Spine

Spina Bifida Presentation and Treatment

Spina bifida is a neural tube defect that leads to a congenital defect in the posterior bony wall of the spinal canal [vertebral arch] involving the laminae and spinal cord malformation that occurs in varying degrees of severity and range of presentation from an incidental finding on x-ray to stillbirth.

Spina bifida is most commonly seen in the lumbosacral region. Sometimes the contents of the canal may protrude through the defect.

The average worldwide incidence of spina bifida is 1 case per 1000 births, but marked geographic variations occur.

The term bifida is derived from the Latin bifidus which means “in 2 parts.”

Development of the spinal cord

During the 2nd week of intrauterine life, a dorsal groove appears on the surface of the embryo, which is known as the neural groove. The margins of the neural groove unite into a tube known as the neural tube and the lumen, within it, is called the neural canal.

The neural tube becomes separated from the surface by an ingrowth of the mesoderm.

In front of the neural tube, there is a solid rod of cells, known as the notochord. Around the notochord, the vertebral bodies develop.

From each of the bodies, there extend two projections which grow around the neural tube to form the vertebral arch or neural arch.

Failure of fusion of these arches gives rise to spina bifida.

Etiology

Neural tube defects result from failed closure and abnormal differentiation of the embryonic neural tube. These occur between the 17th and 30th day of gestation.

Anencephaly and myelomeningocele are the most common neural tube defects.

Myelomeningocele occurs due to a failed closure of the caudal end of the neural tube resulting in a sac which contains dysplastic spinal cord, nerve roots, meninges, vertebral bodies, and skin.

The etiology in most cases of spina bifida is multifactorial.

Most infants born with spina bifida are born to mothers with no previously affected children

Genetic

Up to 10% of fetuses with a neural tube defect detected in early gestation have an associated chromosome abnormality.

Maternal risk factors

Folic acid deficiency [about 50% of cases are attributed]
Pregestational diabetes – increases the risk of CNS malformation
Maternal obesity
Hyperthermia
Maternal diarrhea
Intrauterine exposure to antiepileptic drugs and drugs used to induce ovulation
Maternal exposures to
- Fumonisins [toxins produced by fungi]
- Electromagnetic fields
- Hazardous waste sites
- Disinfection by-products found in drinking water

Note on the tethered cord

A fibrous band, the membrana reunions connects the skin to the spinal theca.

At one stage the spinal cord reaches the distal end of the vertebral column. Gradually the cord lags behind in growth in comparison to the vertebral column in intrauterine life so that at birth the distal end of the cord lies at the third lumbar vertebra.

Later on, due to more development of the vertebral column, the distal end of the cord lies at the lower end of the first lumbar vertebra in adults. With the growth of the body, the membrana reunions pull on the theca and nerve roots. This causes some neurological deficiencies e.g. foot drop, nocturnal enuresis or a backache. Such symptoms appear late in childhood or in adult life.

Types of Spina bifida

Spina Bifida Occulta

In Spina Bifida Occulta, though there is a failure of the neural arches to unite, and a small gap exists in one of the vertebral arches, usually in the lumbar or sacral regions. There is no protrusion of the cord or membranes. Frequently only one vertebra is affected and the gap is filled with fibrous tissue.

Subtle signs of underlying abnormality in bifida occulta are dimple, skin pigmentation or hairy patch. Otherwise, spina bifida occulta is almost always without consequences.

A spinal cord lipoma or a fibrous cord may be present underneath these subtle signs.

Problems with micturition or a foot deformity may be seen in some cases of occulta.

In later ages, the patient may present with tethered cord.

Many cases of spinal bifida occulta are symptomless. Either they remain undiagnosed or diagnosed by accident when an x-ray taken for some other reasons.

Clinical Presentation

Present since birth
There is some abnormality in the local skin either a skin dimple or a local patch of hair or a naevo-lipoma or simple lipoma.
Neurological examinations must be performed, as in adolescent or in adult life manifestations of such deficiency may be revealed in the form of a backache, nocturnal enuresis, local anesthesia, local paresis or even foot drop.
X-ray is often confirmatory as it will show the bony defect.

Treatment

Presence of tuft of hair or lipoma may lead to a cosmetic complaint and this is treated by excision of these lesions.
If there are neurological symptoms due to membrana reunions, [tethered cord syndrome] the membrana reunions is excised in its whole length from the skin through the vertebral gap to the spinal meninges.
Extradural or intradural lipomas causing compression of neural tissue should be excised.

Spina bifida cystica

In this type, the spine is bifid and a cyst forms. Meningocele actually refers to a cystic swelling of the dura and arachnoid which protrudes through the spina bifida defect in the vertebral arch. A person with a meningocele may have no neurologic sequelae.

When cord tissue extends into the meningocele, it is called a myelomeningocele. Meningomyelocele is a form of spina bifida cystica is the most common type of spina bifida, accounting for 94% of cases. [Spina bifida occulta not included in this figure]

The most severe type of spina bifida cystica is the myelocele [also called myeloschisis] where the open neural plate has spread out onto the surface and is covered just by epithelium.

Meningocele

In this condition protrusion of meninges occurs through the defect in the neural arch. Such protrusion contains only cerebrospinal fluid. So it gives rise to a cystic swelling.

Usually the duramater stops at the margin of the defect and usually the pia and arachnoid protrude. The overlying skin remains intact.

It is common in the lumbosacral region. Meningocele also occurs in the skull, where it is more common in the occipital region or at the root of the nose.

Clinical Features

It is present since birth
It is a cystic swelling, highly translucent, compressible swelling
Expansile impulse is present when the child cries or coughs
The overlying skin is normal and free
On careful palpation the edge of the bony defect is palpable
Neurological manifestations are usually absent (Compare with myelomeningocele, where neurological manifestations are usually present).
This condition may be associated with hydrocephalus and this combination is known as Arnold-Chiari syndrome.
X-ray is confirmatory and will show the bony defect
Infection and rupture are possible complications

Treatment of Meningocele

An operation should be performed as early as possible, but the child’s condition and strength should be sufficient to withstand the operation. This operation is often performed within a few days of birth.

The skin and the sac are opened with incisions perpendicular to each other. This will minimize the chance of postoperative C.S.F. leakage.
The redundant part of the sac is excised
The margins of the excised sac are sutured together in the midline
To strengthen the bony gap, the adjacent erector spinae muscle and the overlying fasciae are approximated over the gap with the help of lateral release incisions (to minimize tension in the suture line).
The skin is closed.

Meningomyelocele

Clinical Features

Meningomyelocele is the commonest variety of spina bifida in the living children.
The bony defect may usually extend over 3 or more segments.
Skin may be absent or atrophic, and meninges may be exposed.
Patient can have spastic or flaccid paralysis.
Neurological manifestations are almost always present.
X-ray will show the bony defect. There may be other abnormalities of the vertebrae, like scoliosis or kyphosis or even hemivertebra.
Other symptoms in infants – lethargy, poor feeding, irritability, stridor or eye coordination problem.
Older children may present with cognitive changes, motor weakness, spasticity, problems of bladder/bowel, cranial nerve dysfunction, backache or deformities of the lower limb.
Increase in foot deformities, worsening of spinal deformity or new onset of hip dislocation, progressive neurologic defects in growing children may suggest a tethered cord [tissue attachments cause stretching of spinal cord.]

Based on the level of involvement, myelomeningocele patients frequently can be classified as belonging to one of the following groups, based on the neurosegmental level of the lesion:

Thoracic

upper limb and neck musculature well innervated
Function of trunk musculature variable
No power in lower limbs.

High lumbar

Variable hip flexor and hip adductor
Absence of hip extension, hip abduction,
Absent knee and ankle movements

Thoracic and high-lumbar groups tend to have increased prevalences of lumbar lordosis, abduction and external rotation contractures of hip, flexion contracture of knee and foot equines.

Low lumbar

Present – hip flexors and adductors, medial hamstring, and quadriceps
Variable – lateral hamstrings, hip abductors, and ankle dorsiflexors
Absent – Ankle plantar flexors

These often have hip and knee flexion contractures, increased lumbar lordosis, genu valgum, calcaneo-valgus and overpronation of foot.

Sacral

Hip, knee normal
Ankle plantar flexor strength is variable.

These patients often exhibit mild hip and knee flexion contractures and increased lumbar lordosis with variable foot and ankle deformities with various ankle and foot positions.

Associated Findings

Complications of hydrocephalus
Symptoms of Chiari II malformation- Lower brainstem and/or upper cervical spinal cord compression causing apnea, dysphagia, stridor, nystagmus or upper limb weakness.
Spinal deformities
- Congenital – vertebrae and rib anomalies
- Acquired due to muscle imbalance
Lower limb deformities
Short Stature
Cranial nerve dysfunction – Ocular muscle palsies, dysphagia and dysphonia.
Tethered spinal cord – pain, sensory changes, spasticity, and progressive scoliosis.
Syringomyelia
Renal Problems
- Neurogenic bowel and bladder
- Bladder incontinence
- Hydronephrosis due to a contracted bladder
- Infections and renal failure
- Vesicoureteral reflux
Congenital Abnormalities
- Facial clefts
- Heart malformations
- Genitourinary tract anomalies

Treatment of Myelomeningocele

The operation must be performed as early as possible. Child’s condition should also be considered, as it should withstand the operation.

Delay in operation may cause

Infection within the sac and postoperative problems.
The sac may rupture and will make operation extremely difficult with infection spreading throughout the subarachnoid space.
There will be more adhesion of nerves with the wall of the sac, which will be difficult to separate.
Gradually extensive paralysis of the legs and incontinence may occur, so that surgical intervention may become contraindicated.

Additional Management which may be needed

Bladder and bowel management
Bracing and orthotics
Physical Therapy/ occupational Therapy/ recreational Therapy
Shunting for hydrocephalus and syringomyelia
Chiari malformation repair
Hip relocation and other deformity correction procedures

Syringomyelocele

In this condition, the central canal of the spinal cord is dilated and the spinal cord lies within the sac together with the peripheral nerves arising from the cord.

This is the rarest variety of spina bifida.

Gross neurological deficits and paralytic manifestations are present.

Myelocele

This is the gravest form of spina bifida, in which besides the bony defect there is also a defect of development of the spinal cord. The development is arrested before the time of closure of the neural furrow. So that the posterior part of the spinal cord is not developed.

The elliptical raw surface of the neural furrow can be seen, deep to which lies the anterior part of the spinal cord. At the top end of the defect, the central canal of the spinal cord opens on the surface and discharges the cerebrospinal fluid constantly.

Majority of the cases are stillborn. Even if a few born alive, they die within a few days from infection of the cord and meninges.

Evaluation of Spina Bifida

As the most common type of spina bifida is myelomeningocele, the evaluation discussion is centered around that.

Screening test for neural tube defects can be performed by blood tests or amniocentesis for alpha-fetoprotein estimation combined with ultrasonography. The fetal presence of an open neural tube defect is marked by an elevated alpha-fetoprotein level.

In children with spina bifida, apart from routine laboratory screening examination, urine studies for culture, urodynamic studies for bladder evaluation and latex sensitivity tests become important.

X-rays provide information for early evaluation when an infant is born.

Most of the children on MRI would show a tethered cord but only about 20% are symptomatic.

CT is useful for tracking hydrocephalus.

Prevention of Spina Bifida

Increased use and accuracy of prenatal diagnosis and option for early pregnancy termination and the introduction of primary prevention in the form of folic acid therapy has resulted in a decline of cases of spina bifida.

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Tuberculosis of Spine Presentation and Treatment

By Arun Pal Singh

Tuberculosis of spine or TB spine or spinal TB was first described by Percivall Pott. He noted this as a painful kyphotic deformity of the spine associated with paraplegia. Since then condition is also referred to as Pott’s disease or Pott’s spine. It is also called vertebral tuberculosis. Because tuberculosis is also called Koch’s lesion, the term spinal Koch’s is also used. Another term used is caries spine or spinal caries.

Spine tuberculosis is the commonest form of skeletal tuberculosis. It constitutes about 50 percent of all cases of bone and joint TB.

Spine TB is most commonly found in the first three decades of life but can occur in any age group.

There is no gender predilection.

Tuberculosis of the spine occurs most commonly in the lower thoracic region. It is followed by lumbar, upper dorsal, cervical and sacral regions in decreasing order of frequency.

Tuberculosis of spine is also referred to as tuberculous spondylitis. Tuberculosis of the spine used to be a disease of early childhood in the past. But with improved public health measures, this age incidence has changed, and adults are more frequently affected.

