A review of the diagnosis and treatment of atlantoaxial dislocations

Atraumatic atlantoaxial subluxation in pediatric enthesitis-related juvenile idiopathic arthritis: illustrative case

BACKGROUND

Juvenile idiopathic arthritis (JIA) is the most common pediatric rheumatological disease, yet cervical spine involvement remains an underrecognized but potentially devastating manifestation. Atlantoaxial subluxation (AAS) arises from inflammatory changes causing ligamentous laxity and instability.

OBSERVATIONS

A 13-year-old female presented with progressive neck pain. Imaging revealed a 10-mm atlantodental interval on CT, along with hyperintensity and stretching of the transverse atlantal ligament on MRI. She underwent a posterior C1-2 open reduction and fusion. Subsequent rheumatological workup confirmed enthesitis-related JIA, based on polyarticular arthritis, HLA-B27 positivity, and elevated inflammatory markers. To contextualize this case, the authors performed a systematic review and meta-analysis of JIA-related AAS across 21 studies. The pooled incidence of AAS was 14%, with a mean age at JIA onset of 8.47 years and a female predominance of 62%. Enthesitis-related arthritis emerged as the most frequently reported subtype, and 94.4% of patients with AAS improved posttreatment.

LESSONS

This case and supporting literature underscore the importance of early detection and multidisciplinary management of AAS in pediatric patients with JIA. Timely neurosurgical stabilization, combined with optimized immunosuppressive therapy, can prevent neurological compromise. Future research should focus on standardized diagnostic thresholds and outcome measures to guide best practices. https://thejns.org/doi/10.3171/CASE25121.

Treatment for Atlanto-occipital Dislocation, Vertical Atlanto-axial Dislocation, and Acute Subdural Hematoma Presenting with Out-of-hospital Cardiac Arrest: A Case Report

A male patient in his 50s had a head-on collision while driving. Prehospital emergency services recorded pulseless electrical activity on an electrocardiogram, and chest compressions were initiated. Before hospital arrival, return of spontaneous circulation was achieved after 17-min resuscitation during transport. His Glasgow Coma Scale score was 6, with unequal-size pupils unresponsive to light stimuli. A head computed tomography scan revealed a left acute subdural hematoma with a marked midline shift, and computed tomography of the cervical spine showed that the atlanto-occipital and atlanto-axial joint spaces were significantly widened. Initially, an emergency decompressive craniectomy for hematoma evacuation was performed, followed by posterior cervical fixation surgery in the subacute phase. After brain surgery, neurocritical care management was implemented for brain protection. Cervical spine magnetic resonance imaging revealed multiple ligament injuries at the craniovertebral junction, which confirmed the diagnosis of atlanto-occipital and atlanto-axial dislocation. On day 9, posterior fixation from the occiput to the fourth cervical vertebrae was performed. Subsequently, he was transferred to a rehabilitation hospital on day 45. No neurological sequelae were noted except for the neck rotation limitations due to the fixation surgery, and he could return to his previous job. Although craniovertebral junction ligamentous injuries are rare, they may coexist with severe traumatic brain injury. A careful reading of preoperative images focusing on the inter-joint space is important to detect craniovertebral junction ligamentous injuries in patients with traumatic brain injury inflicted with high-energy trauma.

Clinical manifestations of rheumatoid arthritis, including comorbidities, complications, and long-term follow-up

Symmetric inflammatory polyarthritis is the most prominent manifestation of rheumatoid arthritis (RA). However, RA can practically affect any organ system, whether hematologic, neurological, cardiac, lung, skin, eyes, or kidneys. Systemic involvement in RA can be severe when there is interstitial lung disease, scleritis, amyloidosis, pure red cell aplasia, or myelodysplasia. Cardiovascular disease is the leading cause of death in patients with RA with a similar cardiovascular risk to that with diabetes mellitus. Patients with RA are at an increased risk of infections or osteoporosis, largely due to treatment-related etiologies. Rheumatoid vasculitis is a devastating long-term complication of RA which is fortunately becoming rarer over time due to better disease activity control. While the risk of mortality overall seems to be reducing over time, the excess mortality risk with RA compared with the general population persists. Fibromyalgia, anxiety, depression, fatigue, and physical inactivity remain important comorbidities associated with RA.

Efficacy of Atlantoaxial Joint Steroid Injections in Managing Cervicogenic Headache: A Case Series

Introduction

The International Headache Society divides headaches into primary (vascular and muscular) and secondary (inflammatory). Secondary headaches include headaches secondary to inflammation caused by injuries to the head and neck. Cervicogenic headache (CGH) is thought to be referred pain arising from irritation caused by cervical structures innervated by spinal nerves C1, C2, and C3; therefore, any structure innervated by the C1-C3 spinal nerves could be the source of a CGH. Pain from the lateral atlanto-axial joint (AAJ) is one of several causes of CGH. The pain is perceived in the upper neck and can be referred to the occiput, ear, vertex, and forehead.

Case Report

Patients who attended our pain clinic were presented with complaints of pain in the upper cervical, occipital, and sometimes periorbital and retro-orbital area and around the post-auricular area. On the numerical rating pain scale, patients had pain score of 8-9/10. Three patients had a history of trauma to the cervical region and 2 had a history of rheumatoid arthritis (RA). Patients suffering from RA also had pain in bilateral wrist joints along with neck pain. On examination, there was tenderness along the facet joint line on both sides, when the site of maximum tenderness was checked under the C-Arm machine, it was found at the AAJ on both sides. Patients having a history of trauma first had conservative treatment with analgesics while rheumatoid patients with analgesics and disease-modifying anti-rheumatoid drugs. When patients had no satisfactory pain relief with conservative treatment then patients were considered for fluoroscopy (C-Arm) and 0.5-1 mL Iohexol 300 guided AAJ steroid injection with dexamethasone. After steroid injection, all patients had good-to-excellent results and were followed up for 4 months. Trauma patients got complete relief whereas patients having a history of RA had only mild pain.

Conclusion

AAJ steroid injection with dexamethasone is an effective pain-relieving procedure for acute pain relief in patients having severe pain due to cervical trauma or due to RA involving AAJ.

An early evaluation of robot-assisted and conventional techniques for posterior approach atlantoaxial displacement instrumentation - a systematic review and meta-analysis

Atlantoaxial dislocation (AAD) is a serious condition in which the first two cervical vertebrae lose their anatomical position and stability. This may lead to neurological complications, including death. The treatment of AAD remains controversial, and posterior instrumentation with pedicle screw placement is one of the commonly used methods. The goal of this study is to evaluate the effectiveness of robot-assisted (RA) surgery compared to conventional techniques for posterior AAD instrumentation. Following Cochrane and PRISMA guidelines, five major databases were searched from inception to December 2024. Studies evaluating RA surgery compared to freehand (FH) or computer navigation methods were included. Outcomes included screw accuracy, surgery time, radiation exposure, and complications. A random-effects mean difference (MD) and odds ratio (OR) were used. After a comprehensive search, three studies were included. Two studies compared RA to FH, and one compared RA to navigation. Blood loss (MD -103.11 [-148.73, -57.49], p < 0.01) and radiation dose (MD -8.19 [-10.18, -6.19], p < 0.01) were lower in the RA group compared to FH. Operating time was significantly longer in the RA group compared to conventional methods (MD 36.55 [30.07, 43.04], p < 0.01). The number of correct screws (OR 2.15 [1.11, 4.15], p = 0.02) and satisfactory screws (OR 3.18 [1.13, 8.90], p = 0.03) was higher in the RA group. RA surgery provides significantly higher pedicle screw accuracy compared to FH and navigation methods, although at the cost of increased surgery time. Blood loss and radiation exposure were lower in the RA group compared to FH. While the results are promising, this meta-analysis included only three small trials. Future randomized controlled trials are needed to fully evaluate the effectiveness of RA surgery for AAD instrumentation.

Complications in Occipitocervical Surgery

The occipitocervical junction is formed by the foramen magnum (FM) and the adjacent anatomical structures of the C1 and C2 vertebrae. The FM is formed anteriorly by the basilar part of occipital bone. Anterolaterally, it borders the occipital condyles and hypoglossal canal as well as the jugular foramen. Posteriorly, the FM is formed by the squamous part of the occipital bone with the internal occipital crest. In the midline, named landmarks at the anterior margin are the basion and, at the posterior margin, the opisthion. Vital anatomic structures are located in the FM or pass through. Among these are the medulla oblongata, meninges, anterior and posterior spinal arteries, vertebral arteries, and spinal roots of the accessory nerve. The FM is firmly anchored to the cervical canal via strong ligamentous support.Pathologies in this area can be of congenital, acquired, traumatic, neoplastic, or infectious origin, with the respective surgical indications and approaches depending on the nature and location of the pathology. If the pathology is occipitoatlantal, the occiput is usually involved in surgery. On the other hand, if the pathology is only at the level of C1-C2, surgery may be limited to these two vertebrae.In this section, we present the surgical management of exemplary congenital cases, and we discuss the complications and what needs to be done to deal with them.

