the axis articulates directly with the occipital condyles


The classic clinical sign is the cock robin head appearance with the head tilted toward and rotated away from the side of the dislocation. The Axis (C2 vertebra) also known as epistropheus forms the pivot upon which the first cervical vertebra (the Atlas), which carries the head, rotates. Surgery may become necessary if there is significant compression of the brainstem, spinal cord, the lower cranial nerves or cervical arteries. The axis is connected to the occipital bone by membrana tectoria, which is the upward continuation of the posterior longitudinal ligament, the alar ligaments between the lateral aspect of the apex of the dens and medial side of the occipital condyles, the apical ligament of the dens between the apex of the dens and the anterior margin of the foramen magnum, and the ligamentum nuchae.

Of those 24 (not counting the sacrum and coccyx), two vertebrae are fortunate enough to have names.

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On plain radiographs, a retropharyngeal hematoma or other soft-tissue swelling may be the only sign of injury. The articular surfaces of the condyles are convex from before backward and from side to side, and look downward and lateralward.

Doesn't matterbothnumbers are correct.

(A) Anterior view of atlas and axis, (B) lateral view of the left side of atlas and axis, and (C) posterior view of atlas and axis. The atlanto-axial joint is a compound synovial joint.

The head is removed at the juncture between the atlas vertebra and the occipital condyles (occipito-atlantal joint) of the skull. Learn more here. From: Schmidek and Sweet Operative Neurosurgical Techniques (Sixth Edition), 2012, M. Yashar S. Kalani, Nicholas Theodore, in Principles of Neurological Surgery (Third Edition), 2012, Occipital condyle fractures (OCFs) are frequently missed on plain radiographs. The muscles are semisplinalis servicis ,the rectus capitis posterior major,the inferior oblique, the spinalis cervicis , the interspinalis and the multifidus. Fig. Its under surface is concave from before backward and convex from side to side. The LibreTexts libraries arePowered by NICE CXone Expertand are supported by the Department of Education Open Textbook Pilot Project, the UC Davis Office of the Provost, the UC Davis Library, the California State University Affordable Learning Solutions Program, and Merlot.

In most cases Physiopedia articles are a secondary source and so should not be used as references. Breast and prostate cancer were the most common, followed by lung and colorectal carcinomas (Rodrguez-Pardo et al., 2016). If such fractures are not associated with the more ominous AOD, patients usually present without neurological deficit and complain only of upper cervical pain.

The diagnosis is usually on the basis of computed tomography (CT), and MRI may be useful in determining the extent of associated ligamentous injuries, although this has little utility from a treatment perspective. Above: C2, also known as axis with (A) an anterior view and (B) a posterior view. hbspt.cta._relativeUrls=true;hbspt.cta.load(189659, '8e3cfb2b-6dc6-40e7-91e6-1d53dcc783a8', {"useNewLoader":"true","region":"na1"}); There are 33 vertebrae in your vertebral column. Axis allows both the skull and the atlas to rotate, so the head can be turned from side to side by neck muscles. The alar ligaments (Mauchart's ligament) have a length of approximately 10 mm and may occasionally insert to the atlas (Panjabi et al., 1991a).

The paracondylar approach is achieved via drilling of the area lateral to the condyle to resect lesions of the jugular process and of the posterior aspect of the mastoid.5,11,13, Nancy McLaughlin, Sheri K. Palejwala, in Principles of Neurological Surgery (Third Edition), 2012.

At the base of either condyle the bone is tunnelled by a short canal, the hypoglossal canal.

Fig. The temporal bone syndrome involves metastasis to the internal auditory canal, which can result in both hearing loss and otalgia. You're born with 33, but the sacrum and coccyx fuse to the rest of the spine, making it 24 by the time you're an adult.

(C) Axial T1-weighted post-contrast MRI reveals a metastatic lesion of the right occipital condyle. It is also a pivot joint. It is this joint between the skull and C1 that enables an individual to nod their head "yes."

Anderson Cancer Center. As the first vertebra in the column, atlas in a sense holds up the skull (similar in shape to Atlas holding up the world).

The hearing loss can be conductive from eustachian tube dysfunction, and/or sensorineural from involvement of the cochlear nerve. It presents in front a median longitudinal ridge, separating two lateral depressions for the attachment of the Longus colli muscles. The foramina (the holes) give passage to the vertebral artery and vertebral vein.