Before the availability of modern antitubercular drugs, the mortality rate of the patients was about 30 percent. With the use of modern antitubercular drugs, the outcomes of the treatment have been changed.

Anatomy of Spine

Detailed anatomy of spine is discussed separately. Here A general overview with terms is presented.

Human spine or vertebral column is a structure made of multiple small units called vertebra and extends from just below the base of skull to a point just below the beginning of gluteal cleft.

A vertebra is the smallest unit of vertebral column. Plural term is vertebrae. Vertebrae have been modified according to the function they are expected to serve in different parts of the spine.

Spine appears straight in anteroposterior view (That means looking from front or back) but in lateral view or looking from a side, we can see multiple curves in the spine in different regions.

These curves are called kyphotic if they are concave in anterior(front) and convex on posterior (back) and lordotic if they are convex in anterior and concave on posterior.

Spine is divided into five regions

Cervical Spine

This part of the spine is present in the neck and consists of first seven vertebrae. Thus the first vertebra is called C1 and last vertebra is called C7. The cervical spine has a normal lordotic curve.

Thoracic Spine

Also called dorsal spine, it is below the cervical spine and spans upper trunk or thorax or area corresponding to the chest. It contains a total of 12 vertebrae which are designated as T1 to T12

Thoracic spine has a normal kyphotic curve.

Lumbar Spine

It follows thoracic spine and consists of 5 vertebrae, L1 to L5. Anatomical variations in which 4 or 6 vertebrae might be present in lumbar spine are known.

Sacral Spine

Sacral spine is composed of five sacral vertebrae S1 to S5. Vertebrae in sacral spine are fused to each other. This part of spine follows lumbar spine and is present in the pelvic area.

Coccyx or Coccygeal Spine: This is also known as tailbone. It consists of four fused vertebrae (the coccygeal vertebrae) below the sacrum.

Vertebra

Vertebrae, the structural units of the spine are stacked together to form the entire vertebral column. Discs are cushion-like structures acting as shock absorbers between two vertebrae.

They also permit some movement between the vertebral bodies and the transmission of weight.

Each vertebra consists of an anterior body which is attached to a posterior ring called posterior neural arch [pedicle and laminae together].

Two struts of bones called pedicles arise from body and join two converging struts called laminae. Pedicles, laminae and posterior surface of body forms boundaries of spinal canal, which is the space for passage of spinal canal.

This spinal canal is the space where spinal cord passes. There is a transverse process on either side of the arch which serves as attachment to various muscles and ligaments. Posteriorly is the posterior spinous process that also serves as an attachment to ligaments and muscles of the spine.

The neural foramen is the opening where the nerve roots exit the spine and travel to the rest of the body. There are two neural foramina located between each pair of vertebrae, one on each side.

Muscles and Ligaments

Various muscles and ligaments attach to the spine. They help the spine to stabilize and allow it to carry various movements.

Pathology of Tuberculosis of Spine

The bacteriae reach the site of infection via bloodstream. The focus of infection usually begins in the cancellous bone of the vertebral body. Occasionally, it is in the posterior neural arch, transverse process, or subperiosteally deep to the anterior longitudinal ligament in front of the vertebral body. Up to 5% of spinal tuberculosis has been reported in posterior elements.

As the disease progresses, the area of infection gradually enlarges and spreads to involve two or more adjacent vertebrae by extension beneath the anterior longitudinal ligament or directly across the intervertebral disc.

Sometimes there may be multiple vertebrae may be involved which are separated by normal vertebrae termed as skip lesions. The infection may be disseminated to distant vertebrae via the paravertebral abscess.

As the tuberculosis of spine progresses, vertebral bodies lose their mechanical strength due to progressive destruction under the force of body weight. Extreme weakening leads to angular kyphotic deformity.

The severity of the deformity depends upon the extent of destruction, the level of the lesion, and the number of vertebrae involved.

Kyphosis is most marked in the thoracic area because of the normal dorsal curvature. In the lumbar area, it is less because of the normal lumbar lordosis because of which the body weight is transmitted posteriorly and collapse is partial.

The collapse is minimal in the cervical spine because most of the body weight is borne through the articular processes.

Healing takes place by gradual fibrosis and calcification of the granulomatous tuberculous tissue. Eventually, the fibrous tissue is ossified, with resulting bony ankylosis of the collapsed vertebrae.

Paravertebral abscess [abscess around vertebra – literal meaning], formation occurs in almost every case. With the collapse of the vertebral body, tuberculous granulation tissue, caseous matter, and necrotic bone and bone marrow are extruded through the bony cortex and accumulate beneath the anterior longitudinal ligament.

These cold abscesses gravitate along the fascial planes and present externally at some distance from the site of the original lesion.

In the lumbar region, the abscess gravitates along the psoas fascial sheath and usually points into the groin just below the inguinal ligament.

In the thoracic region, the longitudinal ligaments limit the abscess, which is seen in the radiogram as a fusiform radiopaque shadow at or just below the level of the involved vertebra.

Thoracic abscess may reach the anterior chest wall in the parasternal area by tracking via the intercostal vessels.

Neural Deficit in Spine Tuberculosis

Neurological complications may arise due to compression of the cord by the abscess, caseating or granulating mass, intervertebral disc or edge of bone c. Other contributory factors may be thrombosis of the local vessels and edema of the cord.

The neural deficit can be paraparesis, to begin with, and eventually, lead to paraplegia. It occurs most often in the mid-or upper-thoracic region, where the kyphosis is most acute, the spinal canal is narrow, and the spinal cord is relatively large.

The neural deficit in TB spine occurs due to pressure on the tissues of the cord, as follows. Other factors are cord edema and inflammation.

Following can contribute to the pressure on the spinal cord.

Extradural Mass formed by tubercular abscess [fluid pus, granulation tissue or caseous material.
Extradural Granuloma and Tuberculoma
Sequestra [dead bone] from avascular diseased vertebral bodies or intervertebral disc
Granulation tissue on the with peridural fibrosis [cicatrization or scar formation]
Infarction of the cord by thrombosis or arteritis.
Cord atrophy

Paraplegia due to tuberculosis of the spine can be early onset or late onset.

Early onset paraplegia occurs during the active phase of the vertebral disease usually within first 2 years of the onset.

Late-onset paraplegia occurs many more than 2 years after the disease has persisted and could be due to recrudescence of the disease or mechanical pressure on the cord.

It is also called paraplegia associated with the healed disease.

Types of Lesions in Spinal Tuberculosis

Four types of the lesion are known in spinal tuberculosis

Paradiscal type – On either side of the disc
Central type – central part of the vertebral body
Anterior type – anterior surface of the vertebral body
Appendiceal type (involving pedicles, laminae, spinous process or transverse processes).

Paradiscal Lesion

In this type, the infection is on either side of the disc, involving two vertebrae. This is the most common type of presentation. The narrowing of the disc space is often the earliest radiological finding, often associated with a fuzziness of The narrowing of the disc space may either be due to either atrophy of the disc tissue or prolapsed.

Central Type of Lesion

The infection starts from the center of the vertebral body, where it reaches through Batson’s venous plexus or through the branches of the posterior vertebral artery.

On x-ray, the diseased vertebral body loses the normal bony trabeculae and many show areas of destruction or the body may be expanded or ballooned out like a tumor and finally collapse like vertebra plana.

Loss of disc space is minimal.

Anterior Lesion

The infection starts beneath the anterior longitudinal ligament and the periosteum.

On x-ray, the peripheral portion of the vertebral body shows erosion as shallow excavations. Vertebral collapse and a decrease in the disc space is usually minimal and occurs late.

Appendiceal Lesion

This involves isolated infection of the pedicles, transverse processes, laminae, and the spinous process does occur.

These lesions are not generally visible on routine x-rays.

CT or MRI is better at detecting these lesions.

Presentation of Tuberculosis of Spine

The onset of is usually insidious. Initial symptoms are vague, consisting of generalized malaise, easy fatiguability, loss of appetite and weight, and loss of desire to play outdoors in children. There may be an afternoon or evening fever.

However, the acute presentation of tuberculosis is known.

A backache is usually minimal and may be referred segmentally.

Muscle spasm makes the back rigid. The motion of the spine is limited in all direction. The patient may complain of inability to flex spine when picking an object up from the floor. For doing this, the patient flexes his hips and knees, keeping the spine in extension.

On examination, the spine is stiff and painful on movement. The stiffness of the spine is noticed by an increase of depth of spinal midline gutter as paraspinal muscle spasm makes them prominent.

There may be a localized kyphotic deformity which would be tender on palpation.

A cold abscess may be noticed. The abscesses may be palpated as fluctuant swellings in the groin, iliac fossa, retropharynx, or on the side of the neck, depending upon the level of the lesion.

In spite of the vast spectrum of the disease, the early cases may not have any clinical finding except for tenderness in the region of the complaint. Several of these symptoms and sign may be absent even in cases of the active vertebral disease.

A history of contact with a known case of tuberculosis or a recent visit to an endemic area should be asked.

A kyphus in the thoracic region may be the first noticeable sign. As the kyphosis increases, the ribs will crowd together and a barrel chest deformity may develop.

When the lesion is situated in the cervical or lumbar spine, a flattening of the normal lordosis is the initial finding.

The gait of the person with Pott’s disease is peculiar, reflecting the protective rigidity of the spine. His steps are short, as he is trying to avoid any jarring of his back. In tuberculosis of the cervical spine, he holds his neck is in extension and supports his head with one hand under the chin and the other over the occiput.

Neural Deficit in TB Spine

The compression of neural structures leads to signs of neurological deficit. The compression of neural structures is indicated by

Spasticity of the limbs [uper and lower limbs in case of the cervical spine and lower limbs in case of dorsal and lumbar spines]
Hyperactive deep tendon reflexes
Spastic gait
Motor weakness
Disturbances of the bladder and anorectal function.

A neural deficit in tuberculosis could be caused by the following factors

Inflammatory

Inflammatory edema – recovers by rest and drug therapy
Tuberculous granulation tissue – mostly recovers by rest and drug therapy
Tuberculous abscess – recovers by conservative therapy, rarely requires evacuation and decompression
Tuberculous caseous tissue – May subside by conservative therapy, sometimes requires evacuation and decompression

Mechanical

Tubercular debris- Solid debris requires removal and decompression
Sequestra from vertebral body and disc – Require operative removal and decompression
Constriction of cord due to stenosis of vertebral canal- Requires operative decompression
Localized pressure due to internal gibbus along anterior wall of the vertebral canal – Requires operative decompression

Intrinsic

Prolonged stretching of the cord over a severe deformity – Decompression, release of cord, and anterior transposition may lead to recovery
Atrophy of cord – Does not recover completely
Infective thrombosis/endarteritis of spinal vessels – Does not recover appreciably
Pathological dislocation of spine – Rare complication, causes irreparable severance of cord
Tuberculous meningomyelitis – Does not recover completely
Syringomyelic changes – poor recovery
Spinal Tumor syndrome – Poor recovery
Diffuse extradural granuloma or tuberculoma or peridural fibrosis -Present as spinal tumor syndrome

Neural deficit in spine TB is classified as follows

Stage 1

Patient walks normally and is not aware of any deficit
Extensor plantar response
Ankle clonus
May be accompanied by brisk tendon reflexes

Stage 2

Clumsy gait
Incoordinated jumpy gait
Weakness, walks with support

Stage 3

Severe weakness
Patient bedridden and cannot walk because
<50% sensory deficit

Stage 4

The patient has paraplegia with flexor spasms or paraplegia in flexion.
Paraplegia in extension with spontaneous flexor spasms
Sphincter disturbances
Flaccid paralysis [ occurs due to very severe cord compression]

Neural deficit in tuberculosis is of slow onset.

The earliest symptom may be twitching of muscles in the lower limbs and clumsiness while walking.

Motor functions are almost always affected before and to a greater extent than the sensory functions due to anterior site because the disease is mostly in the anterior part [motor tracts are anterior too] and probably the motor tracts are more sensitive to compression of the cord.

The paralysis as noted above may pass from spastic motor paraparesis to spastic paraplegia in extension and then on spastic paraplegia in flexion.

In severe compression of the cord, flexor spasms may occur which refers to involuntary flexions of the lower limb. This indicates complete loss of conductivity in the pyramidal and extrapyramidal neural tracts.

Bladder and anal sphincters may be involved.

There may be a sensory deficit. The sense of position and vibration are the last to disappear.

In severe cases all spasticity disappears and the paralysis becomes flaccid (areflexic paraplegia) with anesthesia and loss of sphincter control.

Sometimes, the insult to the cord is sudden [such as ischemia] and the patient may present with flaccid paralysis ”spinal shock” and later gradually change into spasticity.

