INTRODUCTION TO INTERVERTEBRAL DISC ANATOMY,

PIVD (LUMBAR) AND ITS MANAGEMENT

Presented by:

Dr. Ben TungoePG, M.S(Orthopedics)

Central Institute of OrthopedicsVMMC & Safdarjung Hospital, New

Delhi

ANATOMY OF INTERVERTEBRAL DISC• fibro cartilaginous structure.

• contributes 25% of the height of spinal column.

• function of shock absorption, transmitting compressive loads between vertebral bodies.

• Composed of the central nucleus pulposus(NP), the peripheral annulus fibrosus(AF) and the end plates(EP).

• The end plate is a bilayer of cartilage that separate the IVD from the vertebral body(VB) and serves as growth plate for the VB.

NUCLEUS PULPOSUS:

– Highly hydrated structure, approx. 88% water

– Hydrophilic matrix: composed of proteoglycans(PG) interspersed within an irregular mesh of type-2 collagen and elastin fibers.

– The proteoglycans have a large number of anionic glycosaminoglycans(GAG) side chains i.e chondroitin sulfate and keratan sulfate which allows the nucleus to imbibe water.

– Low collagen and high PG ratio.

– Characterised by compressibility.

ANNULUS FIBROSUS

-composed of concentric rings/lamellae of highly organised Type-1 collagen fibres which are interwoven.

-high collagen and low PG ratio

-the fibres are oriented 60 degree to the vertical axis of spine and parallel within each lamella and perpendicular between adjacent lamallae.

-lamallae are thicker anteriorly and laterally and thinner posteriorly

-AF functions to contain the NP and maintain its pressurization under compressive loads.

-characterized by extensibility and tensile strength

BLOOD AND NERVE SUPPLY

• Blood Supply  – the disk is avascular with capillaries terminating at

the end plates– nutrition reaches nucleus pulposus

through diffusion through pores in the endplates • annulus is not porous enough to allow

diffusion 

• Innervation– the dorsal root ganglion gives rise to the

sinuvertebral nerve which innervates the superficial fibers of annulus• no nerve fibers extend beyond the superficial

fibers– neuropeptides thought to participate in sensory

transmission include• substance P• calcitonin• VIP• CPON

Distribution of load in the inter-vertebral disc.

(A) In the normal, healthy disc, the nucleus distributes the load equally throughout the annulus.

 (B) As the disc undergoes degeneration, the nucleus loses some of its cushioning ability and transmits the load unequally to the annulus.

 (C) In the severely degenerated disc, the nucleus has lost all of its ability to cushion the load, which can lead to disc herniation.

Disc Biomechanics

• Disc– viscoelastic characteristics

• demonstrates creep which allows for deformity over time• demonstrates hysteresis which allows for energy absorption with repetitive axial

compression– this property decreases with time

• Stresses– annulus fibrosus

• highest tensile stresses– nucleus pulposus

• highest compressive stress– Intra-discal pressure is position dependent

• pressure is lowest when lying supine• pressure is intermediate when standing• pressure is highest when sitting and flexed forward with weights in the hands• when carrying weight, the closer the object is to the body the lower the pressure

• Stability– following subtotal discectomy, extension is most stable loading mode

Pathoanatomy • Disc Herniation

– herniated disks are associated with a spontaneous increase in the production of • osteoprotegrin (OPG)• interleukin-1 beta• receptor activator of nuclear factor-kB ligand (RANKL)• parathyroid hormone (PTH)

• Disc aging leads to an overall loss of water content and conversion to fibrocartilage. Specifically there is – decrease in 

• nutritional transport • water content• absolute number of viable cells• proteoglycans• pH

– increase in• an increase keratin sulfate to chondroitin sulfate ratio • lactate• degradative enzyme activity• density of fibroblast-like cells 

– fibroblast-like cells reside in the annulus fibrosus only– no change in

• absolute quantity of collagen

SPECTRUM OF DEGENERATIVE JOINT DISEASES OF SPINE

• Internal disc disruption• Disc herniation• Degenerative spondylolisthesis• Spinal stenosis• Adult spinal deformities

Spectrum of changes(Kirkaldy Willis Concept)Internal disc disruption

Disc herniation

Intervertebral space decrease

Overloading of facet joints, ligamentous instability

Instability of motion segment

Degenerative spondylolisthesis

Attempt to stabilise by formation of osteophytes and ligaments hypertrophy

Spinal stenosis

Adult spinal deformity

Etiology of Intervertebral disc degeneration

Repetitive mechanical activities – Frequent bending, twisting, lifting, and other similar activities without breaks and improper stretching

Living a sedentary lifestyle – more prone to herniated discs because the muscles that support the back and neck weaken, which increases strain on the spine.

