Upper Cervical Trauma

Dynamic in vivo 3D atlantooccipital kinematics during multiplanar physiologic motions

Normal biomechanics of the upper cervical spine, particularly at the atlantooccipital joint, remain poorly characterized. The purpose of this study was to determine the intervertebral kinematics of the atlantooccipital joint (occiput-C1) during three-dimensional in vivo physiologic movements. Twenty healthy young adults performed dynamic flexion/extension, axial rotation, and lateral bending while biplane radiographs were collected at 30 images per second. Motion at occiput-C1 was tracked using a validated volumetric model-based tracking process that matched subject-specific CT-based bone models to the radiographs. The occiput-C1 total range of motion (ROM) and helical axis of motion (HAM) was calculated for each movement. During flexion/extension, the occiput-C1 moved almost exclusively in-plane (ROM: 17.9 ± 6.9°) with high variability in kinematic waveforms (6.3°) compared to the in-plane variability during axial rotation (1.4°) and lateral bending (0.9°) movements. During axial rotation, there was small in-plane motion (ROM: 4.2 ± 2.5°) compared to out-of-plane flexion/extension (ROM: 12.7 ± 5.4°). During lateral bending, motion occurred in-plane (ROM: 9.0 ± 3.1°) and in the plane of flexion/extension (ROM: 7.3 ± 2.7°). The average occiput-C1 axis of rotation intersected the sagittal and coronal planes 7 mm to 18 mm superior to the occipital condyles. The occiput-C1 axis of rotation pointed 60° from the sagittal plane during axial rotation but only 10° from the sagittal plane during head lateral bending. These novel results are foundational for future work on upper cervical spine kinematics.

Clinical Diagnosis and Treatment of 43 Cases of Occipital Condylar Fractures: A Single-Center Retrospective Study

OBJECTIVE

This study aimed to examine the mechanism of occipital condyle fractures (OCFs), their clinical symptoms, computer tomography (CT) scan findings, treatment options, and classification.

METHODS

A retrospective analysis was conducted on 43 patients with OCFs who were admitted to our neurosurgery center between 2017 and 2023.

RESULTS

The investigation covered their clinical symptoms, CT scan results, and treatment outcomes. It was found that 25.6% of the patients suffered from severe craniocerebral injuries with Glasgow Coma Scale (GCS) scores of 3-8 points, 9.3% had moderate injuries with GCS scores of 9-12 points, and 65.1% exhibited mild injuries with GCS scores of 13-15 points. Of these patients, 90.7% showed improvement upon discharge, 4.7% succumbed to their injuries, and another 4.7% developed paraplegia. Symptoms indicative of OCF in individuals with CCJ injuries included neck pain, swelling, cranial nerve palsy, and posterior pharyngeal wall swelling. Frequently observed complications in OCF patients included cerebral contusion, occipital bone fractures, and skull base fractures. Employing thin-layer CT scans of the CCJ area, along with sagittal and coronal CT reconstructions, is essential for identifying OCFs. The fractures were classified into 3 types based on the Anderson-Montesano classification, which, when modified, provides enhanced treatment guidance.

CONCLUSIONS

OCFs are predominantly present in cases of high-energy trauma, with high-resolution thin-layer CT scans serving as the preferred diagnostic method. The application of the modified Anderson-Montesano classification, distinguishing between stable and unstable fractures, facilitates the determination of suitable treatment strategies. Stable OCFs can be managed using a rigid neck brace, while unstable OCFs may require Halo-vest frame fixation or surgical intervention.

The Reliability of the AO Spine Upper Cervical Classification System in Children: Results of a Multi-Center Study

BACKGROUND

There is no uniform classification system for traumatic upper cervical spine injuries in children. This study assesses the reliability and reproducibility of the AO Upper Cervical Spine Classification System (UCCS), which was developed and validated in adults, to children.

METHODS

Twenty-six patients under 18 years old with operative and nonoperative upper cervical injuries, defined as from the occipital condyle to the C2-C3 joint, were identified from 2000 to 2018. Inclusion criteria included the availability of computed tomography and magnetic resonance imaging at the time of injury. Patients with significant comorbidities were excluded. Each case was reviewed by a single senior surgeon to determine eligibility. Educational videos, schematics describing the UCCS, and imaging from 26 cases were sent to 9 pediatric orthopaedic surgeons. The surgeons classified each case into 3 categories: A, B, and C. Inter-rater reliability was assessed for the initial reading across all 9 raters by Fleiss's kappa coefficient (kF) along with 95% confidence intervals. One month later, the surgeons repeated the classification, and intra-rater reliability was calculated. All images were de-identified and randomized for each read independently. Intra-rater reproducibility across both reads was assessed using Fleiss's kappa. Interpretations for reliability estimates were based on Landis and Koch (1977): 0 to 0.2, slight; 0.2 to 0.4, fair; 0.4 to 0.6, moderate; 0.6 to 0.8, substantial; and >0.8, almost perfect agreement.

