Degenerative Lumbar Spine Disease

Transcription

1 Beth Israel Deaconess Medical Center A Member of Caregroup Harvard Medical School Degenerative Lumbar Spine Disease Michael Barnett, HMS III Core Radiology Clerkship BIDMC PCE

2 Overview Patient Presentation: Ms. S Clinical Work-up of Low Back Pain Menu of Radiological Tests Lumbar Spine Anatomy Patient Imaging: Ms. S Discussion of Degenerative Spine Disease 2

3 Our Patient, Ms. S 88 year old woman with chronic low back pain 4 year history of back pain Radiation: left hip, thigh, calf, ankle L5 dermatome distribution The pain is inconstant Relief with sitting Ms. S is normally an active woman Controls pain with Celebrex and epidural steroid injections Presents to the pain clinic after 3 epidural steroid injections failed to provide relief 3

4 Clinical DDx Low Back Pain Musculoskeletal Bone Fracture, spondylosis, spondylolisthesis Joints Facet joint degeneration Disks Herniation, annular tears Ligaments Ligament hypertrophy or ossification Muscles Strain Systemic Disease Infection Osteomyelitis, spondylodiscitis, epidural abscess Inflammatory Arthritis RA, AS, Psoriasis Neoplastic Primary tumors, metasstatic cancecr, lymphoma, multiple myeloma Visceral Condition CV: Aortic aneurysm GU: stones, infection GI: pancreatitis, ulcers Gyn: Endometriosis, PID Adapted from Stern, SD, Cifu AS and Altkorn D, From Symptom to Diagnosis, McGraw-Hill: NY,

5 Low Back Pain A challenging issue in outpatient medicine Point prevalence as high as 33% Lifetime prevalence as high as 80% Fifth most common reason for physician visits in US 1 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 5

6 Low Back Pain Work-Up Imaging can create more questions than answers Especially 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 :18,

7 However, it is important to be aware of red flags which necessitate imaging 7

8 Red Flags with LBP Fracture Age >70 History of osteoporosis Trauma Corticosteroid use Tumor Age >50 History of previous cancer Unexplained weight loss Infection Fever, chills Recent skin or urinary infection Immunosuppresion IVDU Recent spine surgery Neurologic Sciatica New onset urinary/fecal incontinence Abnormal neurologic exam: motor, sensory, reflexes 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, Accessed 10/17/2008 8

9 Menu of Tests for Low Back Pain Assessment More Commonly Used: Plain Films CT and CT Myelography MRI Bone 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 9

10 L-Spine Plain Films Pros: Fast, no contraindications Good for evaluating bony structures Trauma Bony degeneration Spine alignment Cons: Poor soft tissue discrimination Frequently will need CT/MRI anyway Radiation exposure Lumbar spine plain X-ray film Image courtesy Dr. Kleefield, BIDMC 10

11 CT and CT Myelography Pros: Excellent resolution of bony anatomy Trauma eval Degenerative bony changes Good for visualizing calcifications and gas Myelography: useful for LBP eval when MRI is contraindicated Cons: Poor differentiation of soft tissues within the spine Radiation exposure Myelography: invasive procedure Lumbar Spine CT Image courtesy Dr. Kleefield, BIDMC 11

12 Magnetic Resonance Imaging (MRI) Pros: Excellent soft tissue discrimination No radiation exposure Most sensitive modality for evaluating the spine Cons: Less sensitive for evaluating bony anatomy and calcifications Contraindicated for patients with metal devices, etc. Expensive Lumbar Spine MRI T2 Image from PACS, BIDMC 12

13 Simplified LBP Diagnostic Algorithim Red Flags? NO Conservative management, reevaluate in 4 weeks YES Concerned about tumor, infection, or acute neurologic deficits? OR Trauma MRI CT and/or Plain Films Subacute neurologic symptoms? (i.e sciatica) YES No further evaluation MRI NO YES Re-eval in 4-6 weeks Improvement? MRI 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, Accessed NO 13

14 Lumbar Spine: Sagittal Anatomy T12 L1 L2 L3 L4 L5 Ligamentum flavum Note thickness Vertebral disk Note central high T2 signal (NP) and low peripheral signal (AF) Spinal canal Note the width and amount of CSF Normal Lumbar Spine MRI Sagittal T2 MRI Image from PACS, BIDMC Schematic images from Drake, Vogl and Mitchell, Gray s Anatomy for Students, New York: Elsevier,

15 Lumbar Spine: Bone and Joint Anatomy aka facet joint Images from Drake, Vogl and Mitchell, Gray s Anatomy for Students, New York: Elsevier,

16 Lumbar Spine: Axial Anatomy Psoas NP AF Paraspinal Image courtesy of Dr. Kleefield Lumbar Spine MRI Axial T2 Image from PACS, BIDMC Ligamentum flavum - Note the thickness here Facet joint - Note how the joint surfaces align and the thin layer of high signal fluid between layers of low signal cartilage Vertebral 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 16

17 Due to her neurologic symptoms and lack of response to pain control Ms. S had an MRI of her lumbar spine

18 Ms. S: Extradural Masses and Spinal Stenosis on MRI T12 L1 Findings Spinal canal stenosis from L2-L5 due to extradural masses L2 L3 Protruding low signal masses in posterior spinal canal L2-L5 L4 L5 * * Disks - Low signal intensity from L2-L5 in addition to extension of disk into the spinal canal Normal MRI Sagittal T2 Ms. S Lumbar Spine MRI Sagittal T2 Vertebrae - Posterior displacement of the L4 vertebrae Images from PACS, BIDMC 18

