[Atlantoaxial rotatory subluxation - a cause of torticollis in children]. / Atlantoaxial subluxation kan vara en orsak till tortikollis hos barn.

Atlantoaxial rotatory subluxation is an important differential diagnosis in young children with torticollis. The condition rarely results in neurological deficits. Radiological examinations such as computer tomography (CT) and magnetic resonance imaging (MRI) are useful to determine the diagnosis. It is important for doctors in all areas of healthcare to be aware of the condition, as persistent problems or surgery can be avoided by early detection and treatment.

Imaging Characterization of Non-Rheumatoid Retro-Odontoid Pseudotumors: Comparison with Atlantoaxial Manifestation of Rheumatoid Arthritis.

Backgroundand Objectives: To date, imaging characterization of non-rheumatic retro-odontoid pseudotumors (NRROPs) has been lacking; therefore, NRROPs have been confused with atlantoaxial joint involvement of rheumatoid arthritis (RA). It is important to differentiate these two disease because the treatment strategies may differ. The purpose of this study is to characterize imaging findings of NRROPs and compare them with those of RA. Material and Methods: From January 2015 to December 2019, 27 patients (14 women and 13 men) with NRROPs and 19 patients (15 women and 4 men) with RA were enrolled in this study. We evaluated various imaging findings, including atlantoaxial instability (AAI), and measured the maximum diameter of preodontoid and retro-odontoid spaces with magnetic resonance imaging (MRI) and computed tomography (CT). Results: Statistical significance was considered for p < 0.05. AAI was detected in eight patients with NRROPs and in all patients with RA (p < 0.0001). Seventeen patients with NRROPs and six patients with RA showed spinal cord compression (p = 0.047). Compressive myelopathy was observed in 14 patients with NRROPs and in 4 patients with RA (p = 0.048). Subaxial degeneration was observed in 25 patients with NRROPs and in 9 patients with RA (p = 0.001). Moreover, C2-3 disc abnormalities were observed in 11 patients with NRROPs and in 2 patients with RA (p = 0.02). Axial and longitudinal diameter of retro-odontoid soft tissue and preodontoid and retro-odontoid spaces showed significant differences between NRROP and RA patients (p < 0.0001). Furthermore, CT AAI measurements were differed significantly between NRROP and RA patients (p < 0.05). Conclusions: NRROPs showed prominent retro-odontoid soft tissue thickening, causing compressive myelopathy and a high frequency of subaxial and C2-3 degeneration without AAI.

Determination of cutoff values on computed tomography and magnetic resonance images for the diagnosis of atlantoaxial instability in small-breed dogs.

OBJECTIVE: To determine cutoff values for the diagnosis of atlantoaxial instability (AAI) based on cross-sectional imaging in small-breed dogs. STUDY DESIGN: Retrospective multicenter study. SAMPLE POPULATION: Client-owned dogs (n = 123) and 28 cadavers. METHODS: Dogs were assigned to three groups: a control group, a "potentially unstable" group, and an AAI-affected group, according to imaging findings and clinical signs. The ventral compression index (VCI), cranial translation ratio (CTR), C1-C2 overlap, C1-C2 angle, atlantoaxial distance, basion-dens interval, dens-to-axis length ratio (DALR), power ratio, and clivus canal angles were measured on CT or T2-weighted magnetic resonance (MR) images. Receiver operating characteristic (ROC) analysis was performed to define cutoff values in flexed (≥25°) and extended (<25°) head positions. RESULTS: Cutoff values for the VCI of ≥0.16 in extended and ≥0.2 in flexed head positions were diagnostic for AAI (sensitivity of 100% and 100%, specificity of 94.54% and 96.67%, respectively). Cutoff values for the other measurements were defined with a lower sensitivity (75%-96%) and specificity (70%-97%). A combination of the measurements did not increase the sensitivity and specificity compared with the VCI as single measurement. CONCLUSION: Cutoff values for several imaging measurements were established with good sensitivity and specificity. The VCI, defined as the ratio between the ventral and dorsal atlantodental interval, had the highest sensitivity and specificity in both head positions. CLINICAL SIGNIFICANCE: The use of defined cutoff values allows an objective diagnosis of AAI in small-breed dogs. The decision for surgical intervention, however, should remain based on a combination of clinical and imaging findings.

Cervical Myelopathy Due to Idiopathic Retro-odontoid Pseudotumor.