Rarely, the disease may present like a ”spinal tumor syndrome” due to a localized tuberculoma or a diffuse granuloma or due to peridural fibrosis.

Differential Diagnosis of Tuberculosis of Spine

Mostly the diagnosis of tuberculosis can be made by clinical and radiological examination by its characteristic findings.

Doubtful cases need to be confirmed by biopsy and/or culture.

The differential diagnoses vary with age of presentation. Congenital defects of the spine, Calve’s disease are common d/ds in young patients. Schmorl’s disease and Scheuermann’s disease may sometimes cause confusion in adolescent patients.

Tuberculosis is suggested by the presence of constitutional symptoms [fever, malaise etc], characteristic radiological appearance and disc space is well maintained. Local signs like pain, spasm, and tenderness are less pronounced in other diseases than TB spine.

In adults, malignancy is major d/d.

Following is a list of main differentials of the tuberculous spine.

Infections

Bacterial Spondylitis

This may follow infection or surgery of urogenital tract, or postabortal or postpartum infections. Also called pyogenic osteomyelitis, it presents as sudden onset disease with severe localized pain, spasm and high-grade fever with chills and rigors.

Bone destruction is eventually followed by sclerosis and new bone formation and even bony ankylosis.

Typhoid Spine

This is a rare complication of enteric fever. Most of the cases present at the time intervals of 4 weeks to a few months after the episode of typhoid fever.

Excruciating pain and muscle spasm. The radiological picture resembles that of tuberculosis and low-grade pyogenic spondylitis. Confirmation can be obtained by agglutination tests, therapeutic trial or by biopsy.

Brucella Spondylitis

This can produce changes in the spine which can be very similar to those seen in tuberculosis of the spine. The diagnosis is best established by identification of the causative organisms, agglutination tests or by biopsy.

Fungal Spondylitis

Actinomyces group or blastomycosis group can be responsible for the infection of vertebrae.

In blastomycosis, paravertebral abscess formation is a common feature. In actinomycosis sclerosis and destruction of bone proceed hand in hand.

A collapse of the vertebra is rare, sometimes the involved vertebrae may produce an appearance described as ”honeycomb” or ”lattice-like” and the condition is usually accompanied by multiple sinus formations and involvement of the subcutaneous tissues.

Diagnosis can be confirmed by a demonstration on the mycotic organism from the discharging sinuses, pus or from the diseased bone.

It is quite rare.

Syphilis

The commonest site of involvement is thoracolumbar and lumbar spine though it is of rare occurrence after modern antibiotics which cure syphilis much earlier.

Three types are known

Arthralgic type of syphilitic spondylitis
Gummatous type of syphilitic spondylitis
Charcot’s disease of the spine.

Xrays show gross disorganization and destruction of the involved vertebrae along with proliferative new bone formation extending into the adjacent paraspinal tissues. It is extremely difficult to differentiate this condition on x-rays alone.

Diagnosis is confirmed by serological tests, tissue biopsy or by the response to antisyphilitic treatment.

Hydatid Disease

Hydatid disease of the spine is a very rare condition

Tumors

Benign Tumor

Following benign tumorous conditions may clinically and radiologically have some resemblance with spinal tuberculosis.

Hemangioma
Giant-cell-tumor
aneurysmal bone cyst

Malignant Tumor

Ewing’s sarcoma

Osteogenic sarcoma
Fibrosarcomas
chondrosarcomas
Multiple Myeloma
Lymphomas
Metastases

Histiocytosis-X

eosinophilic granuloma (spine-Calve’s disease)
Hand-Schuller-Christan disease
Letterer-Siwe disease

Spinal Deformities

Hemivertebrae
Block Vertebrae [Fusion of two or more vertebral bodies]
Neural arch defects

Spinal Osteochondrosis

It is an ischemic lesion of the apophysis of several vertebrae occurring in early adolescence. A rounded kyphosis develops because of fragmentation, and mild wedging of several vertebral bodies.

The absence of any constitutional reaction, spasm or any radiological paravertebral shadows and bony destruction, together with minimal local symptoms distinguishes this condition from infective lesions of the spine.

Spondylolisthesis

It is a forward displacement of one vertebra on another. The commonest sites are between L5 and S1, and L4 and L5.

Destruction of posterior articular elements or destruction of pars interarticularis with or without the involvement of paradisical regions due to tuberculous process or other infective lesions may result in spondylolisthesis.

Imaging in Tuberculosis of Spine

Xrays

In addition to the lesion-specific appearance of the disease [ radiolucent lesion, fuzzy vertebral margins, reduced disc space, vertebral collapse – refer to types of the lesions], the following findings may be noted.

Findings are suggestive, but not pathognomonic. Routine views are anteroposterior and lateral views of the spine. Chest radiograms are taken to rule out outer foci of systemic disease in case of a suspected person.

Paravertebral shadows

Paravertebral shadows in TB of the spine is produced by extension of tuberculous granulation tissue and the collection of an abscess in the paravertebral region.

In the cervical region, this presents as increased prevertebral space.

Prevertebral space is soft tissue shadow between the vertebral bodies and pharynx and trachea. On an average, the normal space between the pharynx and spine above the level of cricoid cartilage is 0.5 cm and below this, it is 1.5 cm.

An increased space suggests collection in the prevertebral space.

In the upper thoracic spine, abscess appears V-shaped shadow stripping the lung apices laterally and downwards.

It may also show as squaring of borders of superior mediastinum.

Shifting of tracheal shadow to one side may be present on AP view.

Normal tracheal shadow is concave anteriorly in lateral view of the thoracic spine. Any change in the contour should raise the suspicion of the disease from C7 to D4 vertebrae.

Below that region [D4 vertebra is watershed], a typical fusiform-shape (bird nest appearance) shadow suggests paravertebral abscess.

Abscesses below the diaphragm tend to extend along the course of psoas muscle which may be noted as the bilateral widening of the psoas shadow but is less common.

Kyphus

This occurs in typical para discal lesion due to the collapse of two vertebral bodies.

Lateral Shift and Scoliosis

A lateral curvature and deviation have been recognized as one of the rare deformities of Pott’s disease.

CT and MRI

CT and MRI provide cross-sectional imaging which describes the extent of involvement better and are good at showing the presence of an epidural component and cord compression. MRI is the investigation of choice for this, with CT with contrast being a distant second.

In addition to this, MRI also reveals the status of the spinal cord health.

These show vertebral destruction and paraspinal collections.

Lab Studies

Most of the times, especially in endemic regions, the diagnosis of tuberculosis is clinicoradiological but lab tests are called for help when a clear diagnosis cannot be reached out at.

Routine lab investigations done in Pott’s spine are complete blood count, ESR, and CRP. Liver and kidney functions should also be assessed during treatment.

CBC might show lymphocytosis but could be normal as well.

ESR and CRP are generally elevated but in some cases, the increase is not seen.

ESR is deemed to be inflammation marker and some authors recommend serial ESR levels to assess the decrease in activity of the tubercular disease.

Tuberculin skin test is found positive in most of the patients with spine TB who are not infected with HIV

Microbiological Studies

The tissue for microbiological studies can be obtained through CT guided biopsy. This is more useful in cases with an equivocal diagnosis.

AFB staining of the tissue
Culture and sensitivity.

Treatment of Tuberculosis of Spine

The treatment of spinal tuberculosis is mainly by chemotherapy. Presence of neurological deficit complicates the matters and for sake of simplicity, I have divided the treatment into two groups

Treatment of Spine Tuberculosis Without Neural Deficit

The prevention of neural deficit in tuberculous disease of the spine is of paramount importance, it can be largely achieved by early diagnosis of spinal caries and its prompt and suitable treatment.

These patients are treated with antitubercular chemotherapy which consists of isoniazid, rifampicin, pyrazinamide, and ethambutol as the first line of drugs. However, depending upon the patient profile, drugs may be added or replaced.

Gradual mobilization of the patient is encouraged in the absence of neural deficit with the help of suitable spinal braces. After 3 to 9 weeks of starting of treatment, the patient is put on back extension exercises. Spinal brace is continued for about 18 months to 2 years.

Surface cold abscesses may be aspirated, deeper collections may not be required to drain.

Open drainage of the abscess is performed if aspiration fails to clear the collection.

Sinuses in a large majority of cases heal within 6 weeks to 12 weeks from the onset of the treatment

Periodic evaluation of the patient with X-rays and ESR is done to assess the activity of the disease and decreasing ESR is deemed to be a sign of reducing bacterial activity.

Treatment of Spine Tuberculosis With Neural Deficit

Patients with neural deficit require a more aggressive approach. Classical approach was to put all the patients on chemotherapy and strict bed rest.

Some authors in the recent past suggested a radical approach which advocated operating almost every tubercular lesion with [or even without] neural deficit to debride the tissue and relieve the pressure on neural structures.

While the first approach produced less than desirable results, the second one is associated with an increased surgical burden and associated mortality.

Middle path regime solves this problem to a great extent by taking the best of both approaches.

It puts the patient on chemotherapy and rest and observes for a response. The premise of the treatment is that, as the drugs act on the bacteriae, the reduced destruction and pus production leads to lesser pressure on the neural structures which tend to recover once milieu gets better by use of medicine.

This regime advocates surgery for the patients of TB of the spine who do not get better with the initial treatment or are not candidates for conservative treatment.

The surgery is indicated in the following situations

Every patient with neural complications will not be cured by antitubercular drugs and rest alone, however, all patients do not need surgical decompression.

An absolutely conservative approach to Pott’s paraplegia is considered unjustifiable as one might be losing very valuable time. Irreparable damage of the cord may take place if the deterioration progresses to complete loss of motor and sensory function.

Indications for surgery in presence of neural deficit are

Neurological complications which do not start showing signs of progressive recovery to a satisfactory level after a fair trial of conservative therapy (3 to 4weeks).
Patients with spinal caries in whom neurological complications develop during the conservative treatment
Patients with neurological complications which become worse while they are undergoing therapy with antituberculous drugs and bedrest
Patients who have a recurrence of neurological complication
Patients with prevertebral cervical abscesses, neurological signs, and difficulty in deglutition and respiration
Advanced cases of neurological involvement such as marked sensory and sphincter [bladder/bowel] disturbances, flaccid paralysis or severe flexor spasms.

In the cases who started showing progressive recovery complications on triple-drug therapy between 3 to 4 weeks and progressed to complete recovery surgical decompression was considered unnecessary.

Surgery in Spinal Tuberculosis

Surgery in the spinal tuberculosis is required mostly for decompression of the neural structures or drainage of abscesses.

Surgery is also done for deformity correction in severe kyphus.

In children, posterior spinal fusion is done so as to correct the deformity with growth.

Operative Procedures for Decompression of Neural Tissues

Decompression and debridement with or without bone grafting
- Cervical spine and cervicodorsal junction- anterior approach
- Dorsal spine and dorsolumbar junction – anterolateral approach or transpleural approach
- Lumbar spine and lumbosacral junction – extraperitoneal approach.
Laminectomy for posterior spinal disease, extradural granuloma or tuberculoma
Anterior transposition of the cord through the anterolateral in severe kyphotic deformity causing paraplegia.

Recovery after surgery has been observed after 24 hours to 12 weeks after the decompression. Most of the patients showed the first evidence of objective recovery within 3 weeks of the decompression, however, others took a longer time to recover. The time taken for near complete recovery varied between 3 to 6 months and in few cases more than a year.

Extensor plantar response, a sign of pyramidal tract involvement, lasts for a very long time.

Patients who recover are able to return to their full activity within 6 to 12 months of the treatment. Brace is recommended for about 2 years.

Prognosis

The prognosis of the disease is determined by the severity and duration of the disease.

If diagnosed and treated in very early stages, before bony destruction and deformity have occurred, the patient usually recovers completely without any residual problem.

After, vertebral collapse, the deformity occurs. This deformity would persist after the treatment as well when tubercular activity has finished.

If this deformity is severe, it could cause mechanical back pain in later years.

With the neural deficit, the prognosis is better if there is

partial cord involvement
Neural complications are of short duration
Early onset neural deficit
Slow progression of neural complications
Young patient
Good general condition of the patient

The prognosis is relatively poor if there is

Complete cord involvement
- Severe flexor spasms
- Flaccid paralysis
- Gross sensory loss
Long-standing neural complication
Late-onset neural deficit
Rapid development of neural complications
Patient is of older age
Poor general condition of the patient. Irrespective of the mode of treatment the patients who show neural recovery various modalities generally recover in the following order. Vibration and joint sensation; temperature, touch, pain, voluntary motor activity, sphincter functions and wasting of muscles.

