains untested.

METHODS

Patients were classified into FD and non-FD groups based on imaging investigations at admission. The primary outcome was change in American Spinal Injury Association (ASIA) motor score (AMS) at 1-year follow-up. Secondary outcome measures included ASIA impairment scale (AIS) grade conversion and functional independence measure score at 1-year postinjury, as well as length of acute hospitalization. Baseline characteristics and long-term outcomes were also compared for patients with unilateral and bilateral FD.

RESULTS

Of 421 patients who enrolled, 135 (32.1%) had FD and 286 (67.9%) had no FD. Patients in the FD group presented with a significantly worse AIS grade and higher energy injury mechanisms (P < 0.01). Patients with bilateral FD had a greater severity of baseline neurological deficit compared with those with unilateral FD, measured by AIS grade and AMS. The mean length of acute hospitalization was 41.2 days among patients with FD and 30 days among patients without FD (P = 0.04). At 1-year follow-up, patients with FD experienced a mean AMS improvement of 18.0 points, whereas patients without FD experienced an improvement of 27.9 points (P < 0.01). In the adjusted analysis, patients with FD continued to demonstrate less AMS recovery compared with the patients without FD (P = 0.04).

CONCLUSION

Compared with patients without FD, cervical SCI patients with FD tended to present with a more severe degree of initial injury and displayed less potential for motor recovery at 1-year follow-up.

Surgical treatment for unilateral cervical facet dislocation in a young child aged 22 months old: a case report and review of the literature

PURPOSE

Cervical unilateral facet dislocation (UFD) in the younger children (0-10 years old) has rarely been reported in the literature and most surgeons have no experience for this kind of injury. Here, we reported a rare case of cervical UFD in a 22-month-old girl.

METHODS

Clinical and radiological findings of this patient were described. Because closed reduction failed, operative reduction and fixation was performed using titanium miniplates. We also reviewed the related literature.

RESULTS

There was a significant improvement in neurological function during the follow-up period, and no complications developed. To our knowledge, the only similar case reported in the literature was a 9-year-old boy, who was successfully treated by closed reduction and immobilized with a rigid cervical collar.

CONCLUSIONS

Cervical UFD in young children is definitely a great challenge, and each patient requires individual treatment. Closed reduction along with rigid immobilization is the first choice at the early stage, and operative treatment is indicated for cases that involved neurological deterioration, demonstrated recurrence,significant instability and failed closed reduction. However, long-term results and complications of surgical treatment in the pediatric population are worrisome.

Evaluation of the subaxial injury classification system

Study design:

Retrospective clinical study of patients treated for subaxial cervical spine trauma (SCST) at a tertiary medical center.

Purpose:

Evaluate the validity of the Subaxial Injury Classification (SLIC) system in surgical versus non-surgical decision making for SCST.

Inclusion criteria:

Age >12 years, presence of SCST with complete clinical and radiological (CT and MRI) data.

Exclusion criteria:

Patients with incomplete radiographic or clinical data, pathological fractures, isolated upper cervical trauma (occiput to C2), isolated transverse process or spinous process fractures, chronic or age indeterminate fractures, isolate MRI findings, and severe systemic trauma with death prior to either surgical or non-surgical treatment.

Results:

Fourteen patients were treated non-surgically (C), whereas 24 were treated surgically (S). In the C group, the SLIC score ranged from 0 to 5 points (standard deviation [SD] = 1.20 points; mean 1.07; median 1). Just 1 patient had an SLIC score greater than 2 (7.1% of the patients). In the S group, the SLIC score ranged from 1 to 10 points (standard deviation [SD] = 2.03 points; mean 5.6; median 6). Just 2 patients had an SLIC score smaller than 4 (both with 1 point each, 8.3% of the total group). All the other 22 (accounting for 91.6%) patients had an SLIC of 4 or more points.

Conclusions:

Our study suggests that the SLIC classification looks to be a promising system to aid spinal surgeons in the decision-making process of subaxial cervical trauma, but a large prospective cohort study is required.

An evidence-based medicine process to determine outcomes after cervical spine trauma: what surgeons should be telling their patients

STUDY DESIGN

A systematic review of the available medical literature from 1980 to 2010 was conducted and combined with expert opinion from a recent survey of experts regarding cervical spine fractures. Using an objective, hierarchical approach, the best available evidence is presented for health-related quality-of-life outcomes for these injuries.

OBJECTIVE

To provide an evidence-based set of guidelines for cervical spine injuries in order to reduce variability in the information given to patients and their families.

