Post on 16-Feb-2017
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