Recurrence or relapse of a tuberculous lesion [ Also called recrudescence of the Disease] poses a special problem. The commonest cause is grumbling activity of infection caused by resistance strain of acid-fast bacilli.

Surgery may be required in these cases.

Atypical Presentation of the Tuberculosis of Spine

The classical form of tuberculosis is usually easy to recognize. However, atypical forms of the disease may occur involving other parts of the vertebra or also in the form of the extraosseous involvement of the neural and perineural tissue.

These are relatively uncommon and more difficult to diagnose.

Posterior Complex Tuberculosis

Posterior spinal tuberculosis is the lesion caused by Mycobacterium tuberculi in the posterior elements of the vertebral arch. The location is

It has been reported with patients suffering from HIV infection.

The lesion commonly arises in the dorsal, dorsolumbar and lumbar vertebrae. Cervical lesions involving the posterior complex are extremely rare.

The clinical picture is often similar to that of typical spinal tuberculosis. However, posterior abscesses may present earlier while the typical radiographic changes will not be present.

In fact, a conventional x-ray is not of much use in early diagnosis and one must have a high index of suspicion and get a CT Scan or an MRI done early to avoid delay in diagnosis.

CT Scan or MRI can determine the site and extent of the lesion, the presence of any vertebral body involvement or encroachment of the spinal canal. These are able to pick up the diagnosis at an earlier stage.

The lesion may occur in elements of the vertebral arch including the laminae, pedicles, transverse or spinous processes. Rarely the apophyseal joints may be involved.

The lesions may be in isolation or in combination with each other.

Classification

Lesions involving the vertebral arch – lamina and pedicles
Lesions involving the processes of the vertebral arch i.e. the transverse articular and spinous process.
A combination of both

The primary mode of treatment is anti-tuberculosis chemotherapy. Neurological involvement may warrant surgical treatment.

Intraspinal Tuberculous Granuloma (Tuberculoma)

Tuberculosis can involve neural and perineural tissue directly invading the spinal cord or meninges.

Spinal tiberculoma could be

Extra dural
Sub dural
Sub dural and extra dural
Arachnoidal [no dural involvement
Intramedullary

Extradural Granuloma

These typically present with compression of the cord. MRI or CT myelography is required to localize these lesions.

Where an extra dural granuloma is present surgery is advocated as there is a risk of healing with scar tissue on drug treatment only.

If there is anterior body disease is present then the anterior or antero-lateral decompression is recommended.

If there are associated neural arch lesions or when no osseous lesion is present, laminectomy and excision of the extra dural granuloma is recommended.

Subdural Granuloma

Presents with compressive myelopathy with no radiological localization of lesions. Myelography, myelo CT or MRi is required to localize the lesion.

Laminectomy at the level of the lesion is recommended. Where the dura is tense it needs to be opened to remove the sub dural granuloma.

Intramedullary Tuberculoma

These are very rare and patients present with a picture of severe spinal cord compression with a rapidly progressive course.

The presence of a tuberculous lesion elsewhere or in the past may be a clue to the diagnosis. MRI is the most useful investigation sequential.

Anti-tubercular chemotherapy is the mainstay of the disease.

Single Vertebral Disease

Single vertebral disease without involvement of the disc spaces is also considered as atypical spinal tuberculosis.

It may present as a cystic lesion involving the body or as vertebra plana simulating lesions such as eosinophillic granuloma.

Here the diseased vertebral body is weakened by the permeation of granulation tissue and collapses. It protrudes radially and may cause the neurological deficit.

Plain radiograph will slow collapse of a singe vertebral body with preservation of adjoining disk spaces.

CT Scan and MRI may help in differentiating it from other lesions such as eosinophillic granuloma, solitary plasmacytoma, metastatic disease.

However, the histological evidence is required in these atypical lesions and all efforts should be made to establish a tissue diagnosis.

In the event of neurological deficit anterior decompression is recommended as laminectomy may worsen the neurological deficit.

Other forms of Atypical Tuberculosis

These may include

Multiple vertebral skip lesions
- 2 – 7% of cases
Giant Tuberculous Abscess with little or no demonstrable bony focus.
- May present as cold abscess in the thigh, loins or as a psoas abscess.
Sclerotic Vertebrae with intervertebral bony bridging.
- Seen occasionally in healthy individuals with good immunity.
- On x-ray, lateral osteophytes with little evidence of erosion or destruction can be seen.
Pan Vertebral Disease
- concomitant involvement of anterior and posterior elements.
- Have severe instability

Intervertebral Disc Anatomy and Biomechanics

By Arun Pal Singh

Intervertebral disc is kind of cushion between two vertebrae. The discs absorb the forces across the vertebra and provide cushion during motion of vertebrae, thus preventing grinding of vertebrae against each other.

Discs are avascular structures, and in fact largest structure of the body without blood supply.

They receive nutrition via osmosis from surrounding structures. Discs are attached to vertebral bodies by hyaline cartilage.

On x-ray, the disc is not visible but a gross idea about its height can be made by looking at intervertebral space, which is space between two vertebrae.

Structure of Intervertebral Disc

Each disc is made up of two parts: the annulus fibrosus and the nucleus pulposus.

Annulus Fibrosis

Annulus or anulus is the word derived from the Latin word anus which means ring. The annulus is a ring-like tough structure that surrounds and encases the other structure of the intervertebral disc, called nucleus pulposus.

The annulus provides rotational stability and resists compressive stress.

The annulus is made of water and type I collagen fibers which are oriented at different angles horizontally to create the strength. Water and proteoglycans are other constituents.

Multiple layers or lamellae of collagen fibers arranged in a unique circumferential orientation along the disc periphery.

Each lamella is oriented at a 30-degree angle to the horizontal axis of the disc, and this pattern alternates in successive lamellae. The outer collagen fibers attach to the ring apophysis, and the inner layers attach to the end plate surround the nucleus.

High collagen/ low proteoglycan ratio makes the disc flexible enough.

Fibroblast-like cells are responsible for producing type I collagen and proteoglycans.

Nucleus Pulposus

It is gel-like elastic substance within the annulus fibrous and is composed of the same material as annulus fibrosis – water, collagen, and proteoglycans but in different concentration and structural arrangements.

nucleus pulposus is composed of type II collagen, water, and proteoglycans. Nucleus pulposus contains approximately 88% water.

This hydrophilic matrix provides the height of the intervertebral disc and makes it compressible enough.

Viscoelastic matrix makes annulus fibrous elastic and enables distribution of the forces smoothly to the annulus and the endplates.

In contrast to annulus fibrous nucleus pulposus as low collagen / high proteoglycan ratio.

It contains chondrocyte-like cells which are responsible for producing type II collagen and proteoglycans and allows to tolerate hypoxic conditions.

Blood Supply of Intervertebral disc

The intervertebral disc is avascular because the capillaries terminate at the vertebral endplates. The nutrition reaches nucleus pulposus through diffusion through pores in the endplates

Nerve Supply of Intervertebral Disc

Sinuvertebral nerve originates from the dorsal root ganglion gives rise to the innervates the superficial fibers of the annulus.

The disc is not innervated beyond the superficial fibers

Vertebral End Plate

The vertebral endplates that are in direct contact with the disc, consisting of cortical bone in the periphery, which in adolescence is referred to as the ring apophysis, and compressed cancellous bone in the central disc area, which covers nearly 70% of the disk.

The outer 30% consists of dense cortical margin and is the strongest area of the end plate.

Nutrition of Intervertebral Disc

The nutrition of these cells is derived from diffusion across the hyaline cartilage and subcortical end plates.

The cells in the central part of the disc lie closest to the end plate. By virtue of their position they lie nearest to vascular supply and are responsible primarily for nutrient and waste product exchange. The ultrastructure of the bony endplate comprises numerous sinusoids with specialized loops of capillaries that come into close contact with the underlying cartilaginous layer.

Simple diffusion of molecules across the cartilage occur depending on the size of small nutrients. As there is anaerobic metabolism due to anaerobic avascular nature of the disc, the latent pH within the disc under normal conditions is acidic.

Microscopic Constitution of Disc

Collagen

Collagen provides strength to the intervertebral disc and is most abundant in the outer annulus, making almost 70% of dry weight of annulus. [In contrast, collagen forms only 20% of the dry weight of nucleus pulposus]

The type of collagen is type I collagen, which is highly cross-linked for increased strength, and small amounts of types II, III, V, VI, and XI collagen.

Fibroblasts that diminish in a number closer to the disc center are interspersed.

The inner annulus contains a relatively greater proportion of chondrocytes and varying amounts of type II collagen fibrils in a loose, nonorganized manner. The central nucleus is a gelatinous core containing chondrocyte-like cells and nearly 85% of type II collagen.

Proteoglycans

Proteoglycans consist of a protein core covalently attached to a glycosaminoglycan subunit. The glycosaminoglycan units are hydrophilic in nature and retain water in its normal state.

Chondroitin sulfate and keratan sulfate are the most common glycosaminoglycans found in the disc, the former more prevalent in the normal. Multiple proteoglycan subunits are attached to a central hyaluronate filament by a link protein, a kind of glycoprotein.

The entire structure forms aggregate molecules, of which aggrecan is the largest found in the annulus, Others are versican, decorin, biglycan, and fibromodulin. Fibroblasts and chondrocytes are suspected within this mesh framework along with remnants of notochordal-like cells.

Gradient

The gradient of the cellular and extracellular matrix components from the fibrous well-organized periphery to the randomly organized gelatinous center.

The gradient progresses through four less distinct zones of the disc

Outer annulus
Inner annulus
Transition zone
Central nucleus

Production and Remodeling of Disc

Chondrocytes and fibroblastic cells are within an extensive, intricate extracellular matrix.

These cells are responsible for homeostasis of the extracellular matrix, including matrix formation, maintenance, and remodeling.

The cells are responsible for production and constant remodeling of the principal components of the extracellular matrix collagen and proteoglycans.

Biomechanics of Intervertebral Disc

Highly hydrated amorphous central disc structure that in the normal state is constantly under expansible stress.

The nucleus retains water and expands, providing stiffness and resistance to compressive forces. This mechanism effectively transfers compressive load on the nucleus to a radially directed force with tensile stress to the annulus.

Constant load on the disc applies pressure to the nucleus, reducing the ability of the proteoglycans and, thus, the nucleus to hold water, causing creep of the disc.

After pressure is relieved, the time-dependent viscoelastic properties of the disc nucleus allow it to retain water.

The annular fiber orientation within the lamellae allows for resistance to tension. Because lamellae are oblique, it results in tension or relaxation of the fibers in different areas within the disk and with different forces. The phenomenon is called anisotropy.

In the anterior or posterior translation of a vertebral body and disc along the horizontal axis, all of the fibers of the annulus are stretched in the direction of the applied force.

However, fibers aligned in the direction of the force will undergo stain while the remaining fibers actually will be brought closer to one another and will relax.

Annulus fibrosus has highest tensile stresses and nucleus pulposus has highest compressive stress.

This alternating tension and relaxation with translation and axial rotation maintain the stability of the intervertebral segment.

In axial compression, the nucleus expands radially toward the inner aspect of the annulus fibers; the annulus fibers also expand circumferentially.

Anterior flexion of sagittal plane rotation causes the anterior annulus compression. The nucleus also is compressed eccentrically over its anterior aspect, after which it deforms and migrates posteriorly. The posterior annular fibers expand radially the shifting nucleus, and the fibers stretched in line with these forces resist further motion.

As rotation occurs, the weight of the upper body and trunk lead to shear strain forces at the disc and slight translation, which is resisted by the active and passive constraints of the posterior column, may occur.

Lumbar range of motion varies between vertebral levels and individuals.

The instantaneous axis of rotation continually changes throughout the range of motion and typically is located posterior toe the midvertebral body and below the superior endplate of the inferior vertebral body except at L5-S1, where it is located posterior to the disc space.

Function of Intervertebral Disc

It allows spinal motion and provides stability
It serves as a link to attach adjacent vertebral bodies together
The disc is responsible for 25% of spinal column height

Changes in Intervertebral Disc with Aging and Disease

Aging of disc leads to an overall loss of water content and there is conversion to fibrocartilage.

There is a decrease in nutritional transport along with a decrease in water content. The pH becomes acidic and there is a reduction in the number of viable cells and proteoglycans.

Along with that, there is an increase in keratin sulfate to chondroitin sulfate ratio, lactate. the activity of enzymes causing degradation decreases.

In disc herniation, there is increased production of osteoprotegerin, interleukin-1 beta, receptor activator of nuclear factor-kB ligand (RANKL) and parathyroid hormone.