Traumatic injury to lumbar discs- commonly occurs when lifting while bent at the waist, rather than lifting with the legs while the back is straight.

Obesity – overloading the motion segment.

Poor posture – Improper spinal alignment

Tobacco abuse – toxins reduces the disc’s ability to absorb nutrients, which results in the weakening of the disc.

Mutation- in genes coding for proteins involved in the regulation of the extracellular matrix, such as MMP2 and THBS2,

Cellular and Biochemical Changes of the Intervertebral Disc

Decrease proteoglycan content.

Loss of negative charged proteoglycan side chain. Water loss within the

nucleus pulposus. Decrease hydrostatic property. Loss of disc height. Uneven stress distribution on the annulus.

Thompson Grading( based on sagittal sections of fresh cadaveric specimen)

Pfirmann Grading on MRI

MODIFIED PFIRMANN GRADING

MODIFIED PFIRMANN GRADING

Adam’s classification(based on discography)

Concentric tears :circumferential lesions, involves

outer layers of the annular wall.

Radial tears:characterized by an annular tear

which permeates from the deep central part of the disc (nucleus pulposus) and extends outward toward the annulus, in either a transverse or cranial-caudal plane.

Transverse tears:also known as “peripheral tears” or “rim lesions,” are horizontal ruptures of fibers, near the insertion in the bony ring apophyses.

ANNULAR TEARS

L4-L5 CT diskogram demonstrating a large left posterolateral radial anular tear associated with a left foraminal and extraforaminal herniaton

Herniated discs in the cranio-caudal (vertical) direction through a break in one or both of the vertebral body endplates are referred to as “intravertebral herniations” (also known as Schmorl’s nodes).

They are often surrounded by reactive bone marrow changes.

Nutrient vascular canals may leave scars in the endplates, which are weak spots representing a route for the early formation of intrabody nuclear herniations

INTRAVERTEBRAL HERNIATIONS

PROLAPSED INTERVERTEBRAL DISC

• Mostly seen in lumbar region followed by cervical region.• Affects young adults 30-40 years who still have relatively

maintained disc height.• Male:female ratio 3:1• 95% involves L4-5 and L5-S1(most common)• Herniates through the postero-lateral corner of annulus

fibrosus(thin region)• Most commont causes:– Sudden violent trauma (sports injuries)– Less severe trauma in degenerated annulus(lifting,

bending, coughing, sneezing etc)

Anatomic classification

Disc protrusion: the herniated portion of the disc covered with a thin layer of annulus

Disc extrusion: disc material herniated through annulus but remains continuous with disc space

Disc sequestration: the disc fragment herniates through the annulus and loses contact with the originating disc space

Classification based on the location of the disc herniation

• Posterolateral/paracentral prolapse:– Commonest– PLL weakest in this area– Herniated disc impinges on the traversing nerve

roots(e.g the L5 nerve root in L4-5 disc prolapse)

• Central prolapse: – may present with back pain only or Cauda-

equina(severe cases)

• Foraminal/extra foraminal/far lateral herniation:– Less common– The herniated disc impinges on the exiting nerve

roots(e.g. L4 nerve root in L4-5 level)

Clinical features: History

• History of episode of trauma• Radicular pain (buttock and thigh pain, extending below the knee

following the distribution of the involved nerve roots) • aggravated by flexion, sitting, straining, sneezing, cough• decreased by rest, especially in the semi-Fowler position• Other symptoms:– Weakness Corresponding to level of neurological

involvement– Paraesthesia in dermatomal distribution– Cauda equina

• Natural course of symptomatic PIVD is slow resolution of symptoms over 6-8 weeks period in 80% of cases

Cauda Equina syndrome

• Emergency– Aggressive evaluation and management– Large central herniation

• Most consistent symptoms(Tay & Chacha)– saddle anesthesia– bilateral ankle areflexia – bladder symptoms

• Other symptoms-– numbness and weakness in both legs, – rectal pain, – numbness in the perineumBowel

disturbances

Clinical Features- Signs

• Antalgic gait– Affected hip more extended

and knee more flexed than normal side

• Trendelenberg gait (L5 nerve root)

