Understanding lumbar disc herniation

Clinical aspects of Lumbar Disc herniation useful for undergraduates and also for quick review of Post graduates.Deals with mechanism,patho physiology,differential diagnosis,clinical tests,diagnosis,treatment and biomechanics of lumbar disc prolapse.

2. Introduction
Low back pain is one of the most common
causes for patients to seek medical care.
Prevalence is almost 100 % in a life time.
Only 1% of patients will have nerve root
compression.
1-3% have lumbar disc herniation.
Most common site L4-L5 , L5-S1

3. A herniated lumbar disc can press on the
nerves in the spine and may cause pain,
numbness, tingling or weakness of the leg
called "sciatica." Sciatica affects about 1-
2% of all people, usually between the ages
of 30 and 50.
A herniated lumbar disc may also cause
back pain, although back pain alone
(without leg pain) can have many causes
other than a herniated disc.

5. Anatomy
The spine is made up of a series of
connected bones called "vertebrae.“
The disc is a combination of strong
connective tissues which hold one
vertebra to the next and acts as a
cushion between the vertebrae.
The disc is made of a tough outer
layer called the "annulusfibrosus"
and a gel-like center called the
"nucleus pulposus.“
As you get older, the center of the
disc may start to lose water content,
making the disc less effective as a
cushion.

6. Anatomy -Normal Lumbar Disc
In between each of the five lumbar
vertebrae (bones) is a disc, a tough fibrous
shock-absorbing pad.
Endplates line the ends of each vertebra
and help hold individual discs in place.
Each disc contains a tire-like outer band
(called the annulus fibrosus) that encases
a gel-like substance (called the nucleus
pulposus).

7. Nerve roots exit the
spinal canal through
small passageways
between the
vertebrae and discs.
Pain and other
symptoms can
develop when the
damaged disc pushes
into the spinal canal
or nerve roots

8. Disc herniation occurs
when the annulus
fibrous breaks open or
cracks, allowing the
nucleus pulposus to
escape.
This is called a
Herniated Nucleus
Pulposus (HNP) or
herniated disc

9. Nomenclature with respect to Disc
Pathology
Disc degeneration : dehydration , decreased
height , end plate sclerosis , osteophytes ,
annulus fissures.
Disc bulge : generalized displacement of disc
material through an annulus fissure pushing
the peripheral annulus fibers into the canal.
Disc Herniation : Herniation of disc material
through a full thickness tear of the annulus
fibroses.
1)Focal : < 25 % of disc circumference.
2)Broad based : > 25 % of disc circumference.
Disc herniation : divided into
1)protrusion : Herniated fragment doesn’t have
a neck.
2)Extrusion : herniated fragment has a neck.
3)Sequestration or migration.

12. Types of Disc Herniation
Posteriolateral Disc
Herniation:Protusion posteriolateraly
into vertebral canal ,compress the roots of
spinal nerves.
Central(Posterior) Herniation: Less
frequent compresses the spinal cord it
self may result in caudaequina
syndrome.
Lateral Disc Herniation: Compresses
nerve root laterally above the level of
herniation.

13. Biomechanics of spine
Motion Segment
Two adjacent vertebrae
Intervertebral disc
Six degrees of freedom
Flexion-extension
Lateral flexion
Axial rotation

15. Intervetebral Disc
Soft fibro-cartilaginous cushions
Between two vertebra
Allows some motion
Serve as shock absorbers
Total –23 discs
¼
th
of the spinal column's length
A vascular
Nutrients diffuse through end plates

16. Functions of Intervertebral Disc
Movement of fluid within the nucleus
Allows vertebrae to rock back and forth
Flexibility
Act to pad and maintain the space
between the twenty-four movable
vertebrae
Act as shock absorbers
Allow extension and flexion

17. Intervertebral Disc Anatomy
Spongy center
Nucleus pulposus
Surrounded by a tougher outer fibrous ring
Anulus fibrosus