Clinical Significance of Intervertebral Disc

Disc Prolapse

Also called disc herniation or slipped disc. In this condition, the nucleus pulposus along with protrudes out from a weakness in the annulus fibrosus and indents on the nerve root in the vicinity.

This condition can lead to radiating pain in the lower limb, commonly known as sciatica.

The bulge is usually posterior, especially in the lateral area.

Schmorl nodes are another kind of herniation, where the nucleus pulposus, herniates on vertebral endplates.

This is referred to as vertical disc herniation.

Degeneration of Disc

The disc degenerates with age. Before age 40 approximately 25% of people show evidence of disc degeneration at one or more levels. Beyond age 40, more than 60% of people have it.

In degeneration, the nucleus pulposus begins to dehydrate and the concentration of proteoglycans in the matrix decreases. This limits the ability of the disc to absorb shock. The annulus fibrosus also becomes weaker with age and has an increased risk of tearing.

Sclerosis of the bones underlying the end plates also occur.

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Lumbar Spine Anatomy

By Arun Pal Singh

Lumbar spine anatomy is unique because it is formed by strong vertebrae. It is unique in being strong and flexible. Lumbar spine provides mobility in many different planes including flexion, extension, side bending, and rotation.

Lumbar spine consists of 5 vertebrae linked by joint capsules, flexible ligaments/tendons, and muscles.

The lumbar spine is very strong and protects the highly sensitive spinal cord and spinal nerve roots. It can withstand excessive loads while simultaneously protecting neurologic function and providing flexibility and stability.

This intricate interplay between the different anatomic components of the lumbar spine provides efficient motion and function that enables us so much mobility.

Lumbar spine consists of 5 lumbar vertebrae named L1 to L5. The topmost vertebra is L1 and it articulates with the D12 vertebra of the dorsal spine. The lowermost lumbar vertebra is L5 which articulates with S1 of the sacrum.

The five vertebral bodies and intervertebral disks of the lumbar spine withstand significant physiologic loads. The intervertebral segment of the lumbar spine consists of a three-articulation complex, the disk-vertebral body, and two posterior apophyseal (facet) joints, to resist these high loads and stresses.

Structure of Lumbar Spine

The vertebral bodies are a cylindrical mass of cancellous bone with a cortical shell. In between are the discs consisting of the annulus fibrosus, the nucleus pulposus, and the cartilaginous and bony endplates of the vertebral bodies.

The vertebral bodies and discs from the anterior column of the spine, which is responsible for resisting approximately 80% of axial compressive loads and maintaining spinal rigidity and alignment.

The intervertebral disc maintains separation of the vertebral bodies.

The anterior part of the disk is thicker than the posterior part and is responsible for most of the lumbar lordosis because the vertebral bodies are near uniform in shape.

Nearly two-thirds of lumbar lordosis is localized between the L4 and S1 segments.

The posterior column of the spine consists of

Spinous processes
Lamina
Transverse processes
Facet Joints

These structures control movement and resist forces.

The facet joints have hyaline cartilaginous surfaces articulations formed by the superior and inferior articular processes of subjacent vertebrae with a fibrous joint capsule.

The superior articular process faces posterior and medially, and the inferior articular process faces lateral and anteriorly.

The joint surface is oblique to the sagittal plane and facilitates slight flexion and extension or sagittal plane rotation as each articular process slides on the other.

The alignment of the facet joints relative to the sagittal plane ranges from 120 degrees to 150 degrees. This orientation resists anterior or posterior translation in normal anatomic alignment and axial rotation in the horizontal plane.

This complex bony anatomy serves as a load-bearing structure, a passive restraint to torsional stain and excessive tensioning of annulus fibrosus, and as a means of protection against disk injury.

Structure of Lumbar Vertebra

L2, L3, and L4 are typical lumbar vertebrae. L1 and L5 have some peculiarities and are atypical lumbar vertebrae.

Vertebrae are composed of the following 3 functional parts:

The vertebral body
The vertebral (neural) arch
The bony processes (spinous and transverse

Body

The vertebral body of each lumbar vertebra is large, wider from side to side than from front to back, and a little thicker in front than in back. It is flattened or slightly concave above and below, concave behind, and deeply constricted in front and at the sides.

There are no rib facets present, a feature that distinguishes lumbar vertebrae from thoracic.

Vertebral bodies are together connected by the intervertebral discs. The size of the vertebral body increases from L1 to L5.

L5 vertebra has the heaviest body, smallest spinous process, and thickest transverse process.

The epiphyseal ring is the cortical ring on the distal surface of a vertebra. It acts as an anchor to annulus fibrosus of disc and also serves as growth zone.

The surface within epiphyseal ring is covered by hyaline cartilage.

Vertebral or Neural Arch

Each vertebral arch is composed of

2 pedicles
2 laminae
7 bony processes held together by facet joints and ligaments
- 1 spinous process
- 4 articular processes – 2 superior and 2 inferior
- 2 transverse processes

Pedicles are posteriorly directed strong bony bars from the upper part of the vertebral body which meets laminae to complete neural arch posteriorly.

Pedicle sagittal width increases from L1 to L5 [9 mm to up to 18 mm] and increases in angulation as well in the axial plane [10-20 degrees]

The laminae form the posterior portion of the vertebral arch. In the upper lumbar region the lamina is taller than wide but in the lower lumbar vertebra, the lamina is wider than tall. The lamina connects the spinous process to the pedicles.

Neural arch along with the posterior surface of vertebra form vertebral foramen which harbors nerve root in meninges.

Bony Processes

The spinous process is thick, broad, and projects backward. Its posterior end is rough and uneven.

Four articular processes arise from each vertebra, two projecting upward and two downward from the junctions of pedicles and laminae.

The facets on the superior processes are concave, and look backward and medialward. Those on the inferior are convex and are directed forward and lateralward.

Superior articular processes form a facet joint with the inferior articular process of the superior vertebra. Similarly, inferior articular processes form a facet joint with superior articular facets of the inferior vertebra.

The transverse processes project in the coronal plane. These long and slender processes are horizontal in the upper three lumbar vertebrae and incline a little upward in the lower two.

These processes from the junctions of the pedicles and laminae in upper three vertebrae but in the lower two they move forward and originates from the pedicles and posterior parts of the vertebral bodies.

Three tubercles are seen in the transverse process of a lower lumbar vertebrae

Lateral or costiform process [lateral]
Mammillary process [superior]
Accessory process [inferior]

Neural Foramina

Neural foramina are openings in the vertebral column on either side from where nerve roots exit.

They are numbered by vertebra above them. For example, the L1 foramen is beneath L1 vertebrae.

Each foramen is bounded superiorly and inferiorly by the pedicle, anteriorly by the intervertebral disc and vertebral body, and posteriorly by facet joints. The same numbered spinal nerve root, recurrent meningeal nerves, and radicular blood vessels pass through each foramen.

Fifth Lumbar Vertebrae

The fifth lumbar vertebra has a body much deeper in front than behind to accommodate the prominence of the sacrovertebral articulation.

The spinous process is smaller and there is a wide interval between the inferior articular processes.

Transverse processes are thicker and originate anterior than usual.

Intervertebral Discs

Discs connect and cushion the vertebrae while allowing enough movements.

Their size varies depending on the adjacent vertebrae size.

Each disc consists of the nucleus pulposus which is mucoid substance embedded with reticular and collagenous fibers, surrounded by the annulus fibrosus, a fibrocartilaginous lamina.

The anterior fibers of annulus fibrosus are strengthened by the anterior longitudinal ligament. Posteriorly most of the fibers are attached to the cartilage plate.

[Read on Disc anatomy and Biomechannics]

Vertebral joints

There are symphyseal joints between the vertebral bodies. These are formed by a layer of hyaline cartilage on each vertebral body and an intervertebral disc between the layers.

Facet joints or zygapophysial joints or Z-joints are the joints between inferior and superior articular processes of vertebrae as discussed earlier.
Facet joints are synovial joints and permit simple gliding movements.

The region between the superior articular process and the lamina is the pars interarticularis. This area is important as it is areas of spondylolisthesis.

Ligaments of Lumbar Spine

Anterior Longitudinal Ligament

The anterior longitudinal ligament runs down the anterior surface of the vertebral bodies from the occiput to the sacrum. The anterior longitudinal ligament is thicker and narrower in the thoracic region. The ligament firmly attaches to the edges of the vertebral bodies.

This is thick and slightly more narrow over the vertebral bodies and thinner but slightly wider over the intervertebral discs. It also loosely attaches to the annulus of the disc.

It is a three-layered ligament – superficial, intermediate and deep.

Posterior Longitudinal Ligament

The posterior longitudinal ligament arises from the posterior aspect of the basiocciput, is continuous with the membrana tectoria, and runs over the posterior surfaces of the bodies of the vertebrae, down to the coccyx. It is within the vertebral canal.

Ligaments of Lumbar spine — Image Credit

Intertransverse Ligaments

These ligaments are situated between the transverse processes. In the thoracic region, they are closely connected with the deep muscles of the back.

Capsular Ligaments

The capsular ligaments are attached to the articular margins of the articular processes. The fibers are oriented perpendicular to the facet joint and are stronger in the thoracic and lumbar region than in the cervical region.

Ligamentum Flavum

Also called Yellow Ligament, the ligamentum flavum connects the anteroinferior edge of the lamina to the posterosuperior edge of the lamina below. The ligamentum flavum is thicker in the thoracic region. This ligament is composed mainly of elastic fibers, and that elasticity serves to preserve the upright posture and to assist the vertebral column to resume after flexion.

Interspinous Ligaments

The interspinous ligaments connect adjacent spinous processes and runs obliquely from the anterior inferior aspect of the spinous process above to the posterior superior aspect of the spinous process

Supraspinous Ligament

This strong ligament is a strong fibrous cord, which connects together the tips of the spinous processes from the C7 to the sacrum.

Iliolumbar Ligament

The iliolumbar ligaments attach to the ilium and L5 vertebra transverse processes act to limit anterior translation and rotation making the lumbosacral junction a very stable articulation.

Muscles of Lumbar Spine

muscles-lumbar-spine — Muscles of Lumbar Spine
Image Credit: Medscape

Functionwise, the muscles of the lumbar spine can be grouped together as extensors, flexors, lateral flexors, and rotators.

Lumbar spine musculature works in a synergistic way from both the left and right side muscle groups.

Extensor Muscles

Erector Spinae

Erector spinae [sacrospinalis] is the primary extensor and largest group of intrinsic back muscles. In the lower lumbar spine, the erector spinae appears as a single muscle but divides into 3 vertical columns of muscles (iliocostalis, longissimus, spinalis) in the upper part. Iliocostalis is most lateral and spinalis is most medial.

All of these have a common origin from a thick tendon attached to the sacrum, the lumbar spinous processes, and the iliac crest.

Transversospinal

This muscle group lies deep to the erector spinae and takes origin from the mamillary processes, from the laminar area just medial to the posterior sacral foramina in the sacrum, from the tendinous origins on the erector spinae, and the medial surface of the posterior superior iliac spine.

These include

3 semispinalis muscles, spanning 4-6 vertebral segments
- Semispinalis thoracis
- Semispinalis cervicis
- Semispinalis capitis
multifidus, spanning 2-4 vertebral segments
rotatores, spanning 1-2 vertebral segments
- Rotatores cervicis
- Rotatores thoracis
- Rotatores lumborum
Interspinales
Intertransversarii

It is a fasciculated muscle group and each fascicle is directed superomedially toward the inferior and medial margin of the lamina and adjacent spinous process. The superficial layer attaches from 3-4 levels above, the intermediate layer attaches 2 levels above, and the deep layer attaches 1 level above.

Along with extension, this muscle group also takes part in the rotation.

Segmental

These form the deepest layer. These can be divided into two groups. The levatores costarum are not present in the lumbar spine but the other group formed by interspinales and intertransversarii is.

Interspinales is between the spinous processes of contiguous vertebrae. Intertransversarii pass between adjacent transverse processes. They are postural stabilizers and work to increase the efficiency of larger muscles.

Forward flexors

Iliothoracic

These are abdominal wall muscles namely rectus abdominis, external abdominal oblique, internal abdominal obliquus, and the transversus abdominis. These are also called extrinsic flexors.

Femorospinal

Psoas major and iliacus muscles form this group of iliac flexors.

Lateral flexors

This movement is a combination of side bending and rotation. The muscles that participate in side bending are ipsilateral the oblique and transversus abdominal muscles and quadratus lumborum.