• List– abrupt planar shift– Axillary disc –same side– Shoulder disc- opposite side

• Thigh and calf muscle wasting• Loss of lumbar lordosis• Paraspinal spasm- central

furrow sign

Provocative tests– straight leg raise

• a tension sign for L5 and S1 nerve root• technique

– can be done sitting or supine– reproduces pain and paresthesia in leg at 30-70 degrees hip flexion

• sensitivity/specificity– most important and predictive physical finding for identifying who is a good candidate for surgery

– contralateral SLR• crossed straight leg raise is less sensitive but more specific

– Lesegue sign• SLR aggravated by forced ankle dorsiflexion

– Bowstring sign• SLR aggravated by compression on popliteal fossa

– Kernig test• pain reproduced with neck flexion, hip flexion, and leg extension

– Naffziger test• pain reproduced by coughing, which is instigated by lying patient supine and applying

pressure on the neck veins– Milgram test

• pain reproduced with straight leg elevation for 30 seconds in the supine position

SLUMP TEST

FLIP TEST

Clinical features -Neurology

L1 L2

Clinical Features- Neurology

L3

Clinical Features- Neurology

L4

Clinical Features- Neurology

L5

Trendelenberg test

Clinical Features- Neurology

S1

Clinical Features- Red Flags

• Extremes of age (<15yr , >55yr)• Neurological deficits• Fever• Unexplained weight loss(10lb in 6months)• Malaise• Rest pain/ night pain• Significant trauma• Drug and alcohol abuse

Non Organic Signs Of Waddell

Described by Waddel in post op patients

1. Non anatomic tenderness

2. Simulation sign

3. Distraction sign

4. Regional sensory or motor disturbance

5. Overreaction(most sensitive)

Differential Diagnosis

SPINAL CAUSES:-Trauma-Infection: Osteomyelitis or discitis ( with nerve root pressure)-Inflammation: Arachnoiditis, ankylosing spondylitis-Neoplasm: Benign or malignant with nerve root pressure(multiple myeloma,

extradural tumors)

EXTRASPINAL CAUSES:

• Peripheral vascular disease• Gynaecological conditions• Orthopaedic conditions ( osteoarthritis of hip, Muscle related disease, Facet joint

arthropathy)• Sacroiliac joint disease• Neoplasm• Peripheral nerve lesions

• Neuropathy (Diabetic, tumour, alcohol)• Local sciatic nerve conditions (Trauma, tumour)• Inflammation (herpes zoster)

KEY DIAGNOSTIC POINTSLUMBAR DISC PROLAPSE Leg pain greater than back pain SLRT + Neurological deficit present

ANNULAR TEARS Back pain greater than leg pain Bilateral SLRT positive

FACET JOINT ARTHROPATHY Localized tenderness present unilaterally

over joint Pain occurs immediately on spinal

extension Pain exacerbated with ipsilateral side

bending

SPINAL STENOSIS Heaviness(no pain) develops after walks

a limited distance. Flexion relieves symptoms No neurological deficit SLRT -ve

MYOGENIC OR MUSCLE RELATED Pain localised to affected muscle Pain increases on prolonged muscle use Pain reproduced with sustained muscle

contraction against resistance Contralateral pain with side bending

Investigations- Plain Radiographs

• FINDINGS:– Loss of lumbar lordosis– Loss of disc height

X ray views

• AP and Lateral views• Oblique views

– Spondylolisthesis and lysis– Hypertrophic changes around foramina in cervical spine

• Lateral flexion/ extension views• Ferguson View

– 20 degrees caudocephalic AP – fifth root compression by a large transverse process of the L5 vertebra

against the ala of the sacrum.

• Angled caudal views – facet or laminar pathological conditions.

X ray- Signs of Instability

• Indirect Signs– Disc space narrowing, – Sclerosis of end plates – Osteophytes– Traction spur – Vacuum Sign

• Direct signs– Translational abnormalities on dynamic films

Vacuum sign• radiolucent defect • presence of nitrogen gas

accumulations in annular and nuclear degenerative fissures

• typical central vacuum phenomenon gas collection that fills large neo-cavity occupying both the nucleus an annulus.

• indicative of advanced disc degeneration.

CT scanAdvantages:• provides superior imaging of cortical and trabecular bone

compared with MRI.• It provides contrast resolution and identify root compressive

lesions such as disc herniation.• differentiate between bony osteophyte from soft disc.• diagnose foraminal encroachment of disc material due to its

ability to visualize beyond the limits of the dural sac and root sleeves.

