Degenerative Lumbar Spine Disease

Michael Barnett, HMS IIICore Radiology Clerkship

BIDMC PCE

Beth Israel DeaconessBeth Israel Deaconess HarvardHarvardMedical CenterMedical Center MedicalMedicalA Member of A Member of CaregroupCaregroup SchoolSchool

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OverviewOverview

Patient Presentation: Ms. SClinical Work-up of Low Back PainMenu of Radiological TestsLumbar Spine AnatomyPatient Imaging: Ms. SDiscussion of Degenerative Spine Disease

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Our Patient, Ms. S

88 year old woman with chronic low back pain4 year history of back pain

Radiation: left hip, thigh, calf, ankle L5 dermatome distribution

The pain is inconstantRelief with sitting

Ms. S is normally an active womanControls pain with Celebrex and epidural steroid injections

Presents to the pain clinic after 3 epidural steroid injections failed to provide relief

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Clinical DDx Low Back PainMusculoskeletal

BoneFracture, spondylosis, spondylolisthesis

JointsFacet joint degeneration

DisksHerniation, annular tears

LigamentsLigament hypertrophy or ossification

MusclesStrain

Adapted from Stern, SD, Cifu AS and Altkorn D, From Symptom to Diagnosis, McGraw-Hill: NY, 2006.

Systemic DiseaseInfection

Osteomyelitis, spondylodiscitis, epidural abscess

Inflammatory ArthritisRA, AS, Psoriasis

NeoplasticPrimary tumors, metasstatic cancecr, lymphoma, multiple myeloma

Visceral ConditionCV: Aortic aneurysmGU: stones, infectionGI: pancreatitis, ulcersGyn: Endometriosis, PID

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Low Back PainA challenging issue in outpatient medicinePoint prevalence as high as 33%Lifetime prevalence as high as 80%Fifth most common reason for physician visits in US1 in 5 patients report substantial limitations in activity due to LBP

Wilson JF, In The Clinic: Low Back Pain. Ann Internal Medicine 2008: 148(9):ITC5-1-ITC5-16

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Low Back Pain Work-UpImaging can create more questions than answersEspecially in the elderly, degenerative spinal is incredibly common in asymptomatic subjects

Disk herniation: 25-50%Disk degeneration: 25-70%Annular tears: 14-33%

Most LBP resolves spontaneously, as do many radiographic findings

Carragee, EJ Persistent Low Back Pain, NEJM 2005 352:18, 1891-8.

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However, it is important to be aware of red flags which necessitate imaging …

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Red Flags with LBPFracture

Age >70History of osteoporosisTraumaCorticosteroid use

Adapted from Stern, SD, Cifu AS and Altkorn D, From Symptom to Diagnosis, McGraw-Hill: NY, 2006 and Lieberman, G Primary Care Radiology:Radiologic assessment of low back pain, http://eradiology.bidmc.harvard.edu/primarycare/index.html Accessed 10/17/2008

InfectionFever, chillsRecent skin or urinary infectionImmunosuppresionIVDU Recent spine surgery

NeurologicSciaticaNew onset urinary/fecal incontinenceAbnormal neurologic exam: motor, sensory, reflexes

TumorAge >50History of previous cancerUnexplained weight loss

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Menu of Tests for Low Back Pain Assessment

More Commonly Used:Plain FilmsCT and CT MyelographyMRIBone Scintigraphy - assessing for metastatic cancer

Less Commonly Used:Plain Myelography - supplanted by CT myelography

Discography - contrast injection into disk to assess for disk source of pain

Spinal Angiogram - assess vasculature of spine

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L-Spine Plain Films

Pros:Fast, no contraindicationsGood for evaluating bony structures

TraumaBony degenerationSpine alignment

Cons:Poor soft tissue discriminationFrequently will need CT/MRI anywayRadiation exposure

Image courtesy Dr. Kleefield, BIDMC

Lumbar spine plain X-ray film

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CT and CT MyelographyPros:

Excellent resolution of bony anatomy

Trauma evalDegenerative bony changesGood for visualizing calcifications and gas

Myelography: useful for LBP evalwhen MRI is contraindicated

Cons:Poor differentiation of soft tissues within the spineRadiation exposureMyelography: invasive procedure

Image courtesy Dr. Kleefield, BIDMC

Lumbar Spine CT

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Magnetic Resonance Imaging (MRI)

Pros:Excellent soft tissue discriminationNo radiation exposureMost sensitive modality for evaluating the spine

Cons:Less sensitive for evaluating bony anatomy and calcificationsContraindicated for patients with metal devices, etc.Expensive

Image from PACS, BIDMC

Lumbar Spine MRI T2

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Simplified LBP Diagnostic Algorithim

Red Flags?