Rotators

Lumbar spine rotation is by oblique muscles such as the extensors and lateral flexors assisted by the antagonist muscle groups to counter the primary effect of these muscles.

The transversospinal muscle group, when contracted unilaterally cause the trunk to rotate in the contralateral direction. They are divided into 3 groups: muscles. The rotatores lumborum are small, irregular, and variable muscles connecting the superoposterior part of the transverse process of the vertebra below to the inferolateral border of the lamina of the vertebra above.

Blood Supply of Lumbar Spine

Paired lumbar arteries arise from the aorta, opposite the bodies of L1-L4. Each pair travels anterolaterally around the side of the vertebral body and gives off various branched opposite when reaches laterally to the vertebral canal.

Periosteal and equatorial branches supply the vertebral bodies

Spinal branches enter the intervertebral foramen, divide into smaller anterior and posterior branches to supply vertebral body, vertebral arch, meninges, and spinal cord.

The larger branches of the spinal branches continue as radicular or segmental medullary arteries and supply nerve roots and to the spinal cord, respectively.

Venous plexuses are formed by veins along the vertebral column both inside and outside the vertebral canal. Vasivertebral veins emerge from the foramen on the posterior surfaces of the vertebral bodies and drain into the internal vertebral venous plexuses. The intervertebral veins anastomose with veins from the cord and venous plexuses and drain into the lumbar segmental veins.

Lumbarization and Sacralization

These are anatomical variations of the lumbar spine

In lumbarization, the first sacral vertebra, which is normally fused to rest of sacrum remains unfused. On x-ray, the lumbar spine appears to have six vertebrae and the sacrum appears to have only four segments instead of five.

In sacralization, the last lumbar vertebra (L5) fuses to the sacrum on one side or both, or to the ilium, or giving an appearance of four lumbar vertebrae.

These anomalies are observed at about 3% of people and most are asymptomatic.

read more on lumbarization and sacralization.

Vertebral Canal and Its Content

The vertebral canal contains the spinal cord [which terminates at L2] its meninges, spinal nerve roots, and blood vessels supplying the cord and other structures.

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Cervical Spondylosis Causes and Treatment

By Arun Pal Singh

Cervical spondylosis is a term for degenerative changes (wear and tear) of the vertebral discs of the cervical spine. It is considered to be a normal part of aging. It is not symptomatic in many people but may cause recurring neck pain.

Read Anatomy of Cervical Spine

In cervical spondylosis, the edges of the vertebrae often develop small, rough protrusions of the bone (osteophytes) which are in response to thinning of discs.

Mostly asymptomatic, these osteophytes may cause compression on nearby muscles, ligaments, or nerves to cause pain in the neck and surrounding area. Involvement of a nerve leading to pain and other symptoms in the upper limb is called cervical radiculopathy.

Cervical spondylotic myelopathy refers to changes in the cord due to cervical spondylosis that causes weakness of the hands and other parts of the body.

Cervical spondylotic myelopathy is discussed separately as its presentation is quite different.

Cervical Spondylosis with severe anterior osteophytes cervical spine

Causes of Cervical Spondylosis

Age-related wear and tear is the biggest factor for the development of cervical spondylosis. However repeated occupational trauma like carrying loads, professional dancing, gymnastics etc. which put repeated strains on the neck may contribute.

Familial cases have also been reported suggesting possible genetic factors also. Smoking is another suggested risk factor.

Conditions that cause increased mobility or instability to a segment of the cervical spine like congenitally fused spine, cerebral palsy, Down syndrome etc may be risk factors for cervical spondylosis.

Pathophysiology of Cervical Spondylosis

Cervical spondylosis is the result of disc degeneration. With age, intervertebral discs lose water, fragment, and collapse. This causes increased mechanical stress at the cartilaginous endplates. This further causes bone formation under the periosteum. This is an attempt by the body to stabilize adjacent vertebrae.

Osteophytes may cause narrowing of the intervertebral foramina [A canal through which the nerve root comes out of spine] and irritation of nerve root. Degradation of intervertebral discal proteoglycans also causes irritation of nerve root. This would lead to cervical radiculopathy.

Cervical spondylotic myelopathy occurs when the changes in cord occur because of degenerative changes causing mechanical compression, spinal cord ischemia and stretch injury to the spinal cord. Patients with narrow spinal canal are predisposed to developing cervical spondylotic myelopathy. Space may be further worsened by hypertrophy of the ligamentum flavum, thickening of bone, degenerative kyphosis, and subluxation.

[Cervical spondylotic myelopathy]

Presentation of Cervical Spondylosis

Intermittent neck and shoulder pain is the most common complaint in cervical spondylosis. The pain usually comes and goes but may persist in some persons with occasional exacerbation.

The pain is often accompanied by stiffness, with radiation into the shoulders or skull. A headache, unilateral or bilateral upper limb may be involved. The pain may stop at the shoulder or occur till the fingers.

Paresthesiae may accompany pain in the cervical region, the upper limb, shoulder or interscapular region. Radiation to the chest may also occur.

Physical examination reveals neck stiffness and numbness in the affected root.

Lab Studies

Laboratory values are mostly normal in cervical spondylosis.

Imaging Studies

Routine anteroposterior x-rays of the cervical spine demonstrate loss of cervical lordosis, disc space narrowing, osteophytes, facet joint osteoarthritis etc.

CT and MRI are no routinely done for cervical spondylosis. MRI may be indicated in cases where radiculopathy is not amenable to treatment or in cases of spondylotic myelopathy to assess cord damage.

Treatment of Cervical Spondylosis

The pain of cervical spondylosis and Cervical radiculopathy usually resolves without intervention. The treatment includes neck immobilization, drug treatments, lifestyle modifications and physical modalities like traction, manipulation, and exercises.

Neck Immobilization

Soft collar, Philadelphia collar, rigid orthoses, and Minerva jacket are commonly used for immobilization of the neck. The collar is worn as long as possible during the daytime. With the improvement of symptoms, the wearing of collar should be during strenuous activity. Prolonged use of collar may reduce muscle tone and cause neck stiffness from disuse.

Drug Therapy

Nonsteroidal anti-inflammatory drugs are the mainstay of drug treatment for reducing inflammation and pain. Patients with chronic symptoms should receive tricyclic antidepressants like amitriptyline.

Muscle relaxants such as thiocolchicoside, tizanidine, carisoprodol, and cyclobenzaprine may help patients with neck spasms.

Use of opioid drugs is restricted to patients who are not relieved with above drugs or do not tolerate nonsteroidal anti-inflammatory drugs or have moderate-to-severe pain due to significant structural spondylosis.

Lifestyle Modification

Lifestyle modifications include posture improvements, ergonomic changes in the workplace, relaxation techniques to avoid strain on the cervical spine.

Surgery

Surgery is indicated in patients with

Intractable pain [Pain that is not responding to treatment]
Progressive neurologic deficits
Documented compression of nerve roots or of the spinal cord

The aim of surgical treatment is decompression of the neural structures/spinal cord and fusion of the unstable spine.

The surgeries done are foraminotomy, anterior cervical discectomy with fusion, cervical disc replacement etc.

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Whiplash Injury of Cervical Spine

By Arun Pal Singh

The term whiplash injury is used for a neck injury caused by a sudden movement of the head forwards, backwards or sideways.

The injury is also called Whiplash Associated Disorders. An acute whiplash injury follows sudden or excessive hyperextension, hyperflexion, or rotation of the neck and causes neck pain and other symptoms. Whiplash injury is common in road traffic accidents, and may also be caused by sports injuries, falls or assaults. Most cases of whiplash injury occur as the result of rear-end vehicle collisions.

Most of the injuries happen in C5 and C6 cervical vertebrae.

A whiplash injury from an automobile accident is called a cervical acceleration-deceleration injury. Whiplash associated disorders sometimes include injury to the brain.

The most common areas of the spine affected by whiplash are the neck and middle of the spine. Rear end collision in a motor vehicle is common cause of whiplash injury. Injury might also occur in kinematics may be roller coaster rides at an amusement park, skiing accidents, airplane travel, or simply from being hit, kicked or shaken.

Rates of whiplash are higher in persons using a seat belt with shoulder restraint [than with no restraint], poor posture and poorly-fitted head restraints.

Whiplash injury is more common in women than men.

Mechanism of Whiplash Injury

The exact mechanism of whiplash injury is not known. Impulsive stretching of the spine, mainly anterior longitudinal ligament stretching or tear, as the head snaps forward and then back again causing a whiplash injury is thought to be the cause.

Injury can occur in two ways –

Cervical hyperextension injuries occur when an injury occurs by hyperextension of the neck followed by flexion. This occurs when persons sitting in the stationary or slow-moving vehicle being struck from behind. The person’s body is thrown forward but the head lags, resulting in hyperextension of the neck. When the head and neck have reached maximum extension, the neck then snaps into flexion.

A rapid deceleration injury occurs when the force flexes the neck followed by hyperextension. When the head is thrown forward, it flexes the cervical spine. The chin limits forward flexion but the forward movement may be sufficient to cause longitudinal distraction and neurological damage. Hyperextension may occur in the subsequent recoil.

Classification of Whiplash Injuries

Whiplash-associated disorders can be classified by the severity of signs and symptoms

Grade 0: no complaints or physical signs.
Grade 1: indicates neck complaints but no physical signs.
Grade 2: indicates neck complaints and musculoskeletal signs.
Grade 3: neck complaints and neurological signs.
Grade 4: neck complaints and fracture/dislocation
- Most cervical spine fractures occur predominantly at two levels – at the level of C2 or at C6 or C7.
- Most fatal cervical spine injuries occur in upper cervical levels, either at the cranio-cervical junction C1 or at C2.

Presentation of Whiplash Injuries

The pain and other symptoms of a whiplash injury may not develop until 6-12 hours or even after a few days.

The symptoms may include

Pain in neck and jaw with or without a decrease in the range of movements
Tightness in paraspinal muscles muscle tightness and spasm
Interscapular pain, shoulder pain
Reduced range of movements and neck tenderness
A headache, dizziness, vertigo, blurring of vision.
Numbness, weakness, paraesthesia, sphincter disturbance and increase in reflexes in upper limbs and lower limbs in cases of cord injury
Retropharyngeal [behind the pharynx] swelling and difficulty in swallowing.
Insomnia, anxiety (general anxiety and/or travel anxiety when in a car) or depression.

The examination should be done to look for parts injured, ascertain the level of spinal injury and any associated injury like a head injury.

For all patients presenting with acute whiplash injury, spinal cord compression should be excluded. Risk factors for serious injury include a history of neck surgery presence of osteoporosis or risk factors for osteoporosis like premature menopause, use of systemic steroids etc.

Neurological deficit is rare in soft-tissue injuries associated with whiplash. Stretching of the esophagus with resulting edema, dysphagia, and retropharyngeal hemorrhage may occur. Vocal-cord damage with hoarseness has been reported.

Trauma to the cervical sympathetic chain may occur with symptoms of nausea, vomiting, dizziness, Horner’s syndrome, and even complex regional pain syndrome type I.

Persistent radicular pain after cervical trauma requires further investigation to rule out nerve root involvement.

Differential Diagnosis

It is essential to consider serious injury in the immediate period following injury. Other possible causes of acute neck pain and stiffness include vertebral fractures, cervical disc herniation, subarachnoid hemorrhage, meningitis.

Persistent neck pain and stiffness also occurs in cervical spondylosis and other chronic pathologies of the cervical spine.

List of causes of neck pain

Lab Studies

Laboratory investigations are mostly normal in whiplash injury patients

Imaging

X-rays

Anteroposterior, lateral and anteroposterior odontoid peg views are standard x-ray projections done for whiplash injury.

Guidelines for selecting a patient for radiography – Canadian C-spine rule

CT Scanning

CT is superior to plain radiography and is indicated immediately if:

The patient had a Glasgow coma scale <13
The patient has been intubated or is being scanned for multi-region trauma.

CT is also done in cases where x-rays are suspicious or abnormal or are normal in presence of strong clinical suspicion.

CT is also done in cases of children<10 years as odontoid view x-ray is not done in these cases.

MRI

MRI is better for detecting soft tissue injuries such as an intervertebral disc, posterior longitudinal ligament, and interspinous ligament injury etc.

MRI should be done in patients with indicated for patients with neurological even in presence of normal radiographs.

MRI can distinguish hematoma from edema, which can have prognostic importance.

CT Myelography

Not routinely done. This is indicated if MRI is not available or contraindicated or patient is not able to tolerate MRI

Treatment of Whiplash Injuries

The course of minor injuries is usually self-limited and can be managed by analgesic drugs, neck support like the cervical collar and local cold/heat therapy.

