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Spinal hematoma

Spinal hematomas are a rare clinical entity and are often idiopathic. Prompt diagnosis and treatment are crucial, lest they cause permanent neurological damage. Identifying the location of the hematoma is important for treatment, as is distinguishing it, to the extent possible, from other entit...

Spinal hydatid disease

Spinal hydatid disease is an uncommon manifestation of hydatid disease, caused by the larval stage of Echinococcus granulosus, or less commonly E. alveolaris or E. multilocularis, and describes a spectrum of disease involving the spinal cord, the spine, or both. For a general discussion, and fo...

Spinal instability neoplastic score (SINS)

The spinal instability neoplastic score (SINS) helps to assess tumor related instability of the vertebral column. It has been shown to useful in guiding the mobilization or operative management of patients with neoplastic spinal disease. Studies have reported good inter-observer agreement among...

Spinal interventional procedures

Back pain is a common condition that is often difficult to treat. Lumbar degenerative facet joints, lumbar disc disease and sacroiliac joint pain account for nearly 70% of cases of lower back pain. Unfortunately, as the incidence of degenerative changes in the spine is so high (e.g. disc abnorm...

Spinal meningeal cyst

Spinal meningeal cysts are diverticulae of the arachnoid or dura mater or of the nerve root sheath. They are uncommon, usually asymptomatic and typically found incidentally at MRI. Clinical presentation They cysts are usually asymptomatic, but if they are large, they may cause mass effect and...

Spinal meninges

The spinal meninges (singular: meninx) are contained within the spinal canal and encase the spinal cord, spinal nerve roots and the cauda equina. Gross anatomy They are composed of three layers (outer to inner) dura mater (also known as theca or pachymeninx) arachnoid mater pia mater Colle...

Spinal meningioma

Meningiomas arising from the coverings of the spinal cord are one of the two most common intradural extramedullary spinal tumors, representing 25-30% of all such tumors 2. This article specifically relates to spinal meningiomas. For a discussion on intracranial meningiomas and a general discus...

Spinal metastases

Spinal metastases is a vague term which can be variably taken to refer to metastatic disease to any of the following: vertebral metastases (94%) may have epidural extension intradural extramedullary metastases (5%) intramedullary metastases (1%) Each of these are discussed separately. Below...

Spinal muscular atrophy

Spinal muscular atrophy is a type of congenital neuromuscular disease affecting anterior horn cells of the brainstem and spinal cord. Epidemiology This disorder affects 1 in 6000-10000 infants 1. Clinical presentation Spinal muscular atrophy typically affects infants and young children, pres...

Spinal nerve sheath tumors

Spinal nerve sheath tumors are the most common intradural extramedullary mass. This article is an overview of spinal nerve sheath tumors. For a discussion on the epidemiology, clinical presentation, pathology and treatment/prognosis of spinal schwannomas and neurofibromas, please refer to spina...

Spinal neurenteric cysts

Spinal neurenteric cysts are a rare type of foregut duplication cyst, accounting for ~1% of all spinal cord tumors. They are usually classified as spinal or intracranial and are associated with vertebral or CNS abnormalities respectively. Pathology Neurenteric cysts result from incomplete res...

Spinal neurofibroma

Spinal neurofibromas are benign peripheral nerve sheath tumors, usually of the localized subtype. This article specifically relates to spinal neurofibromas. For a general discussion of neurofibromas, including their epidemiology and pathology, refer to neurofibroma. For a discussion of the gene...

Spinal paraganglioma

Spinal paragangliomas are tumors of neuroendocrine origin that rarely involve the central nervous system, usually the filum terminale and cauda equina. They are indolent and considered WHO grade I lesions 5. Paragangliomas overall are most commonly located within the adrenal gland (pheochromoc...

Spinal pia mater

The spinal pia mater (or pia mater spinalis) is the innermost layer of the spinal meninges. In congruence to the cranial pia being closely related to the surface of the brain, the spinal pia is closely related to the surface of the spinal cord. Gross anatomy The spinal pia mater is continuou...

Spinal pilocytic astrocytoma

Although rare, pilocytic astrocytomas are the most common spinal cord tumors in the pediatric population. This article specifically relates to spinal pilocytic astrocytomas. For a discussion on intracranial pilocytic astrocytomas refer to pilocytic astrocytoma. For a general discussion on spina...