Conservative management, re-

evaluate in 4 weeks

Concerned about tumor, infection, or acute neurologic

deficits?

YES

MRI

TraumaCT and/or Plain Films

Subacute neurologic symptoms?(i.e sciatica)

YESMRI

NO

Re-eval in 4-6 weeks Improvement? MRI

YES

No further evaluation

NO

OR

NO

Adapted from Stern, SD, Cifu AS and Altkorn D, From Symptom to Diagnosis, McGraw-Hill: NY, 2006 and Lieberman, G Primary Care Radiology:Radiologic assessment of low back pain, http://eradiology.bidmc.harvard.edu/primarycare/index.html Accessed 10/17/2008

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Lumbar Spine: Sagittal Anatomy

L5

L4

L3

L2

L1

T12

Ligamentum flavumNote thickness

Spinal canalNote the width andamount of CSF

Vertebral diskNote central high T2 signal (NP) and low peripheral signal (AF)

Normal Lumbar Spine MRI Sagittal T2

Schematic images from Drake, Vogl and Mitchell, Gray’s Anatomy for Students, New York: Elsevier, 2005. MRI Image from PACS, BIDMC

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Lumbar Spine: Bone and Joint Anatomy

Images from Drake, Vogl and Mitchell, Gray’s Anatomy for Students, New York: Elsevier, 2005.

aka facet joint

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Lumbar Spine: Axial Anatomy

Ligamentum flavum - Note the thickness hereFacet joint - Note how the joint surfaces align and the thin layer of high signal fluid between layers of low signal cartilageVertebral disk - Note the clean, concave margin of the annulus fibrosus (AF) next to the dura of the spinal canal. Nucleus pulposus = NP. Neural foramina - This is an important area because the nerve roots exit here; note the space between the vertebral body (VB) and the facet joints here

Psoas

Paraspinal

NP

AF

Image from PACS, BIDMCImage courtesy of Dr. Kleefield Lumbar Spine MRI Axial T2

Due to her neurologic symptoms and lack of

response to pain control Ms. S had an MRI of her lumbar

spine …

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Ms. S: Extradural Masses and Spinal Stenosis on MRI

L5

L4

L3

L2

L1

T12

Normal

FindingsSpinal canal stenosis from L2-L5 due to extradural masses

Protruding low signal masses in posterior spinal canal L2-L5

Disks - Low signal intensity from L2-L5 in addition to extension of disk into the spinal canal

Vertebrae - Posterior displacement of the L4 vertebraeMs. S

**

Images from PACS, BIDMC

Lumbar Spine MRI Sagittal T2MRI Sagittal T2

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Differential Diagnosis: Extradural Mass

DegenerativeDisk herniationSpinal stenosisLigament ossificationSynovial cyst

NeoplasticPrimary vertebral tumorOthers: meningioma, neurogenic tumorLymphomaMetastasis

InfectionOsteomyelitisEpidural abscess

TraumaEpidural scarIatrogenicHematomaFracture fragment

OthersLipomatosisPaget’s diseaseExtramedullaryhematopoesisAmyloidosisGranulomatousdiseases

Adapted from: Reeder, M. Gamuts in Radiology: Fourth Edition. Springer 2003.

Image from PACS, BIDMC

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Ms. S: Facet Arthropathy on MRI

Low signal mass in posterior spinal columnSpinal canal - marked reduction of CSF signal and compression of canal

Facet joint arthropathy - osteophyte formation and distortion of joint alignment

MRI Axial T2

L4 vertebral body

*

PACS, BIDMC

PACS, BIDMC

Psoas

Paraspinal

NP

AF

MRI Axial T2

Normal Ms. S

PACS, BIDMC

Ms. S: Disk Bulge on MRI

Disk - Bulging of disk beyond margin of L4 vertebraeFacet joint arthropathy - osteophyte formation and distortion of

joint alignment

MRI Axial T2

L3-L4 disk

Psoas

Paraspinalmuscles

Psoas

Paraspinal

NP

AF

MRI Axial T2

PACS, BIDMC

Normal Ms. S

PACS, BIDMC

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Ms. S’s Diagnosis: Degenerative Spinal Stenosis

Most likely: degenerative spinal stenosisBroad radiological differential

However, characteristic set of findings presentOsteophytes + misalignment: facet joint arthropathyLow signal posterior masses: ligamentum flavum hypertrophyDisc extension into canal: disc bulgePosterior vertebrae displacement: spondylolisthesis

