Transcript Slide 1

Does the Increase in Spine
Surgery Reflect an Increase in
Disease?
Sohail K. Mirza, MD MPH
Professor, Department of Orthopedics and
Joint Professor, Department of Neurological Surgery
University of Washington
NASS Format
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UW Tech Transfer (Synthes)
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Depuy, Surgical Dynamics, Synthes
(to UW Dept. of Orthopedics)
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X Depuy, Synthes (to Dept of Orthop)
Disclosure
• I hold the University of Washington Surgical
Dynamics Endowed Chair for Spine Outcomes
Research (approx $90k in 2006).
• I receive royalties for surgical drills licensed by
Synthes Spine through UW Office of Technology
Transfer (approx. $16k in 2006).
• UW Department of Orthopedics receives spine
fellowship support, research support, and
endowments from Synthes Spine and Depuy Spine. I
work with the spine fellows and am involved with two
of the research projects supported by these funds.
• I prepared all the slides.
Sohail K. Mirza, MD, MPH
Professor, Department of Orthopedics and Sports Medicine
and Department of Neurological Surgery, University of Washington
Harborview Medical Center, Box 359798
325 Ninth Avenue
Seattle, WA 98104
Email: [email protected] Tel: 206 731 3658 Fax: 206 731 3227
Does the increase in spine surgery
reflect an increase in disease?
no
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Show site abstracts
1,865,196 results on 5/17/2002
707,000,000 results on 6/ 5/2007
26,100,000 results on 1/15/2008
New Technologies
Resolution of pedicle screw litigation
New posterior fixation devices
New anterior fixation devices
Cages
Bone graft substitutes
Bone morphogenetic proteins
Minimally invasive spine surgery
Computer-assisted surgery
Artificial discs
New Clinical Knowledge: RCTs
1. Fusion results in better pain and function
outcome in patients with spondylolisthesis.
2. Fusion with instrumentation results in a
higher fusion rate.
3. Instrumentation is associated with a
higher complication rate.
4. Artificial disc replacement may avoid
complications of fusion.
Normal
Degeneration
Biochemical Changes
•
•
•
•
Water content
Proteoglycan content
Chondroitin to sulfate ratio
Collagen network
Collagen
Repetitive Sequence (GLY – X – Y )
X: proline
Y: hydroxyproline
Triple helix
Tryptophan substitution?
Ala-Kokko
Science 1999
JAMA 2001
Spine 2002
Col9A2: Glutamine  Tryptophan
Disc disease 6/157 (vs. 0/174 controls)
COL9A3: Arginine  Tryptophan
Disc disease 12% (vs. 5% controls)
Trp allele  3X risk for disc disease
Association with Collagen IX Tryptophan Alleles
Matsui, Mirza, Eyre JBJS-B 2004
Association with Collagen IX Tryptophan Alleles
Spinal Stenosis with Spondylolisthesis
Potential Physiological Basis for
Disc-associated Back Pain
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•
•
•
•
Initiation of a chemotactic response
Vascular ingrowth
Increased sensory innervation
Endplate cartilage defects
Inflammation
Variation
Ratio of Back Surgery Rates
Deyo, Mirza CORR 2006
Variation in Lumbar Fusion Rates
Per 1000 Medicare
Enrollees 2002-2003
Weinstein, Lurie et al Spine 2006
Geographical Variations in Spine Surgery Rates
(rate per 1,000 enrollees within the 2001 U.S. Medicare population)
Low-rate states
Hawaii
Vermont
New Jersey
New York
Low-rate cities
Terre Haute, IN
Bronx, NY
Honolulu, HI
Wilkes-Barre, PA
Manhattan, NY
McAllen, TX
Huntington, WV
Hackensack, NJ
Lebanon, NH
Newark, NJ
East Long Island, NY
Paterson, NJ
Deyo, Mirza CORR 2006
1.8
2.6
2.7
2.7
High-rate states
Montana
Oregon
Idaho
Wyoming
1.6
1.7
1.8
2.0
2.1
2.1
2.2
2.2
2.3
2.3
2.3
2.4
High-rate cities
Ft. Collins, CO
Eugene, OR
Idaho Falls, ID
Slidell, LA
Amarillo, TX
Newport News, VA
Billings, MT
Greeley, CO