Limitations• cannot differentiate between scar tissue and new disc

herniation• does not have sufficient soft tissue resolution to allow

differentiation between annulus and nucleus

Investigations- MRI• Most accurate and sensitive modality for the diagnosis of

subtle spinal pathology.• It allows direct visualization of herniated disc material and

its relationship to neural tissue including intrathecal contents.

• Advantages over myelography– No radiation– Non invasive– No intrathecal contrast – More accurate in far lateral disc– Disc disease of LS junction– Early disc disease

Advantages of MRI over CT– imaging the disc– directly images neural structures– shows the entire region of study (i.e., cervical,

thoracic, or lumbar).– ability to image the nerve root in the foramen

Limitations– Showing abnormal anatomy in asymptomatic

patient.– MRI findings can’t correlate with severity of

symptoms.

Indications for MRI • pain lasting > one month and not

responding to non-operative management or• red flags are present– infection (IV drug user, h/o of fever and chills)– tumor (h/o or cancer)– trauma (h/o car accident or fall)– cauda equina syndrome (bowel/bladder changes)

Massive lumbar disc extrusion at L5–S1 in a 44-year-old man. Sagittal (a) and axial (b) T1-weighted images; sagittal (c) and axial (d) T2-weighted images. The extruded disc compresses and displaces the right S1 nerve root. On the sagittal T1-weighted image, the continuity between the extruding portion and the parent disc can clearly be identified.

GADOLINIUM ENHANCED CONTRAST MRI

-Investigation of choice for recurrent disc prolapse-it allows to distinguish between post surgical fibrosis(enhances with gadolinium) and recurrent herniated disc(doesn’t enhance with gadolinium)

Myelography• Unnecessary if clinical and CT or MRI findings are in

complete agreement.• Indications– suspicion of an intraspinal lesion,– patients with spinal instrumentation, – questionable diagnosis resulting from conflicting clinical

findings and other studies . – previously operated spine – marked bony degenerative change that may be

underestimated on MRI– arachnoiditis

Air contrast is used rarely -Only in situations in which the patient is extremely allergic to iodized materials

Discography- Uses• Evaluate equivocal abnormality seen

on myelography, CT or MRI• Isolate a symptomatic disc among

multiple level abnormality• diagnose a lateral disc herniation• establish discogenic pain• select fusion levels• evaluate the previously operated spine

– distinguish between mass effect from scar tissue or disc material

Electrodiagnostic studies

• Applied when clinical examination and imaging fail to provide a clear diagnosis or perhaps conflicting diagnoses

• May include needle electromyelography, somatosensory evoked potentials or cervical root stimulation

• May help differentiate primary cervical disorders from peripheral nerve entrapments syndromes or pain eminating from the intrinsic shoulder pathology

MANAGEMENT

• NON OPERATIVE MANAGEMENT– 90% respond to conservative management– Rest in semi-fowler position,ice packs, analgesics,

muscle relaxants, oral steroids, physical therapy and exercises

– Selective nerve root blocks: transforaminal SNRB with local anesthetic agent and long acting corticosteroid combination

– Lumbar epidural steroid injection

Epidural Steroid injection• Contraindications

– infection at the injection site– systemic infection– bleeding diathesis– uncontrolled diabetes mellitus– congestive heart failure.

• Complications• Minor

– Non-positional headaches– facial flushing insomnia– low-grade fever, – transient increased back or lower

extremity pain• Major

– vasovagal reaction– Dural puncture – Positional headache– epidural abscess, – epidural hematoma, – Dura-cutaneous fistula,– Cushing syndrome

Epidural Steroid injection Techniques

• Interlaminar Approach

• Transforaminal Approach

• Caudal Approach

Bed Rest• no data to suggest that bed rest alters the

natural history of lumbar disc herniation or improves outcomes.

• Consensus of 2 days (if used)

Semi Fowlers Position

Physical Therapy• Excercises• Back School• Others : IFT, SWD, TENS, Traction

Excercises

• Better than medical care alone• Flexion-based isometric exercises appear to

have the most support in the literature• Offer benefit by decreasing local muscle

spasm and stabilizing the spine.• Begin when acute pain diminishes

ExercisesGENERAL RULES FOR EXERCISE• Do each exercise slowly. Hold the exercise position for a slow

count of five.• Start with five repetitions and work up to ten. Relax

completely between each repetition.• Do the exercises for 10 minutes twice a day.• Care should be taken when doing exercises that are painful. A

little pain when exercising is not necessarily bad. If pain is more or referred to the legs the patient may have overdone it.