18. Annulus Fibrosus
Strong radial tire–like structure
Series of lamellae
Concentric sheets of collagen fibers
Connected to end plates
Orientated at various angles
Under compression
○Become horizontal
Encloses nucleus pulpous

19. In Bending
Increased tensile force posteriorly
Increased compressive force anteriorly
In Rotation
Reorientation of collagenous fibers
Tightening of fibers traveling in one direction
Loosening of fibers traveling in opposite
direction

20. Nucleus Pulpous
Has more water and PGs
PG are macro-molecules
Attract and retain water
Hydrophilic gel–like matter
Resists compression
Amount of water
Activity related
Varies throughout the day

21. Type II collagen
strand + hydrophilic
proteoglycan
Water content 70 ~
90%
Confine fluid within
the annulus
Convert load into
tensile strain on the
annular fibers and
vertebral end-plate

22. What happens on weight
bearing
Nucleus pulpous imbibes water
Develops internal pressure
Pressure exerted in all directions
Lateral forces
Against annulus
Superiorly and inferiorly directed forces
Against end plates
Increases stiffness
of end plate and annulus fibrosus

23. What happens on weight
bearing
Under normal physiologic activities
Pure tensile loading doesn’t occur
But annulus undergoes tensile loading during
Bending
Axial rotation
Extension

24. Changes in Disc during Prolapse
Decrease proteoglycan
content
Water loss within the nucleus
pulposus
Decrease hydrostatic property
Loss of disc height
Uneven stress distribution on
the annulus

25. Factors Contributing to spinal
stability
Spinal Stability
Neural
Passive
Subsystem
Active
Subsystem

26. Passive Subsystem
Control of segmental
movement at end of range
and in neutral joint
position.
Spinal ligaments offer
restrain towards the
end of range of movement
and do not provide
substantial support in
neutral position.
Passive
Subsystem
Articular
Osseous
Spinal
Ligaments

27. Active Subsystem
Force generating
capacity of muscles
themselves which
provides mechanical
ability to stabilize the
spinal segment.
Muscle Force Spinal Stability

28. Neural
Control of these muscles for spinal
support is described as neural control of
subsystems.
Muscles are programmed in response to
feedback from sensory cues from
ligaments.

29. Backpaincanresultfromdeficitin
controlofthespinalsegmentwhen
abnormallylargesegmentalmotions
causecompressionorstretchonneural
structuresorabnormaldeformationof
ligamentsandpainsensitivestructures.

30. Fact
As reported by various studies it is well
recognized that osseo ligamentous
spine is inherently unstable and requires
combination of muscle force and
stiffness to make it secure and stable
structure.
Dysfunction in any of these three
systems cannot be compensated for by
the others.

31. Pathogenesis of Disc Prolapse

34. Mechanism of Pain Production in Lumbar Disc
Herniation
Chemical
Neural
Chemical:ItisduetoreleaseofChemicalinflammatory
mediatorsasaresultofannulartear,discherniation.Release
canalsooccurincasesoffacetjointproblemandspinal
stenosis.MediatorsreleasedareInterleukin(IL)-1,(IL)-
8,TNF(Tumornecrosingfactor)α,SubstanceP.Inadditionto
painandinflammationTNFalsocontributestodegenerationof
disc.
Neural:Itisduetomechanicalcompressionofneural
structureseithernerverootorspinalcord.Compressionof
motornerveleadstoweaknessandthatofsensorynerve
leadstonumbness.

35. Types of pain in Disc Herniation
Discogenic: It is the one which occurs as a result
of damage to disc structure either because of
herniation,tears or compression leading to
release of inflammatory peptides there by causing
pain.
Radicular:Results from mechanical compression
of nerve root due to discal material and also due
to inflammation which leads to neural irritation
there by producing symptoms such as sensory
loss, motor weakness and paresthesia.