Spinal primitive neuroectodermal tumor

Spinal primitive neuroectodermal tumors (PNETs) are rare. Most cases are secondary to metastatic spread through the subarachnoid space from a primary intracranial tumor although rare cases of primary spinal PNETs have been reported. This article specifically relates to spinal PNETs. For a discu...

Spinal schwannoma

Spinal schwannomas are benign nerve sheath tumors within the spinal canal, typically arising from spinal nerve roots and it is the most common nerve sheath tumor of spine 11. They are one of the two most common intradural extramedullary spinal tumors, representing 15-50% of such lesions. This a...

Spinal stenosis

Spinal stenosis is a condition in which a portion of the spinal canal narrows to the point at which it can exert pressure on the nerves that travel through the spine. Spinal stenosis is not to be confused with foraminal stenosis which is the narrowing of the foramina with subsequent compression...

Spinal subarachnoid space

The spinal subarachnoid space is the space between the arachnoid mater and pia mater in the spine and is continuous with the intracranial subarachnoid space. It communicates with the intracranial subarachnoid space via the foramen magnum and ends at the level of the S2 vertebra. It is a relat...

Spinal subdural hematoma

Spinal subdural hematomas (SSDH) are much less common than epidural hematomas; however, progression of symptoms due to compression tends to be faster 1. Epidemiology Spinal subdural hematomas are a rare entity, much more so than epidural hematomas. In a meta-analysis of over 600 spinal hematom...

Spinal subdural space

The spinal subdural space is a potential area between the spinal arachnoid mater and the spinal dura mater. Unlike the cranial subdural space, the spinal subdural space does not contain any bridging veins, and thus hemorrhage into this area only occurs in very rare cases 1. It only contains a ...

Spinal subependymoma

Spinal subependymomas are very rare low-grade tumors (WHO I) of the spinal cord. Like intracranial subependymomas, that are far more common, spinal subependymomas are slow growing, discrete tumors with little if any contrast enhancement. Epidemiology Due to the small number of cases reported ...

Spinal synovial cyst

Spinal synovial cysts are cystic formations connected to the facet joint and containing synovial fluid lined by a cuboid or pseudostratified columnar epithelium. They may result in lumbar radiculopathy in a significant number of cases. Clinical presentation They may be asymptomatic and found i...

Spinal vascular malformations

Spinal vascular malformations (SVM) are rare but knowledge of them is important as if undiagnosed and untreated they can lead to serious complications. Pathology There are two main types of SVMs 1,2: spinal arteriovenous fistula (AVF): 70% of SVMs pial: small, large, or giant dural AVF (DA...

Spinocerebellar tract

The spinocerebellar tracts are afferent neurons that convey proprioceptive data from the spinal cord to the cerebellum. There are anterior (or Gowers' tract) and posterior spinocerebellar tracts, the latter also referred to as Flechsig's tract. Both the anterior and posterior spinocerebellar tra...

Spinothalamic tracts

The spinothalamic tracts are ascending pathways in the spinal cord primarily concerned with sensory function. They are responsible for transmitting pain, temperature, coarse (non-discriminative) touch and pressure sensations 1. Unlike other tracts main spinal tracts, the spinothalamic tracts de...

Splenius capitis muscle

The splenius capitis is a strap-like muscles that, along with the splenius cervicis, comprise the superficial layer of intrinsic back muscles. Gross anatomy Attachments origin: ligamentum nuchae, and the tips of the spinous processes and associated supraspinous ligaments of C7 and the upper t...

Splenius cervicis muscle

The splenius cervicis is part of the superficial layer of the intrinsic back muscles. It is one of the two muscles in this group, the other being the splenius capitis. Summary origin: spinous processes of T3-T6 insertion: transverse processes of C1-C3 innervation: dorsal rami of the lower ce...

Split fat sign

The split fat sign is feature that can be seen typically on MRI images with peripheral nerve sheath tumors. It is seen as a fine rind of fat around the lesion. It is best appreciated on T1 weighted images 1. On coronal or sagittal images (i.e.images along the direction of the nerve) a tapered ri...

Spondylodiskitis

Spondylodiskitis, also referred to as diskitis-osteomyelitis, is characterized by infection involving the intervertebral disc and adjacent vertebrae. Epidemiology Spondylodiskitis has a bimodal age distribution, which many authors consider essentially as separate entities: pediatric older po...