Narrowed by history Chronic nature of pain Relief with sitting (neurogenic claudication) Advanced ageNo other red flags: no evidence of infection, tumor, trauma

Neurological signs possibly consistent with stenosispresent at L4-L5, but most severe stenosis is L3-L4

Let’s discuss in more detail the degenerative spine

disease found in Ms. S’s imaging

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Facet joint arthropathy and ligamentum flavum hypertrophy

Degenerative change in facet joints can be due to:

OsteoarthritisDisk degeneration

Ligamentum flavumhypertrophy

Due to vertebral instability

Joint changes only present in a few percent of asymptomatic patients

Image from Katz and Harris NEJM 2008

Katz JN and Harris, MB. Lumbar Spinal Stenosis, NEJM 2008 358:818-25

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Companion Patient #1: Facet joint arthropathy

PACS, BIDMC

Hypertrophic bone formation (CT>MRI)Joint space narrowing

Associated: ligamentum flavum hypertrophyNot seen here: subchondral sclerosis (CT>MRI)

Image courtesy Dr. Kleefield, BIDMC

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Axial T2 MRIAxial T2 MRI

Companion Patient #1 Ms. S

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Disk Herniation

Many asymptomatic individuals have evidence of disk herniationOften spontaneously regressesIf herniation is symptomatic, results in symptoms in nerve root inferior to level of herniation

i.e L3-L4 herniation --> L4 radiculopathyDifferent types of herniation

Disk Bulge (technically not herniation), Protrusion and Extrusion

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Ms. S: Disk Bulge

Circumferential increase in

diameter without annulus rupture

(not a true herniation)

PACS, BIDMC

Ms. S

Axial T2 MRI

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Companion Patient #2: Disk Protrusion

Focal bulge without complete annulus rupture

Image courtesy Dr. Kleefield, BIDMC

Companion Patient #2

Axial T2 MRI

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Companion Patient #3: Disk Extrusion

Nucleus pulposus ruptures through annulus fibrosus and extends into epidural space

Image courtesy Dr. Kleefield, BIDMC

Companion Patient #3

Sagittal T2 MRI

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Spondylolisthesis

Spondylolisthesis = slippage of vertebrae anteriorly or posteriorly

Can be caused by congenital factors, degenerative disease, trauma, or systemic diseaseSevere displacement result in radiculopathyby compression or stretchAlso contributes to spinal canal stenosis

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Companion Patient #4: Spondylolisthesis

L5

L4

L3

L2

L1

T12

Two examples of posterior spondylolisthesisImages courtesy Dr. Kleefield, BIDMC and PACS, BIDMC

Ms. S Companion Patient #4

Sagittal T2 MRI Sagittal CT Lumbar Spine

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ConclusionsMs. S’s continued symptoms are consistent with an L5 radiculopathyHowever, her imaging is not consistent with this

She has more severe degeneration elsewhereWhat can be done?

Surgery can be consideredContinued pain managementAlternative therapies: acupuncture, exercise

Sometimes imaging can confuse the clinical picture, especially with low back pain

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AcknowledgementsAcknowledgements

Dr. Gillian Lieberman - for her help, encouragement and this opportunity Dr. Alice Fisher - for guidanceDr. Jonathan Kleefield - for many images and encouragementMaria Levantakis - making everything happenLarry Barbaras - webmaster

Dr. Gillian Lieberman - for her help, encouragement and this opportunity Dr. Alice Fisher - for guidanceDr. Jonathan Kleefield - for many images and encouragementMaria Levantakis - making everything happenLarry Barbaras - webmaster

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References

(1) Carragee, EJ Persistent Low Back Pain, NEJM 2005 352:18, 1891-8.(2) Katz JN and Harris, MB. Lumbar Spinal Stenosis, NEJM 2008 358:818-25.(3) Modic MT and Ross JS, Lumbar Degenerative Disk Disease, Radiology 2007 245: 43-61.(4) Wilson JF, In The Clinic: Low Back Pain. Ann Internal Medicine 2008: 148(9):ITC5-1-ITC5-16.(5) Rumboldt Z, Degenerative Disorders of the Spine, Semin Roentgenology 2006 327-361.(6) Reeder, M. Gamuts in Radiology: Fourth Edition. Springer 2003. (7) Weissleder, R et al Primer of Diagnostic Imaging: Third Edition Philadelphia: Mosby, 2003. (8) Stern, SD, Cifu AS and Altkorn D, From Symptom to Diagnosis, McGraw-Hill: NY, 2006. (9) Lieberman, G Primary Care Radiology:Radiologic assessment of low back pain, http://eradiology.bidmc.harvard.edu/primarycare/index.html Accessed 10/17/2008