36. Causes
Obesity
Practicing Poor Posture
Tobacco Abuse
Mutation
Repetitive Mechanical Activities
Living Sedentary Life Style
Traumatic Injuries To Discs

37. Effect of Posture on Disc Load

38. Signs and Symptoms
The lumbar spine consists of the five
vertebrae in the lower part of the spine,
each separated by a disc, also called a
lumbar disc.
The discs in this part of the spine can
be injured by certain movements, bad
posture, being overweight and disc
dehydration that occurs with age.

39. Signs and Symptoms
Although the lumbar vertebrae are the
biggest and strongest of the spinal
bones, risk of lumbar injury increases
with each vertebrae down the spinal
column because this part of the back
has to support more weight and stress
than the upper spinal bones.

40. Signs and Symptoms
The lumbar disc is the most frequent site
of injury in several sports including
gymnastics, weightlifting, swimming and
golf, although athletes in general have a
reduced risk of disc herniation and back
problems.

41. Signs and Symptoms
Symptoms of disc herniation in the lower back are
slightly different from symptoms in the cervicalor
thoracicparts of the spine.
The spinal cord ends near the top lumbar vertebrae
but the lumbar and sacral nerve roots continue
through these spinal bones.
lumbar disc herniation may cause:
Lower back pain
Pain, weakness or tingling in the legs, buttocks
and feet
Difficulty moving your lower back
Problems with bowel, bladder or erectile function,
in severe cases

42. Clinical features

43. Clinical features

44. Clinical features

45. L4
Quads/Tibialis Anterior
Patellar reflex
Sensory Great toe and
medial leg

46. L5
Strength of Ankle and
great toe dorsiflexion
Extensor Hallucis
Longus
Sensory to dorsum of
foot

47. S1
Ankle reflexes and
sensation of posterior
calf and lateral foot
Peroneals/Gastroc
Achilles reflex
Sensory to lateral and
plantar foot

48. Diagnosis
Initial diagnosis of lumbar herniation generally is based on the symptoms of
lower back pain.
Need to examine sensation, reflexes, gait,postureand strength.
Gait Slow and Deliberate walk, holding their loins with hand.
Posture Deviation of Posture to one side Sciatic Scoliosis
Movement In flexion,extension,rotation and side flexion and Movt of Hip.
Muscle Strength Test :To strength of Specific muscles to look for signs of
pinched nerve.
Mayo tomes: For testing motor nerve root levels
Sensory Testing: To test ones ability to feel light touch, Protective
Sensations (pinprick,hot,cold).
Deep Tendon Reflexes: To look for decreased or absent reflex due to
nerve root compression.

50. Differential Diagnosis
Lumbar Spondylosis Pelvic Pathology
Facet Syndrome Vertebral Tumors
Spondylolisthesis Vascular Insufficiency
Lumbar Strain
Lumbar Sacralization
Pyriformis Syndrome
Sacroillitis
Discitis
Aortic Dissection
Epidural abscess
Tumors and arthritis of HIP Joint

51. Special Clinical Test frequently used
Straight Leg Raise Test/
Lasegue Test
Well Leg Raise Test
Bowstring Test
Slump Test

52. Bonnet Test
Prone Knee Bending Test
Belt Test

53. Patientmay also be suggestedforfollowingDiagnostic tests:
X-ray--High-energy radiation is used to take pictures of the
spine.
Magnetic Resonance Imaging (MRI)--An MRI provides
detailed pictures of the spine that are produced with a
powerful magnet linked to a computer.
Computed Tomography (CT) Scan--A CT scan uses a thin
X-ray beam that rotates around the spine area. A computer
processes data to construct a three-dimensional, cross-
sectional image.
Electromyography (EMG)--This test measures muscle
response to nervous stimulation.