Spondylolisthesis

Spondylolisthesis denotes the slippage of one vertebra relative to the one below. Spondylolisthesis can occur anywhere but is most frequent, particularly when due to spondylolysis, at L5/S1 and to a lesser degree L4/L5. Terminology Although etymologically it is directionless (see below) and c...

Spondylolisthesis grading system

A commonly adopted method of grading the severity of spondylolisthesis is the Meyerding classification. It divides the superior endplate of the vertebra below into 4 quarters. The grade depends on the location of the posteroinferior corner of the vertebra above. This classification was original...

Spondylolisthesis Wiltse classification

Spondylolisthesis can be classified according to broad etiologies as described by Wiltse in 1981 1. Typically when reporting studies with spondylolisthesis the Wiltse type is merely stated without referring to its number, whereas the grade of spondylolisthesis is explicitly stated: e.g. "Grade 1...

Spondylolysis

Spondylolysis is a defect in the pars interarticularis of the neural arch, the portion of the neural arch that connects the superior and inferior articular facets. It is commonly known as pars interarticularis defect or more simply as pars defect. Epidemiology Spondylolysis is present in ~5% ...

Spondyloptosis

Spondyloptosis is a term to denote grade V spondylolisthesis - a vertebra having slipped so far with respect to the vertebra below that the two endplates are no longer congruent. It is usually anterolisthesis of L5 on S1 but can be seen elsewhere rarely 1,2.

Spondylosis

Spondylosis (plural: spondyloses) is used as a broad descriptive term referring to degeneration of the spinal column from any cause; it is usually further qualified by the part of the spine affected, e.g. cervical spondylosis. History and etymology It derives from the Ancient Greek word σπόνδυ...

Straight back syndrome

Straight back syndrome refers to decreased thoracic kyphosis ("flattening") and decreased anteroposterior thoracic diameter, such that there is compression of cardiovascular or bronchial structures. It should not be confused with flat back syndrome, which refers to decreased lumbar lordosis, o...

Subacute combined degeneration of the cord

Subacute combined degeneration of the cord (SACD) is caused by vitamin B12 deficiency. Epidemiology Most common in patients older than 40 and especially older than 60 7. Clinical presentation The clinical presentation of SACD is usually with loss of vibration and proprioception in the hands...

Subaxial cervical spine injury classification

The subaxial cervical spine injury classification (SLIC) system is a severity score for cervical spine trauma that helps in determining treatment and prognosis. Classification Injury morphology no abnormality: 0 points simple compression fracture: 1 point burst fracture: 2 points distracti...

Subluxed facet joint

Subluxed facet joint is the mildest form of facet dislocation in which the ligamentous injury leads to partial uncovering of facet joint (c.f. complete uncovering in perched facet). This results in mild anterior displacement of one vertebral body on another (anterolisthesis).

Suboccipital muscle group

The suboccipital muscle group contains four paired muscles, three of which pairs belong to the suboccipital triangle. These muscles all lie below the occipital bone and are responsible for postural support of the head, as well as extension, lateral flexion and rotation. As these muscles are smal...

Suboccipital triangle

The suboccipital triangles are a paired triangular-shaped space formed by the configuration of three paired muscles in the posterior neck between the occipital bone, C1 and C2. Gross Anatomy The suboccipital triangle has an inferomedial pointing apex (pointing towards the nuchal ligament) form...

Sugar coating

So-called "sugar coating" or zuckerguss (German for sugar icing) refers to the appearance of diffuse linear/sheetlike leptomeningeal contrast enhancement in the brain or spinal cord due to drop metastases or leptomeningeal carcinomatosis. It is seen both as a result of CNS involvement from dista...

Sulcal artery

Sulcal arteries are penetrating branches from the anterior spinal artery and extend posteriorly through the anterior median fissure of the spinal cord. The sulcal arteries supply the anterior two-thirds of the spinal cord at any cross-sectional level. Successive sulcal arteries generally altern...

Supraspinous ligament

The supraspinous ligament runs along the tips of adjacent spinous processes and is particularly thick in the cervicothoracic region. Above the level C7 spinous process the ligament no longer directly attaches to the spinous process but rather continues as the nuchal ligament up to its attachment...

Swischuk line

The Swischuk line is helpful in differentiating pathological anterior displacement of the cervical spine from physiological displacement, termed pseudosubluxation. Measurement the line is drawn from anterior aspect of posterior arch of C1 to anterior aspect of posterior arch of C3 the anterio...