Other treatments, like ultrasound and massage and exercises, may also help.

Most cases resolve in a few days. But other neck strains may take weeks or longer to heal.

Overall treatment modalities for whiplash injury involve

Soft cervical collar

Analgesics
Bed rest
Gradually increased activity for the first 1 to 2 weeks.
Physiotherapy
Isometric exercises, heat, traction
Transcutaneous-electrical nerve stimulation
Nerve block with local anesthetic and/or steroids.

Surgical treatment may be required in serious injuries.

Prognosis

The consequences of whiplash range from mild pain for a few days to severe disability.

Following factors may indicate long-term chronicity and disability

A negative attitude
Fear avoidance behavior
Reduced activity
Not willing to participate in active movement regimen
Depression, low morale and social withdrawal.
Social or financial problems.

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Normal Cervical Spine Xray

By Arun Pal Singh

Normal Cervical Spine X-ray

The cervical spine is the part of the spine that is present in the neck region. It is formed by first 7 vertebrae of the spine numbered from C1 to C7.

The spine begins with C1 vertebra which is also called Atlas. Next vertebra is Axis.

Seventh cervical vertebra or C7 is also called vertebra prominens.

It must be noted that normal cervical spine x-rays do not exclude significant injury.

The lateral view is often the most informative image. In a lateral view first thing to look for is if the cervical spine is adequately covered in the view. Next, alignment of the vertebrae is looked for. Normal cervical spine x-ray would reveal a smooth lordotic curve and any loss of lordosis indicates spasm.
Vertebrae are studied for smooth cortical outline and height. Disc spaces are looked for any reduction of space. Prevertebral shadow is studied for any increase in width.

A normal cervical spine x-ray – Lateral View

Coverage

All vertebrae are visible should be visible from skull base to the top of T1 is considered adequate.
If T1 is not visible then a repeat image with the patient’s shoulders lowered. Otherwise, a swimmer’s view may be acquired.

Alignment

Anterior line or the line of the anterior longitudinal ligament [line formed by connecting anterior margins of cervical vertebral body], the posterior line the line of the posterior longitudinal ligament formed by connecting posterior margins of cervical vertebrae] and the spinolaminar line or the line formed by the anterior edge of the spinous processes are checked for continuity.

Vertebrae

Cortical outline of all the bones should be checked for fractures.

Disc spaces

The vertebral bodies are spaced apart by the intervertebral discs – not directly visible with X-rays. These spaces should be approximately equal in height increase as we come lower down.

Prevertebral soft tissue

Some fractures cause widening of the prevertebral soft tissue due to the prevertebral hematoma. The width is measured between the anterior line and anterior margin of soft tissue visible on the x-ray.

– The normal prevertebral soft tissue is narrow down to C4 and wider below

– Above C4 -1/3rd vertebral body width

– Below C4 – 100% vertebral body width

This x-ray shows a normal cervical spine. The present x-ray shows vertebra from C1 to C7.

The view in the present picture is lateral view.

As you can view it, normal cervical spine appears lordotic. That means the anterior part of the spine appears convex and posterior concave.

Normal Cervical Spine Xray – AP View

Coverage

The AP view should cover the whole cervical spine and the upper thoracic spine.

Alignment

The lateral edges of the cervical spine are aligned.

Bone

Check for bony integrity to rule out fractures

Spacing

The spinous processes are in a straight line and spaced approximately evenly.

In diseases or spasm of the cervical spine, this lordosis of the normal cervical spine is lost.

Most common of these causes a change in curvature is cervical spondylosis.

For examination of the cervical spine, both anteroposterior and lateral views are required. Though both the views are important, the lateral view is more informative.

Special view radiographs may be required in many cases for proper diagnosis of the disease.

Cervical spine x-ray can be taken in standing position or lying down on the table.

The first method is done routinely on ambulatory patients in the outpatient department. Lying down method is done in cases of injury or patients who cannot stand.

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Thoracic Spine Anatomy

By Arun Pal Singh

Thoracic spine is also called dorsal spine and is constituted by next 12 vertebrae after cervical spine.

If you palpate back of neck from above downwards in mid line, you would come across a sudden projection or bump in the lower part of neck. This projection is posterior spinous process of C7 vertebra and projects out due to its large size. C7 connects on top of T1.

Similarly, the lowest vertebra of the thoracic spine, T12, connects with L1 or first vertebra in lumbar spine. Between these two are ten other thoracic vertebra connected to each other.

Following features are unique to thoracic spine when compared to cervical spine

Rib Cage

Each thoracic segment is accompanied by a pair of ribs. The ribs articulate with the spinal column posteriorly, and the sternum anteriorly.

The first, eleventh, and twelfth pair of ribs articulate with their named vertebra only.

The second through tenth ribs articulate both with their named vertebral body and with the intervertebral disk and the vertebra above.

Each pair of ribs also articulates with the anterior surface of the transverse process of its named vertebrae.

Thoracic spine and rib cage provide both stability and a protect vital organs in thorax.

Thinner Discs

Discs are cushions in between two vertebrae that act as shock absorbers. In the thoracic spine, the intervertebral discs are thinner than at the cervical or lower spine.

Narrower Canal

Spinal canal is narrowest canal in the thoracic spine.

Identification of Thoracic Vertebra

The thoracic vertebrae are identified by the presence of costal facets on the sides of the vertebral bodies. Costal facets of each vertebra articulate with corresponding rib. The costal facets may be two or only one on each side. There are twelve thoracic vertebrae [both typical and atypical thoracic vertebrae], out of which the 2nd to 8th are typical and the remaining 5 i.e.1st, 9th, 10th, 11th and 12th are atypical.

Typical Thoracic Vertebra

The body is heart shaped with roughly the same measurements from side to side and anteroposteiroly. On each side it bears 2 costal facets (demifacets). The superior costal facets are larger and placed on the upper border of the body near the pedicle. They articulate with the head of the numerically corresponding rib. The inferior costal facets are smaller and placed on the lower border in front of the inferior vertebral notch. They articulate with the next lower rib.

The vertebral foramen is comparatively small and circular.

The vertebral Arch

The pedicles are directed straight backwards. The superior vertebral notch is shallow, while the inferior vertebral notch is deep and conspicuous.
The laminae overlap each other from above.
The superior articular processes project upwards from the junction of the pedicles and laminae. The articular facets are flat and are directed backwards and a little laterally and upwards. This direction permits rotatory movements of the spine.
The inferior articular processes are fused to the laminae. Their articular facets are directed forwards and slightly downwards and medially.
The transverse processes are large, and are directed laterally and backwards from the junction of the pedicles and laminae. The anterior surface of each process bears a facet near its tip, for articulation with the tubercile of the corresponding rib. In the upper 6 vertebrae the costal facets on the transverse processes are concave, and face forwards and laterally. In others the facets are flat and face upwards, laterally and slightly forwards.
The spine is long, and is directed downwards and backwards. The 5th to 9th spines are the longest, more vertical and overlap each other. The upper and lower spines are less oblique in direction.

Attachments on a Typical Thoracic Spine Vertebra

The upper and lower borders of the body give attachment, in front and behind respectively, to the anterior and posterior longitudinal ligaments.
The upper borders and lower parts of the anterior surfaces of the laminae provide attachment to the ligamenta flava.
The transverse process gives attachment to (i) the lateral costotransverse ligament (at the tip); (ii) the superior costotransverse ligament (lower border); the inferior costotransverse ligament (anterior surface); (iv) the intertransverse muscles (to upper and lower borders); (v) the levator costae (posterior surface).
The spines gives attachment to the supraspinous and interspinous ligaments. They also give attachment to several muscles including the trapezius, the rhomboids, the latissimus dorsi, the serrate posterior superior and inferior, and many deep muscles of the back.

Atypical Thoracic Vertebrae

First Thoracic Vertebra

The body resembles that of a cervical vertebra. It is broad and not heart shaped. Its upper surface is lipped laterally and beveled anteriorly. The superior costal facet on the body is complete. It articulates with the head of the first rib. The inferior costal facet is a “demifacet” for the second rib.
The spine is thick, long and nearly horizontal.
The superior vertebral notches are well marked, as in cervical vertebrae.

Ninth Thoracic Vertebra

It resembles a typical thoracic vertebra except that the body has only the superior costal facets (demifacets). The inferior costal facets are absent.

Tenth Thoracic Vertebra

It resembles a typical thoracic vertebra except that the body has a single complete superior costal facet on each side, extending on to the root of the pedicle.

Eleventh Thoracic Vertebrae

The body has a single large costal facet on each side, extending on to the upper part of the pedicle.
The transverse process is small, and has no articular facet. Sometimes it is difficult to differentiate between vertebrae T10 and T11.

Twelfth Thoracic Vertebra

The shape of the body, pedicles, transverse processes and spine are similar to those of a lumbar vertebra. However the body bears a single costal facet on each side, which lies more on the lower part of the pedicle than on the body.
The transverse process is small and has no facet, but has superior, inferior and lateral tubercles.
The inferior articular facets are lumbar in type, and are directed laterally (everted), but the superior articular facets are thoracic in type.

Joints of Thoracic Spine

Present throughout Vertebral Column

These joints are present in other regions of spine as well.

There are two types of joints present throughout the vertebral column

Symphyses

Adjacent vertebral bodies are joined by intervertebral discs, made of fibrocartilage.

Facet Joints

These are synovial joints formed by the articulation of superior and inferior articular processes from adjacent vertebrae.

Following joints are unique to thoracic spine.

Costovertebral Joint

Each costovertebral joint consists of the head of the rib articulating with:

Superior costal facet of the corresponding vertebra
Inferior costal facet of the superior vertebra
Intervertebral disc separating the two vertebrae

The joint is stabilized by the intra-articular ligament of head of rib which attaches the rib head to the intervertebral disc. Only slight gliding movements can occur at these joints.

Costotransverse Joint

The costotransverse joints are formed by the articulation of transverse processes of a thoracic vertebra and the tubercle of the adjacent rib. They are present in all vertebrae except T11 and T12.

Ligaments of Thoracic Spine

The thoracic spine is strengthened by the presence of numerous ligaments.

Ligaments Present in Other Parts of Spine Also

Anterior Longitudinal Ligament

This is thick and slightly more narrow over the vertebral bodies and thinner but slightly wider over the intervertebral discs. It also loosely attaches to annulus of disc.

It is a three layered ligment – superficial, intermediate and deep.

Posterior Longitudinal Ligament

Intertransverse Ligaments

These ligaments are situated between the transverse processes. In the thoracic region, they are closely connected with the deep muscles of the back.

Capsular Ligaments

Ligamentum Flavum

Also called Yellow Ligament, the ligamentum flavum connects the anteroinferior edge of the lamina to the posterosuperior edge of the lamina below. The ligamentum flavum is thicker in the thoracic region. This ligament is composed mainly of elastic fibers, and that elasticity serves to preserve the upright posture, and to assist the vertebral column to resume after flexion.

Interspinous Ligaments

The interspinous ligaments connect adjacent spinous processes, and runs obliquely from the anterior inferior aspect of the spinous process above to the posterior superior aspect of the spinous process

Supraspinous Ligament

This strong ligament is a strong fibrous cord, which connects together the tips of the spinous processes from the C7 to the sacrum.

In the cervical spine, the interspinous and supraspinous ligaments thicken and combine to form the nuchal ligament

Ligaments Unique to Thoracic Spine

Radiate ligament of head of rib

This ligament fans outwards from the head of the rib to the bodies of the two vertebrae and intervertebral disc.

Costotransverse ligament

This connects the neck of the rib and the transverse process.

Lateral costotransverse ligament

It extends from the transverse process to the tubercle of the rib.

Superior costotransverse ligament

It passes from the upper border of the neck of the rib to the transverse process of the vertebra superior to it.

Muscles of Thoracic Spine

There are two types of muscles in the back

Extrinsic which are responsible for limb and respiratory movements
Intrinsic which maintain posture and carry out spinal movements.

Extrinsic Back Muscles

The extrinsic back muscles include superficial and intermediate muscles.

The superficial extrinsic back muscles

Trapezius, latissimus dorsi, levator scapulae, and rhomboids.

The function of this muscle group is to connect the upper limbs to the trunk and produce and control limb movements.

The intermediate extrinsic back muscles include serratus posterior superior and inferior. Those are thin, superficial respiratory muscles.

Intrinsic Back Muscles

The intrinsic or deep back muscles maintain posture and control movements of the vertebral column.

The deep back muscles can be grouped into superficial, intermediate, and deep layers

Superficial layer

Splenius capitis
Splenius cervicis muscles.