Traumatic spondylolisthesis of the axis, or a hangman's fracture (Schneider et al., 1965), are classically hyperextension and distraction injuries obtained during judicial hangings (Wood-Jones, 1913), but presently, are more commonly caused by a variety of mechanisms. Jose Alberto Landeiro, Cassius Vincius Corra Dos Reis, in Schmidek and Sweet Operative Neurosurgical Techniques (Sixth Edition), 2012, The OC, which is an oval-shaped osseous structure located at the base of the occipital bone, articulates the skull in relation to the cervical spine. The median atlanto-axial joint is a pivot joint between the dens and a ring formed by the anterior arch and transverse ligament of atlas. I give my consent to Physiopedia to be in touch with me via email using the information I have provided in this form for the purpose of news, updates and marketing.

Top Contributors - Mandeepa Kumawat, Admin, Kim Jackson, George Prudden and WikiSysop. The classification of Anderson and Montesano distinguishes three types of occipital condyle fracture: Minimally displaced fractures are treated conservatively.

Daniel M. Sciubba, James S. Harrop, in Schmidek and Sweet Operative Neurosurgical Techniques (Sixth Edition), 2012. The dens (above, in green), or odontoid process, is a toothlike projection of bone that rises perpendicularly from the upper surface of the body of the axis. ), Injury to the hypoglossal nerve is typically associated with. A craniovertebral joint is exactly what it sounds like: a joint that permits movement between the vertebral column and the skull. Unlike the other vertebrae, C1 has no body and instead of a spinous process, atlas has a small posterior tubercle. Are you an instructor? The occipitaltranscondylar approach exposes the clivus and the lower medulla and is performed after drilling the atlanto-occipital joint, condyle, and lower border of the hypoglossal canal. Among the ligaments that connect the atlas to the axis, the anterior and posterior atlanto-axial ligaments are merely the anterior and posterior longitudinal ligaments.

We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739. [3], Get Top Tips Tuesday and The Latest Physiopedia updates, The content on or accessible through Physiopedia is for informational purposes only. These are generally treated with immobilization if there is minimal displacement, or halo ring traction to reduce the fracture, then immobilization (Francis et al., 1981; Levine and Edwards, 1985). The mechanism is generally from an extension-rotation force. Depending on severity, these fractures may or may not present with neurological deficits ranging from lower cranial nerve deficits to quadriparesis. The anterior portion of the condyle is directed anteriorly and medially toward the basion. The axis, or C2 vertebra, also has a bulbous vertical process not found in any of the other vertebrae called the dens and it is what allows the axis vertebra (C1) above it to rotate. For example, spontaneous epidural hematoma has been reported from an SBM in a patient with hepatocellular carcinoma (Woo et al., 2010). Bilateral OCF can represent a unique presentation of AOD and needs to be evaluated carefully.35, Kelly G. Gwathmey, in Handbook of Clinical Neurology, 2018. If you believe that this Physiopedia article is the primary source for the information you are refering to, you can use the button below to access a related citation statement. We have award-winning 3D products and resources for your anatomy and physiology course!

Craniocervical fixation may be necessary. Type II: Occipital basilar skull fracture extending into the condyle, resulting from direct trauma. By continuing you agree to the use of cookies. Type II injuries are characterized by continuation of a basilar skull fracture into the condyle. The amount of condyle that can be safely removed is controversial; however, biomechanical studies showed that the removal of more than 50% of the condyle leads to considerable hypermobility of the craniocervical junction, in which case fusion is indicated.5,21 The removal of the cortical bone (which forms the external capsule of the condyle) exposes cancellous bone (which forms the core of the condyle).

as part of an atlanto-occipital dislocation or the "occipital ring fracture") are rare, but often fatal. Initial management should include placement in a halo vest, and many of these patients will require posterior occipitocervical fusion (Eismont and Bohlman, 1978; Montane et al., 1991).

Coronal (A) and sagittal (B) CT reconstruction of a patient demonstrating an atlanto-occipital dislocation.