Analysis of Failed Atlantoaxial Reduction: Causes of Failure and Strategies for Revision

OBJECTIVE

The craniovertebral junction (CVJ) presents intricate anatomical challenges. In severe or irreducible malformations, complications such as reduction loss and fixation failure may occur, necessitating revision surgery. The posterior facet joint distraction and fusion (PFDF) technique, offers a solely posterior approach for revisions. Hence, we delineate varied revision scenarios, proposing surgical strategies and technical details to enhance outcomes and mitigate risks, thereby enriching the neurosurgical community's repertoire.

METHODS

This was a retrospective cohort study, analyzed patient data from Xuanwu Hospital, between 2017 to 2023. All patients had a history of surgical treatment for CVJ malformations, and experienced failure or loss of reduction. The distance from the odontoid process tip to the Chamberlain's line (DCL), the atlantodental interval (ADI), clivus-canal angle, cervicomedullary angle, width of subarachnoid space, CVJ area, and width of syrinx were used for radiographic assessment. Japanese Orthopaedic Association (JOA) scores and SF-12 scores were used for clinical assessment. Independent sample t-tests were employed. A significance level of p < 0.05 indicates statistically significant differences.

RESULTS

We analyzed data from 35 patients. For patients who underwent PFDF, the postoperative DCL, ADI, and clivus-canal angle significantly improved. For all patients, the postoperative cervicomedullary angle, width of subarachnoid space, CVJ area, and width of syrinx all demonstrated significant improvement, indicating the relief of neural compression. All patients showed significant improvement in both symptoms and clinical assessments.

CONCLUSION

Severe atlantoaxial joint locking or ligament contracting are the fundamental cause of reduction and fixation failure. Anterior odontoidectomy is indicated for patients with robust bony fusion of the atlantoaxial joint in an unreduced position. The PFDF technique is safe and effective for patients with incomplete atlantoaxial bony fusion. Preoperative assessment of surgical feasibility and vertebral artery status ensures surgical safety and efficacy.

Tomographic Evaluation of the Upper Cervical Spine in Patients with Cleft lip and Palate and Class III Malocclusion

OBJECTIVE

To perform a morphometric analysis of the upper cervical spine (UCS) by means of cone-beam computed tomography (CBCT) for the diagnosis of malformations or craniocervical instabilities in patients with cleft lip and palate (CLP) and class III malocclusion.

MATERIALS AND METHODS

A total of 72 CBCTs from adult patients (48 male and 24 female) with Angle Class III malocclusion were divided into three groups: 1) Unilateral cleft lip and palate (UCLP) (n = 29; male = 65.5%; age = 24, 2 ± 4.2 years); 2) Bilateral cleft lip and palate (BCLP) (n = 18; male = 83.3%; age = 26.4 ± 6.0 years); 3) Control group (CON) (n = 25; male = 56.0%; age = 27.8 ± 9.3 years). The version 11.7 of the Dolphin® software (Chatsworth, California, USA) was used to evaluate the morphometric measurements and anomalies of the UCS. Data were analyzed by descriptive and inferential statistics (p ≤ 0.05).

RESULTS

For the UCLP, BCLP and CON groups, respectively, the measures were: atlantodental interval (2.1 ± 0.5; 2.1 ± 0.4; 2.0 ± 0.3 mm), basion-opisthion (35.9 ± 3.2; 36.4 ± 3.0; 34.7 ± 1.9 mm), hyoid-C3 (34.5 ± 3.7; 34.5 ± 5.2; 35.3 ± 4.5 mm), and hyoid-sella (108.1 ± 9.8; 111.3 ± 9.2; 109.7 ± 10 mm); clivus-canal angle (152.3 ± 13; 150.3 ± 10; 150.7 ± 10°) and Torg-Pavlov index (1.0 ± 0.2; 1.0 ± 0.1; 1.1 ± 0.2). Potentially unstable anomalies and malformations were more prevalent in the UCLP group (34,4%).

CONCLUSION

Subjects with UCLP presented compressive or unstable anomalies on upper cervical spine, more frequently than controls and BCLP, despite the lack of statistically significant differences among groups. Future studies could increase the safety of patients and healthcare professionals specialized in craniofacial anomalies.

Radiographic Indicators of Craniocervical Instability: Analyzing Variance of Normative Supine and Upright Imaging in a Healthy Population

STUDY DESIGN

Single-institution retrospective review.

OBJECTIVE

To establish baseline ranges and variability of 7 radiographic measurements of the cervical spine in a healthy patient population as potential diagnostic tools for craniocervical instability.

SUMMARY OF BACKGROUND DATA

Craniocervical instability, common in patients with connective tissue disease such as Ehlers-Danlos Syndrome, often presents with a wide range of symptoms, including neck pain. Current diagnostic methods employ a range of clinical and radiographic features, but diagnostic challenges remain due to missed indications on static imaging and a lack of standardized measurement values and normalized variance.

METHODS

Seventy-two healthy patients with cervical imaging were analyzed. Surgimap software was used to annotate supine computed tomography images, flexion, extension, and neutral x-ray images for measurement. These measurements included the atlanto-dental interval, clival-axial angle, basion-dens interval, basion-axis interval, perpendicular basion to the inferior aspect of C2, also known as Grabb Oakes measurement, and the hard palate to C1 and hard palate to C2. Statistical analysis assessed differences among imaging modalities, and coefficients of variation were calculated for each measurement.

RESULTS

Our cohort consisted of a total of 72 patients with a mean age of 64 (SD: 13.54). All measurements except for the basion-axial interval and atlanto-dental interval demonstrated a significant difference between extension and flexion x-ray measurements. clivo-axial angle, hard palate to C1, and hard palate to C2 demonstrated the lowest coefficients of variance across imaging modalities.

CONCLUSION

Understanding normal variance in cervical measurements is invaluable for accurate CCI diagnosis. Using a cohort of healthy patients, this study delineates the distribution and spread of 7 cervical measurements, delineating reference values and variability in these key measurements and highlighting their potential for use as imaging markers for CCI.

LEVEL OF EVIDENCE

Level III.

Morphometric analysis of atlas lateral mass in Down syndrome cases with relevance to surgical intervention

PURPOSE

Surgical stabilization of the Atlas vertebrae is indicated for severe atlantoaxial instability (AAI) in patients with Down syndrome (DS). This study aims to evaluate the morphological characteristics of the Atlas lateral mass (ALM) in patients with DS with regard to safe instrumentation for surgical stabilization and to compare them with non-syndromic group.

METHODS

This multicenter, retrospective, case-control study included age- and sex-matched patients with and without DS aged > 7 years with a cervical computed tomography (CT) scan. After three-dimensional CT reconstruction, nine parameters were evaluated for both groups. All included measurements were performed by a neuroradiologist who was blinded to clinical data.

RESULTS

Forty-three of 3,275 patients with DS were included in this study. Matching number of consecutive patients without DS were identified (mean age: 16 years). Patients with DS were significantly shorter than those without DS. Seven of nine parameters related to ALM were significantly lower in patients with DS than in those in the control group, including anterior wall height (AH), posterior wall height (PH), their ratio, and arch-ALM angle. On adjusting data for patient height, patients with DS had a smaller PH, lower PH/AH ratio, and steeper arch-ALM angle than the control group.

CONCLUSIONS

Patients with DS had a smaller posterior ALM wall and a steeper arch-ALM angle than the control group without DS. This information is important for surgical planning of safe posterior ALM exposure and safe instrumentation for surgical stabilization in patients with DS.

Clinical effect and prognosis of transoral or endoscope-assisted transoral release for irreducible atlantoaxial dislocation: A retrospective cohort study

Background

The clinical applications of endoscope-assisted transoral release for irreducible atlantoaxial dislocations are limited. This study aimed to investigate the clinical effect and prognostic factors of traditional and endoscope-assisted transoral release, as well as posterior reduction and fixation, in treating irreducible atlantoaxial dislocations.

Materials and methods

We conducted a retrospective study on 59 patients with irreducible atlantoaxial dislocation who underwent either traditional or endoscope-assisted transoral release, posterior fixation, and fusion between January 2018 and January 2023. Various data, including surgical time, blood loss, drainage volume, oral intake, hospital stay, complications, and neurological status (assessed by the Japanese Orthopedic Association [JOA] score and Oswestry Disability Index [ODI]), were recorded. Imaging parameters such as the atlantodontoid interval (ADI), space available for the cord (SAC), and cervicomedullary angle (CMA) were analyzed and compared. In addition, the correlation between ODI, JOA and patient age, course of disease, preoperative ADI, SAC and CMA were analyzed.