Intermediate layer [Erector spinae muscles]

Iliocostalis
Longissimus
spinalis muscles.

This group is the chief extensor of the vertebral column.

Deep Layer [Transversospinal muscle]

Semispinalis
Multifidus
Rotators

Apart from these, following muscles are present.

Interspinals which connect spinous processes
Intertransverse which connects transverse processes

Anterior spinal muscles

The anterior musculature is found in the cervical and lumbar regions, not in the thoracic region.

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Anatomy of Cervical Spine

By Arun Pal Singh

The portion of the spine encompassing neck region forms the cervical spine. The cervical spine is formed by the first seven vertebrae which are named as C1 to C7.

Anatomically, cervical spine starts where the top vertebra (C1) connects to the bottom of the skull.

Normal cervical spine has a lordosis. That means it is curved with convexity on the anterior aspect. It ends when C7 joins with the first thoracic vertebra.

Understanding the anatomy of cervical spine is vital to understand the various problems and abnormalities of the neck. Anatomy of cervical spine is easier to understand by dividing it in upper and lower cervical regions

Anatomy of Upper Cervical Spine

The bones of the upper cervical spine include

The base of skull surrounding the foramen magnum
Pair of occipital condyles
Atlas vertebra (C1)
Axis vertebra (C2)

Occipital Condyles

The occipital condyles are under-surface facets of the occipital bone which articulates with the superior facets of the atlas vertebra.

The condyles are oval in shape, and their anterior extremities and they are directed forward and medialward.

The articular surfaces of the condyles are convex from before backward and from side to side and look downward and lateralward.

Occipital condyles are covered by hyaline cartilage.

Atlas Vertebra

Atlas (C1) is the first cervical vertebra of the spine.

It is named for the Atlas of mythology because it supports the globe of the head.

The atlas along with the Axis (C2)– forms the joint connecting the skull and spine and are specialized to allow a greater range of motion.

Together they are responsible for the nodding and rotation movements of the head.

Atlas has no body and consists of an anterior and a posterior arch and two lateral masses. It appears like a ring.

Two lateral masses on either lateral side provide the bulk of the atlas bone mass. The transverse foramina are located to the lateral aspect of the lateral masses

Axis Vetebra

The axis is the second vertebra and has a unique shape. It consists of a large bony protuberance and a pars articularis separating the superior from inferior articular processes.

The odontoid process or dens is a 2 to 3 cm long corticocancellous structure with narrowed waist and thickened cortical tip emanating in a rostral (towards the head) direction from the vertebral body.

The odontoid rests in a recess behind the anterior arch of the atlas and the medial walls of the two lateral masses.

The superior articular surface of the axis is the cranial (towards the head) surface of the vertebral body of the axis and lies separated by a narrow osseous recess lateral to the odontoid.

The two inferior articular processes of the axis are located on the inferolateral corner of the neural arch. The transverse foramen of the axis is located in the lateral aspect of the vertebral bodies on either side.

Ligaments of Upper Cervical Spine

The joint surfaces of these three bony components of the upper cervical spine have little or no inherent stability. Thus the stability of this region is mainly determined almost entirely by ligamentous structures

The alar ligaments connect the medial surface of the occipital condyles to the lateral tip of the odontoid. A small portion also attaches obliquely along the medial upper wall of the atlas.

The apical ligament connects between a bony protuberance of the basion (The mid-point on the anterior margin of the foramen magnum on the occipital bone) to the superior tip of the odontoid.

The transverse atlantal ligament connects the medial wall of the anterior third of either lateral mass of the atlas with one another.

Tectorial membrane is the rostral continuation of the posterior longitudinal ligament and is composed of a deep and a superficial layer.

Between the apical ligament and the deep layer of the tectorial membrane is the cruciate ligament bridging the basion and the axis body and a narrow transverse ligament, which extends between the upper ends of the lateral masses of the atlas.

Posteriorly, the upper cervical spine does not have well-developed ligamentous support structures.

The atlantoaxial and atlanto-occipital membranes, respectively form a thin protective barrier rather than an effective restraint mechanism.

Accessory atlantoaxial ligaments and the atlanto-occipital and atlantoaxial joint capsules are additional well-defined ligamentous support structures

Neurovascular Structures

The spinal cord at the craniocervical junction is located between the posterior halves of the lateral masses of the atlas and the pars interarticularis of the axis. It fills about 50% of the neural canal in the upper cervical spine.

C-1 roots emerge from the spinal cord at a right angle and are located posterior to the occipital condyles superior to the lamina of the atlas.
C-2 roots are larger than the C-1 roots and are located posterior and slightly caudal (towards foot) to the atlantoaxial joints.
The vertebral arteries emerge from the transverse foramina of the vertebral body of the axis in a cranial direction lateral to the pars interarticularis and the atlantoaxial joints.

At the level of the atlas the vertebral arteries will enter the transverse foramen, course medially in a shallow bony groove located on the superior surface of the lateral third of the atlas lamina, and then head into the cerebellar fossa.

Anatomy of Lower Cervical Spine or Subaxial Spine

The lower cervical spine or subaxial [below axis vertebra] cervical spine, includes the C3 to C7 vertebral segments. Lower cervical vertebrae have a relatively uniform anatomic configuration as compared to the anatomy of upper cervical spine.

Anterior Elements

The vertebral body is larger in coronal (left to right) than its sagittal diameter (anterior to posterior). Bilateral prominences called uncinate processes are present along the lateral aspects of the superior endplates. The uncinate processes articulate with rounded inferolateral borders of the superior vertebral body and the articulation is called an uncovertebral joint.

This joint marks the lateral extent of the vertebral body.

C3-C6 vertebrae have a typical anatomical structure –

Small body, and broader from side to side than from front to back.
Flattened anterior and posterior surfaces
The upper surface
- Concave transversely
- Presents a projecting lip on either side.
The lower surface
- Concave from front to back
- Convex from side to side
- On either side laterally they have shallow concavities
- Concavities receive uncinate processes to form uncovertebral joints
The vertebral foramen is large and of a triangular form.
The transverse processes are each pierced by the foramen transversarium

Transverse foramina are present consistently in upper six vertebrae but variable in C7. Even when it is present, it is small.

The transverse foramen is formed by the fusion of the anterior and posterior part of the transverse process and part of the pedicle.

Transverse foramina give passage to the vertebral artery and vein in upper six cervical vertebrae. In C7 it contains only vein as well as a plexus of sympathetic nerves.

C7 has enlarged spinous process called vertebra prominence. It is the most prominent structure that can be palpated when we pass our finger downwards from the skull.

Neural foramina of cervical spine allow exit of cervical spinal nerves which are eight in number and are named as C1 to C8.

Between two adjacent vertebrae is interposed intervertebral disc.

The longus colli muscles lie directly over and insert onto the anterolateral aspects of each cervical vertebra.

The sympathetic plexus lies on top of the lateral muscle belly and may be injured aggressive dissection or retraction which can lead to Horner’s syndrome.

The prevertebral (deep) and alar (superficial) fascial layers separate the spine from the overlying esophagus.

Posterior Elements

Pedicles in lower cervical vertebrae project in a posterolateral to anteromedial orientation.

Articular facets are flat

Superior articular facets face backward, upward, and slightly medially
The Inferior facets are forward, downward, and slightly laterally.

The facet joints are formed by the interaction of superior and inferior articular processes. They are also known as the zygapophyseal articulations. The articular surfaces are angled approximately 45 degrees in relation to the transverse axis.

The pillar of bone between the superior and inferior articular processes is commonly referred to as the lateral mass and is It is a useful site for posterior screw or wire stabilization.

The laminae are narrow, and thinner above than below.

The laminae arise from the posteromedial border of the lateral masses project posterior and toward the midline to form bifid spinous processes.

The spinous process is short and bifid.

Ligamentum flavum or yellow ligament is present between space between two laminae.

Ligaments like interspinous and supraspinous ligaments or ligamentum nuchae form a posterior ligamentous complex and its disruption may lead to mechanical instability.

Cervical Nerves

The cervical nerves control many bodily functions and sensory activities.

C1: Head and neck

C2: Head and neck

C3: Diaphragm

C4: Upper body (e.g. Deltoids, Biceps)

C5: Wrist extensors

C6: Wrist extensors

C7: Triceps

C8: Hands

Injury to cervical spine or involvement of spinal nerves affects the area they supply.

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Spine Anatomy Overview

By Arun Pal Singh

Human spine or vertebral column is a structure made of multiple small units called vertebra and extends from just below the base of the skull to a point just below the beginning of gluteal cleft. You can palpate the lower part by following the spine till its lower end.

A vertebra is the smallest unit of the vertebral column. Plural term is vertebrae. Vertebrae have been modified according to the function they are expected to serve in different parts of the spine.

To a naked and unaccustomed eye, the spine appears as a straight column. But that is not the case. It appears straight in anteroposterior view (That means looking from front or back) but in lateral view or looking from a side, we can see multiple curves in different regions.

These curves are called kyphotic if they are concave in anterior(front) and convex on posterior (back) and lordotic if they are convex in anterior and concave on posterior.

Regions of Spine

It is divided into five regions

Cervical

This part is present in the neck and consists of first seven vertebrae. Each vertebra is known by C followed by

the number of the vertebra. Thus the first vertebra is called C1 and the last vertebra is called C7. It has a normal lordotic curve.

Thoracic

This is also called the dorsal spine. It is below cervical and spans upper trunk or thorax or area corresponding to the chest. It contains a total of 12 vertebrae designated as T1 to T12 in a fashion similar to we discussed for cervical vertebrae. It has a normal kyphotic curve.

Lumbar

It follows Thoracic and consists of 5 vertebrae, L1 to L5. Some of the people might have anatomical variations in which 4 or 6 vertebrae might be present in Lumbar spine. In both cases, the extra vertebra is added to or taken from Sacral spine. Accordingly,if there are 4 lumbar vertebrae, it is called sacralization of lumbar vertebra and if there are 6 lumbar vertebrae, it is called lumbarization of sacral vertebra.

Sacral

It is composed of five sacral vertebrae S1 to S5. In contrast to other parts we just discussed, vertebrae in the sacral spine are fused to each other. This part of spine follows lumbar spine and is present in the pelvic area.

Coccyx or Coccygeal

This is also known as the tailbone. It is the final segment of the human vertebral column, of four fused vertebrae (the coccygeal vertebrae) below the sacrum.

The function of the spine is to support and transmit weight of trunk to lower limbs, to aid in the motion of the trunk and to support and protect spinal cord & other vital organs. Spinal Cord is the structure that transmits neural fibers. These fibers further supply the organs in form of nerves.

Structural Arrangement

Vertebrae are the structural units of the spine. They are stacked together to form the entire vertebral column. Between each vertebra, are cushion-like structures called intervertebral discs which act as shock absorbers and also permit some movement between the vertebral bodies. Various ligaments stabilize the spine and also allow movements.

Movements of the spine occur at special joints called facet joints that are formed between two adjacent vertebrae. Various muscles carry out the movements of the spine. These muscles are important for maintaining posture and transmission of loads created during normal activities, work, and play. The strength of these muscles is important and lack of strength would lead to various backache problems.

Vertebrae are shaped in such a way that the spinal cord is protected from damage by the bones of the entire spinal column.

Vertebrae

The vertebrae are responsible for transmission of the weight. Each vertebra consists of an anterior body which is attached to a posterior ring called posterior neural arch. Two struts of bones called pedicles arise from the body and join two converging struts called laminae. Pedicles, laminae and posterior surface of body forms boundaries of spinal canal. This spinal canal is the space where the spinal cord passes. There is a transverse process on either side of the arch which serves as an attachment to various muscles and ligaments. Dead posteriorly is the posterior spinous process that can be felt on our back as bumps. Posterior spinous processes also serve as an attachment to ligaments and muscles of the spine.

Adjacent to the base of transverse processes are bony projections that go superior and inferior. These are called superior and inferior articular facets and take part in the formation of facet joints. There are two facet joints between each between each pair of vertebrae one on each side. They are primarily designed to allow the vertebral bodies to rotate with respect to each other.

Intervertebral Disc

The discs are designed to absorb the stresses carried by the vertebral column while allowing the vertebral bodies to move with respect to each other. They made up of a strong outer ring of fibers called the annulus fibrosus that contains nucleus pulposus.

Neural Foramen

The neural foramen is the opening where the nerve roots exit the spine and travel to the rest of the body. There are two neural foramina located between each pair of vertebrae, one on each side.

Muscles and Ligaments

Various muscles and ligaments attach to the spine. They help the spine to stabilize and allow it to carry various movements.