OBJECTIVE: A retro-odontoid pseudotumor (ROP) is commonly associated with atlantoaxial instability or rheumatoid arthritis. However, ROP in the absence of atlantoaxial instability or rheumatoid arthritis, which is termed idiopathic ROP (IROP), is a rare condition. The pathomechanisms and optimal treatment strategies for IROP remain controversial. The aim of the present study was to evaluate the radiographic and clinical characteristics of IROP patients and to assess the efficiency of atlantoaxial/occipitocervical fusion on IROP regression. METHODS: Data from 5 patients diagnosed with IROP were retrospectively reviewed. Posterior atlantoaxial or occipitocervical fixation and fusion were performed in 4 patients and C1 posterior arch resection alone in 1 patient. The patients' features, surgical procedures, and complications were recorded. The retro-odontoid soft tissue thickness was measured on preoperative and postoperative magnetic resonance imaging to evaluate IROP regression. RESULTS: The mean follow-up time was 37 months. ROP regression was achieved in patients who received atlantoaxial/occipitocervical fusion, but not for the patient with C1 posterior resection alone. There were no observed neurovascular complications associated with surgery. CONCLUSIONS: IROP was related to a restricted range of motion of the subaxial spine. Upper cervical fixation is an optional treatment that produces IROP regression over time. By contrast, direct removal of the IROP is unnecessary.

Cervical spine tenosynovial giant cell tumor involving the atlantoaxial joint in a pediatric patient with medulloblastoma.

Tenosynovial giant cell tumor (TGCT) is a benign condition that arises from tendon sheaths, synovium, or bursae and is classified according to the site of involvement (intra-articular versus extra-articular) and pattern of growth (localized versus diffuse). The diffuse form tends to present as peri-articular masses and are locally aggressive. It usually presents as a mono-articular process affecting larger joints. Spinal involvement is extremely rare, particularly the cervical spine. In this case report, we present a pediatric case of spinal TGCT involving the C1-C2 joint which was incidentally detected in a 13-year-old girl undergoing surveillance for medulloblastoma recurrence. Although spinal TGCT is a benign condition, it remains a diagnostic challenge, which specific to our case can raise the concern for malignancy or metastasis. We also described a percutaneous biopsy approach using a spring-loaded blunt tip coaxial needle to avoid inadvertent vascular injury. The imaging features of spinal TGCT and biopsy approach for atlantoaxial lesion are discussed together with a comprehensive review of the literature.

Surgical treatment for upper cervical deformity with atlantoaxial joint dislocation using individualized 3D printing occipitocervical fusion instrument: A case report and literature review.

ABSTRACT: To introduce a novel technique of using individualized 3D printing occipitocervical fusion instrument (3D-OCF) for the treatment of upper cervical deformity with atlantoaxial joint dislocation.The surgery for deformity of the craniocervical junction area is a challenge in the field of spine. If the surgical deviation is too large to injure the spinal cord or vertebral artery, it will cause catastrophic damage to the patient. Therefore, it is controversial whether these patients should undergo surgical treatment. We provide a novel surgical approach for the challenging upper cervical surgery through 3D-OCF and a typical patient.We present a 54-year-old female patient, who suffered from dizziness and numbness in her limbs for 8 months. After the patient was admitted, we performed the three-dimensional CT scan, modeled using Mimics software 17.0, and designed customized occipitocervical fusion instrument. Besides, we repeatedly perform simulated surgery based on 3D-printed models before surgery.The operative time was 142 minutes and the intraoperative blood loss was 700 mL. X-ray showed reduction of atlantoaxial dislocation and accurate position of internal fixation. The patient's symptoms were significantly relieved: the sensation of dizziness and numbness of limbs was obviously relieved, and the sense of banding in chest, abdomen, and ankle was disappeared. At the last follow-up, imaging showed that 3D-OCF had bone-integration and Syringomyelia was disappeared. The patient's cervical JOA (Japanese Orthopaedic Association) score increased from 10 points to 17 points.Individualized 3D-OCF can improve the safety and accuracy of upper cervical surgery, reduce the operative time and the number of fluoroscopy. Our study provides a novel surgical approach for the challenging upper cervical surgery.

Preoperative Cyst Formation as a Predictive Feature of Spontaneous Regression of Retro-Odontoid Pseudotumor After Posterior Fusion.