Results

No significant differences were observed in age, sex, BMI, preoperative ADI, preoperative SAC, or preoperative CMA. All patients achieved excellent reduction with no significant differences between the two groups. Patients in the endoscopic group experienced significantly reduced blood loss, earlier oral intake, and shorter hospital stays compared to those in the open group (P < 0.05). The ODI and JOA scores improved significantly in both groups at 1, 6, 12, 18, and 24 months postoperatively (P < 0.05). Postoperative ADI, SAC, and CMA values in both groups were significantly better than preoperative values (P < 0.001). The patient age, course of disease and the preoperative ADI were negatively correlated with the postoperative ODI and the JOA improvement ratio (P < 0.01), and the preoperative SAC and preoperative CMA had positive correlations with the postoperative ODI and the JOA improvement ratio (P < 0.01) at 6, 12 and 24 months postoperatively.

Conclusion

Patient age, course of disease, preoperative ADI, SAC and CMA are correlated with the operative prognosis of irreducible atlantoaxial dislocation. The endoscope-assisted transoral approach, compared to the traditional transoral approach, is minimally invasive, resulting in less operative blood loss, earlier oral intake and a shorter length of hospital stay, which could be offered as an alternative for irreducible atlantoaxial dislocation.

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.

Automated Segmentation and Diagnostic Measurement for the Evaluation of Cervical Spine Injuries Using X-Rays

Accurate assessment of cervical spine X-ray images through diagnostic metrics plays a crucial role in determining appropriate treatment strategies for cervical injuries and evaluating surgical outcomes. Such assessment can be facilitated through the use of automatic methods such as machine learning and computer vision algorithms. A total of 852 cervical X-rays obtained from Gachon Medical Center were used for multiclass segmentation of the craniofacial bones (hard palate, basion, opisthion) and cervical spine (C1-C7), incorporating architectures such as EfficientNetB4, DenseNet201, and InceptionResNetV2. Diagnostic metrics automatically measured using computer vision algorithms were compared with manually measured metrics through Pearson's correlation coefficient and paired t-tests. The three models demonstrated high average dice coefficient values for the cervical spine (C1, 0.93; C2, 0.96; C3, 0.96; C4, 0.96; C5, 0.96; C6, 0.96; C7, 0.95) and lower values for the craniofacial bones (hard palate, 0.69; basion, 0.81; opisthion, 0.71). Comparison of manually measured metrics and automatically measured metrics showed high Pearson's correlation coefficients in McGregor's line (r = 0.89), space available cord (r = 0.94), cervical sagittal vertical axis (r = 0.99), cervical lordosis (r = 0.88), lower correlations in basion-dens interval (r = 0.65), basion-axial interval (r = 0.72), and Powers ratio (r = 0.62). No metric showed adjusted significant differences at P < 0.05 between manual and automatic metric measuring methods. These findings demonstrate the potential of multiclass segmentation in automating the measurement of diagnostic metrics for cervical spine injuries and showcase the clinical potential for diagnosing cervical spine injuries and evaluating cervical surgical outcomes.

Autologous rib grafts for craniocervical junction surgery in children: a clinical application

OBJECTIVE

Autologous iliac bone is commonly used as a bone graft material to achieve solid fusion in craniocervical junction (CVJ) surgery. However, the developing iliac bone of children is less than ideal as a bone graft material. The matured rib bone of children presents a potential substitute material for iliac bone. The aim of this study was to evaluate the efficacy of autologous rib grafts for craniocervical junction surgery in children.

METHODS

The outcomes of 10 children with abnormalities of the craniocervical junction who underwent craniocervical junction surgery between January 2020 and December 2022 were retrospectively reviewed. All patients underwent posterior fusion and internal fixation surgery with autologous rib grafts. Pre- and post-operative images were obtained and clinical follow-ups were conducted to evaluate neurological function, pain level, donor site complications, and bone fusion rates.

RESULTS

All surgeries were successful. During the 8- to 24-month follow-up period, all patients achieved satisfactory clinical results. Computed tomography at 3-6 months confirmed successful bone fusion and regeneration of the rib defect in all patients with no neurological or donor site complications.

CONCLUSION

Autologous rib bone is a safe and effective material for bone grafting in craniocervical junction fusion surgery for children that can reduce the risks of donor site complications and increase the amount of bone graft, thereby achieving a higher bone fusion rate.

Metabolic and other morbid complications in congenital generalized lipodystrophy type 4

Morbidity and mortality rates in patients with autosomal recessive, congenital generalized lipodystrophy type 4 (CGL4), an ultra-rare disorder, remain unclear. We report on 30 females and 16 males from 10 countries with biallelic null variants in CAVIN1 gene (mean age, 12 years; range, 2 months to 41 years). Hypertriglyceridemia was seen in 79% (34/43), hepatic steatosis in 82% (27/33) but diabetes mellitus in only 21% (8/44). Myopathy with elevated serum creatine kinase levels (346-3325 IU/L) affected all of them (38/38). 39% had scoliosis (10/26) and 57% had atlantoaxial instability (8/14). Cardiac arrhythmias were detected in 57% (20/35) and 46% had ventricular tachycardia (16/35). Congenital pyloric stenosis was diagnosed in 39% (18/46), 9 had esophageal dysmotility and 19 had intestinal dysmotility. Four patients suffered from intestinal perforations. Seven patients died at mean age of 17 years (range: 2 months to 39 years). The cause of death in four patients was cardiac arrhythmia and sudden death, while others died of prematurity, gastrointestinal perforation, and infected foot ulcers leading to sepsis. Our study highlights high prevalence of myopathy, metabolic abnormalities, cardiac, and gastrointestinal problems in patients with CGL4. CGL4 patients are at high risk of early death mainly caused by cardiac arrhythmias.

Physiotherapeutic Approach Towards Sensory and Motor Recovery in a Patient With Lateral Mass Fixation: A Report of a Rare Case

Atlantoaxial dislocations (AAD) are a diverse set of C1-C2 rotatory subluxations that include the inferior and superior axial facet articulations. C1-C2 segments are both covered by cranial-cervical ligaments, indicating that AAD would damage both joints. Whenever the posterior elements are missing or impaired, lateral mass screw fixation has replaced alternative posterior cervical fixation procedures as the preferred treatment for securing the sub-axial cervical spine. An increase in muscle tone, hyperreflexia, pathological reflexes, digit/hand clumsiness, and gait deviations caused by spinal cord compression at the cervical level are the most common clinical features. A 23-year-old female patient came with the chief complaint of weakness, tingling sensation, and numbness in both upper and lower limbs along with imbalance while walking. She had a history of falls which was managed conservatively. As the symptoms progressed, an MRI, a CT scan, and an X-ray of the neck were done to rule out the level of injury which revealed AAD, and the patient was operated on for C1-C2 lateral mass fixation. Post-operatively, the patient was referred to the physiotherapy department for further management. The patient's quality of life and daily functioning were positively affected after undergoing early intervention as measured by the Functional Independence Measure, Neck Disability Index, Berg Balance Scale, and Dynamic Gait Index.

Severe traumatic atlantoaxial dislocation and type III odontoid fracture treated with occipitocervical fixation: a case report

The combination of atlantoaxial joint dislocation accompanied by an odontoid process fracture is exceptionally rare, with only a few cases reported. The estimated frequency of these cases is < 2% of all upper cervical spine injuries. In this report, the authors describe an unusual case of traumatic atlantoaxial dislocation with a type III odontoid fracture in a 44-year-old male patient. Before the diagnosis, the patient had a history of seeking a masseur for a neck massage. Subsequently, the patient underwent occipitocervical stabilization to address the underlying condition. This procedure aims to treat the instability between the skull and cervical spine and should be considered in the treatment planning if the patient's anatomy suits it.

Unexpected postoperative atlantoaxial rotatory subluxation after excision of melanocytic nevi of the head and neck in older children: two case reports and literature review

Postoperative atlantoaxial rotatory subluxation (AARS) is a rare complication that develops almost exclusively in children following oropharyngeal and otologic surgeries, proposing that oropharyngeal inflammatory responses and excessive head rotation are responsible factors. However, there have been no reports of AARS after excision of a nevus on the head and neck. Here, we present two cases of AARS following limited head rotation during simple nevus excision. Patient 1, a 9-year-old girl, complained of neck pain and limited range of motion after excision of the nevus on the neck. After 2 months, computed tomography and magnetic resonance imaging finally revealed AARS with a ruptured transverse atlantal ligament. A month of halo traction was required for the treatment. Patient 2, an 11-year-old girl, presented with immediate pain and limited neck extension after tissue expander insertion under the upper chest and excision of the nevus on her left cheek. The diagnosis was promptly made using cervical spine radiography. A cervical collar was applied for 1 month. Both patients recovered without any complications after treatment. This report highlights the importance of suspicion for AARS after surgery regardless of surgical duration or amount of head rotation.