54. Diagnostic Imaging
X RAY:
Plain radiographs reveal indirect
findings of disk degeneration in the
form of loss of height of the
intervertebral disk, vacuum
phenomenon in the form of gas in the
disk, and endplate osteophytes.
Moderate bulges appear as nonfocal
protrusion of disk material beyond the
borders of the vertebra; this is
typically broad based, circumferential,
and symmetric.

55. Discography :
A sterile procedure in
which dye is injected
into one of your
vertebral disc and
viewed under special
conditions (fluoroscopy).
The goal is to pinpoint
which disc(s) may be
causing your pain.
Doesn’t provide better
information than MRI in
case of nerve root
compromise

56. CT Scan:
CT scanning with
myelographyis
superior to either one
alone.

57. MRI:
Axial view:demonstrate
the relationship of the
disc herniation to the
midline and the neural
foramen
Saggital view:
demonstrate extension
of disc upward or
downward

58. Grade 1Herniation extends up
to or Less than 50% of Distance
From Non Herniated Posterior
aspect of Disc to Interfacet Line
Grade 2More than 50%of that
distance
Grade 3Herniation Extends
altogether beyond interfacet
line.
INTERFACET LINE

59. Myelography :
used in patient with
equivocal findings on
MRI or
in whom there may be
a significant element
of lateral recess
stenosis.
to better define the
anatomy.

60. EMG:
Electromyography (EMG) can pinpoint
which nerve root is impacted.
An EMG assess the electrical activity of a
nerve root and is sometimes recommended
for patients with back pain. Compression of
a nerve will also slow electrical conduction
along that nerve. EMG’s are also
sometimes useful to distinguish nerve
degeneration (neuropathy) from nerve root
compression (radiculopathy).

61. Diagnostic Nerve Block:
Itinvolvesnumbingaspecificnerveinvolved
incarryingpatientspainbymeansoflocal
anestheticinjectioninissmallamountsto
targetnerveandpatientisthenassessedfor
changeinpainsymptoms.Thishelpsin
confirmingpaingeneratingnerve.

62. Trans Cranial Magnetic
Stimulation:
It is used clinically to measure the
activity and function of specific brain
circuit in humans .It helps in measuring
the connection between primary motor
cortex and muscle to evaluate damage
from Stroke ,Multiple sclerosis, MND
etc. Also injuries and other disorders
effecting facial and other cranial nerves
and spinal cord. It uses electromagnetic
field generator placed near head which
produces small currents in the region of
brain.

63. Treatment
Conservative treatment of lower disc pain usually
is successful over time.
It includes:
Pain medication or pain therapies such as
ultrasound, massage or transcutaneous electrical
nerve stimulation
Anti-inflammatory medication such as aspirin,
ibuprofen and acetaminophen
Physical therapy
Steroid injections
Education in proper stretching and posture
Rest

64. Treatment
However, if your pain doesn't respond to
conservative treatment in two to four
weeks, your condition affects your bowel or
bladder function, or if it threatens
permanent nerve damage, your doctor may
suggest surgery.
Modern methods of surgery allow some
spine operations to be performed through
tiny incisions using miniature instruments
while a microimaging instrument called an
endoscope is used to view the surgery site

65. Treatment
Medication
Anti-inflammatory medicationto relieve pain and
inflamation such as Aspirin, Ibuprofen,Aclofenac
and Acetaminophenetc.
Muscle Relaxants to relieve spinal muscle spasm
such as Clorzaxazone,Carisoprodol,Tizanidine etc.
Opiodsto relive intense pain such as Tramadol.
Oral Steroids for short term to relieve of swelling.
Anti Depressants in chronic cases to block pain
messages from getting to your brain and increase
effect of endorphins body’s natural pain killers.
Gabapentin,Pragabalin.
Education in proper Posture
Rest

66. Treatment
Non Surgical /Conservative Treatment
Conservative treatment of lower disc pain usually is
successful over time.
It includes:
PhysicalTherapy
Pain medication or pain therapies
(Electrotherapeutics)ultrasound, massage or
transcutaneous electrical nerve stimulation, MWD,
Shock Wave Therapy etc
Spinal exercises Mackenzie back exercises,Buttler
Neural Mobilisation,Maitland and Mulligan Spinal
Mobilization, Core Stability Exercises etc.

