Disclosures Low Back PainPathophysiology Depuy/Synthes Spine - - PowerPoint PPT Presentation

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Bobby KB Tay MD Clinical Professor Department of Orthopaedic Surgery University of California at San Francisco Director UCSF Spine Fellowship Medical Director UCSF Spine Center

Low Back Pain…Pathophysiology and Management

Disclosures

Depuy/Synthes Spine honoraria Stryker Spine consultant, honoraria, royalties Fellowship support: AOSpine, Nuvasive, Globus

Low Back Pain

(Zdeblik, Rothman-Simeone, The Spine, 1999)

430% point prevalence 4Annual incidence 15% 480-90% lifetime prevalence 413 million visits for chronic LBP 4most frequent cause of activity limitation in persons under 45 4only 1% require prolonged treatment 4Primary cause of disability in pts < 50 y

Martin, JAMA 2008 US Expenditures for Spine Patients

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Normal Disc Biomechanics

4vertical loading

4nucleus is compressed and absorbs load 4annulus on tension

4segmental motion

4flexion/extension 4bending 4axial rotation

4first two decades

4fluid content of nucleus is high 4annulus intact 426% of asymptomatic 15 year olds have MR evidence of disc degeneration (Tertti et

al, Radiology 1991)

The Aging Disc

4third decade

4dehydration of the nucleus 4loss of clear distinction between nucleus and annulus 4with loss of disc compressibility, the annulus is more susceptible to tearing

The Aging Disc The Aging Disc

4fourth decade

4continued dehydration and collapse of the nucleus 4loss of disc height 4annular tears 4internal disc derangement 4dark disc disease

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The Aging Disc

4age 50

4at autopsy, 85% have disc degeneration (Tertti, Spine 1991)

4spondylosis

4normal degenerative process

• f the spine

4unclear why only some have pain

Pathophysiology of LBP

4Relationship between DDD and LBP is poorly understood 4Pain may be caused by

4Alteration in biomechanics 4Sensitization of nerve endings by chemical mediators 4Neurovascular ingrowth

Chemical irritation

4NP can incite inflammatory and degenerative changes consistent with chemical damage. 4NO, phospholipaseA2, 4Cytokines

4IL-1, IL-6, 4TNF-alpha, PGE2

4MMP1 and MMP3

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Role of DRG

4Link between intrathecal spinal nerve and extrathecal peripheral nerve 4Abundant blood supply 4Secrete calcitonin-gene related peptide, substance-P 4High density of glutamate receptors 4Degradation of HNP by endogenous enzymes may potentiate pain at DRG.

Role of DRG

4Dorsal portions of DRG receive segmental sensory innervation from upper DRG via the sympathetic trunk and lower DRG via the Sinuvertebral nerve

Role of SVN

4Arises from ventral root and gray rami communicantes 4Innervates vertebral canal, PLL, ventral dura, posterior annulus, blood vessels

Facet Joints

4Innervated by medial branches of dorsal primary rami at the segmental level 4Medial descending branch travels caudally and innervates muscles, ligaments, and facet joint below.

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Common causes of LBP and LE pain in adults

4Intervertebral Disc Herniation 4Degenerative Spondylolisthesis 4Spinal Stenosis 4Lumbar Degenerative Disc Disease

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SPORT Studies

4Pooled population of randomized and observational pts

4775 treated surgically, 416 non-op

4Difference in QALYs over 2 years was 0.21 in favor of surgery. 4Surgery was more costly than nonoperative care

4difference in total cost was $14,137

4The cost per QALY gained for surgery relative to nonoperative care

4$34,355 (95% CI: $20,419–52,512) using Medicare population surgery costs.

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SPORT Trial

4Randomization of patients with degenerative spondylolisthesis/ spinal stenosis to operative vs. non-operative care 4Observation cohort 4Operative care:

4Limited decompression

4Open or Endoscopic

4Non-operative care

4PT, ESI, Pain medications 4Journal to track care

SPORT Studies

4Stenosis- with and without spondylolisthesis

4Tosteson A, et al: Ann Int Med 16 December 2008 Volume 149/ 12,| Pages 845-853

4Surgery for stenosis (decompressive laminectomy 81%) improved QALY more than non-operative care

4 634 patients with stenosis, 394 (62%) had surgery 4QALY gain 0.17 4Cost of $77 600 (CI, $49 600 to $120 000) per QALY gained

4Surgery for degenerative spondylolisthesis (fusion 93%) improved QALY more than non-operative care

4601 patients with degenerative spondylolisthesis, 368 (61%) had surgery, 4QALY gain 0.23 4Cost of $115 600 (CI, $90 800 to $144 900) per QALY gained.

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61 y.o woman Eosinophilic granuloma Osteoid Osteoma

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Adult Degenerative Scoliosis

4Degenerative scoliosis is characterized by:

4Adult onset of deformity (de novo) 4Degenerative changes within the deformity:

4Stenosis 4Spondylolisthesis 4Rotatory subluxation 4Lumbar hypolordosis 4Osteoporosis

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Results

443 patients identified with greater than 2 years of clinical follow-up

434 female, 9 male

4Average Age: 63.3yrs (range 40-81) 4Clinical follow-up: 54.9mos (range 24-129) 4Radiographic follow-up: 34.9mos (range 1-97)

Results

489% report improvement of pain after surgery 467% report improvement of function after surgery 492% would definitely or probably repeat choose surgery again

Diagnosis of Discogenic LBP (Zdeblik, Rothman-

Simeone, The Spine, 1999)