Atlantoaxial subluxation and Down syndrome: A cross-sectional analysis

Background

Atlantoaxial subluxation (AAS) is a diagnosis describing misalignment of the C1 vertebra relative to C2. Excessive translation of this joint, located adjacent to the medullary brain stem, can lead to devastating neurological consequences. A higher prevalence of AAS within the Down syndrome (DS) population has been well-established. This study aims to establish a prevalence rate of DS in patients hospitalized for AAS and compare outcomes between AAS patients with and without DS.

Methods

This study utilized the National Inpatient Sample (NIS) provided by the Healthcare Cost and Utilization Project (HCUP). In accordance with HCUP 2023 Clinical Classifications Software Refined files, data were queried using the International Classification of Diseases 10th Edition codes for DS and AAS. Demographics, comorbidities, hospital course, and outcomes were examined and compared using binary and linear multivariate regression. IBM SPSS software was used for data analysis.

Results

Of the 213,095 patients in the NIS database admitted between 2016 and 2020 with AAS as their primary diagnosis, 7.2% were DS patients. DS patients were significantly younger (26.56 ± 20.81 vs. 49.39 ± 27.63, P < 0.01), less likely to be female (33.30% vs. 52.10%), and had fewer comorbidities (diabetes mellitus, hypertension, and hyperlipidemia) than non-DS patients. There was no significant difference in likelihood to undergo surgical fusion between DS patients and non-DS patients with AAS.

Conclusion

This large-scale study using NIS data determined that 7.2% of all patients admitted to hospitals for AAS are DS patients. The analysis of demographics, hospital course, and outcomes can influence the development of treatment protocols for AAS in the DS population.

Whole-Exome Sequencing Analysis Identifies Risk Genes in Atlantoaxial Dislocation Patients with Sandwich Fusion

Sandwich fusion of Klippel-Feil syndrome (KFS), which is a rare congenital disorder involving the fusion of cervical vertebrae, poses significant challenges in the diagnosis and treatment of atlantoaxial dislocation (AAD). While the disorder's genetic basis is not well-understood, the rarity of the sandwich fusion makes it difficult to study. Whole-exome sequencing (WES) was conducted on 68 unrelated Chinese patients with sandwich fusion. The study compared their genetic data with a control group of 219 individuals without musculoskeletal disorders. Various analyses, including mutational burden assessments, were employed to identify potential pathogenic genes. The study identified significant genetic variations in patients with sandwich fusion, highlighting genes like KMT5A, HYDIN, and PCDHB4 as potential contributors. Notably, severe cases exhibited oligogenic effects, with mutations in genes like MEOX1 associated with the severity of spinal issues. These findings offer critical insights into the genetic basis of sandwich fusion and provide a foundation for future research and therapeutic development.

Comprehensive Physiotherapeutic Management of Atlas Occipitalization: A Case Report

The atlas (C1) and occipital bone at the base of the skull fuse together in atlas occipitalization, an uncommon congenital abnormality. Because it can result in cervical spine instability, nerve impingement, and related symptoms including stiffness, pain, and neurological impairments, it poses a challenging therapeutic problem. We describe the case of a female patient, 27 years old, who had gradually deteriorating neck discomfort, stiffness, and limited cervical mobility for six years prior to presentation. Her symptoms worsened over time despite conservative treatment, so more testing was necessary. Atlas occipitalization, congenital fusion at the C7 and D1 vertebrae, and other related cervical spine pathologies were identified by imaging examinations. The intricacies of atlas occipitalization and related cervical spine pathologies are highlighted in this case study, along with the diagnostic difficulties and interdisciplinary therapeutic strategy needed to address them. To improve cervical range of motion (ROM), lessen discomfort, and improve functional results, the patient underwent a thorough musculoskeletal examination and was given a customized physiotherapeutic intervention.

Vertebral artery dissection caused by atlantoaxial dislocation in a patient with Marfan syndrome

A small number of case reports have documented a link between atlantoaxial dislocation (AAD) and vertebral artery dissection (VAD), but this association has never been described in patients with hereditary connective tissue disorders. We present a case of an 18-year-old female patient, diagnosed with Marfan syndrome since the age of one, who underwent brain MRA for intracranial aneurysm screening revealing tortuosity of the internal carotid and vertebral arteries as well as atlantoaxial dislocation. Since the patient was asymptomatic, a wait-and-see approach was chosen, but a follow-up MRA after 18 months showed the appearance of a dissecting pseudoaneurysm of the V3 segment of the left vertebral artery. Despite the patient being still asymptomatic, it was decided to proceed with C1-C2 stabilization to prevent further vascular complications. Follow-up imaging showed realignment of the atlantoaxial joint and reduction of the dissecting pseudoaneurysm of the left vertebral artery. In our patient, screening MRA has led to the discovery of asymptomatic arterial and skeletal abnormalities which, if left untreated, might have led to severe cerebrovascular complications. Therefore, AAD correction or close monitoring with MRA should be provided to MFS patients with this craniovertebral junction anomaly, even if asymptomatic.

Comparison of the diagnostic performance of the Swischuk line method and the anterior atlantodental interval method in atlantodental subluxation

BACKGROUND

Atlantodental subluxation (ADS) is a serious condition that can result in sudden death. Measuring the anterior atlantodental interval (AADI method) is the gold standard for diagnosis but the complex anatomy of this region can make diagnosis difficult, especially for beginners. Therefore, we would like to use a simpler method, the Swischuk line method, to diagnose ADS. The purpose of our study was to evaluate the diagnostic performance of the Swischuk line method for ADS on lateral cervical spine radiographs compared to the AADI method.

METHODS

A retrospective study was conducted with patients who presented with ADS (ADS group, n = 32, mean age 57.78 years, age range 34-82 years, 10 men, 21 women) and an age- and sex-matched control group (n = 32). The diagnostic performance of the AADI method and the Swischuk line method for ADS was assessed using lateral cervical radiographs in both flexion and neutral postures by an experienced musculoskeletal radiologist (reader 1), a senior resident (reader 2), and a junior resident (reader 3) in the radiologic department.

RESULTS

In the flexion posture, the AADI method and the Swischuk line method showed excellent diagnostic performance with AUCs > 0.9 for readers 1 2 and reader 3. In a neutral posture, the diagnostic performance of the AADI and Swischuk line methods was decreased. With a 1 mm cut-off value using the Swischuk line method in flexion posture, the sensitivity was 75% or more, the specificity was 100%, and the accuracy was 87.50% or more 90.63% for all readers. With a 2 mm cut-off value, the sensitivity was low (37.50-46.88%) but the specificity was 100% for all three readers. In a neutral posture, the sensitivity for both methods decreased, though specificity remained high (> 80%).

CONCLUSIONS

The Swischuk line method was found to be reliable and showed high sensitivity and specificity with a cut-off value of 1 mm for the diagnosis of ADS in cervical lateral radiographs in flexion posture. It can be used as a complement to the AADI method.

Traumatic posterior dislocation of atlanto-axial joint with anterior arch fracture in the patient of atlanto-occipital assimilation: A case report

INTRODUCTION AND IMPORTANCE

Traumatic atlanto-axial dislocation (AAD) is relatively uncommon and can pose life-threatening risks. In this case, we describe a patient with a combination of AAD, an anterior arch fracture of the atlas, and a rare congenital anomaly known as atlanto-occipital assimilation (AOA).

CASE PRESENTATION

A 70-year-old man presented with posterior neck pain and right-sided torticollis following an accident that collision with a car while riding an electric scooter. Radiographic findings confirmed posterior AAD with anterior arch fracture of C1 in the inherent setting of AOA. The patient showed no neurologic deficit, so a closed reduction technique using Gardner-Wells tongs was attempted in an awakened state, and successful reduction could achieve without a neurologic deficit. After about three months of rigid brace application, head and neck motion was allowed, and no recurrence of dislocation or cervical pain occurred during the follow-up period of about one year.

CLINICAL DISCUSSION

Because the posterior AAD is usually accompanied by anterior arch fracture of atlas, the transverse atlantal ligament remained intact. So nonoperative management after manual reduction was possible. The presence of a C1 anterior arch fracture observed in our case can be regarded as an indicator predicting the success of closed reduction of AAD.

CONCLUSION

Our case highlighted the successful nonoperative management of traumatic posterior AAD with an accompanying anterior arch fracture of the atlas in a peculiar inherent combination of AOA through the closed reduction technique and rigid cervical brace application.

