Degenerative Disorders of Lumbar Spine

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Lower back and leg painLower back and leg pain

Bao HengBao Heng

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Lumbar disc herniationLumbar disc herniation

Lumbar spinal stenosisLumbar spinal stenosis

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Lumbar disc herniationLumbar disc herniation

 Anatomy Anatomy

Clinical featuresClinical featuresRadiological examRadiological exam

Differential diagnosisDifferential diagnosisTreatmentTreatment

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 Anatomy Anatomy

Intervertebral discIntervertebral disc

1.1. Annulus fibrosus Annulus fibrosus

2.2. Nucleus pulposusNucleus pulposus

3.3. End plateEnd plate

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 Anulus fibrosus Anulus fibrosus

Anulus fibrosus makes up peripheralAnulus fibrosus makes up peripheral

portion of disk structureportion of disk structure

Composed of fibrocartilage and type IComposed of fibrocartilage and type I

collagencollagen

Anulus is wider anteriorly than posteriorlyAnulus is wider anteriorly than posteriorly 

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Nucleus pulposusNucleus pulposus

Nucleus pulposus consists of a network of Nucleus pulposus consists of a network of 

delicate collagenous fibers in a mucoprotein geldelicate collagenous fibers in a mucoprotein gel

Nucleus has a high water content,apparentlyNucleus has a high water content,apparentlythe result of imbibition by the gel;the result of imbibition by the gel;

It functions to resist compressive loads;It functions to resist compressive loads;

water content declines with advancing agewater content declines with advancing age

Gradual loss of proteoglycan content explainsGradual loss of proteoglycan content explains

the loss of water w/ agingthe loss of water w/ aging

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Disc pressure / failureDisc pressure / failure

Intradiscal pressure is higher when sittingIntradiscal pressure is higher when sittingthan when standing; - sitting-leaningthan when standing; - sitting-leaningforward > sitting > standing > lying on sideforward > sitting > standing > lying on side

> supine;> supine;Rotation combined w/ flexion are the worstRotation combined w/ flexion are the worst

positions for disc injury;positions for disc injury; It is elevated by bending forward, bendingIt is elevated by bending forward, bending

to side, lifting, coughing, sneezing, andto side, lifting, coughing, sneezing, andstraining;straining;Asymmetric & cyclic loading combined w/Asymmetric & cyclic loading combined w/

lateral bend, compression, and flexion arelateral bend, compression, and flexion arerisk factors for disk herniation;risk factors for disk herniation; 

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Sciatic nerveSciatic nerve

 Anterior branchs of L4,L5,S1-3 Anterior branchs of L4,L5,S1-3

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L4 rootL4 root

••Foot inversion (tibialis anterior m.)Foot inversion (tibialis anterior m.)

••Patellar reflexPatellar reflex

••Medial aspect of foot sensationMedial aspect of foot sensation

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L5 rootL5 root

••Great toe extension (extensor hallicusGreat toe extension (extensor hallicus

longus m.)longus m.)

••No reflexNo reflex

••Dorsum (top) of foot sensationDorsum (top) of foot sensation

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S1 rootS1 root

••Foot eversion (peroneus longus m.)Foot eversion (peroneus longus m.)

••Achilles tendon reflexAchilles tendon reflex

••Lateral foot sensationLateral foot sensation

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Posterolateral disc herniationPosterolateral disc herniation 

Protruded disc usuallyProtruded disc usuallycompresses next lower nerve ascompresses next lower nerve asthat nerve crosses level of discthat nerve crosses level of disc

in its path to its foramenin its path to its foramen

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Central (posterior) herniationCentral (posterior) herniation

In the lower lumbar segments, centralIn the lower lumbar segments, central

herniation may result in S1 radiculopathyherniation may result in S1 radiculopathy

Cauda equina syndromeCauda equina syndrome

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Far lateral disc herniationFar lateral disc herniation

Compress the nerve root above the level of theCompress the nerve root above the level of theherniation (hence a L4-L5 far lateral herniationherniation (hence a L4-L5 far lateral herniation

may result in a L4 radiculopathy)may result in a L4 radiculopathy)Occurs in 6-10% of all lumbar disc herniations;Occurs in 6-10% of all lumbar disc herniations;

L4 nerve root is most often involved;L4 nerve root is most often involved; Patient typically have intense radicular painPatient typically have intense radicular pain

(sciatic 25% and femoral 75% of the time)(sciatic 25% and femoral 75% of the time)

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Far lateral disc herniationFar lateral disc herniation

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Symptoms and signs

Low back pain with radiation of

severe pain down the back of the

leg to the ankle and foot.