(Think of them as BFFsyou won't find one without the other.). (arrows) There is diffuse homogeneous enhancement of the tumor. Metastases are the cause of nearly half of all isolated hypoglossal nerve palsies (Keane, 1996), making it the most common cause of isolated hypoglossal nerve palsy. Thus, symptomatic treatment is indicated and may include external immobilization in a collar.62 Type III injuries (avulsion of a condylar fragment by the alar ligament) may be unstable and require rigid external immobilization in a collar or halo or even ORIF, if other injuries such as atlantoaxial instability are present.62 Patients not treated may develop lower cranial nerve palsies, which still have a significant chance of resolving with immobilization.63, The need for surgical intervention to treat OCF is rare, and conservative management of all isolated OCFs is generally supported, even in cases of brainstem compression with neurological injury.

Onset of neurologic symptoms may be immediate or delayed. All of the cervical vertebrae are smaller in size compared to thoracic and lumbar vertebrae. A smaller longitudinal band extends from the dens to the ventral margin of foramen magnum. The occipital condyles are undersurface protuberances of the occipital bone in vertebrates, which function in articulation with the superior facets of the atlas vertebra. Functionally it allows the head to move from side to side, up and down, as well as to rotate. The transverse ligament of atlas passes behind the dens between the tubercles on the inner side of the lateral masses (Tubbs et al., 2002). Care should be taken as one approaches the hypoglossal canal, which will be located immediately lateral in the superior portion of the condyle emerging from the skull at 2 (left) and 10 oclock (patients right). SekulaJr., in Schmidek and Sweet Operative Neurosurgical Techniques (Sixth Edition), 2012. There is loss of the normal bone marrow signal identified contralateral to the mass (long arrow) in the patient's normal occipital condyle.

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They are frequently unilateral and are often isolated cervical spine injuries in patients with head injuries. The first two cervical vertebrae are specially modified to allow rotation, flexion, and extension of the head. A pivot joint is made by the end of one articulating bone rotating in a ring formed by another bone and its ligaments.

There are case reports in the literature reporting minor head trauma causing unilateral traumatic hypoglossal palsy without fracture.100 Patients with tongue deviation, dysphagia, or dysarthria should be evaluated for hypoglossal nerve injury. Check out our free Atlas & Axis eBook!

An atlantodental interval of greater than 3.5mm is also suggestive of an incompetent transverse ligament. The atlas and the occipital bone form the atlanto-occipital joint, which allows neck flexion. Or is it 24? Legal. These transverse foramina serve as passages for paired vertebral arteries (right and left) traveling to the head.

The pedicles are broad and strong, especially in front, where they coalesce with the sides of the body and the root of the odontoid process. (Bottom) Illustration of a cervical vertebra showing the locations of the spinal cord in the vertebral foramen, spinal nerves, meninges surrounding the spinal cord, and intervertebral disc separating the bodies of articulating vertebrae. Patients failing immobilization may eventually require C12 fusion.

This article incorporates text in the public domain from page 131 ofthe 20th edition of Gray's Anatomy (1918), Learn how and when to remove this template message, "Occipital condyle fractures: clinical presentation and radiologic detection", https://en.wikipedia.org/w/index.php?title=Occipital_condyles&oldid=1091636294, Wikipedia articles incorporating text from the 20th edition of Gray's Anatomy (1918), Articles needing additional references from April 2018, All articles needing additional references, Creative Commons Attribution-ShareAlike License 3.0, Type I: Isotated impaction fracture of the occipital condyle, due to compression by the atlas or. Radiological assessment includes evaluation of C1 and C2 by thin cut CT for evaluation of the atlas fracture and any concomitant C2 fractures, and an open mouth radiograph to assess the integrity of the transverse ligament. 1173185, Axis (anatomy) - Wikiwand /www.wikiwand.com/en/Axis_(anatomy) (accessed 26 June 2018), Cervical Spine Anatomy: Overview, Gross Anatomy, B D Chaurasia's Human Anatomy Regional and Applied Dissection and Clinical Volume 3 Head, Neck and Brain Fourth edition CBS Publishers and distributors. A synovial joint is a freely moveable joint, differing from other types of joints due to the presence of synovial fluid, which lubricates the joint.

Above: Lateral view of the skull with the occipital bone (and its occipital condyles) colored green and the first cervical vertebra or C1 (articulates with the occipital condyles) colored pink.

Injury to the hypoglossal nerve is typically associated with occipital condyle fracture. The inferior articular facets lies posterior to the transverse process and is directed downwards and forwards to articulate with the third cervical vertebra. The skull articulates with C1 via the occipital condyles. Type III injuries involve complete avulsion of the condyle and are presumed to result from excessive loading in rotation or lateral bending.4. The atlas articulates with the occipital condyles above and the axis below.