Multimodal Management of Coexisting Atlantoaxial Subluxation and Spinal Stenosis in an Older Adult: A Case Report and Literature Review

This case report investigates the diagnostic and therapeutic challenges caused by the coexistence of atlantoaxial subluxation and spinal stenosis in a 70-year-old male patient with chronic progressive numbness in both hands. A detailed assessment showed that the patient's symptoms were primarily caused by spinal stenosis, not atlantoaxial subluxation. Considering the patient's age and preference for nonsurgical treatment, a conservative chiropractic care plan was implemented, significantly improving his symptoms and quality of life. This case highlights the potential benefit of conservative chiropractic care in managing such complex cases, emphasizes the need for meticulous diagnosis, and requires further research to validate these findings and develop comprehensive management guidelines.

Study on articular surface morphology of atlantoaxial lateral mass based on differential manifold

OBJECTIVES

To propose a surface reconstruction algorithm based on a differential manifold (a space with local Euclidean space properties), which can be used for processing of clinical images and for modeling of the atlantoaxial joint. To describe the ideal anatomy of the lateral atlantoaxial articular surface by measuring the anatomical data.

METHODS

Computed tomography data of 80 healthy subjects who underwent cervical spine examinations at our institution were collected between October 2019 and June 2022, including 46 males and 34 females, aged 37.8 ± 5.1 years (28-59 years). A differential manifold surface reconstruction algorithm was used to generate the model based on DICOM data derived by Vision PACS system. The lateral mass articular surface was measured and compared in terms of its sagittal diameter, transverse diameter, articular surface area, articular curvature and joint space height.

RESULTS

There was no statistically significant difference between left and right sides of the measured data in normal adults (P > 0.05). The atlantoaxial articular surface sagittal diameter length was (15.83 ± 1.85) and (16.22 ± 1.57) mm on average, respectively. The transverse diameter length of the articular surface was (16.29 ± 2.16) and (16.49 ± 1.84) mm. The lateral articular surface area was (166.53 ± 7.69) and (174.48 ± 6.73) mm2 and the curvature was (164.03 ± 5.27) and (153.23 ± 9.03)°, respectively. The joint space height was 3.05 ± 0.11mm, respectively. There is an irregular articular space in the lateral mass of atlantoaxial, and both upper and lower surfaces of the articular space are concave. A sagittal plane view shows that the inferior articular surface of the atlas is mainly concave above; however, the superior articular surface of the axis is mainly convex above. In the coronal plane, the inferior articular surface of the atlas is mostly concave above, with most concave vertices located in the medial region, and the superior articular surface of the axis is mainly concave below, with most convex vertices located centrally and laterally.

CONCLUSION

A differential manifold algorithm can effectively process atlantoaxial imaging data, fit and control mesh topology, and reconstruct curved surfaces to meet clinical measurement applications with high accuracy and efficiency; the articular surface of the lateral mass of atlantoaxial mass in normal adults has relatively constant sagittal diameter, transverse diameter and area. The distance difference between joint spaces is small, but the shape difference of articular surfaces differs greatly.

Radiological assessment and follow-up of a nonsurgically treated odontoid process fracture after a motor vehicle accident in Egypt: a case report

An odontoid process fracture is a serious type of cervical spine injury. This injury is categorized into three types based on the location of the fracture. Severe or even fatal neurological deficits can occur due to associated cord injury, which can result in complete quadriplegia. Computed tomography is the primary diagnostic tool, while magnetic resonance imaging is used to evaluate any associated cord injuries. These injuries can occur either directly from the injury or during transportation to the hospital if mishandled. There are two main treatment approaches: surgical fixation or external nonsurgical fixation, with various types and models of fixation devices available. In this case study, computed tomography follow-up confirmed that external fixation can yield successful results in terms of complete healing, even in cases complicated by other factors that may impede healing, such as pregnancy.

C1-C2 coronal and sagittal joint angle based treatment algorithm for the need of transoral odointectomy in complex craniovertebral junction anomalies with Clinico-Radiological outcome analysis

OBJECTIVE

Craniovertebral junction (CVJ) pathology by virtue of its complexity is a surgical challenge in the realm of neurosurgery. We analyzed the need for transoral odointectomy in view of their C1-C2 joint coronal and sagittal angle of 58 patients with complex CVJ anomalies treated surgically. The clinical and radiological outcome of the patients was assessed and a treatment algorithm is proposed.

METHODS

A total of 58 cases were included in the Prospective study over the period of 2 years. Patients were evaluated clinically, investigated, and operated with reduction and rigid internal fixation with screws and rod. The clinical outcome was measured by Modified Japanese orthopedic association score(mJOA) and radiologically by conventional craniometrics indices. Paired 't' test used for statistical analysis.

RESULTS

Mean age of patients: 30 years, with mean, follow up: 20.5 months. 46(80%) patients were operated by posterior and 12(20%) by combined approach (anterior transoral with posterior). Occipitocervial fixation was done in 15(25.8%) cases and C1-C2 fixation in 43(74.2%) cases. As compared to patients with low coronal angle, the patient with coronal angle >65° needed anterior decompression (87.5%) and all (100%) had Occipitocervical fixation. Clinical outcome analysis showed significant improvement in mean mJOA score (preop 11.9 Vs postop 14.6) after surgery. All craniometrics indices were significantly improved after surgery. The overall complication rate was 10% with a mortality of 1.7%. 6 months follow up completed in all patients with a 100% fusion rate.

CONCLUSION

Occipitocervical fixation and anterior decompression is required in increased C1-C2 joint CA (>65°) for bony realignment and adequate decompression. Measurement of C1-C2 joint coronal and sagittal angle in complex CVJ anomalies will easily anticipate the surgeon regarding the need for anterior decompression inform of transoral odointectomy.

STRANGULATION-INDUCED ATLANTOAXIAL ROTATORY SUBLUXATION TREATED WITH CLOSED REDUCTION

BACKGROUND

Cervical subluxation is a broad class of injuries in which there are degrees of misalignment of vertebral bodies in relationship to adjacent vertebra. Atlantoaxial rotatory subluxation (AARS) is a subtype of cervical subluxation resulting from exaggerated rotation of the C1-C2 complex. Inflammatory, infectious, post-surgical, and traumatic etiologies are recognized and well-described. AARS is predominantly seen in children and occurs rarely in adults.

CASE REPORT

We submit the case of an otherwise healthy adult male patient presenting to the emergency department with strangulation-induced C1-C2 subluxation with a rotational component that was treated at the bedside by neurosurgery with closed reduction. Why Should an Emergency Physician Be Aware of This? Clinicians must consider a broad range of serious pathologies in a patient presenting with torticollis, especially in the setting of strangulation. Although extremely rare in adults, AARS must be considered in the differential diagnosis, as early identification increases the likelihood of successful nonoperative treatment.

Overstrain on the longitudinal band of the cruciform ligament during flexion in the setting of sandwich deformity at the craniovertebral junction: a finite element analysis

BACKGROUND CONTEXT

In the setting of "sandwich deformity" (concomitant C1 occipitalization and C2-3 nonsegmentation), the C1-2 joint becomes the only mobile joint in the craniovertebral junction. Atlantoaxial dislocation develops earlier with severer symptoms in sandwich deformity, which has been hypothesized to be due to the repetitive excessive tension in the ligaments between C1 and C2.

PURPOSE

To elucidate whether and how the major ligaments of the C1-2 joint are affected in sandwich deformity, and to find out the ligament most responsible for the earlier development and severer symptoms of atlantoaxial dislocation in sandwich deformity.

STUDY DESIGN

A finite element (FE) analysis study.

METHODS

A three-dimensional FE model from occiput to C5 was established using anatomical data from a thin-slice CT scan of a healthy volunteer. Sandwich deformity was simulated by eliminating any C0-1 and C2-3 segmental motion respectively. Flexion torque was applied, and the range of motion of each segment and the tension sustained by the major ligaments of C1-2 (including the transverse and longitudinal bands of the cruciform ligament, the alar ligaments, and the apical ligament) were analyzed.

RESULTS

Tension sustained by the longitudinal band of the cruciform ligament and the apical ligament during flexion is significantly larger in the FE model of sandwich deformity. In contrast, tension in the other ligaments is not significantly changed in the sandwich deformity model compared with the normal model.

CONCLUSIONS

Considering the importance of the longitudinal band of the cruciform ligament to the stability of the C1-2 joint, our findings implicate that the early onset, severe dislocation, and unique clinical manifestations of atlantoaxial dislocation in patients with sandwich deformity are mainly due to the enlarged force loaded on the longitudinal band of the cruciform ligament.