67. Epidural Steroid injectionspotent anti-
inflammatory quickly relieve pain. Injected in
epidural nerve space.
Intradiscalprocedures: (Out Patient
Procedures)
Chemonucleolysis:Itinvolves introduction of
enzyme chymopapainin to nucleus pulposus
which decreases the swelling in disc and
provides meaningful relief.
Ozonucleolysis/Ozone discolysis:Itis by
means of injection of ozone in to troubled
disc .It works by reducing the ability of disc to
hold water. By inhibiting inflammatory
nocciceptors,it helps in increasing the
fibroblastic activity for repair and also
increases immunosupressor cytokinins.Also
helps in improving microcirculation.

68. Minimal Invasive
Procedures:
Nucleoplasty:Itreducesproduction
ofbreakdownproductswithindisc
whichbulgediscwall.ItusesCool
radiofrequency to interrupt
productionoftheseproductsand
graduallyreducediscbulge.
Laser Disectomy /Per cutaneous
laser disc decompression: Done
under C-Arm fluoroscopic guidance
with laser of different wavelengths.

69. Intra discal electrothermic
therapy(IDET):
MinimallyInvasiveOutpatient
proceduretotreatlowbackpain
causedbytearsorsmall
herniationsoflumbardisc.It
involvescauterizationofnerve
endingswithinthediscwallto
helpblockpainsignalsby
meansofelectrothermal
cathetersunderaccurate
temperature.

70. Treatment
Surgical Treatment
Only about 10 percent of adult lumbar disc patients
require surgery and even fewer children and
adolescents.
Objectives of Surgical Treatment:
1.Relief of Nerve Compression
2.Allowing the nerves to recover.
3.Relief of associated back pain.
4.Restoration of normal function.
Discectomy-Two Types 1.Microdisectomy
2.Endoscopic Disectomy:The surgery usually includes
removing the part of the disc that has squeezed
outside its proper place.
Laminectomy:The surgeon also may want to remove
the back part of the vertebrae, called the lamina.
Foramenotomy:To surgically open the foramen, the
holes on the side of the vertebrae through which the
nerves exit.

71. Treatment
LumbarFusion:Usedwhenpatientshave
symptomsfromdiscdegeneration,disc
herniationorspinalinstability.Itisonly
indicatedforrecurrentlumbardisc
herniation.Itinvolvesfusingtwoormore
bonestogetherintoasolidbonebymeans
ofnewfusioncagescrewwhicharebone
graftfilledhollowscrewsthathelpsboneof
spinetohealtogether.
ADR:ArtificialDiscReplacement(ADR)or
TotalDiscReplacement.Itinvolves
replacingdegeneratedintervertebraldisc
withartificialdevice.Usedforchronic
degenerativediscdisease.

72. Alternative Medicine
Chiropractic spinal
manipulation
Acupuncture/Dry Needling
Massage
Yoga

73. Treatment
Future Therapeutic modalities in
treatment of Disc herniation.
Bone Morphogenetic Protein :Has some potential
for treatment of disc disease. It has antiapoptotic
effect on cells of nucleus pulposus .It has also
shown to increase extracellular matrix production.
Stem Cell transplantation: It has emerged as
another promising treatment .In this autologous
disc derived chondrocytes are introduced into the
area of disc damage and has shown to increase
extracellular matrix.

74. GeneTherapy:Itinvolvestransductionof
genesthathavethepotentialtointerferewithdisc
degenerationoreveninduceregeneration.It
requiresidentificationofrelevantgenesthatplay
roleindiscdegenerationanddeliveringpotentially
therapeuticgenesintodisccells.

75. DO AND DONTS

76. THANK YOU