Neurological signs such as motor

and sensory loss and occasionally

bladder involvement.

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Spasm of the spinal muscles with

tenderness over the lower lumbar

spine on the side of the lesion.The muscular spasm may produce a

scoliosis.

There may be a history of previous

episodes of back pain and sciaticaor of a previous injury.

P t i f th L4/5

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Protrusion of the L4/5

disc

Protrusion of the L4/5 disc may cause L5

root pressure with pain radiating down the

leg to the dorsum of the foot.

Numbness on the outer side of the calf andmedial two-thirds of the dorsum of the

foot

Weakness of dorsiflexion, particularly

of the foot and toes.

P t i f th

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Protrusion of the

L5/S1

The S1 nerve root is compressed

Pain and numbness on the outer side ofthe foot and under side of the heel.

Weakness of both eversion and

antarflexion of the foot

The ankle jerk is diminished or absent

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Protrusion of the L3/4

Protrusion of the L3/4 disc may

cause pressure on the L4 nerve root

Numbness over the front of the kneeand leg

The knee jerk is diminished.

Weakness of the knee extensors.

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Central protrusion

Central protrusion of a lower lumbar disc

can press on the cauda equina and lead to

urinary retention.

On examination there is usually perianal

numbness and a patulous anus.

Emergency decompression is essential to avoid

permanent damage to sphincter innervation.

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Cauda equinaCauda equina

The spinal cord ends in the lumbar area andThe spinal cord ends in the lumbar area and

continues through the vertebral canal ascontinues through the vertebral canal as

spinal nerves. Because of its resemblancespinal nerves. Because of its resemblance

to a horse's tail, the collection of theseto a horse's tail, the collection of these

nerves at the end of the spinal cord isnerves at the end of the spinal cord is

called the cauda equina. These nerves sendcalled the cauda equina. These nerves send

and receive messages to and from theand receive messages to and from the

lower limbs and pelvic organs.lower limbs and pelvic organs.

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Limitation of lateral flexion of the

lumbar spine to the same side will be

most marked with a protrusion lateral

to the nerve root

while limitation of lateral flexion to

the opposite side will be most marked

with a protrusion medial to the nerve

root.

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Straight Leg RaiseStraight Leg Raise 

In a normal person, this can be done toIn a normal person, this can be done to

about 75 or 80 degrees of flexion at theabout 75 or 80 degrees of flexion at the

hip without sharp pain radiates down tohip without sharp pain radiates down tothe leg.the leg.

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Well leg or cross leg sign: if there is a leftWell leg or cross leg sign: if there is a left

sided herniation, raising the right leg maysided herniation, raising the right leg may

cause pain to shoot down the course of thecause pain to shoot down the course of theleft sciatic nerve.left sciatic nerve.

Sciatic stretch test: this test is performedSciatic stretch test: this test is performed

after a straight leg raising test by lowering theafter a straight leg raising test by lowering the

affecting leg a few degrees belowaffecting leg a few degrees belowthe point .the point .

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RadiographsRadiographs

 Traction spursTraction spurs 

Disc space narrowingDisc space narrowing 

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C TC T

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MRIMRI

There is a 29% prevalence of discThere is a 29% prevalence of disc

herniation in asymtomatic individualsherniation in asymtomatic individuals

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MRIMRI

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Differential diagnosis

Secondary tumours and 

 multiple myeloma of the

lumbar spine which usuallycause vertebral destruction

with sparing of the discs.

Fractures and infections

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Natural HistoryNatural History

Prognosis of disc herniation is generallyPrognosis of disc herniation is generally

good regardless of treatment;good regardless of treatment;

Patients operated on for proven discPatients operated on for proven disc

herniations improved more rapidly thanherniations improved more rapidly than

patients treated non operatively;patients treated non operatively; 

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Natural HistoryNatural History

Within 4-5 years both operative andWithin 4-5 years both operative and

non operative treatment groups willnon operative treatment groups will

generally have comprable neurologicgenerally have comprable neurologicrecovery; hence long term resultsrecovery; hence long term results

are similar w/ or w/o surgery;are similar w/ or w/o surgery;

Of all patients who sustain acuteOf all patients who sustain acutesciatica, less than 25% will requiresciatica, less than 25% will require

surgery;surgery;