CLINICAL SIGNIFICANCE

The enlarged force loaded on the longitudinal band of the cruciform ligament can add to its laxity and thus reducing its ability to restrict the cranial migration of the odontoid process. This is in accordance with our clinical experience that dislocation of the atlantoaxial joint in patients with sandwich deformity is mainly craniocaudal, which means severer cranial neuropathy, Chiari deformity, and syringomyelia, and more difficult surgical treatment.

Traumatic Posterior Atlantoaxial Dislocation With an Associated Fracture: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVE

To investigate the clinical presentation, mechanism of injury, patients' characteristics, diagnosis, treatment, and prognosis of traumatic posterior atlantoaxial dislocation with fracture (TPAD).

BACKGROUND

TPAD is an extremely rare entity, with a limited number of cases reported in the literature. Although rare, a thorough understanding of the pathogenesis and management of such cases is required due to the high risk of spinal cord compression and the severity of neurological deficits. We conducted a systematic review of all cases of TPAD with fractures reported in the literature.

METHODS

This systematic review was conducted following the Preferred Reporting Items for Systematic reviews and Meta-analysis guidelines. Relevant literature was retrieved from the Pubmed database. All published English-written studies involving human subjects with relevant data regarding TPAD were included.

RESULTS

Two case series and 20 case reports published between 1924 and 2021 describing 28 patients with TPAD were included. The median age at presentation was 51.5 years, with male predominance (83%). The most common fracture pattern was Anderson and D'alonzo type II odontoid fracture (78%). Neurological exam at presentation was intact in 52% of patients. The primary diagnostic imaging was computed tomography employed in 96% of cases. The management consisted of 2 stages protocol, initially, a temporary axial traction was employed (54%), and later definitive surgical treatment was employed (93%). The posterior surgical approach was favored in 82% of cases.

CONCLUSION

TPAD with fracture occurred in the majority of cases with Anderson and D'alonzo type II odontoid fracture, predominantly in males. Diagnosis is usually established based on computed tomography imaging; further imaging may not be indicated as it does not seem to alternate the patient's management course. Surgical intervention was employed in almost all cases, with favored results through posterior C1-C2 fusion.

LEVEL OF EVIDENCE

Level-IV.

Radiological Features in Type II Odontoid Fractures in Older Adults After High- and Low-Energy Trauma

STUDY DESIGN

Retrospective study.

OBJECTIVES

Although type II odontoid fractures mainly occur due to high-energy trauma (HET), the number of odontoid type II fractures after low-energy trauma (LET) in the elderly is on the rise. However, there is a paucity of conclusive evidence on the relationship between trauma mechanism and cervical spine alignment in the elderly population. Consequently, we examined cervical alignment and osteoporotic and osteoarthritic patterns in elderly individuals (aged ≥65 years) with type II odontoid fractures.

METHODS

We retrospectively assessed cervical spine alignment in 76 elderly individuals who experienced type II odontoid fractures after HET (n = 36) and LET (n = 40) between 2005 and 2020. Osteoporotic and osteoarthritic changes on computed tomography and cervical alignment parameters on sagittal plane radiographs were examined.

RESULTS

Moderate and severe osteoporosis of the dens-body junction and osteoarthritis of the atlanto-odontoid joint were more prevalent in the LET than the HET group (P<.005). The anterior atlantodental interval (ADI) was significantly smaller in the LET group than in the HET group (.7 [.7] millimeter vs 1.2 [.8] mm; P=.003). An ADI equal 0 mm indicative for anterior fusion of C1/C2 was present in 37.5% of patients of the LET group. The C0-C2 angle, C1-C2 lordosis, and C2-C7 sagittal vertical axis were significantly different (HET vs LET: 33.2 [7.2]° vs 41.6 [11.4]°, P=.005; 28.1 [7.0]° vs 34.0 [8.0]°, P=.002; and 16.1 [11.1] millimeter vs 27.1 [12.4] mm, P=.008; respectively).

CONCLUSION

Significantly higher rates of osteoporotic and degenerative changes were observed after LET. Furthermore, previous cervical malalignment represents a risk factor for type II odontoid fractures after LET.

Advances in surgical treatment for atlantoaxial instability focusing on rheumatoid arthritis: Analysis of a series of 67 patients

AIM

An estimated 88% of rheumatoid arthritis (RA) patients experience various degrees of cervical spine involvement. The excessive movement of the atlantoaxial joint, which connects the occiput to the upper cervical spine, results in atlantoaxial instability (AAI). AAI stabilization is usually achieved by C1 lateral mass-to-C2 pedicle screw-rod fixation (LC1-PC2 fixation), which is technically challenging in RA patients who often show destructive changes in anatomical structures. This study aimed to analyze the clinical results and operative experiences of C1-C2 surgery, with emphasis on the advancement of image-guided surgery and augmented reality (AR) assisted navigation.

METHODS

We presented our two decades of experience in the surgical management of AAI from April 2004 to November 2022.

RESULTS

We have performed surgery on 67 patients with AAI, including 21 traumatic odontoid fractures, 20 degenerative osteoarthritis, 11 inflammatory diseases of RA, 5 congenital anomalies of the os odontoideum, 2 unknown etiologies, 2 movement disorders, 2 previous implant failures, 2 osteomyelitis, 1 ankylosing spondylitis, and 1 tumor. Beginning in 2007, we performed LC1-PC2 fixation under C-arm fluoroscopy. As part of the progress in spinal surgery, since 2011 we used surgical navigation from presurgical planning to intraoperative navigation, using the preoperative computed tomography (CT) -based image-guided BrainLab navigation system. In 2021, we began using intraoperative CT scan and microscope-based AR navigation.

CONCLUSION

The technical complexities of C1-C2 surgery can be mitigated by CT-based image-guided surgery and microscope-based AR navigation, to improve accuracy in screw placement and overall clinical outcomes, particularly in RA patients with AAI.

C1-C2 subluxation in enthesitis-related arthritis: two case reports and literature review of ten cases

BACKGROUND

C1-C2 subluxation is a rare complication of enthesitis-related arthritis (ERA). If left untreated, it may lead to functional impairment or cervical spinal cord compression. This study aims to highlight key points regarding the management of C1-C2 subluxation in ERA.

CASE PRESENTATION

We present two cases of C1-C2 subluxation: an 8-year-old boy with ERA and 16-year-old boy with ERA with bilateral sacroiliitis. Ten cases of ERA in the literature were reviewed. The diagnosis of C1-C2 subluxation is mostly based on radiographs and cervical spine computed tomography. All patients were treated with non-steroidal anti-inflammatory drugs. Six ERA patients were treated surgically for cervical fusion. Most ERA patients with sacroiliitis had cervical collar protection. Neurologic abnormalities after treatment were not reported. Despite the use of cervical collar, cervical fusion and persisting ankylosis were found in two ERA patients with sacroiliitis without surgical treatment.

CONCLUSIONS

Cervical spine protection and ruling out spinal cord compression should be prioritized, in addition to controlling the underlying inflammation in ERA. Cervical halter traction may be applied after severe cervical inflammation is excluded. To reduce the risk of complications, early recognition and appropriate treatments of C1-C2 subluxation in ERA are essential.

Atlantoaxial Subluxation in a 10-Year-Old Girl With Down Syndrome: A Case Report

Down syndrome is the most common inherited chromosomal disorder caused by trisomy 21. Atlantoaxial instability (AAI) is more common in children with Down syndrome, resulting from ligament laxity and odontoid dysplasia. We report the case of a 10-year-old girl with Down syndrome submental. She came to the ER with a history of abnormal gait for one week and was admitted with a case of ataxia for investigations. Moreover, we discovered that she had atlantoaxial subluxation, which was treated surgically.

A pictorial review of imaging findings associated with upper cervical trauma

The diagnosis of cervical spine injury in the emergency department remains a critical skill of emergency room physicians as well as radiologists. Such diagnoses are often associated with high morbidity and mortality unless readily identified and treated appropriately. Both computed tomography (CT) and magnetic resonance imaging (MRI) often are crucial in the workup of spinal injury and play a key role in arriving at a diagnosis. Unfortunately, missed cervical spine injuries are not necessarily uncommon and often precede detrimental neurologic sequalae. With the increase in whole-body imaging ordered from the emergency department, it is critical for radiologists to be acutely aware of key imaging features associated with upper cervical trauma, possible mimics, and radiographic clues suggesting potential high-risk patient populations. This pictorial review will cover key imaging features from several different imaging modalities associated with upper cervical spine trauma, explore patient epidemiology, mechanism, and presentation, as well as identify confounding radiographic signs to aid in confident and accurate diagnoses.

Posterior pedicle screw fixation combined with local steroid injections for treating axial eosinophilic granulomas and atlantoaxial dislocation: A case report

BACKGROUND

Eosinophilic granuloma (EG) is a proliferative condition that affects the cells of bone tissue. There are no specific clinical signs or imaging manifestations in the early stages of the disease, making it simple to overlook and misdiagnose. Because of the disease's rarity, there is presently no standardized treatment principle. There are few accounts of such occurrences affecting the axis among children. We discovered a case of a child whose EG resulted in atlantoaxial joint dislocation and destruction of the axial bone.