Instead, it is ringlike and consists of an anterior and posterior arch, as well as two lateral masses. This syndrome occurs with metastasis to the occipital condyle, and accounts for 16% (Laigle-Donadey et al., 2005a) of cases of skull base syndromes. The medial aspect of the occipital condyle is drilled, allowing for direct visualization of the subarachnoid origin of the vertebral artery, which is essential in order to obtain its proximal control in cases it is needed. The body is deeper in front than behind, and prolonged downward anteriorly so as to overlap the upper and front part of the third vertebra. About 20% of these patients will present with a normal neurological exam, and mortality is extremely high (Management of pediatric cervical spine and spinal cord injuries, 2002). The OC, which is an oval-shaped osseous structure located at the base of the occipital bone, articulates the skull in relation to the cervical spine. hbspt.cta._relativeUrls=true;hbspt.cta.load(189659, '7da024a9-4451-44f6-a682-29eaf2d8974b', {"useNewLoader":"true","region":"na1"}); hbspt.cta._relativeUrls=true;hbspt.cta.load(189659, 'd81c2b40-64cb-4f78-a901-2d949123900d', {"useNewLoader":"true","region":"na1"}); When you select "Subscribe" you will start receiving our email newsletter. A pivot joint in action. An occipitoatlantal transarticular transcondilar approach is performed after the condyle and the C1 superior articular facet are removed.

Alexander Taghva, Carl L. Lauryssen, in Handbook of Clinical Neurology, 2012.

(B) Axial T1-weighted noncontrast magnetic resonance imaging (MRI) reveals a metastatic lesion of the right occipital condyle (short arrows). The atlas (C01) and axis (C02) are two of the most important vertebrae in the spine. The atlanto-axial joint is composed of two lateral joints between the superior facets of the axis and inferior facets of the atlas and a median joint between the dens of the axis and the anterior arch and transverse ligament of atlas. To their margins are attached the capsules of the atlanto-occipital joints, and on the medial side of each is a rough impression or tubercle for the alar ligament. The tectorial membrane that covers the capsule of the atlanto-axial joints passes from the back of the lateral mass of the atlas downwards and medially to the back of the body of the axis, and attaches to the margins of the foramen magnum superiorly. If the sum total overhang of the C1 lateral masses on C2 is greater than 6.9mm, there likely exists a disruption of the transverse ligament (Spence et al., 1970; Fielding et al., 1974), and in unclear cases, MRI may be able to directly assess the ligament (Dickman et al., 1996). ScienceDirect is a registered trademark of Elsevier B.V. ScienceDirect is a registered trademark of Elsevier B.V. Schmidek and Sweet Operative Neurosurgical Techniques (Sixth Edition), Principles of Neurological Surgery (Third Edition), Management of pediatric cervical spine and spinal cord injuries, 2002, Diagnosis and management of traumatic atlanto-occipital dislocation injuries, 2002, Eismont and Bohlman, 1978; Montane et al., 1991, Spence et al., 1970; Fielding et al., 1974, Levine and Edwards, 1986; Hadley et al., 1988; Sonntag et al., 1988; Fowler et al., 1990; McGuire and Harkey, 1995; Lee et al., 1998; Isolated fractures of the atlas in adults, 2002, Lourie and Stewart, 1961; Fielding and Hawkins, 1977; Phillips and Hensinger, 1989, Fielding and Hawkins, 1977; Phillips and Hensinger, 1989, Amyes and Anderson, 1956; Husby and Sorensen, 1974, Francis et al., 1981; Levine and Edwards, 1985, Endoscopic Approaches to Skull Base Lesions, Ventricular Tumors, and Cysts, This syndrome occurs with metastasis to the, (Courtesy of the Department of Neurosurgery at the University of Texas M.D. Belk, J.A.

This ligament is observed also in dogs, cats and primates (Hecker, 1922). The transverse processes serve as the attachment sites of muscles that assist in rotating the head.They are levator scapulae , the sclenus medius anteriorly and the splenius cervicis posteriorly. This is often also accompanied by neck stiffness (Moris et al., 1998). If you shake your head as if to say "no," that is head rotation. Physiopedia articles are best used to find the original sources of information (see the references list at the bottom of the article). Physiopedia is not a substitute for professional advice or expert medical services from a qualified healthcare provider. According to the classification scheme originally described by Anderson and Montesano,4 the fracture pattern determines treatment. This is called the accessory atlanto-axial ligament (Arnold's ligament) (Tubbs et al., 2004).

