CT findings of degenerative arthritis of the atlantoodontoid joint

Indian Journal of Radiology and Imaging, 2016

Odontoid process is the central pillar of the craniovertebral junction. Imaging of this small structure continues to be a challenge for the radiologists due to complex bony and ligamentous anatomy. A wide range of developmental and acquired abnormalities of odontoid have been identified. Their accurate radiologic evaluation is important as different lesions have markedly different clinical course, patient management, and prognosis. This article seeks to provide knowledge for interpreting appearances of odontoid on computed tomography (CT) and magnetic resonance imaging (MRI) with respect to various disease processes, along with providing a quick review of the embryology and relevant anatomy.

Neuroradiology, 1997

European Spine Journal, 2005

Above the age of 70 years, fracture of the odontoid process is the most common cervical spine injury . Un-like the younger population, in whom odontoid process fractures are caused by high-energy injuries, in the elderly population they are frequently caused by low-energy trauma like falls [8, 10]. The classification system detailed by Anderson and D' Alonzo for odontoid process fractures is Abstract Odontoid fractures are common in the elderly following minor falls. Almost all of them have osteoarthritis of the cervical spine below the axis vertebra. As a result, there is increased stress on the spared upper cervical spine, resulting in a higher incidence of injuries. As movement in the upper cervical spine involves participation of five joints, degeneration in any one particular joint may affect the biomechanics of loading of the upper cervical spine. We aimed to analyse the relationship of odontoid fractures to the pattern of upper cervical spine osteoarthritis in the elderly. We studied the CT-scan images of the cervical spine in 23 patients who were over the age of 70 years and had odontoid fractures. In each patient, the type of odontoid fracture and the characteristics of the degenerative changes in each joint were analysed. Twenty-one of 23 patients had Type -II odontoid fractures. The incidence of significant atlanto-odontoid degeneration in these individuals was very high (90.48%), with relative sparing of the lateral atlantoaxial joints. Osteoporosis was found in 13 of 23 patients at the dens-body junction and in seven of 23 patients at

British Journal of Neurosurgery, 2016

Osteoarthritic degeneration at the cranio-vertebral junction (CVJ) is an underrecognized source of suboccipital and neck pain, limited range of motion and cervicogenic headaches. Correlation of radiographic findings with clinical symptoms is often difficult. Limited evidence currently exists to support the use of bone single-photon emission computed tomography/computed tomography (SPECT/CT) in this subgroup of patients. The aim of this study was to describe the scintigraphic patterns of joint arthropathy at the CVJ on bone SPECT/CT in patients with suboccipital/neck pain and cervicogenic headache. Patients with more than 3 months of suboccipital/neck pain/cervicogenic headache and abnormal SPECT/ CT findings at the CVJ were included. Patients with known/suspected malignancy, trauma, infectious processes and previous surgery at the CVJ were excluded. Neck disability index (NDI), visual analogue scale (VAS) and treatment were recorded for each patient. Patterns of osteoblastic activity at the CVJ on bone SPECT/CT were described and correlated with arthritic changes on conventional scans. Eighteen patients were included (10 females, mean age 68). Mean NDI score was 22. Mean VAS was 7.5. On bone SPECT/CT, it was found that 13 patients had high osteoblastic activity unilaterally at the atlantoaxial joint (AAJ); two patients at the atlanto-dental joint (ADJ), one at the occipito-atlantal joint (OAJ), one at both OAJ and ADJ and one at the level of C2 pars/pedicle unilaterally. Metabolic activity on SPECT/CT was associated with severe degenerative changes on CT scans. The ability of hybrid bone SPECT/CT to precisely localize osteoblastic activity at the CVJ may provide significant improvement in the diagnosis and treatment of patients with suboccipital/neck pain and joint arthropathy at the CVJ. Further clinical studies are needed to establish the real clinical impact of bone SPECT/CT in the treatment of patients with suboccipital neck pain.

