Atlanto-occipital Injuries Research Articles

Upper Cervical Spine Injuries — A Secondary Publication

Objectives: Based on anatomical knowledge of the upper cervical spine, it is necessary to be familiar with the classification, diagnosis, and treatment strategies currently used clinically for upper cervical spine injuries. Summary of literature review: Upper cervical spine injuries are major injuries with potentially fatal consequences. The occipitocervical junction, which is composed of several structures, protects the brain and cranial nerves. We need to know the mechanism of each type of damage, and in particular, we must understand the anatomy of the occiput, atlas, and axis, as well as the definitions of landmarks of the positional relationships among all structures. Materials and methods: This study reviewed the latest literature on upper cervical spine injuries. Results: In occipital condyle fractures and atlanto-occipital injuries, we should understand how to evaluate instability and the treatment methods according to each classification. In atlas injuries, it should be evaluated whether the transverse atlantal ligament has been damaged. In axis fractures, it is necessary to understand the surgical method according to the shape of the odontoid fracture. Conclusions: Knowledge of soft tissue and bony structural relationships in the upper cervical spine is required for the diagnosis and treatment plan of upper cervical injuries.

Clinical characteristics of upper cervical spine injuries in children: a retrospective case series.

Pediatric cervical spine injuries (CSI) can be devastating, and children < 8 years are particularly at risk for upper CSI given unique anatomical differences. Diagnosis of these injuries can be delayed due to variable clinical presentations and a paucity of existing literature. The authors aimed to characterize the spectrum of pediatric upper CSI. This was a retrospective, single-center case series of trauma patients aged < 16 years who were assessed at a level I pediatric trauma center and diagnosed with upper CSI between 2000 and 2020. Patients were included if they had evidence of bony or ligamentous injury from the occiput to C2 on imaging or autopsy. Data were obtained from manual chart review and analyzed using descriptive statistics. In total, 502 patients were screened and 202 met inclusion criteria. Of these, 31 (15%) had atlanto-occipital (AO) joint distractions, 10 (5%) had atlanto-axial (AA) joint distractions, 31 (15%) had fractures of C1-2, and 130 (64%) had ligamentous injury without joint distraction. Of the patients with AO injury, 15 patients had complete dislocation. They presented as hemodynamically unstable with signs of herniation and 14 died (93%). In contrast, 16 had incomplete dislocation (subluxation). They usually had stable presentations and survived with good outcomes. Of the patients with AA injury, 2 had complete dislocation, presented with arrest and signs of herniation, and died. In contrast, 8 patients with subluxation mostly presented as clinically stable and all survived with little residual disability. The most common fractures of C1 were linear fractures of the lateral masses and of the anterior and posterior arches. The most common fractures of C2 were synchondrosis, hangman, and odontoid fractures. Overall, these patients had excellent outcomes. Ligamentous injuries frequently accompanied other brain or spine injuries. When these injuries were isolated, patients recovered well. Among upper CSI, AO and AA joint injuries emerged as particularly severe with high mortality rates. Both could be divided into complete dislocations or incomplete subluxations, with clear clinical differences and the former presenting with much more severe injuries. Lateral cervical spine radiography should be considered during resuscitation of unstable trauma patients to assess for these CSI subtypes. Fractures and ligamentous injuries were clinically heterogeneous, with presentations and outcomes depending on severity and associated injuries.

Unilateral atlanto-occipital injury: A case series and detailed radiographic description.

ContextAtlanto-occipital dissociation is a highly lethal ligamentous injury at the craniocervical junction (CCJ). Previous studies have described rare cases of milder forms of atlanto-occipital injury (AOI) which might be managed nonoperatively, but there is a paucity of literature on this subject.Aims:We retrospectively reviewed our institutional experience to characterize the injury patterns, treatments, and clinical courses of patients with unilateral AOI.Methods:We included patients with radiographic evidence of unilateral occipitocervical joint capsular disruption, distraction, or edema ± injury of the apical ligament, tectorial membrane, anterior atlanto-occipital membrane, posterior atlanto-occipital membrane, alar ligaments, or cruciate ligament. The long-term outcomes were gathered from medical records, and six patients were available for Neck Disability Index via phone call at the time of the study.Results:Eight patients were included in the study. The mean age was 45.1 years ± 26.5. Causes of trauma included motor vehicle collision for five patients (5/8, 62.5%), falls for two (2/8, 25), and assault for one (1/8, 12.5%). All patients had a widened condyle-C1 interval >2 mm. Three patients underwent occipitocervical fusion, one patient underwent atlantoaxial fusion, and another received subaxial fusions for other injuries. Three patients underwent no surgical intervention. All patients were seen at least once as an outpatient following hospital discharge. There were no delayed neurologic injuries or deaths.Conclusions:We propose that ligamentous injury at the CCJ functions more as a spectrum rather than dichotomous diagnosis, of which a subset can likely be safely managed nonoperatively.