OBJECTIVE: Although the spontaneous regression of pseudotumors after posterior fusion has been reported, the predictive factors remain unclear. We examined the radiological features that predict for the regression of retro-odontoid pseudotumors after posterior fusion, with a specific focus on cyst formation. METHODS: We included 28 patients with a diagnosis of retro-odontoid pseudotumor using preoperative magnetic resonance imaging. The radiographic parameters and pseudotumor thickness were measured pre- and postoperatively. The regression rate for each pseudotumor was calculated. The presence of a cyst around the retro-odontoid pseudotumor was investigated. If present, the cyst thickness was measured. To elucidate the predictors for the postoperative regression of pseudotumors, the patients were divided into 2 cohorts: the regression group with a regression rate >40% and the no-regression group with a regression rate of <40%. Multivariate logistic regression analysis, including the demographic data and preoperative radiographic parameters as independent variables, was performed. RESULTS: The mean pseudotumor size had decreased significantly from 8.8 ± 3.6 mm preoperatively to 5.3 ± 2.0 mm postoperatively (P < 0.0001). The mean regression rate was 35.9% during a magnetic resonance imaging follow-up period of 8.6 months (range, 6-12 months). Cystic lesions were noted in 10 patients (35.7%) preoperatively. The mean cyst size was 4.7 ± 1.9 mm. All cysts were located dorsal to the pseudotumors and were involved at the maximum spinal compression levels. Nevertheless, all the cysts had disappeared postoperatively. Multivariate logistic regression analysis revealed that the pseudotumor regression group had had a significantly greater proportion of cysts (57.1% vs. 14.3%; odds ratio, 11.7; P = 0.013). CONCLUSIONS: The presence of cystic lesions protruding from retro-odontoid pseudotumors might serve as a predictive factor for the spontaneous regression of pseudotumors after posterior fusion.

An Intraoperative Surprise! A Rare Case Report of Primary Craniovertebral Junction Hydatid Disease Mimicking a Bony Tumor.

BACKGROUND: Craniovertebral junction (CVJ) hydatid disease, although rare, forms an important differential diagnosis of CVJ bony pathologies, especially in endemic areas due to the sheer volume of cases presented there. The authors report a rare case of CVJ hydatid disease mimicking a bony expansile tumor on imaging. CASE DESCRIPTION: A 21-year-old woman presented with a left-sided neck tilt and pain for 3 months, intermittent low-grade fever, and features of high cervical myelopathy (Nurick grade II). Magnetic resonance imaging and computed tomography imaging showed a solid enhancing mass with numerous small cystic areas with bony erosion of the basiocciput, C1 and C2 vertebrae, suggestive of an expansile bony lesion (osteoblastoma/giant cell tumor/aneurysmal bone cyst). She underwent a posterior approach for decompression and spinal fixation, and multiple clear grape-like cysts were encountered that were confirmed to be hydatid cysts on histopathology. All visible cysts were excised and instrumented fusion of the CVJ performed. Albendazole was continued for 6 weeks and at 3 months' follow-up, the patient remains asymptomatic with no recurrence on imaging. CONCLUSIONS: The authors conclude that in tropical regions, hydatid disease of the cervical spine should be considered in the differential diagnosis of patients presenting with high cervical compressive myelopathy, especially when associated with fever. Spinal hydatosis may mimic a bony lesion on imaging and should be kept in mind, as in addition to routine decompression, use of scolicidal agents and intact removal of cysts have a significant effect on reducing the recurrence rate and improving the outcome.

Management of CVJ tuberculosis: the changing paradigm.

BACKGROUND: The literature seems fractured for the management of craniovertebral junction (CVJ)-tuberculosis (TB). Presently, non-surgical management has been in vogue for neurologically intact patients. On the contrary, severely disabled cases of CVJ-TB continue to attract discussion, tilted towards surgical intervention. We present our experience with the non-surgical management of CVJ-TB tailored to their neurological status. METHODS: Authors managed 37 cases (2004-2019; age 1-57 years, mean 36 years) of CVJ-TB, of which eighteen (18/37, 48.6%) were severely disabled (Nurick grade ≥ 3) with a mean follow-up of 84 months (48-192 months). Irrespective of the clinical status and radiological findings, all patients were managed on medical management only. Needle aspiration established pathology in 23 (62.2%) cases, while 9 (24.3%) cases required drainage of an abscess. All patients received 18 months of anti-tubercular therapy (ATT). In patients with Nurick grade ≥ 3 and documented AAD, we applied halo vest for 12 months to achieve cervical immobilization. Only hard cervical collar for 3 months was prescribed in patients with no documented AAD. RESULTS: All minimally disabled cases (Nurick grade ≤ 2, n = 19) responded favorably (n = 18) to ATT, except for an infant, who succumbed to irreversible hypoxic brain damage due to the obstructed aero-digestive gateway. Of the severely disabled cases (Nurick grade ≥ 3, n = 18), 16 cases had favorable outcomes with only external orthosis (12) and 18-month ATT. One patient succumbed to multiple cerebral infarcts, while one required realignment surgery at CVJ due to fusion in malaligned position. CONCLUSION: The authors conclude that the disability grading of CVJ-TB is pertinent only for assessing the functional disability of patients at presentation, with minimal relevance in deciding its management strategy. Irrespective of neurological disability, almost all patients respond favorably to external immobilization and ATT.