RESULTS

Twenty-six cases were read by 9 raters twice. Sub-classification agreement was moderate to substantial with α κ estimates from 0.55 for the first read and 0.70 for the second read. Inter-rater agreement was moderate (kF 0.56 to 0.58) with respect to fracture location and fair (kF 0.24 to 0.3) with respect to primary classification (A, B, and C). Krippendorff's alpha for intra-rater reliability overall sub-classifications ranged from 0.41 to 0.88, with 0.75 overall raters.

CONCLUSION

Traumatic upper cervical injuries are rare in the pediatric population. A uniform classification system can be vital to guide diagnosis and treatment. This study is the first to evaluate the use of the UCCS in the pediatric population. While moderate to substantial agreement was found, limitations to applying the UCCS to the pediatric population exist, and thus the UCCS can be considered a starting point for developing a pediatric classification.

LEVEL OF EVIDENCE

Level III.

Cervical spine trauma

Cervical spine trauma encompasses a wide of injuries, ranging from stable, minor lesions to unstable, complex lesions that can lead to neurologic sequelae or vascular involvement. The Canadian C-Spine Rule and the NEXUS criteria aim to identify individuals with a low risk of cervical spine trauma who can safely forgo imaging tests. In high-risk patients, an imaging test is indicated. In adult patients the imaging test of choice is multidetector computed tomography. Complementary imaging tests such as CT angiography of the supra-aortic vessels and/or magnetic resonance imaging are occasionally necessary. It can be challenging for radiologists to diagnose and classify these lesions, because some of them can be subtle and difficult to detect. This paper aims to describe the most important imaging findings and the most widely used classification systems.

[Analysis of cervical instability and clinical characteristics in treatment-naive rheumatoid arthritis patients]

OBJECTIVE

To study the proportion of cervical spine instability in treatment-naive rheumatoid arthritis (RA) patients, to investigate the associated neck symptoms, and to analyze the clinical characteristics in treatment-naive RA patients and treated RA patients.

METHODS

RA patients who underwent cervical spine X-ray imaging from the Department of Rheumatology and Immunology of Peking University Third Hospital and Peking University Shenzhen Hospital from August 2015 to October 2019 and had clinical records of medication administration were included. Clinical and laboratory data including cervical symptoms and X-ray imaging data of cervical spine were collected. The constituent ratio of cervical spine instability in treatment-naive RA patients was statistically analyzed. The clinical data and laboratory data were analyzed by t-test, u-test and chi square to explore the clinical characteristics of the treatment-naive RA patients with cervical instability.

RESULTS

Of the 408 RA patients, 105 patients were treatment-naive. Of the 105 treatment-naive patients, 82.9% (87/105) were female, with an average age of (52±14) years, the median duration of the disease was 24 months, the shortest history was 2 weeks, and the longest history was 30 years. 28.6% (30/105) of the treatment-naive RA patients showed cervical spine instability. The prevalence of cervical instability was 13.6% in the treatment-naive RA patients with disease duration less than 24 months. Among them, there were no significant differences in neck symptoms between cervical spine instability group and none cervical spine instability group. The patients with cervical spine instability had a longer duration of disease [60 (18, 180) months vs.16 (8, 51) months], a higher proportion of peripheral joint deformity (63.3%vs.21.3%), and a lower hemoglobin [(106.90±21.61) g/L vs. (115.77±14.69) g/L]. There was no significant difference in the occurrence of cervical instability in the treatment-naive RA patients compared with treated RA patients. Among the RA patients with cervical instability, there was no statistically significant difference in the composition of each type between the patients with treatment-naive RA and patients with treated RA, except for a shorter duration of disease [120.0 (72.0, 240.0) months vs. 60.0 (27.0, 167.5) months].

CONCLUSION

28.6% of treatment-naive RA patients showed cervical spine instability. Cervical instability was also common in RA patients with a duration less than 24 months. There was no significant correlation between cervical instability and neck symptoms. Patients with cervical spine instability had a long-term disease, a higher proportion of peripheral joint deformity and a lower hemoglobin. Controlling the condition of RA early may help to control the progression of cervical involvement in patients with RA.