• Do the exercises every day without fail.

FOR ACUTE STAGE

BRIDGING EXERCISE KNEE HUGS

FOR RECOVERY OR SUBACUTE STAGE

EXTENSION CONTROLHAMSTRING STRETCH

KNEE ROLLS

Physical therapy• TENS

– Trans-cutaneous electrical nerve stimulation– release of endogenous analgesic endorphins– Central nervous system process in which a control center is altered to block

transmission of pain– Deyo RA et al ‘TENS is no different from a placebo’

• Intermittent Pelvic Traction– Goal- distract the lumbar vertebrae.– enlargement of the inter-vertebral foramen, – creation of a vacuum to reduce herniated discs,– placement of the PLL under tension to aid in reduction of herniated discs, – relaxation of muscle spasm, – freeing of adherent nerve roots– Does not alter natural history of disease

Lifestyle Modifications

• Avoidance of– Repetitive bending /twisting/ lifting– Contact sports– Heavy weights– 2wheelers, Auto rickshaws– Soft mattress( Spring, foam)

• Posture training • Back support while sitting• Firm mattress (rubberised foam, coir )

Intra-discal Electrothermal Therapy

• Low back pain of discogenic origin• Not useful in radiculopathy• posterolateral placement of a probe around the inner

circumference of the annulus followed by heating of the probe.

• Pre Requisites– Normal neurology – Negative SLR. – absence of compressive lesions on MRI – positive concordant discogram

• Conflicting outcomes requiring refinement of indications

Operative management• Standard discectomy

• Limited Discectomy

• Microsurgical Lumbar discectomy

• Endoscopic discectomy

• Additional Exposure– Hemi laminectomy– Total Laminectomy– Facetectomy

• Percutaneous Discectomy• Chemo-nucleolysis• Arthrodesis• Disc replacement

SURGICAL MANAGEMENT • Indications

– persistent disabling pain lasting more than 6 weeks that have failed non-operative options (and epidural injections)

– progressive and significant weakness– Cauda-equina syndrome

• Rehabilitation– patients may return to medium to high-intensity activity at 4 to 6 weeks

• Outcomes: improvement in pain and function greater with surgery

• Positive predictors for good outcome of surgery– leg pain is chief complaint – positive straight leg raise– weakness that correlates with nerve root impingement seen on MRI– married status

• Negative predictors for good outcome of surgery: worker’s compensation

STANDARD DISECTOMY • Prone position• With bolsters• Knee chest position• Allows abdomen to

hang free, – minimizing epidural

venous dilation and bleeding

• Lateral position with affected side up

Salient Points• Lamina exposed cephalad and caudad

to the level of the herniated disc• 1-2 sq cm area of lamina removed

exposing dura and nerve root• Visualise lateral edge of nerve root• Remove sequestered disc• Incise Annulus and remove central and

lateral part of nucleus• Nerve root must freely move 1cm

inferomedially– Foraminotomy

• Free fat graft to reduce post op scarring

Far lateral microdiskectomy

• indications– for far-lateral disc herniations

• technique– utilizes a paraspinal approach of Wiltse

Additional Exposure Techniques

• Large disc herniation, lateral recess stenosis or foraminal stenosis, may require a greater exposure of the nerve root.

• If the extent of the lesion is known before surgery, the proper approach can be planned

Hemilaminectomy• required when

identifying the root is a problem.

• Eg. Conjoined root

Total Laminectomy• Reserved for patients

with spinal stenosIs that are central in nature,

• Occurs typically in cauda equina syndrome.

Facetectomy

• reserved for – foraminal stenosis – severe lateral recess stenosis

• If more than one facet is removed, a fusion should be considered

• Especially in a young, active individual with a normal disc height at that level.