A case of acute calcium pyrophosphate arthritis in two rare sites of involvement: The cervical facet and atlantoaxial joint.

Calcium pyrophosphate dihydrate deposition (CPPD) disease, also known as pseudogout, in which crystals are deposited in the joints and/or soft tissues, leads to a variety of articular and periarticular disorders. Herein we report a 67-year-old female patient with neck pain who was diagnosed as CPPD disease of both the atlantoaxial joint and right C4-C5 facet joint with radiological findings. The combined use of computed tomography and magnetic resonance imaging can be helpful in establishing a diagnosis and providing the correct treatment.

Recurrent Stroke in a Child With Atlantoaxial Instability Following Chiropractic Manipulation.

Pediatric stroke presents with a variety of signs and symptoms. Correct modality of imaging is essential in decreasing the time from symptom onset to appropriate management. Evaluation of pediatric stroke should include both blood work as well as imaging in a parallel rather than a sequential matter. We report a case of a child with a bow hunter's stroke that was challenging to diagnose. This type of stroke happens when the vertebral artery is occluded at the atlantoaxial or subaxial level during neck rotation. This case demonstrates that workup of stroke should be comprehensive to include all mechanical and anatomic possibilities before investigating rarer hypercoagulable disorders.

Flexed radiographic angles for determination of atlantoaxial instability in dogs.

OBJECTIVE: To determine a flexed position for radiographic diagnosis of atlantoaxial instability (AAI) and to identify radiographic measurement cutoffs to differentiate affected dogs from neurologically healthy toy breeds. STUDY DESIGN: Retrospective case series and prospective case controls. ANIMALS: Thirty-nine client-owned toy breed dogs in which AAI had been diagnosed and 20 neurologically healthy client-owned toy breed dogs. METHODS: Medical records from three institutions were retrospectively reviewed to identify dogs affected with AAI. Flexed lateral images were reviewed, and measurements were obtained by using anatomic landmarks. Radiography was performed with control dogs to obtain the same measurements. RESULTS: Flexed lateral radiographs of thirty dogs affected with AAI were found to be positioned at a mean of 51° flexion. When flexed lateral radiographs were evaluated with a cutoff value for atlas to axis angle (AAA) >10°, evaluation of all breeds represented revealed a 90% sensitivity and 90% specificity. When this cutoff was evaluated in Yorkshire terriers, Chihuahuas, and mixes of these breeds, the sensitivity was 92%, and the specificity was 92%. When the control sample was positioned at 51° ± 10°, only two of the dogs were within the AAA cutoff value of >10°. There was no difference between the measurements obtained by using the flexed lateral view (mean = 50.9°) and the exaggerated flexed lateral view (mean = 38.9°) in the control sample. CONCLUSION: This study established objective measurements for the positioning and diagnosis of AAI on flexed lateral radiographs in toy breed dogs. CLINICAL SIGNIFICANCE: Atlantoaxial instability can be objectively diagnosed in sedated or anesthetized toy breed dogs when applying 51° flexion to cervical radiographs.

Tenosynovial giant cell tumor of the cervical spine: a case report.

Introduction: Tenosynovial giant cell tumors (TSGCTs) generally occur in the limb joints, and only rarely in the spine. This case report describes a patient with TSGCT of the spine at C1-C2, which was treated surgically and diagnosed as TSGCT. Case presentation: A 32-year-old woman with a 4-month history of neck pain and numbness in both upper extremities was referred to our department. Magnetic resonance imaging (MRI) revealed a neoplastic lesion extending from the left epidural space to the erector spinae muscles at the C1-C2 vertebral level, which was isointense on T1-weighted images, heterogeneously hypointense on T2-weighted images, and showed heterogeneous enhancement on gadopentetate dimeglumine (Gd-DTPA)-enhanced T1-weighted images. Computed tomography showed no findings suggestive of bone destruction of the vertebral body. Because the neurological symptoms were progressive, total macroscopic resection of the tumor was performed via a posterior approach. Histopathological examination of the resected specimen revealed the diagnosis of TSGCT. Improvement of the both the neck pain and upper-extremity numbness was noted postoperatively. An MRI obtained 6 months after the surgery revealed no evidence of tumor recurrence and the postoperative course was uneventful. Discussion: TSGCT of the upper cervical spine (C1-C2) is rare, and this is the tenth reported case. If a tumor is heterogeneously hypointense on T2-weighted MRI, which reflects hemosiderosis, the possibility of this tumor should be considered in the differential diagnosis.