4physical examination 4plain radiography 4magnetic resonance imagery 4provocative discography

4morphology 4disc pressure 4response at the involved level 4response at the adjacent levels

Diagnosis of Discogenic LBP (Zdeblik, Rothman-

Simeone, The Spine, 1999)

4physical examination 4plain radiography 4magnetic resonance imagery 4provocative discography

4morphology 4disc pressure 4response at the involved level 4response at the adjacent levels

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Diagnosis of Discogenic LBP (Zdeblik, Rothman-

Simeone, The Spine, 1999)

4physical examination 4plain radiography 4MRI 4provocative discography

4morphology 4disc pressure 4response at the involved level 4response at the adjacent levels

Diagnosis of Discogenic LBP (Zdeblik, Rothman-

Simeone, The Spine, 1999)

4physical examination 4plain radiography 4magnetic resonance imagery 4provocative discography

4morphology 4disc pressure 4response at the involved level 4response at the adjacent levels

Natural History

(Rhyne, et al, Spine 1995)

425 patients with low back pain and positive discograms followed over five years 468% showed clinical improvement 424% with worse LBP and disability

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Management-NON OPERATIVE

4Physical therapy, lumbar stabilization 4r/o sacroiliac and iliolumbar sources 4Job/behavior modification

Spinal Arthrodesis and Clinical Outcome

Surgery for degenerative lumbar spondylosis (Cochrane Review) Gibson JNA, Waddell G, Grant IC Reviewers' conclusions: There is no scientific evidence about the effectiveness of any form of surgical decompression or fusion for degenerative lumbar spondylosis compared with natural history, placebo, or conservative treatment.

Citation: Gibson JNA, Waddell G, Grant IC. Surgery for degenerative lumbar spondylosis (Cochrane Review). In: The Cochrane Library, Issue 2 2002. Oxford: Update Software.

4Comparison of clinical effectiveness of surgical stabilization (Fusion/Ligamentotaxis) to intensive rehabilitation in patients with chronic low back pain 4Surgical group with statistically better ODI improvement (Estimated mean difference=-4.1) 4No difference in SF-36 or functional test (Shuttle) 4No clear evidence that spinal stabilization was better than intensive rehabilitation

Provocative Discography

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Discogenic Pain

4Nerve endings: outer third & lateral annulus; PLL & ligamentum flavum 4Pain can be provoked when injecting normal

• r abnormal disc

Results:

• 50% (4/8) of patients had a positive PD, but no CLBP.
• 85% (7/8) of patients experienced concordant pain on PD to

their usual discomfort from bone graft sites.

• Conclusions:
• The ability of a patient to separate spinal from nonspinal

sources of pain on PD is questioned.

• A response of concordant pain on PD may be less meaningful

than often assumed.

4Carragee Spine 2000

447 post-discectomy patients 420 asymptomatic, 27 recurrent symptoms 440% non painful Post-discetomy patients had pain at

• perated segment during discography

463% of patients with recurrent sx had positive disc

415/27 had concordant pain.

4Carragee Spine 2000

4Patients with neck pain and no low back pain 4Positive in 10% with good cervical surgery outcome 4Positive in 40% of patients with poor result after neck surgery 4Positive in 80% of patients with somatization disorder

Discography and Psychology

4Block Spine 1996

4Pts with elevated scores on hysteria and hypochondriasis on MMPI were more likely to report pain on injection of a nondisrupted disc.

4Ohnmeiss Spine 1995

4Pain with unusual pain drawings and elevated MMPI are more likley to report pain on injection of non-distrupted disc

4Carragee

440% patients with abnormal psych profile reported back pain 12 months after discography.

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Discography and surgical outcome

Study Concordant disco Calhoun JBJS 1988 Blumenthal Spine 1988 Linson Spine 1991 Newman Spine 1992 Derby 1999 Madan JS Disord Tech 2002 88% good results 74% good results 64%-83% good 86.1% good 89% favorable 75% good 41 pts had surgery without disco with 81% good results 52% good results with nonconcordant but +disco

Treatment Options

4IDET 4discectomy 4decompression 4fusion +/- instrumentation 4spine arthroplasty?

Inconsistent results !!!!

Long-term Follow-up of Lower Lumbar Fusion Patients

462 patients with median 33 year follow-up 472% response rate 445% had adjacent segment instability 442% had adjacent spinal stenosis 4these rates were significantly higher than normal controls 4NO correlation between radiographic findings and clinical symptoms

(Lehmann, Spratt, Spine 1987)

Lumbar Total Disc Replacement

Charite

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Clinical Results: ProDisc

(Thierry Marnay, 8th IMAST, 2001)

4of 58 patients at 7-11 years follow-up

4low back pain VAS 8.5 -> 3.2 4radicular pain VAS 7.1 -> 2.1

453% male 433% two level replacements 466% had previous spine surgery 464% Completely satisfied, 29% satisfied 4no displacement or subsidence 45 patients required revision to ASF for persistent pain

4all of these five had already had 2 or more low back surgeries

SB Charite III

4Retrospective case series 485 cases/78 available for followup at mean 11 years 434 male/44 female 4Mean age 50 years 420% heavy laborers, 40% previous surgery 437 single level, 40 two level, 1 three level 4>90% “good to excellent” results Coventry outcome

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Prevention

4Posture 4Posture 4Posture 4Your body’s neutral spine

Basic Exercises

4Squat 4Hamstring Stretch 4Abdominal Strength/ Awareness