Lumbar Microsurgical Discectomy • first reported by Williams in 1978• procedure of choice for herniated lumbar disc• Decompression of the involved nerve root with

minimum trauma to the adjacent structures.• Advantages– decreased operative time, – Decreased morbidity, – less loss of blood, – shorter stay in the hospital,– earlier return to work.– Visibility for assistant

Lumbar Microsurgical Discectomy

• Drawbacks– inadequate exposure – incomplete decompression– Costly equipment

• Contraindications– Previously operated– Spinal Canal Stenosis

Microsurgical Lumbar Discectomy

• Requirements– operating microscope with a 400-mm lens,– small-angled Kerrison rongeurs of appropriate

length,– microinstruments, – combination suction–nerve root retractor

Microsurgical Lumbar Discectomy• Original Guidelines

– Avoidance of laminectomy and of trauma to the facets, – Preservation of all extradural fat, – Blunt perforation of the anulus fibrosus rather than

incision with a scalpel, – Preservation of healthy, non-herniated intervertebral

disc material,– Remove only as much disc as is necessary to relieve the

neural elements from visible and palpable compression.

• New Guidelines– Subtotal discectomy through an incision, made with a

scalpel,in the anulus fibrosus; – using bipolar coagulation; – Removing the medial portion of the facet for exposure

when necessary

Percutaneous endoscopic Discectomy• Mechanically decompress a herniated

lumbar disc via a posterolateral cannula

• Reduced morbidity • Reduced hospital stay• No anaphylactic reactions and

neurological complications associated with chemonucleolysis

Contraindications– Presence of sequestered fragments– Lumbar canal stenosis– Lumbosacral discs

Post op management• Immediate post op– Monitor neurology– Turn in bed , semi fowler position– Walk with assistance to toilet– Oral analgesics and muscle relaxants for pain– Bladder stimulants to assist in voiding– Discharge- after walking and voiding(day of surgery in

microscopic discectomy)– minimize sitting and riding in a vehicle to comfort– Increase walking on a daily basis– Avoid stooping bending lifting

Post op management

• Delayed– Core strengthening between week 1 & 3– Lifting bending stooping gradually after 3 weeks– Long trips avoid for 4-6weeks– Walking jobs with minimal lifting 2-3weeks– Prolonged sitting jobs 4-6 weeks– Heavy labor, long driving 6-8weeks– Exceptionally heavy manual labour- AVOID

COMPLICATIONS• Infection – Superficial wound

infection , Deep disc space infection• Thrombophlebitis/ Deep vein

thrombosis• Pulmonary embolism• Dural tears may result in

Pseudomeningocoele, CSF leak, Meningitis

• Postoperative cauda equine lesions• Neurological damage or nerve root

injury• Urinary retention and urinary tract

infection

CHEMONUCLEOLYSIS

Chymopapain injected into the disc

Degrades the proteoglycans in the

nucleus

Water holding capacity of the disc

is decreased

Shrinkage of the disc

Chemo nucleolysis• Contraindications

– Sequestered disc– Spinal stenosis– previous injection of chymopapain– allergy to papaya or its derivatives; – Previous surgical treatment of the lumbar spine; – herniation of more than two discs; – a rapidly progressive neurological deficit;– neurogenic dysfunction of the bowel or the bladder, or both;– spondylohisthesis.– Spinal tumour– Pregnancy– Diabetic neuropathy

Chemo nucleolysis

• Complications– Neurological• cerebral hemorrhage, • paraplegia,• paresis, quadriplegia, • Guillain-Barre syndrome, • seizure disorder.

– Anaphylaxis• Procedure is not in favour now

Disc Excision & Arthrodesis• First suggested by Mixter and Barr

• Indicated for– Marked segmental instability– Done when facets are destabilized bilaterally to prevent

Iatrogenic Spondylolisthesis

• Disadvantages of fusion:– Alters the biomechanics of spine– Loss of motion and overall shift in the sagittal alignment– Causes degenerative changes in the adjacent spinal motion

segments

Total Disc Replacement• CHARITE artificial disc (Depuy spine) was the first implant

approved by FDA for total disc replacement in october 2004.

• Presently, there are only three lumbar disc prostheses with FDA approval: – the INMOTION, which is a modification of the Charite (Depuy

Spine, Raynham, MA),– the ProDisc-L (DePuy Synthes), – the activL (Aesculap, Center Valley,PA).

• All are approved only for single-level disc replacement.

ADVANTAGES OF DISC REPLACEMENT

• Removes the disc/presumed main source of pain• Restore disc height----relieves load across the

facet joints----improves the pattern of load bearing between vertebrae.

• Segmental stability, preservation and improvement of segmental motion

• Maintain lordosis curve• Limit disability and early return to work

PRE REQUISITES FOR DISC REPLACEMENT

• Normal facet joints• Good bone quality(non

osteoporotic)• No spondylolisthesis or

spinal deformity• No infection• Single disc level

PRO DISC L

PRO DISC L

THANK YOU