Articles
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742 results found
Article
AO Spine classification of thoracolumbar injuries
The AO Spine classification of thoracolumbar injuries is a commonly used thoracolumbar spinal fracture classification system 1,2.
The current AO Spine system (2013) supercedes the more complex and less reproducible AO Magerl classification 3. Unlike the other widely used system, the thoracolumb...
Article
AO Spine classification of upper cervical injuries
The AO Spine classification of upper cervical injuries is a concise and comprehensive system for categorizing the spectrum of traumatic bony and ligamentous injuries involving the occipital condyles, atlas (C1), or axis (C2).
Usage
The AO Spine upper cervical classification system is relativel...
Article
AO Spine classification systems
The AO Spine classification systems is a group of imaging morphology-based classification system, combined with clinical factors for injury of spinal trauma. It is designed to be a simple and reproducible method of describing injury patterns 1-3.
AO Spine has published four injury classificatio...
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Apical ligament
The apical ligament is a small ligament that joins the apex (tip) of the dens of C2 to the anterior margin (basion) of the foramen magnum. It is the weak, fibrous remnant of the notochord and does not contribute significantly to stability.
The more posterior alar and cruciate ligaments are stro...
Article
Arachnoid cyst
Arachnoid cysts are relatively common benign and asymptomatic lesions occurring in association with the central nervous system, both within the intracranial compartment (most common) as well as within the spinal canal. They are usually located within the subarachnoid space and contain CSF.
On ...
Article
Arachnoiditis
Arachnoiditis is a broad term encompassing inflammation of the meninges and subarachnoid space.
Terminology
Arachnoiditis affecting the cauda equina may be referred to as spinal/lumbar adhesive arachnoiditis.
Clinical presentation
Lumbar spine arachnoiditis can result in leg pain, sensory c...
Article
Arachnoiditis ossificans
Arachnoiditis ossificans is considered a sequela of chronic arachnoiditis where there is a development of calcification-ossification of the arachnoid membrane usually of the thoracic and lumbar spines. It is an extremely rare cause of spinal canal stenosis and consequent neurological compromise....
Article
Arcuate foramen
The arcuate foramen (foramen arcuate atlantis, ponticulus posticus or posterior ponticle, or Kimerle anomaly) is a frequently encountered normal variant of the atlas and is easily appreciated on a lateral plain film of the craniocervical junction.
Epidemiology
Incidence is ~8% (range 1-15%) an...
Article
Arterial vasocorona
The arterial vasocorona is part of the spinal cord blood supply and is formed by pial anastomoses between the anterior and posterior spinal arteries on the surface of the spinal cord. It encircles the cord and supplies the peripheral lateral aspect of the spinal cord.
Engorgement of arterial v...
Article
Artery of Adamkiewicz
The artery of Adamkiewicz, also known as the great anterior radiculomedullary artery or arteria radicularis anterior magna, is the name of the dominant thoracolumbar segmental medullary artery, which supplies the lower spinal cord by reinforcing the anterior spinal artery.
Gross anatomy
The ar...
Article
Arthritis
Arthritis (plural: arthritides) refers to inflammation of the joints, caused by a broad range of etiologies.
Terminology
Arthropathy is a broader term referring to any disease of the joint, whereas arthritis is a type of arthropathy specifically referring to inflammation of the joint.
Patholo...
Article
ASAS classification criteria - active sacroiliitis on MRI
The Assessment in SpondyloArthritis International Society (ASAS) classification criteria, published in 2009 1 with the revised 2016 consensus definition of a positive MRI (i.e. active sacroiliitis) still in use in 2019 6, utilizes imaging features of the sacroiliac joints on x-ray and MRI as one...
Article
Atlanto-axial articulation
The atlanto-axial articulation is a complex of three synovial joints, which join the atlas (C1) to the axis (C2).
Gross anatomy
Articulations
paired lateral atlanto-axial joints: classified as planar-type synovial joint between the lateral masses of C1 and C2, though somewhat more complex in ...
Article
Atlantoaxial fixation
Atlantoaxial fixation refers to various surgical techniques to stabilize the atlantoaxial complex.
History and etymology
The first effort of an atlantoaxial stabilization was made by Mixter and Osgood in 1910 by fixation of the spinous processes with a heavy silk thread 1,2.
Posterior cervic...
Article
Atlanto-axial subluxation
Atlanto-axial subluxation is a disorder of C1-C2 causing impairment in rotation of the neck. The anterior facet of C1 is fixed on the facet of C2. It may be associated with dislocation of the lateral mass of C1 on C2.
Epidemiology
Atlanto-axial subluxations are often associated with high energ...
Article
Atlantodental interval
The atlantodental interval is used in the diagnosis of atlanto-occipital dissociation injuries and injuries of the atlas and axis.
Measurement
The anterior atlantodental interval is the horizontal distance between the posterior cortex of the anterior arch of the atlas (C1) and the anterior cor...
Article
Atlanto-occipital articulation
The atlanto-occipital articulation (also known as the C0-C1 joint/articulation) is comprised of a pair of condyloid synovial joints that connect the occipital bone (C0) to the first cervical vertebra (atlas/C1).
Gross anatomy
Articulations
Each joint is comprised of two concave articular surf...
Article
Atlanto-occipital assimilation
Atlanto-occipital assimilation is the fusion of the atlas (C1) to the occiput and is one of the transitional vertebrae.
Epidemiology
Atlanto-occipital assimilation occurs in approximately 0.5% (range 0.08-3%) of the population 2-5. It is thought to affect males and females equally.
Associati...
Article
Atlanto-occipital dissociation injuries
Atlanto-occipital dissociation injuries are severe and include both atlanto-occipital dislocations and atlanto-occipital subluxations.
Pathology
The tectorial membrane and alar ligaments provide most of the stability to the atlanto-occipital joint, and injury to these ligaments results in inst...
Article
Atlas (C1)
The atlas (plural: atlases) is the first cervical vertebra, commonly called C1. It is an atypical cervical vertebra with unique features. It articulates with the dens of the axis and the occiput, respectively allowing rotation of the head, and flexion, extension and lateral flexion of the head. ...
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