SUMMARY OF BACKGROUND DATA

Patients' expectations regarding quality-of-life outcomes are highly dependent on the information provided by surgeons early in the treatment course. Our previous work has demonstrated that there is substantial variability in what surgeons tell patients regarding outcomes of cervical spine injuries, thus patients' expectations will differ and outcomes vary.

METHODS

Four common cervical spine injuries (C1 burst, Hangman fracture, odontoid fracture, and unilateral facet fracture) treated both surgically and nonsurgically were considered. We assessed the evidence regarding 5 health-related quality-of-life outcomes: time to return to work, activity level, hospital stay, the proportion of patients who are pain free and patients who have regained full range of motion at 1 year after the injury.

RESULTS

Published outcome data were available for most injuries. Using consensus expert opinion and the literature, answers to each question were achieved. Overall, expert opinion was relatively homogeneous across injury types, suggesting that experts do not distinguish between specific injuries when advising patients of expected outcomes such as pain.

CONCLUSION

By overcoming gaps in the literature with consensus expert opinion, our study provides surgeons and others with evidence-based medicine guidelines for patient-centered outcomes after cervical spine injury. This information can be presented to patients to frame expectations of typical outcomes during and after treatment to optimize patient care and quality of life.

Spinal facet joint biomechanics and mechanotransduction in normal, injury and degenerative conditions

The facet joint is a crucial anatomic region of the spine owing to its biomechanical role in facilitating articulation of the vertebrae of the spinal column. It is a diarthrodial joint with opposing articular cartilage surfaces that provide a low friction environment and a ligamentous capsule that encloses the joint space. Together with the disc, the bilateral facet joints transfer loads and guide and constrain motions in the spine due to their geometry and mechanical function. Although a great deal of research has focused on defining the biomechanics of the spine and the form and function of the disc, the facet joint has only recently become the focus of experimental, computational and clinical studies. This mechanical behavior ensures the normal health and function of the spine during physiologic loading but can also lead to its dysfunction when the tissues of the facet joint are altered either by injury, degeneration or as a result of surgical modification of the spine. The anatomical, biomechanical and physiological characteristics of the facet joints in the cervical and lumbar spines have become the focus of increased attention recently with the advent of surgical procedures of the spine, such as disc repair and replacement, which may impact facet responses. Accordingly, this review summarizes the relevant anatomy and biomechanics of the facet joint and the individual tissues that comprise it. In order to better understand the physiological implications of tissue loading in all conditions, a review of mechanotransduction pathways in the cartilage, ligament and bone is also presented ranging from the tissue-level scale to cellular modifications. With this context, experimental studies are summarized as they relate to the most common modifications that alter the biomechanics and health of the spine-injury and degeneration. In addition, many computational and finite element models have been developed that enable more-detailed and specific investigations of the facet joint and its tissues than are provided by experimental approaches and also that expand their utility for the field of biomechanics. These are also reviewed to provide a more complete summary of the current knowledge of facet joint mechanics. Overall, the goal of this review is to present a comprehensive review of the breadth and depth of knowledge regarding the mechanical and adaptive responses of the facet joint and its tissues across a variety of relevant size scales.

[A case of unilateral dislocation of C3 right facet joint treated with lateral mass plating]

Facet joint dislocations of the cervical spine are distractive-flexion injuries that account for 6 to 10 % of traumatic lesions of the subaxial cervical spine. Distractive-flexion injuries of the cervical spine were classified into four stages by Allen and Fergusson. These unstable lesions predominate at the fifth and sixth levels and all aspects of their management are subject to controversy, including their classification. Attempting reduction before surgery, performing MRI before or after closed reduction, choosing between surgery and external contention, the anterior versus the posterior approach are still matters of controversy between experts. The authors report a stage 2 distractive-flexion injury of the right facet joint of the third cervical vertebra treated by lateral mass plating as described by Roy-Camille (1995).

Interval, acute onset airway obstruction associated with a fracture of the C4 vertebra in a patient with ankylosing spondylitis

We report a 92-year-old female with ankylosing spondylitis who suffered a non-displaced cervical fracture of the C4 vertebral body as the result of a mechanical fall. A rigid cervical collar was used to maintain stability. The patient later went on to develop upper airway obstruction as a result of fracture displacement. She was emergently intubated for airway protection. To our knowledge, this is the first report of interval, acute onset upper airway obstruction caused by cervical instability following trauma and fracture in a patient with ankylosing spondylitis. This example highlights one of the potential complications of rigid cervical collar immobilization in patients with spinal instability.