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TreatmentTreatment

Nonoperative treatmentNonoperative treatment

Pain relief is best achievedPain relief is best achievedby immobilizing the spine andby immobilizing the spine and

strengthening the back musclesstrengthening the back muscles

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Nonoperative treatment

Bed rest

Nonsteroidal anti-inflammatory

agentsActive physical therapy

Skin traction for sciatic irratation

Epidural steroid injection

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Epidural abscess

Male, 43 yrs , fever ,painMale, 43 yrs , fever ,pain After Epidural steroid injectionAfter Epidural steroid injection

compulsive positioncompulsive position Abscess

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SurgerySurgery

Opened surgeryOpened surgery

Minimally invasive surgeryMinimally invasive surgery

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ComplicationsComplications

InfectionsInfections

RecurrenceRecurrence

InstabilityInstability

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Postoperative discitisPostoperative discitis

Preoperative

postoperative

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Lumbar instabilityLumbar instability 

10 years after surgery10 years after surgery

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Lumbar stenosisLumbar stenosis

Spinal stensosis is a narrowing of theSpinal stensosis is a narrowing of the

spinal canal or neural foramina producingspinal canal or neural foramina producing

root ischemia and neurogenic claudicationroot ischemia and neurogenic claudication

Although degenerative spondylolisthesisAlthough degenerative spondylolisthesis

is common cause of stenosis, 10% of is common cause of stenosis, 10% of 

adults > 65 yrs may have this finding &adults > 65 yrs may have this finding &many are asymptomatic;many are asymptomatic;

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Clinical FindingsClinical Findings 

 Patients are usually 60 years or older;Patients are usually 60 years or older; Unilateral or bilateral leg pain, w/ or Unilateral or bilateral leg pain, w/ or 

without back pain;without back pain;

Pain occurs when the patient is uprightPain occurs when the patient is uprightand particularly when walkingand particularly when walking

Typical symptom is leg pain, numbness,Typical symptom is leg pain, numbness,and weakness developing after patientand weakness developing after patient

walks a predictable distance; - patientwalks a predictable distance; - patientseeks relief by sitting, leaning forward toseeks relief by sitting, leaning forward to"relieve pressure"relieve pressure

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Phalen testPhalen test 

With patient upright, bend the patient intoWith patient upright, bend the patient into

extension for a full minuteextension for a full minute

This should accentuate the spinal stenosis;This should accentuate the spinal stenosis;

Positive test will produce a crescendo of legPositive test will produce a crescendo of leg

symptoms followed by rapid relief of thesesymptoms followed by rapid relief of these

symptoms when the patient flexes forward,symptoms when the patient flexes forward,

places his hands on examinationplaces his hands on examinationtable, and places one foot on stooltable, and places one foot on stool

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CT scan:CT scan:

Evaluate for lateral stenosis & centralEvaluate for lateral stenosis & central

stenosisstenosis

Dural sac w/ AP diameter of < tenDural sac w/ AP diameter of < ten

millimeters is consistent w/ clinicalmillimeters is consistent w/ clinical

syndrome of lumbar stenosis;syndrome of lumbar stenosis;

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Surgical TreatmentSurgical Treatment 

DecompressionDecompression 

Laminae are minimally trimmed for Laminae are minimally trimmed for 

exposure;exposure; Includes widening of lateral recess;Includes widening of lateral recess;

Removal of medial rim of facetsRemoval of medial rim of facets

Adult DegenerativeAdult Degenerative

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gg

SpondylolisthesisSpondylolisthesis 

Often occurs as a result of degenerativeOften occurs as a result of degenerativedisc disease and facet deficiency;disc disease and facet deficiency;

It is often associated w/ intersegmentalIt is often associated w/ intersegmental

instability and w/ central stenosis;instability and w/ central stenosis; Involves L4-L5 level four times more oftenInvolves L4-L5 level four times more often

than the L5/S1 level;than the L5/S1 level;Often causes radiculopathy related toOften causes radiculopathy related to

nerve compression within the foramen (ie,nerve compression within the foramen (ie,L4/L5 spondylithesis will cause a L4L4/L5 spondylithesis will cause a L4radiculopathy)radiculopathy)

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Dynamic radiographsDynamic radiographs 

Flexion-Extension X-raysFlexion-Extension X-rays

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Non Operative TreatmentNon Operative Treatment 

NSAIDSNSAIDS

Epidural steroidsEpidural steroids

BracingBracing

Change of job typeChange of job type

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SurgerySurgery

Decompression of the nerve rootsDecompression of the nerve roots

Stabilization by posterolateral fusionStabilization by posterolateral fusion

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