CASE SUMMARY

After having pharyngeal discomfort for more than six months without a clear explanation, a 6-year-old boy was brought to our hospital. Following a careful evaluation, the pathology indicated a strong likelihood of an axial EG. Ultimately, we decided to treat the boy with posterior pedicle screw fixation and local steroid injections.

CONCLUSION

EGs of the upper cervical spine are quite uncommon in children, and they are exceedingly easy to overlook or misdiagnose. Posterior pedicle screw fixation and local steroid injections are effective treatments for patients with axial EGs affecting the atlantoaxial junction.

Delayed Diagnosis of Cervical Epidural Hematoma in a 3-Year-Old Boy: A Case Report

CASE

A 3-year-old boy presented to the emergency department with torticollis after a fall. With normal cervical radiographs and neurologic exam, he was diagnosed with cervical strain and discharged. After 2-week progressive symptoms, he was referred to a pediatric spine surgeon. Magnetic resonance imaging (MRI) revealed a cervical epidural hematoma, which was then surgically evacuated. He recovered fully and remains symptom-free 2 years later.

CONCLUSION

Pediatric spinal epidural hematoma is a rare condition with potentially serious outcomes yet often nonspecific symptoms. Timely management based on a comprehensive evaluation of symptoms and imaging findings is crucial in improving patient outcomes.

Atlantoaxial Instability after Treatment of Atlantoaxial Rotatory Fixation: A Case Report

Introduction

We encountered a case of atlantoaxial subluxation (AAS) after treatment of atlantoaxial rotatory fixation (AARF). Reports of developing AAS after AARF are extremely rare.

Case Report

An 8-year-old male who feels neck pain was diagnosed with AARF type II according to the Fielding classification. Computed tomography (CT) showed that the atlas was rotated 32° to the right relative to the axis. Neck collar, Glisson traction, and reduction under anesthesia were performed. Five months after the onset of AARF, the patient was diagnosed with AAS due to dilatation of atlantodental interval (ADI) and underwent posterior cervical fusion.

Conclusion

AARF treatments, such as long-term Glisson traction and reduction under general anesthesia, which exert a stress on the cervical spine, may damage the alar ligaments, apical ligaments, lower longitudinal band, and Gruber's ligament. Transverse ligament damage can also occur during the treatment of AARF, especially if AARF is refractory or requires long-term treatment. In addition, knowledge of the pathophysiology of atlantoaxial instability after AARF treatment is important.

Prevalence and radiographic features of atlantoaxial dislocation in adult patients with Kashin-Beck disease

PURPOSE

Kashin-Beck disease (KBD) is an endemic osteoarthropathy affecting the epiphyseal growth plate of multiple joints in young and adolescent patients. Previous studies have focused on the visible deformed extremities instead of the spinal radiological features, especially the atlantoaxial joint. The aim of this study was to determine the prevalence and radiographic features of atlantoaxial dislocation (AAD) in adult patients with KBD.

METHODS

This study was conducted on KBD patients in three typical endemic counties between October 2017 and November 2019. The patients were evaluated by collecting basic information, clinical signs and symptoms. They underwent dynamic cervical radiography, by which AAD was diagnosed. For those patients with confirmed or suspected AAD, computed tomography (CT) imaging was performed to observe the odontoid morphology and degenerative changes in the lateral atlantoaxial joints. Radiographic evaluations were reviewed to determine the prevalence and features of AAD.

RESULTS

A total of 39 (14.6%) of 267 KBD patients were diagnosed with AAD. Compared with the non-AAD patients, the detection rate of AAD was associated with a longer disease duration and stage and was not associated with age, sex or BMI. Thirty-two patients had symptoms at the neck or neurological manifestations, while seven had no symptoms. There were three types of morphologies of the odontoid process in AAD patients: separating in 19 cases, hypoplastic in 15 cases and intact in five cases. Anterior dislocation was noted in 29 cases, and posterior dislocation was noted in ten cases. Thirty-four cases were reducible, and five were irreducible. The lateral atlantoaxial joints had different severities of degenerative changes in 17 cases.

CONCLUSIONS

This study revealed that the prevalence of AAD was 14.6% in adult KBD patients. The radiographic features of AAD include manifestations of odontoid dysplasia and chronic degenerative changes in atlantoaxial joints. KBD patients with severe stages and longer disease duration were more vulnerable to the occurrence of AAD. We postulate that this atlantoaxial anomaly might originate from chondronecrosis of the epiphyseal growth plate of the odontoid process in young and adolescent individuals. This study may provide a clinical reference to help clinicians screen, prevent and treat AAD in adult patients with KBD.

Clinical and Radiographic Features of the Atlantoaxial Dislocation Associated With Kashin-Beck Disease

OBJECTIVES

Keshin-Beck disease (KBD) is a particular type of osteoarthritis that affects many joints. However, the deformity of atlantoaxial joint has been rarely reported in KBD, and therefore its clinical and radiograph features have not been identified.

METHODS

We reviewed data in 14 patients who were diagnosed with atlantoaxial dislocation (AAD) in KBD at our institution. The demographic data, clinical history, imaging data, operative data, and Japanese Orthopaedic Association score were collected for evaluation.

RESULTS

The mean age at presentation was 50 ± 1.7 years old. The most common features of AAD in KBD were the osteoarthritis, characterized by hypertrophic dens and anterior arch of the atlas. The average inner anteroposterior diameter (IAPD) of C1 was 28 ± 3.5 mm and the average spinal canal diameter was 14 ± 3.3 mm, which were respectively lower than the control level. Five patients had severe C1 stenosis (IAPD < 26mm). Separated odontoid process, like os odontoideum, was seen 9 patients. The tip of dens fused to C1 was observed in 4 patients; 12 patients had high-riding vertebral artery; and 5 patients had severe C1 stenosis, and they underwent C1 laminectomy with C1-C2 interarticular fusion or occipital-cervical fusion. All the patients displayed neurologic improvement after surgery.

CONCLUSIONS

The atlantoaxial level could be affected by KBD, which may lead to typical abnormalities and cause AAD. A C1 laminectomy with an C1-C2 interarticular fusion or occipital-cervical fusion is recommended for the patient with severe stenosis.

Atlantoaxial dislocation with associated type II odontoid fracture in adolescent with cervical spondylitis tuberculosis: A case report

INTRODUCTION AND IMPORTANCE

Atlantoaxial dislocation is a loss of joint stability between the C1 (atlas) and C2 (axis) spine and could be associated with type II odontoid fracture. In a few previous studies, atlantoaxial dislocation with odontoid fracture has been reported to be the complication of upper cervical spondylitis tuberculosis (TB).

CASE PRESENTATION

A 14-year-old girl came with sudden neck pain and difficulty moving her head that has worsened in the last 2 days. There was no motoric weakness in her limbs. However, tingling in both hands and feet was felt. X-ray examination showed atlantoaxial dislocation with odontoid fracture. Traction and immobilization using Garden-Well Tongs obtained the reduction of the atlantoaxial dislocation. Transarticular atlantoaxial fixation using cerclage wire and cannulated screw with an autologous graft from the iliac wing was performed through the posterior approach. A postoperative X-ray showed stable transarticular fixation with excellent screw placement.

CLINICAL DISCUSSION

The application of Garden-Well tongs as a treatment for cervical spine injury has been documented in the previous study with a low rate of complications such as pin loosening, the asymmetrical position of the pin, and superficial infection. The reduction attempt did not significantly improve Atlantoaxial dislocation (ADI). Thus surgical treatment of atlantoaxial fixation using cannulated screw and c-wire with the application of an autologous bone graft is performed.

CONCLUSION

Atlantoaxial dislocation with an odontoid fracture in cervical spondylitis TB is a rare spinal injury. The use of traction with surgical fixation is needed to reduce and immobilize atlantoaxial dislocation and odontoid fracture.

Non-Surgical Management of Upper Cervical Instability via Improved Cervical Lordosis: A Case Series of Adult Patients

Injury to the head and neck resulting from whiplash trauma can result in upper cervical instability (UCIS), in which excessive movement at C1 on C2 is observed radiologically. In some cases of UCIS there is also a loss of normal cervical lordosis. We postulate that improvement or restoration of the normal mid to lower cervical lordosis in patients with UCIS can improve the biomechanical function of the upper cervical spine, and thus potentially improve symptoms and radiographic findings associated with UCIS. Nine patients with both radiographically confirmed UCIS and loss of cervical lordosis underwent a chiropractic treatment regimen directed primarily at the restoration of the normal cervical lordotic curve. In all nine cases, significant improvements in radiographic indicators of both cervical lordosis and UCIS were observed, along with symptomatic and functional improvement. Statistical analysis of the radiographic data revealed a significant correlation (R² = 0.46, p = 0.04) between improved cervical lordosis and reduction in measurable instability, determined by C1 lateral mass overhang on C2 with lateral flexion. These observations suggest that enhancing cervical lordosis can contribute to improvement in signs and symptoms of upper cervical instability secondary to traumatic injury.