Folia Morphologica, 2015

Background: Detailed study of the craniovertebral junction (CVJ) is necessary to completely understand the mechanism of its flexion and extension. Materials and methods: One cadaver head was sectioned in the sagittal plane. Also, in 22 volunteers, examined using the multislice computed tomography (MSCT), 14 parameters and 2 angles were measured in the neutral position, flexion and extension. Results: The obtained measurements showed the anterior part of the occiput to move inferiorly in flexion, and the anterior atlas arch and the tip of the dens to get closer to the basion. At the same time, the opisthion moves superiorly, but the cervical spine bends anteriorly. Consequently, the dens-opisthion diameter and the opisthion-posterior atlas arch distance slightly decrease in length, whilst the arches of the atlas (C1), axis (C2) and C3 vertebra become more distant. Following extension, the posterior part of the occiput moves inferiorly, so that the basion-dens tip, the basion-axis arch, and the basion-posterior atlas arch distances increase in length. In contrast, the distances of the C1-C3 arches decrease in length. The angle between the foramen magnum and the dens tip decreases 1.620 on average in flexion, but increases 3.230 on average in extension. The angle between the axis body and the opisthion also decreases in flexion (mean, 3.360) and increases in extension (mean, 6.570). Among the congenital anomalies, a partial agenesis of the posterior atlas arch was revealed (4.5%), as well as an anterior dehiscence of the C1 foramen transversarium (13.6%). Conclusions: The mentioned measurements improved our understanding of the CVJ biomechanics. The obtained data can be useful in the evaluation of the CVJ instability caused by trauma, congenital anomalies and certain spine diseases.

Revista da Associação Médica Brasileira, 2020

SUMMARY INTRODUCTION Retro-odontoid pseudotumor (ROP) is a rare disease that affects the atlantoaxial joint and, in general, is associated with local biomechanical alterations that may or may not cause instability. METHODS Descriptive study of the literature available in databases MEDLINE/PubMed, LILACS, and Scopus. The research was conducted in April 2019. DISCUSSION ROP is, possibly, a syndromic designation that encompasses a significant variety of diseases of the atlantoaxial joint. There are different pathophysiological mechanisms implicated in its genesis. The patients, almost in their entirety, present with severe myelopathy, and most of them are treated surgically, with the posterior decompression being the most commonly used method, with or without arthrodesis. Evolution is usually favorable. CONCLUSION The ROP is still poorly recognized as a differential diagnosis between the diseases of the cranial-cervical junction. The information available in the literature analyzed was...

Journal of Clinical Neuroscience, 2008

Os odontoideum is a condition in which a smoothly corticated ossicle exists dorsal to the anterior arch of C1, taking the place of the rostral dens, but with no bony connection to the body of the axis. Three patients presented with this condition: the first with Lhermitte's phenomenon 10 years after significant trauma, the second as an incidental finding during routine cervical spine imaging following a road traffic accident, and the third with recurrent transient quadriparesis precipitated by falls from a surfboard. Patients had at least 10 mm of sagittal instability on dynamic imaging and the second patient had a minimum sagittal canal diameter of only 11.5 mm. Posterior atlanto-axial fixation was successfully achieved in all cases using polyaxial screws and rods with the assistance of computed tomography-based image guidance. Image guidance provided an invaluable aid to preoperative planning and intraoperative placement of the posterior spinal instrumentation.

Neurologia i Neurochirurgia Polska, 2010

International Journal of Rheumatic Diseases, 2014

We aim to draw attention to occult, atraumatic fractures of the odontoid process in patients with rheumatoid arthritis (RA) and to underline difficulties encountered during clinical and radiological diagnosis. A forty-seven years old man with RA for 4 years had occipital pain for 1 year without any history of trauma. Later, he developed weakness in the upper extremities, but he did not realize weakness in the lower extremities due to deformities. Contrast magnetic resonance imaging revealed a linear fracture of odontiod process and myelopathy. Cervical computed tomography scan revealed an old fracture border with separated and almost disappeared remnant of the tip of the odontoid without free particles in the cord. It was impossible to evaluate atlantoaxial and vertical subluxations with craniometric measurements due to destruction of the tip of odontoid. Following occipitocervical fusion and decompression and a rehabilitation program, his muscle strength improved; however, functional myelopathy stage did not change. Atraumatic fractures of the odontoid process may be more common than reported and may cause compression of the spinal cord or brain stem. Surgery is the treatment of choice but functional recovery is limited once neuronal damage has occurred. Erosion of the critical landmarks makes it difficult to diagnose and follow up atlantoaxial subluxation and/or vertical subluxation, therefore clinicians should consider radiographical follow-ups during the course of the disease.

Injury, 1995