Rapid City, SD
Casper, WY
Boise, ID
Bend, OR
Overall U.S. Rate
4.5
7.4
7.5
8.4
9.2
8.0
8.0
8.2
8.2
8.3
8.3
8.4
8.6
8.6
9.5
9.9
10.2
Variation in Lumbar Fusion Rates
Rate Per 1000 Medicare Enrollees
Weinstein, Lurie et al Spine 2006
Variation in Lumbar Surgery Rates
Laminectomy
Fusion
Variation in
Regional Rates
Weinstein, Lurie et al Spine 2006
8X
20X
Causes of Variation
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Lack of scientific evidence
Financial Incentives and Disincentives
Clinical Training and Professional Opinion
New technology
Weinstein, Lurie et al Spine 2006
Growth
Procedure Comparisons (2001)
Lumbar Fusions for
Degenerative
Disease
Number of procedures, 2001
(listed as primary procedure)
Hip
Knee
Replacement Arthroplasty
122,316
329,900
363,536
113%
13%
15%
4.5
5.4
4.5
4
4
4
Mean total hospital charges, 2001
$39,900
$28,234
$25,309
Median total hospital charges
$26,887
$24,017
$22,335
$4.9 Billion
$9.3 Billion
$9.2 Billion
% increase in volume 1996-2001
Mean hospital stay, days
Median hospital stay, days
National Hospital Bill, 2001
(mean charges times no. of
hospitalizations)
Deyo, Nachemson, Mirza NEJM 2004
Annual Number of Operations in U.S.
Data from National Inpatient Sample, HCUP/AHRQ
Deyo, Nachemson, Mirza NEJM 2004
Inpatient Medicare Reimbursement
Weinstein, Lurie et al Spine 2006
Inpatient Medicare Reimbursement
1992
2003
30 per 100k
110 per 100k
Spending for Lumbar Fusion $75 million
$482 million
Percent Spending for Fusion 14%
47%
Rate of Lumbar Fusion
Weinstein, Lurie et al Spine 2006
Deyo, Mirza et al Spine 2005
Deyo, Mirza et al Spine 2005
Deyo, Mirza et al Spine 2005
Deyo, Mirza et al Spine 2005
Deyo, Mirza et al Spine 2005
Deyo, Mirza et al Spine 2005
Office Visits for Back Pain
Deyo, Mirza, Martin Spine 2006
National Health Interview Survey 2002
Deyo, Mirza, Martin Spine 2006
National Health Interview Survey 2002
Deyo, Mirza, Martin Spine 2006
National Health Interview Survey 2002
Deyo, Mirza, Martin Spine 2006
US Prevalence of Back Pain
Deyo, Mirza, Martin Spine 2006
US Prevalence of Back Pain
Deyo, Mirza, Martin Spine 2006
Potential Financial
Conflicts of Interest
Favorable Results in
Industry-Sponsored Research
Sponsor
Odds Ratio
Sponsor of study
For-profit organizations
Manufacturer of drugs
Spinal device manufacturer
Jacobs, Galante, Mirza, Zdeblick JBJS 2006
3.6
5.3
8.0
3.3
95% CI
2.6 to 4.9
2.0 to 14.4
1.1 to 53.2
2.4 to 4.5
Favorable Results
Field
Spine
Hip
Knee
Industry-funded
73%
93%
75%
Independent
44%
37%
20%
“Surgeons have often touted procedures
that ultimately proved to be disappointing.”
April 8, 2002
April 8, 2002
“Trisha Bryant assumed that the procedures her surgeon
recommended were necessary and had been validated by
research. I, too, made that assumption….If Trisha had
explored the medical literature, however, she would have
discovered that every aspect of her case– the
interpretation of the MRI scan, the diagnosis of spinal
instability, the rationale for fusing vertebrae, the impending
discography– was
controversial…”
April 8, 2002
“… within the surgical profession there’s a curious gap between rhetoric and reality.”
“Each approach to
diagnosis and
treatment is
essentially a
franchise, and there
are too many
franchises battling.”
Seth Waldeman
Pain Medicine, HSS
“Spinal instability is
routinely given as a
diagnosis to these
patients with
chronic lower-back
pain. It is a term
used to justify an
operation. And it is
a great diagnosis,
because it can’t be
directly disproved.”
Surgeon who performs two to
three spinal fusions a week.
Conclusions
•
Biological basis for “discogenic back pain” is not
known.
•
Rates of lumbar fusion for chronic back pain have
increased without increase in prevalence of back pain.
•
Investigator-sponsor financial conflicts are common.
Thank you.