19 Differential Diagnosis: Extradural Mass Degenerative Disk herniation Spinal stenosis Ligament ossification Synovial cyst Neoplastic Primary vertebral tumor Others: meningioma, neurogenic tumor Lymphoma Metastasis Infection Osteomyelitis Epidural abscess Trauma Epidural scar Iatrogenic Hematoma Fracture fragment Others Lipomatosis Paget s disease Extramedullary hematopoesis Amyloidosis Granulomatous diseases Image from PACS, BIDMC Adapted from: Reeder, M. Gamuts in Radiology: Fourth Edition. Springer

20 Ms. S: Facet Arthropathy on MRI Ms. S Normal L4 vertebral body Psoas NP * AF Paraspinal PACS, BIDMC MRI Axial T2 PACS, BIDMC MRI Axial T2 PACS, BIDMC Low signal mass in posterior spinal column Spinal canal - marked reduction of CSF signal and compression of canal Facet joint arthropathy - osteophyte formation and distortion of joint alignment 20

21 Ms. S: Disk Bulge on MRI Ms. S Normal L3-L4 disk Psoas Psoas NP AF Paraspinal muscles Paraspinal MRI Axial T2 PACS, BIDMC MRI Axial T2 PACS, BIDMC Disk - Bulging of disk beyond margin of L4 vertebrae Facet joint arthropathy - osteophyte formation and distortion of joint alignment

22 Ms. S s Diagnosis: Degenerative Spinal Stenosis Most likely: degenerative spinal stenosis Broad radiological differential However, characteristic set of findings present Osteophytes + misalignment: facet joint arthropathy Low signal posterior masses: ligamentum flavum hypertrophy Disc extension into canal: disc bulge Posterior vertebrae displacement: spondylolisthesis Narrowed by history Chronic nature of pain Relief with sitting (neurogenic claudication) Advanced age No other red flags: no evidence of infection, tumor, trauma Neurological signs possibly consistent with stenosis present at L4-L5, but most severe stenosis is L3-L4 22

23 Let s discuss in more detail the degenerative spine disease found in Ms. S s imaging

24 Facet joint arthropathy and ligamentum flavum hypertrophy Degenerative change in facet joints can be due to: Osteoarthritis Disk degeneration Ligamentum flavum hypertrophy Due to vertebral instability Joint changes only present in a few percent of asymptomatic patients Katz JN and Harris, MB. Lumbar Spinal Stenosis, NEJM : Image from Katz and Harris NEJM

25 Companion Patient #1: Facet joint arthropathy Companion Patient #1 Ms. S * * Axial T2 MRI Image courtesy Dr. Kleefield, BIDMC Axial T2 MRI PACS, BIDMC Hypertrophic bone formation (CT>MRI) Joint space narrowing Associated: ligamentum flavum hypertrophy Not seen here: subchondral sclerosis (CT>MRI) 25

26 Disk Herniation Many asymptomatic individuals have evidence of disk herniation Often spontaneously regresses If herniation is symptomatic, results in symptoms in nerve root inferior to level of herniation i.e L3-L4 herniation --> L4 radiculopathy Different types of herniation Disk Bulge (technically not herniation), Protrusion and Extrusion 26

27 Ms. S: Disk Bulge Ms. S Circumferential increase in diameter without annulus rupture (not a true herniation) Axial T2 MRI PACS, BIDMC 27

28 Companion Patient #2: Disk Protrusion Companion Patient #2 Focal bulge without complete annulus rupture Axial T2 MRI Image courtesy Dr. Kleefield, BIDMC 28

29 Companion Patient #3: Disk Extrusion Companion Patient #3 Nucleus pulposus ruptures through annulus fibrosus and extends into epidural space Sagittal T2 MRI Image courtesy Dr. Kleefield, BIDMC 29

30 Spondylolisthesis Spondylolisthesis = slippage of vertebrae anteriorly or posteriorly Can be caused by congenital factors, degenerative disease, trauma, or systemic disease Severe displacement result in radiculopathy by compression or stretch Also contributes to spinal canal stenosis 30

31 Companion Patient #4: Spondylolisthesis Ms. S Companion Patient #4 T12 L1 L2 L3 L4 L5 Sagittal T2 MRI Sagittal CT Lumbar Spine Two examples of posterior spondylolisthesis Images courtesy Dr. Kleefield, BIDMC and PACS, BIDMC 31

32 Conclusions Ms. S s continued symptoms are consistent with an L5 radiculopathy However, her imaging is not consistent with this She has more severe degeneration elsewhere What can be done? Surgery can be considered Continued pain management Alternative therapies: acupuncture, exercise Sometimes imaging can confuse the clinical picture, especially with low back pain 32

33 Acknowledgements Dr. Gillian Lieberman - for her help, encouragement and this opportunity Dr. Alice Fisher - for guidance Dr. Jonathan Kleefield - for many images and encouragement Maria Levantakis - making everything happen Larry Barbaras - webmaster 33

34 References (1) Carragee, EJ Persistent Low Back Pain, NEJM :18, (2) Katz JN and Harris, MB. Lumbar Spinal Stenosis, NEJM : (3) Modic MT and Ross JS, Lumbar Degenerative Disk Disease, Radiology : (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 (6) Reeder, M. Gamuts in Radiology: Fourth Edition. Springer (7) Weissleder, R et al Primer of Diagnostic Imaging: Third Edition Philadelphia: Mosby, (8) Stern, SD, Cifu AS and Altkorn D, From Symptom to Diagnosis, McGraw-Hill: NY, (9) Lieberman, G Primary Care Radiology:Radiologic assessment of low back pain, Accessed 10/17/