Sympathetic chain

The sympathetic chain is a component of the autonomic nervous system and is composed of general visceral afferent and efferent axons that allow for involuntary control of bodily functions via the hypothalamus. The overarching function of the sympathetic system is to control the 'fight, fright o...

Syndesmophyte

Syndesmophytes are calcifications or heterotopic ossifications inside a spinal ligament or of the annulus fibrosus. They are seen in only a limited number of conditions including: ankylosing spondylitis ochronosis fluorosis reactive arthritis psoriatic arthritis They can be classified as...

Synovial cyst

Synovial cysts are para-articular fluid-filled sacs or pouch-like structures containing synovial fluid and lined by synovial membrane. They can occur around virtually every synovial joint in the body and also around tendon sheaths and bursae. Communication with the adjacent joint may or may not ...

Syrinx terminology

There are specific terms used when describing a syrinx or other cystic lesions within the spinal cord 1: hydromyelia: fluid accumulation/dilatation within the central canal, therefore, lined by ependyma syringomyelia: cavitary lesion within cord parenchyma, of any cause (there are many); locat...

Systemic lupus erythematosus (CNS manifestations)

Central nervous system manifestations of systemic lupus erythematosus (CNS lupus) describe a wide variety of neuropsychiatric manifestations that are secondary to systemic lupus erythematosus (SLE) in the central nervous system (CNS). For a general discussion, and for links to other system spec...

T11 vertebra

T11 is an atypical thoracic vertebra. In contrast to typical thoracic vertebrae, it contains a single costal facet that articulates with the atypical eleventh rib. There are no facets on the transverse processes.

T12 vertebra

T12 is an atypical thoracic vertebra. In contrast to typical thoracic vertebrae, it contains a single costal facet with no facets on transverse processes.

T1 vertebra

T1 is an atypical thoracic vertebra. In contrast to typical thoracic vertebrae, it contains a complete facet for the 1st rib and a demifacet for the 2nd rib. It contains lips on the upper surface of the body. T1 also has a spinous process more horizontal than other thoracic vertebrae.

Tabes dorsalis

Tabes dorsalis is a form of tertiary late neurosyphilis in which there is demyelination of the posterior columns of the spinal cord. For a general discussion, and for links to other system specific manifestations, please refer to the article on syphilis. Clinical presentation Patients presen...

Tailgut duplication cyst

Tailgut duplication cysts, also known as retrorectal cystic hamartomas, are rare congenital lesions that are thought to arise from vestiges of the embryonic hindgut. Epidemiology There is a recognized strong female predilection. While it can present at any age, presentation is usually at arou...

Tarlov cyst

Tarlov cysts, also called perineural cysts, are CSF-filled dilatations of the nerve root sheath at the dorsal root ganglion (posterior nerve root sheath). These are type II spinal meningeal cysts that are, by definition, extradural but contain neural tissue. Most Tarlov cysts are asymptomatic, ...

Tectorial membrane of the spine

The tectorial membrane is the thin superior continuation of the posterior longitudinal ligament from the body of the axis. It joins the axis body to the clivus on the anterior half of the foramen magnum, and ascends as high as the spheno-occipital synchondrosis and laterally extends to the hypog...

Terminal myelocystocele

Terminal myelocystoceles are an uncommon form of spinal dysraphism representing marked dilatation of the central canal of the spinal cord, herniating posteriorly through a dorsal spinal defect. The result is a skin-covered mass in the lower lumbar region, consisting of an ependyma-lined sac. E...

Tethered cord syndrome

Tethered cord syndrome is a neurological disorder caused by tissue attachments that limit the movement of the spinal cord within the spinal canal. Clinical presentation Tethered cord syndrome is a clinical diagnosis based on neurologic deterioration involving the lower spinal cord 7. Patients ...

Third condyle

The third condyle, also known as condylus tertius or median occipital condyle, is a rare anatomic variant of the occipital condyles. It is a small separate ossicle at the anteromedial margin of the occipital condyle formed by the failure of the embryonic proatlas (4th occipital sclerotome) to un...

Thoracic anatomy

Thoracic anatomy encompasses the anatomy of all structures of the thorax. This anatomy section promotes the use of the Terminologia Anatomica, the international standard of anatomical nomenclature.