Atlanto-axial Pannus in Patients with and without Rheumatoid Arthritis.

OBJECTIVE: Pannus formation in the atlanto-axial joint is a well-recognized complication of rheumatoid arthritis (RA). Occasionally, atlanto-axial pannus is reported when patients without a history of RA undergo magnetic resonance imaging (MRI) of the cervical spine. We sought to further characterize these patients. METHODS: The Partners HealthCare Research Patient Data Registry was free-text searched for "atlanto-axial" AND "pannus" in cervical spine MRI reports from 2001 to 2015. Cases with MRI reports describing pannus were reviewed. Clinical data were extracted by chart review in cases with confirmed atlanto-axial pannus (n = 105). RESULTS: Twenty-nine patients (27.6%) had RA, all of whom except one carried this diagnosis at the time of the MRI scan. Only 1 of 77 patients without a history of RA was subsequently diagnosed with RA (1.3%, 95% CI 0.1-7.0%, median followup 3.6 yrs). Non-RA patients were significantly older (median age 79 vs 63 yrs, p < 0.0001), less frequently female (55% vs 86%, p = 0.0032), and more likely to have undergone prior cervical spine surgery (18% vs 0%, p = 0.016) compared with RA patients. Thirty-four non-RA patients (44.7%) either had a clinical diagnosis of calcium pyrophosphate dihydrate disease (CPPD) or imaging evidence for tissue calcification. There were no significant differences in age or sex between the CPPD subgroup and other non-RA patients. Twenty-eight patients (26.7%) underwent cervical spine surgery. CONCLUSION: Patients without RA diagnosis and incidental atlanto-axial pannus on cervical spine MRI are unlikely to have previously unrecognized RA. Degenerative disease and tissue calcification may contribute to pannus formation in these patients.

Atlanto-axial rotatory fixation complicating ventriculo-peritoneal shunt surgery: a case report and literature review.

INTRODUCTION: Atlanto-axial rotatory fixation (AARF) is a rare complication of ventriculo-peritoneal shunt (VPS) surgery. CASE PRESENTATION: The authors present a unique case of AARF developing early after VP shunting, with persistent torticollis, a "cock-robin" head position, and a thick fibrous band along the catheter path. Due to refractoriness to conservative treatments, AARF, which can be an early-onset complication of VPS surgery, was resolved by removing the distal catheter along with the fibrous band encasing it. CONCLUSION: Surgical removal of the fibrous band might be enough to solve such complication with no need of further surgical fusion procedures.

Instrumented arthrodesis for non-traumatic craniocervical instability in very young children.

PURPOSE: Occipitocervical instrumentation is infrequently required for stabilization of the axial and subaxial cervical spine in very young children. However, when it is necessary, unique surgical considerations arise in children when compared with similar procedures in adults. METHODS: The authors reviewed literature describing fusion of the occipitocervical junction (OCJ) in toddlers and share their experience with eight cases of young children (age less than or equal to 4 years) receiving occiput to axial or subaxial spine instrumentation and fixation. Diagnoses and indications included severe or secondary Chiari malformation, skeletal dysplastic syndromes, Klippel-Feil syndrome, Pierre Robin syndrome, Gordon syndrome, hemivertebra and atlantal occipitalization, basilar impression, and iatrogenic causes. RESULTS: All patients underwent occipital bone to cervical spine instrumentation and fixation at different levels. Constructs extended from the occiput to C2 and T1 utilizing various permutations of titanium rods, autologous rib autografts, Mersilene sutures, and combinations of autografts with bone matrix materials. All patients were placed in rigid cervical bracing or halo fixation postoperatively. No postoperative neurological deficits or intraoperative vascular injuries occurred. CONCLUSION: Instrumented arthrodesis can be a treatment option in very young children to address the non-traumatic craniocervical instability while reducing the need for prolonged external halo vest immobilization. Factors affecting fusion are addressed with respect to preoperative, intraoperative, and postoperative decision-making that may be unique to the toddler population.