This rotation made possible with the C1-C2 articulation enables individuals to move their head side to side to shake their head "no.". 14.13). The apical ligament is 23.5 mm, the transverse ligament 21.9 mm, and the alar ligaments are 10.3 mm in length (Panjabi et al., 1991a).

7.2A,B) (Alker et al., 1978; Bucholz et al., 1979). Accessibility StatementFor more information contact us atinfo@libretexts.orgor check out our status page at https://status.libretexts.org. Once thought to be a rare injury, it is nowadays believed to constitute 1-3% of all blunt craniocervical traumas.

The superior vertebral notches are very shallow, and lie behind the articular processes; the inferior lie in front of the articular processes, as in the other cervical vertebrae.

Such fractures have also been classified on the basis of their radiographic appearance. https://emedicine.medscape.com/article/1948797-overview#a2, https://www.physio-pedia.com/index.php?title=Axis&oldid=220156. The atlas and axis form the atlanto-axial joint, which allows head rotation.

On physical examination, these patients often hold their neck rigidly, have tenderness of the occipital region (Capobianco et al., 2002), and may have fasciculations of the tongue associated with weakness (Posner, 1995a).

Occipital condyle syndrome consists of unilateral pain in the occipital region with ipsilateral hypoglossal neuropathy manifesting as tongue weakness, atrophy, and fasciculations (Laigle-Donadey et al., 2005). Scanga, in Encyclopedia of Meat Sciences, 2004.

The spinous process is large, very strong, deeply channelled on its under surface, and bifid. These injuries are twice as common in children as in adults.

Fracture of an occipital condyle may occur in isolation, or as part of a more extended basilar skull fracture. Khaled M. Aziz, Raymond F. It is most commonly seen in high-energy trauma, often associated with other skull and/or cervical spine injuries.[1][2]. Open reduction and fixation of C12 is recommended in cases that fail to reduce in traction (Fielding and Hawkins, 1977; Phillips and Hensinger, 1989). The atlanto-occipital joint on each side is between the occipital condyles and the superior facets on lateral masses of the atlas. The transverse processes (the protrusions of bone on either side of the ring) serve as the attachment sites of muscles that assist in rotating the head. Isolated condyle fracture is a type of craniocervical injury. In most dinosaurs the occipital condyle is situated at the rear part of the skull, below the foramen magnum, and points toward the posterior of the animal.

23.9).61 Type I fractures (axial load and comminuted fractures) and type II fractures (extension of a skull-base fracture) are usually considered stable if isolated.

The atlas is the top-most bone, sitting just below the skull; it is followed by the axis. The atlas and axis in particular work with the ligaments to move the neck. Due to the pain and disability associated with it, this syndrome warrants timely treatment (Fig. The spinous process serves as the attachment site for many muscles of the spine, particularly those close to the skull, as well as the nuchal ligament.

Symptoms of an isolated occipital condyle fracture resemble those of other craniocervical injuries, including high cervical pain, reduced range of motion, unusual head / neck posture, prevertebral swelling, and possibly lower cranial nerve (IX, X, XI, XII) deficits, tetraparesis or abnormal breathing. The axis articulates with the atlas via its superior articular facets, which are convex and face upward and outward.

The ligaments in the spine support and reinforce the joints between the vertebrae.

Open surgical reduction is recommended for cases with severe angulation or displacement (Tay and Eismont, 2006). Rebecca A. Harrison, Franco DeMonte, in Handbook of Clinical Neurology, 2018. The prevalence of occipital condyle fractures is not definitely known.

With almost universal use of CT scans of the occipitocervical junction in the evaluation of trauma patients, these injuries are now being recognized with increased frequency.55 The true prevalence of OCF is unknown, but most authors have concluded that it is probably more common than typically realized.4,5 The reported incidence of OCF ranges from 4% to 19%, with a mean age of presentation of 32.4 years (range, 7 months to 88 years) and a male predilection of 2:1.56, OCFs commonly occur as isolated injuries.28,29,57 The presence of a retropharyngeal hematoma on a lateral cervical radiograph may be the only clue that serious craniovertebral insult has occurred.58-60 Based on CT-based anatomical studies, Anderson and Montesano have classified these fractures (Fig.