Thoracic spine

The thoracic spine (often shortened to T-spine) forms the middle part of the vertebral column. It extends from below C7 of the cervical spine to above L1 of the lumbar spine. There are 12 thoracic vertebra, termed T1-T12 (some older doctors and texts refer to the dorsal spine and D1-D12). The t...

Thoracic spine (AP view)

The thoracic spine AP view images the thoracic spine, which consists of twelve vertebrae. It is utilized in many imaging contexts including trauma, postoperatively, and for chronic conditions. Patient position the patient is erect or supine, depending on clinical history ideally, spinal imag...

Thoracic spine fracture-dislocations

Thoracic spine fracture-dislocations are severe forms of spinal column injuries that occur secondary to high-energy trauma, in which there is vertebral fracture concomitant with dislocation of facet joints and/or the intervertebral disc space. They are mechanically unstable and are associated wi...

Thoracic spine (lateral view)

The thoracic spine lateral view images the thoracic spine, which consists of twelve vertebrae. It is utilized in many imaging contexts including trauma, postoperatively, and for chronic conditions. It is used in conjunction with the thoracic spine AP view to complete a thoracic spine series. P...

Thoracic spine series

The thoracic spine series is comprised of two standard projections along with a range of additional projections depending on clinical indications. The series is often utilized in the context of trauma, postoperative imaging and for chronic conditions. Radiographs of the thoracic spine are consi...

Thoracolumbar injury classification and severity score (TLICS)

The thoracolumbar injury classification and severity score (TLICS), also sometimes known as the thoracolumbar injury severity score (TISS), was developed by the Spine Trauma Group in 2005 to overcome some of the perceived difficulties regarding the use of other thoracolumbar spinal fracture clas...

Thoracolumbar spinal fracture classification systems

Thoracolumbar spinal fracture classification systems are numerous and represent attempts by various authors to create systems that allow uniform and reproducible classification and description of thoracolumbar fractures which in turn can help with treatment decision making and prognostication. ...

Three column concept of spinal fractures

The three-column concept of thoracolumbar spinal fractures (of Denis) forms the basis of a number of widely used thoracolumbar spinal fracture classification systems. Usage While the three-column concept was initially developed for classification of thoracolumbar spinal fractures, it can also ...

Tight filum terminale syndrome

Tight filum terminale syndrome, or tight filum syndrome, is a subtype of the tethered cord syndrome that is attributed to a thick, short, and/or otherwise inelastic filum terminale rather than other tethering agents. Terminology The term "tight filum terminale syndrome" is synonymous with "tet...

Toothpaste sign

The toothpaste sign in spinal imaging represents an extrusion of an intervertebral disc into the epidural space. It is called after the shape of extruded material relatively to the parent disc in a sagittal plane.

Torticollis

Torticollis (wryneck) is a clinical finding of head tilt with or without rotational spinal malalignment. It is not a diagnosis in itself and there are a wide range of underlying conditions. It is most common in the pediatric age group. Pathology Torticollis can be acute (<1 week) or chronic (...

Transforaminal epidural steroid injection

Transforaminal epidural steroid injections (TFESI), also known as transforaminal nerve root injection or nerve root blocks, are performed for treatment and diagnosis of radicular pain. They differ from selective nerve root blocks (SNRB), as the aim is to get "epidural spill" and get the injectat...

Transforaminal lumbar interbody fusion (TLIF)

Transforaminal lumbar interbody fusion (TLIF) is a spinal fusion procedure performed as an alternative to posterior lumbar interbody fusion (PLIF) when posterior decompression of the spinal canal is not required 1. A facetectomy is usually performed followed by a discectomy and insertion of in...

Transitional vertebra

Transitional vertebra is one that has indeterminate characteristic and features of vertebrae from adjacent vertebral segments. They occur at the junction between spinal morphological segments: atlanto-occipital junction atlanto-occipital assimilation: complete or partial fusion of C1 and the o...

Transpyloric plane

The transpyloric plane, also known as Addison's plane, is an imaginary axial plane located midway between the jugular notch and superior border of pubic symphysis, at approximately the level of L1 vertebral body. It an important landmark as many key structures are visualized at this level, altho...

Transverse myelitis

Acute transverse myelitis (ATM) is an inflammatory condition affecting both halves of the spinal cord and associated with rapidly progressive motor, sensory, and autonomic dysfunction. It is mostly imaged with MRI, which generally shows a long segment (3-4 segments or more) of T2 increased sign...