Posterior Atlantoaxial Screw Placement in a Portuguese Population: A Morphometric Analysis Based on Computed Tomography Scan Measurements

Objective  The present study aims to evaluate the screw length and trajectory angles for posterior atlantoaxial fixation in a Portuguese population, through the study of cervical computed tomography (CT) scans. Methods  Cervical CT scans of 50 adults were measured according to predefined screw trajectories of C1-C2 transarticular (C1C2TA), C1 lateral mass (C1LM), C2 pedicle (C2P), C2 pars and C2 laminar (C2L) screws. For each of these trajectories, screw length and angles were measured and compared between males and females. Results  For the C1C2TA screw trajectory, the mean length, medial, and cranial angles were 34.12 ± 3.19 mm, 6.24° ± 3.06, and 59.25° ± 5.68, respectively, and for the C1LM screw trajectory, they were 27.12 ± 2.15 mm, 15.82° ± 5.07, and 13.53° ± 4.80, respectively. The mean length, medial, and cranial angles for the C2P screw trajectory were 23.44 ± 2.49 mm, 27.40° ± 4.88, and 30.41° ± 7.27, respectively; and for the C2 pars screw trajectory, they were 16.84 ± 2.08 mm, 20.09° ± 6.83, and 47.53° ± 6,97. The mean length, lateral, and cranial angles for the C2L screw trajectory were 29.10 ± 2.48 mm, 49.80° ± 4.71, and 21.56° ± 7.76, respectively. There were no gender differences except for the lengths of the C1C2TA ( p  = 0,020) and C2L ( p  = 0,001) screws, which were greater in males than in females. Conclusion  The present study provides anatomical references for the posterior atlantoaxial fixation in a Portuguese population. These detailed data are essential to aid spine surgeons to achieve safe and effective screw placement.

Fifteen-minute consultation: Evaluation of paediatric torticollis

Torticollis refers to a state in which the neck is twisted due to excessive contraction or shortening of the muscles on one side. Congenital muscular torticollis, which is more common than acquired torticollis, has an incidence of 0.3%-1.9% among all live births. The clinical approach to torticollis depends on the age at presentation, duration of torticollis and presenting symptoms. The underlying aetiology for torticollis varies with the age of the child. Torticollis can be a presenting feature for life-threatening conditions and thus requires careful evaluation.

Establish a new parameter "horizontal view-axial angle" and explore its role in the treatment of atlantoaxial instability diseases

Objective

The objective of the study is to establish a new parameter that can be clearly measured on x-ray images to complement the description of the sagittal alignment of the craniocervical junction. The authors anticipate that this new parameter will enhance surgeons' understanding of the sagittal alignment of the craniocervical junction and play a positive role in the guidance of intraoperative reduction and in the evaluation of postoperative outcomes of patients with atlantoaxial instability.

Methods

From November 2018 to June 2020, a total of 159 asymptomatic subjects who underwent frontal and lateral cervical x-ray examination in the Second Affiliated Hospital of Soochow University were included in the study. Age, gender, previous spinal trauma, and disease history of each subject were recorded. After screening, 127 effective samples were finally obtained. When taking lateral cervical radiographs, all subjects placed their neck in a neutral position and looked straight ahead with both eyes. On the obtained lateral x-ray images, a straight line was drawn from the radix to the anterior clinoid process; another line was made along the posterior edge of the C2 vertebral body; and the angle between the two lines was measured, which was defined as the "horizontal view-axial angle." The angle formed by the tangent of the posterior edge of the C2 vertebra and C7 vertebral body is the "C2-C7 angle," which was used to describe the curvature of the lower cervical vertebra. The normal range of horizontal view-axial angle and its relationship with C2-7 angle were evaluated.

Results

The average C2-C7 angle of male subjects was (14.0° ± 7.4°), while that of female subjects was (11.09° ± 7.36°). The average horizontal view-axial angle of male subjects was (92.79° ± 4.52°), and that of female subjects was (94.29° ± 4.50°). Pearson correlation test showed that there was a significant negative correlation between horizontal view-axis angle and C2-C7 angle.

Conclusions

For patients with atlantoaxial instability diseases, the horizontal view-axis angle is expected to be a sagittal parameter to guide the intraoperative reduction and evaluate postoperative outcomes.

The clinical validity of atlantoaxial joint inclination angle and reduction index for atlantoaxial dislocation

Objective

Atlantoaxial dislocation patients with neurological defects require surgery. Sometimes, release surgery is necessary for irreducible atlantoaxial dislocation to further achieve reduction. Whether release surgery is essential relies on the surgeon's experience and lacks objective reference criteria. To evaluate the value of atlantoaxial joint inclination angle (AAJI) in sagittal and coronal planes and reduction index (RI) in the surgical approach selection for atlantoaxial dislocation.

Methods

Retrospectively analyzed 87 cases (42 males and 45 females, 9-89 years) of atlantoaxial dislocation from January 2011 to November 2020. In addition, 40 individuals without atlantoaxial dislocation were selected as the control group. Imaging parameters were compared between the two groups. According to surgical methods, the experiment group was divided into two groups including Group A(release surgery group) and Group B (conventional operation group). The parameters were measured based on CT and x-ray. The relevant imaging parameters and clinical scores, including the AAJI in sagittal and coronal planes, the atlas-dens interval (ADI) before and after traction, the RI, and JOA scores were measured and analyzed.

Results

The sagittal and coronal atlantoaxial joint inclination angles(SAAJI and CAAJI) in the control group were 7.91 ± 0.42(L), 7.99 ± 0.39°(R), 12.92 ± 0.41°(L), 12.97 ± 0.37°(R), in A were 28.94 ± 1.46°(L), 28.57 ± 1.55°(R), 27.41 ± 1.29°(L), 27.84 ± 1.55°(R), and in B were 16.16 ± 0.95°(L), 16.80 ± 1.00°(R), 24.60 ± 0.84°(L), 24.92 ± 0.93°(R) respectively. Statistical analysis showed that there was a statistical difference in the SAAJI between the control group and the experiment group (P < 0.01), as well as between groups A and B (P < 0.01). The RI in groups A and B was 27.78 ± 1.46% and 48.60 ± 1.22% respectively, and there was also a significant difference between the two groups (P < 0.01). There was negative correlation between SAAJI and RI.

Conclusions

The SAAJI and RI can be used as objective imaging indexes to evaluate the reducibility of atlantoaxial dislocation. And these parameters could further guide the selection of surgery methods. When the RI is smaller than 48.60% and SAAJI is bigger than 28.94°, anterior release may be required.

Chiari Malformation Type 1 in Adults

The term Chiari malformation refers to a heterogeneous group of anatomical abnormalities at the craniovertebral junction. Chiari malformation type 1 (CM1) refers to the abnormal protrusion of cerebellar tonsils through the foramen magnum and is by far the commonest type. Its prevalence is estimated approximately 1%; it is more common in women and is associated with syringomyelia in 25-70% of cases. The prevalent pathophysiological theory proposes a morphological mismatch between a small posterior cranial fossa and a normally developed hindbrain that results in ectopia of the tonsils.In most people, CM1 is asymptomatic and diagnosed incidentally. In symptomatic cases, headache is the cardinal symptom. The typical headache is induced by Valsalva-like maneuvers. Many of the other symptoms are nonspecific, and in the absence of syringomyelia, the natural history is benign. Syringomyelia manifests with spinal cord dysfunction of varying severity. The approach to patients with CM1 should be multidisciplinary, and the first step in the management is phenotyping the symptoms, because they may be due to other pathologies, like a primary headache syndrome. Magnetic resonance imaging, which shows cerebellar tonsillar decent 5 mm or more below the foramen magnum, is the gold standard investigative modality. The diagnostic workup may include dynamic imaging of the craniocervical junction and intracranial pressure monitoring.The management of CM1 is variable and sometimes controversial. Surgery is usually reserved for patients with disabling headaches or neurological deficits from the syrinx. Surgical decompression of the craniocervical junction is the most widely used procedure. Several surgical techniques have been proposed, but there is no consensus on the best treatment strategy, mainly due to lack of high-quality evidence. The management of the condition during pregnancy, restriction to lifestyle related to athletic activities, and the coexistence of hypermobility require special considerations.