C2-fractures: part II. A morphometrical analysis of computerized atlantoaxial motion, anatomical alignment and related clinical outcomes

Knowledge on the outcome of C2-fractures is founded on heterogenous samples with cross-sectional outcome assessment focusing on union rates, complications and technical concerns related to surgical treatment. Reproducible clinical and functional outcome assessments are scant. Validated generic and disease specific outcome measures were rarely applied. Therefore, the aim of the current study is to investigate the radiographic, functional and clinical outcome of a patient sample with C2-fractures. Out of a consecutive series of 121 patients with C2 fractures, 44 met strict inclusion criteria and 35 patients with C2-fractures treated either nonsurgically or surgically with motion-preserving techniques were surveyed. Outcome analysis included validated measures (SF-36, NPDI, CSOQ), and a functional CT-scanning protocol for the evaluation of C1-2 rotation and alignment. Mean follow-up was 64 months and mean age of patients was 52 years. Classification of C2-fractures at injury was performed using a detailed morphological description: 24 patients had odontoid fractures type II or III, 18 patients had fracture patterns involving the vertebral body and 11 included a dislocated or a burst lateral mass fracture. Thirty-one percent of patients were treated with a halo, 34% with a Philadelphia collar and 34% had anterior odontoid screw fixation. At follow-up mean atlantoaxial rotation in left and right head position was 20.2 degrees and 20.6 degrees, respectively. According to the classification system of posttreatment C2-alignment established by our group in part I of the C2-fracture study project, mean malunion score was 2.8 points. In 49% of patients the fractures healed in anatomical shape or with mild malalignment. In 51% fractures healed with moderate or severe malalignment. Self-rated outcome was excellent or good in 65% of patients and moderate or poor in 35%. The raw data of varying nuances allow for comparison in future benchmark studies and metaanalysis. Detailed investigation of C2-fracture morphology, posttreatment C2-alignment and atlantoaxial rotation allowed a unique outcome analysis that focused on the identification of risk factors for poor outcome and the interdependencies of outcome variables that should be addressed in studies on C2-fractures. We recognized that reduced rotation of C1-2 per se was not a concern for the patients. However, patients with worse clinical outcomes had reduced total neck rotation and rotation C1-2. In turn, C2-fractures, especially fractures affecting the lateral mass that healed with atlantoaxial deformity and malunion, had higher incidence of atlantoaxial degeneration and osteoarthritis. Patients with increased severity of C2-malunion and new onset atlantoaxial arthritis had worse clinical outcomes and significantly reduced rotation C1-2. The current study offers detailed insight into the radiographical, functional and clinical outcome of C2-fractures. It significantly adds to the understanding of C2-fractures.

Clinical and radiographic outcomes of pedicle screw fixation for upper thoracic spine (T1–5) fractures: a retrospective cohort study of 27 cases

Object

The use of pedicle screws (PSs) for stabilization of unstable thoracolumbar fractures has become the standard of care, but PS efficacy has not been reported in the upper thoracic spine. The primary outcome of this study was to determine the efficacy of PS fixation to achieve and maintain reduction of unstable upper thoracic spine fractures (T1–5). Secondary outcomes included scores on a 1-year postoperative generic health-related quality of life (QOL) questionnaire and postoperative complications.

Methods

This study was a retrospective analysis and cross-sectional outcome assessment of cases prospectively entered into a spine database from 1997 to 2004. All patients with a traumatic, unstable upper thoracic spine (T1–5) fracture who underwent PS fixation were included. Preoperative CT scans with sagittal plane reformatted images were used to determine kyphotic deformity and compared with immediate postoperative and latest follow-up radiographs or CT scans. Patient charts, operative notes, and the results of postoperative follow-up examinations were reviewed. Patients were mailed the Short Form-36v2 (SF-36 version 2) by an independent study coordinator.

Results

Cases involving 27 patients (23 male, 4 female) were evaluated. The patients' mean age was 39.9 years (range 16–73 years). In all, 251 PSs were passed between T-1 and T-8. The mean true kyphotic deformity was 18.2° preoperatively, 8.7° (p < 0.0005) initially postoperatively, and 10.1° at final follow-up (mean 2.3 years postoperatively). The mean SF-36 physical component summary score was 35.89 while the mental component summary score was 56.43 at a minimum of 1-year postoperatively (mean 3.2 years). There were no intraoperative vascular or neural complications.

Conclusions

In the hands of fellowship-trained spinal surgeons, PS fixation for reduction and stabilization of upper thoracic spine fractures is a safe and efficacious technique. Health-related QOL outcome data are deficient for spine trauma patients and should be an essential component of quantifying treatment outcomes.