Transverse process fracture

Transverse process fractures are a common sequelae of trauma, although they are considered a minor and stable lumbar spine fracture. There is strong association between transverse process fractures and other traumatic injuries. Pathology Transverse process fracture most commonly occur in the u...

Transversospinalis group

The transversospinalis group is the deep layer of the intrinsic back muscles. These muscles lie between the transverse and spinous processes and are grouped by length of the fascicles, as well as region covered. The groups are rotatores, multifidus, and semispinalis. Gross anatomy Rotatores T...

Traumatic spinal cord injury

Traumatic spinal cord injury can manifest as a wide variety of clinical syndromes resulting from damage to the spinal cord or its surrounding structures. It can result from minor injury if the spine is weakened from disease such as ankylosing spondylitis or if there is pre-existing spinal stenos...

Tuberculosis

Tuberculosis encompasses an enormously wide disease spectrum affecting multiple organs and body systems predominantly caused by the organism Mycobacterium tuberculosis. A small proportion can also be caused Mycobacterium bovis. Epidemiology Although tuberculosis continues to be very common in...

Tuberculosis (musculoskeletal manifestations)

Musculoskeletal tuberculosis is always secondary to a primary lesion in the lung. Epidemiology The prevalence of the disease is around 30 million globally and 1-3% of the 30 million have involvement of their bones and/or joints. Mycobacterium tuberculosis is responsible for almost all of the c...

Tuberculous spondylitis

Tuberculous spondylitis, also known as Pott disease, refers to vertebral body osteomyelitis and intervertebral diskitis from tuberculosis (TB). The spine is the most frequent location of musculoskeletal tuberculosis, and commonly related symptoms are back pain and lower limb weakness/paraplegia....

Tuberculous spondylitis versus pyogenic spondylitis

Tuberculous spondylitis and pyogenic spondylitis are both common causes of spinal infection. Imaging findings of these 2 diseases can be challenging to distinguish, yet crucial because the treatments for these infections are particularly different 2. Radiographic features Useful distinguishing...

Typical cervical vertebrae

Of the seven cervical vertebrae, C3 through C6 have typical anatomy, while C7 looks very similar. C1 (atlas) and C2 (axis) have very distinct anatomical features. For a basic anatomic description of the structure a generic vertebra, see vertebrae. Gross anatomy small, oval-shaped vertebral bod...

Typical thoracic vertebrae

Given the twelve thoracic vertebrae are largely similar, most are considered typical thoracic vertebrae with the exceptions T1 and T9 to T12. For a basic anatomic description of the structure of typical vertebrae, see vertebrae. Gross anatomy Relative to cervical and lumbar vertebrae, thoracic...

Ultrasound-guided spinal anesthesia

With the growing incidence of obesity in the western world, ultrasound-guided anesthesia is becoming more common. Spinal anesthesia is traditionally administered by identifying relevant surface anatomy and imaging is rarely used for pre-procedural identification of structures. Indications low...

Uncinate process of the cervical spine

The uncinate process of the cervical spine is a hook-shaped process found bilaterally on the superolateral margin of the cervical vertebral bodies of C3-C7. The uncinate processes are more anteriorly positioned in the upper cervical spine and more posteriorly location in the lower cervical spin...

Uncovertebral joint

Uncovertebral joints, also called Luschka’s joints, are seen bilaterally between adjacent cervical vertebrae, identified by the cat ear shaped uncinate processes of the C3-7 vertebrae (C1 and C2 have no uncinate processes). Gross anatomy Articulations The articulation forms between the uncina...

Unfused spinous process

Unfused spinous process, which is really failure of fusion of the neural arch, is a relatively common anatomical variant and is part of the spectrum of spina bifida occulta. This should be differentiated from accessory ossicles of the spinous process, which appear after non-fusion of the secon...

Unilateral facet dislocation

Unilateral facet dislocation is a relatively stable type of facet dislocation. Pathology Mechanism Flexion/distraction associated with rotation. The inferior articular facet of vertebral above moves over the superior facet of the vertebral below and becomes locked. It usually affects C4-C5 or...

Vanishing vertebrae

Vanishing vertebrae is a rare ischemic manifestation of sickle cell disease, in which a completely infarcted vertebral body literally disappears or vanishes, as a result of infarction. In the few reported cases, the posterior elements remain intact. See also codfish or h-shaped vertebrae ante...

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