Ability of magnetic resonance imaging to accurately determine alar ligament integrity in patients with atlanto-occipital injuries.

Objective:The objective of this study is to evaluate the the reliability of magnetic resonance imaging (MRI) in diagnosing alar ligament disruption in patients with potential atlanto-occipital dissociation (AOD).Materials and Methods:Three-blinded readers performed retrospective review on 6 patients with intra-operative confirmed atlanto-occipital dissocation in addition to a comparison cohort of patients with other cervical injuries that did not involve the atlanto-occipital articulation. Ligament integrity was graded from 1 to 3 as described by Krakenes et al. The right and left ligaments were assessed separately. Inter-observer agreement by patient, by group (AOD vs. non-AOD), and intra-observer agreement was calculated using weighted Cohen's kappa.Results:Interobserver agreement of alar ligament grade for individual patients ranged from slight to fair (κ = 0.05–0.30). Interobserver agreement of alar ligament grade for each group (AOD vs. non-AOD) ranged from fair to substantial (κ = 0.37–0.66). No statistically significant difference in categorical analysis of groups (AOD vs. non-AOD) and grade (0–1 vs. 2–3) was observed. Intraobserver agreement of individual patient's alar ligament grade ranged from moderate to substantial (κ = 0.50–0.62).Conclusion:The use of MRI to detect upper cervical ligament injuries in AOD is imperfect. Our results show inconsistent and unsatisfactory interobserver and intraobserver reliability in evaluation of alar ligament injuries. While MRI has immense potential for detection of ligamentous injury at the craniovertebral junction, standardized algorithms for its use and interpretation need to be developed.

Application of Normative Occipital Condyle-C1 Interval Measurements to Detect Atlanto-Occipital Injury in Children.

Prior studies have found that widening or asymmetry of the occipital condyle-C1 interval on CT is a sensitive and specific marker for atlanto-occipital dislocation. Previously reported abnormal occipital condyle-C1 interval values are not age-specific, possibly leading to false-positive findings in younger children, in whom this joint space is normally larger than that in adults. This study assesses the utility of applying age-specific normative occipital condyle-C1 interval ranges to documented cases of atlanto-occipital injury compared with previously reported abnormal cutoff values. Retrospective review of CT and MR imaging of 14 subjects with atlanto-occipital injury was performed, and occipital condyle-C1 interval measurements were made for each subject. Sensitivities and specificities of proposed occipital condyle-C1 interval cutoffs of 2 and 3 SDs above the mean and previously published occipital condyle-C1 interval cutoffs for atlanto-occipital injury were then calculated on the basis of occipital condyle-C1 interval measurements for each subject. An occipital condyle-C1 interval 2 SDs above the age-specific mean has a sensitivity of 50% and specificity of 89%-100%, depending on the age group. An occipital condyle-C1 interval 3 SDs above the age-specific mean has a sensitivity of 50% and a specificity of 95%-100%. A 4.0-mm occipital condyle-C1 interval has a sensitivity of 36% and a specificity of 100% in all age groups. A 2.5-mm occipital condyle-C1 interval has a sensitivity of 93% and a specificity of 18%-100%. Occipital condyle-C1 interval widening cutoffs used to establish atlanto-occipital injury lack both sensitivity and specificity in children and young teenagers. MR imaging is necessary to establish a diagnosis of atlanto-occipital injury in children and young teenagers when the appropriate mechanism of injury is present.

Normal Development and Measurements of the Occipital Condyle-C1 Interval in Children and Young Adults

Widening of the occipital condyle-C1 interval is the most specific and sensitive means of detecting atlanto-occipital dislocation. Recent studies attempting to define normal measurements of the condyle-C1 interval in children have varied substantially. This study was performed to test the null hypothesis that condyle-C1 interval morphology and joint measurements do not change as a function of age. Imaging review of subjects undergoing CT of the upper cervical spine for reasons unrelated to trauma or developmental abnormality was performed. Four equidistant measurements were obtained for each bilateral condyle-C1 interval on sagittal and coronal images. The cohort was divided into 7 age groups to calculate the mean, SD, and 95% CIs for the average condyle-C1 interval in both planes. The prevalence of a medial occipital condyle notch was calculated. Two hundred forty-eight joints were measured in 124 subjects with an age range of 2 days to 22 years. The condyle-C1 interval varies substantially by age. Average coronal measurements are larger and more variable than sagittal measurements. The medial occipital condyle notch is most prevalent from 1 to 12 years and is uncommon in older adolescents and young adults. The condyle-C1 interval increases during the first several years of life, is largest in the 2- to 4-year age range, and then decreases through late childhood and adolescence. A single threshold value to detect atlanto-occipital dissociation may not be sensitive and specific for all age groups. Application of this normative data to documented cases of atlanto-occipital injury is needed to determine clinical utility.