[Cervical spine involvement in rheumatoid arthritis : Diagnostics and treatment of instability due to rheumatism]. / Rheumatoide Arthritis der zervikalen Wirbelsäule : Diagnostik und Therapie rheumatisch bedingter Instabilitäten.

In addition to involvement of small peripheral joints, the cervical spine is the second most affected body region in rheumatoid arthritis (RA). Due to improvement of pharmaceutical treatment in recent years, new data show that there is a decreasing prevalence of cervical involvement; however, depending on the severity of cervical lesions surgical treatment still plays an important role. The sequelae of involvement of the cervical spine are craniocervical and atlantoaxial instability, which can cause severe pain, neural deficits and even death. Multimodal conservative treatment can lead to an alleviation of pain but in cases of therapy-resistant pain or neural deficits surgical treatment alone is essential to improve patient outcome. For isolated atlantoaxial instability (AAS), atlantoaxial fusion by posterior C1-2 fixation according to Harms and Goel is the method of choice. Posterior stabilization including C0 should be avoided whenever possible due to substantial limitations in range of movement.

"Sandwich Deformity" in Klippel-Feil syndrome: A "Full-Spectrum" presentation of associated craniovertebral junction abnormalities.

Klippel-Feil syndrome (KFS) is defined as congenital fusion of two or more cervical vertebrae resulting from a segmentation failure in the developing spine. According to Samartzis et al., the most commonly fused segments are found at C2/3 (74.1%) and C6/7 (70.4%). In patients with C2/3 fusion, especially when there is additional C1 occipitalization, several secondary anomalies including atlantoaxial dislocation (AAD), basilar invagination (BI), Chiari malformation, and syringomyelia can be identified. In this report, we present a case of a 12-year-old patient with C2/3 and occipitalization and a "Full-Spectrum" presentation of associated CVJ abnormalities including C0/1 fusion, AAD, BI, Chiari malformation, syringomyelia, myelopathy and cranial neuropathy received neurological decompression of the cervico-medullary junction by posterior reduction of the AAD and reconstruction of her CVJ using an unconventional hybrid construct due to a high-riding right vertebral artery in C2. To our knowledge, her "Full-Spectrum" presentation may include the most categories of concomitant abnormalities in the literature. In addition, She received neurological decompression of the cervico-medullary junction using an unconventional hybrid construct due to a high-riding vertebral artery in C2. Three months after the surgery, all of her symptoms recovered significantly. Neither Chiari malformation nor syringomyelia could be identified by MRI two years after the surgery. At the last follow-up (4 years), the patient became completely asymptomatic.

The Grisel's syndrome: A non-traumatic subluxation of the atlantoaxial joint.

INTRODUCTION: Grisel's syndrome consists in rotational subluxation of C1-C2 following ENT infection or surgery. There is no consensus on management. We present 2 cases requiring surgical treatment in our center. CASE REPORTS: Two 10-year-old patients presented torticollis with cervical pain resistant to medical treatment, with onset a few months after tonsillectomy. In both cases, radiological assessment, comprising CT scan and MRI, showed Fielding-Hawkins type-3 C1-C2 rotational subluxation, without ligament lesion. After failure of conservative treatment, posterior reaming, realignment, C1-C2 arthrodesis using lateral masses and pars interarticularis screws and bone graft achieved good fusion and immediate spinal stability in all planes of the atlantoaxial complex. DISCUSSION: Grisel's syndrome consists in non-traumatic subluxation of the atlantoaxial joint with intact atlantoaxial ligaments. Initial pharyngeal inflammation spreads to the prevertebral fascia via direct connections between the periodontoidal venous plexus and pharyngovertebral veins, inducing fasciitis that leads to abnormal relaxation of the atlantoaxial ligaments and reactional muscle contraction with ankylosis. This phenomenon, appearing gradually and insidiously over a period of a few weeks, creates a frozen joint with ankylosis. Medical treatment with NSAIDs, muscle relaxants, and immobilization is usually sufficient; cervical traction may be needed. Surgical treatment by C1-C2 arthrodesis is indicated in case of failure of medical management or onset of neurologic signs. CONCLUSION: Close collaboration between pediatricians, ENT surgeons and neurosurgeons is essential for early diagnosis and management, which is the main prognostic factor for successful medical treatment, avoiding surgery.