Characterization of spinal injuries sustained by American service members killed in Iraq and Afghanistan

This study sought to characterize spine injuries among soldiers killed in Iraq or Afghanistan whose autopsy results were stored by the Armed Forces Medical Examiner System. The Armed Forces Medical Examiner System data set was queried to identify American military personnel who sustained a spine injury in conjunction with wounds that resulted in death during deployment in Iraq or Afghanistan from 2003 to 2011. Demographic and injury-specific characteristics were abstracted for each individual identified. The raw incidence of spinal injuries was calculated and correlations were drawn between the presence of spinal trauma and military specialty, mechanism and manner of injury, and wounds in other body regions. Significant associations were also sought for specific injury patterns, including spinal cord injury, atlantooccipital injury, low lumbar vertebral fractures, and lumbosacral dissociation. Statistical calculations were performed using χ statistic, z test, t test with Satterthwaite correction, and multivariate logistic regression. Among 5,424 deceased service members, 2,089 (38.5%) were found to have sustained at least one spinal injury. Sixty-seven percent of all fatalities with spinal injury were caused by explosion, while 15% occurred by gunshot. Spinal fracture was the most common type of injury (n = 2,328), while spinal dislocations occurred in 378, and vertebral column transection occurred in 223. Fifty-two percent sustained at least one cervical spine injury, and spinal cord injury occurred in 40%. Spinal cord injuries were more likely to occur as a result of gunshot (p < 0.001), while atlantooccipital injuries (p < 0.001) and low lumbar fractures (p = 0.01) were significantly higher among combat specialty soldiers. No significant association was identified between spinal injury risk and the periods 2003 to 2007 and 2008 to 2011, although atlantooccipital injuries and spinal cord injury were significantly reduced beginning in 2008 (p < 0.001). The results of this study indicate that the incidence of spinal trauma in modern warfare seems to be higher than previously reported. Epidemiologic study, level III.

Atlanto-Occipital Injuries in Three Children Treated With Halo Immobilization

ABSTRACTAtlanto-occipital dislocations (AOD) are rare and usually fatal injuries. Atlanto-occipital injuries (AOI) are severe injuries treated with parameters similar to those used for treating AOD. AOD denotes separation of the joint between the occiput and the first cervical vertebrae. Increasing

High rates of neurological improvement following severe traumatic pediatric spinal cord injury.

Retrospective single-center study To determine the long-term outcome of pediatric spinal cord injuries Spinal cord injuries are uncommon events in the pediatric population. In the few large series reported in the literature, recovery of neurologic function was demonstrated after mild injuries but was rare after severe injuries. A total of 4,876 cases of pediatric trauma treated at the Children's Hospital of Los Angeles over a 9-year period (1993-2001) were reviewed. During the study period, 91 cases of spinal cord or spinal column injury were identified, and 30 cases involving a spinal cord injury were identified. Cauda equina injuries were excluded. Seven craniocervical, 12 cervical, 5 thoracic, and 6 thoracolumbar cases were identified. There were 6 cases of spinal cord injury without radiographic abnormality. Eight of the 30 patients received methylprednisolone at the time of admission. Follow-up ranged from 2 to 54 (mean = 19) months. Twenty patients presented with complete injuries (ASIA grade A). Of these, 7 died, 7 had no neurologic recovery, and 6 experienced neurologic improvement. Five of these six eventually became ambulatory with functional gains occurring over a 4- to 50-week period. None of these 5 patients was found to have spinal cord injury without radiographic abnormality. Of the remaining 10 patients (grades B-D), 8 experienced improvements in neurologic function. Cervical dislocation injuries were associated with a low likelihood of neurologic improvement and atlanto-occipital injuries were associated with early death. Recovery of neurologic function following severe traumatic spinal cord injury occurs with a significantly greater incidence in children than adults, and these improvements can occur over a prolonged postinjury period.

Traumatic atlanto-occipital dislocation in children.

During a 5-year period, 11 children were identified as having traumatic atlanto-occipital dislocation injury on the basis of clinical and radiographic findings. Radiographic criteria including the distance between the tip of the dens and the basion (DB distance), the BC/OA ratio (ratio of the distance between the basion and the posterior arch of C-1 divided by the distance between the opisthion and the anterior arch of C-1; normal ratio, < 1), and the width of the atlanto-occipital joint (normal width, < or = 5 mm) were correlated with clinical presentation and outcome. Normal pediatric values for DB distance were reviewed in a series of 110 lateral cervical spine radiographs. The normal DB distance was 8.3 mm +/- 4.2 (mean +/- 2 standard deviations). All 11 children had DB distances greater than 1.4 cm (mean, 1.7 cm). The BC/OA ratio was greater than 1 in only six patients. Of the 11 children, six died with severe neurologic deficits and five survived with minimal or no neurologic sequela. Without the clinical presentation variable, widened DB distance may be the first abnormality identified to suggest atlanto-occipital injury.

Adverse drug reactions in medical inpatients.

Fifteen of 268 children admitted to a general medical ward suffered a definite or probable adverse drug reaction to their treatment. In 6 of these children the reactions were preventable. Anticonvulsants were the most common cause of an adverse reaction.