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>  News Releases >   2006 >   October

Huge increase in spinal fusion nationwide

Dartmouth College Office of Public Affairs • Press Release
Posted 10/17/06 • Susan Knapp • (603) 646-3661

Is it justified based on available medical evidence, Dartmouth researchers ask

Rates of lumbar fusion in the United States have increased more than 250 percent over the past decade, according to a study appearing in the Nov. 1, 2006 edition of the journal, Spine. Yet, study authors from Dartmouth Medical School (DMS) and Dartmouth-Hitchcock Medical Center (DHMC) raise concerns that without scientific or clinical evidence to prove such procedures are effective for most low back conditions, there is no way of knowing if the increase is warranted.

Ratio of Rates of Lumbar Fusion to the U.S. Average
by Hospital Referral Region (2002-03)
Graphic: Ratio of Rates of Lumbar Fusion to the U.S. Average

And, with variations in rates of the surgery as much as 20 times greater in some regions of the U.S. than in others, they call on the medical, academic, corporate and governmental communities to come together to support the necessary research into these conditions that affect millions of people each day.

The cost increase in spinal fusion has been more than 500 percent among Medicare patients alone, rising from $75 million in 1992 to $482 million in 2003. While other common procedures such as laminectomy and disectomy have actually decreased slightly in recent years, rates of lumbar fusion rose from 0.3 per 1000 Medicare enrollees in 1992 to 1.1 per 1000 in 2003. Lumbar or spinal fusion is a procedure designed to stabilize the spine by fusing bones together and theoretically providing protection and relief of back pain for degenerative joints in the back.

"What's most disquieting about these findings is that we really haven't advanced our knowledge as to whether fusion, for several back conditions, works for our patients," said lead author James N. Weinstein, a surgeon, professor, and chair of the Department of Orthopaedics at DMS and DHMC. "Lumbar fusion now accounts from almost 50 percent of all back surgery performed in the U.S. Clearly, we are doing more and more of it, but we have not provided the scientific or clinical evidence to support these procedures."

Weinstein is also a member of the Center for the Evaluative Clinical Sciences (CECS) and Director of the Institute for Informed Patient Choice. He and his co-authors point to the lack of randomized clinical trials as the reason for the uncertainty about the procedure's efficacy and effectiveness.

"Left alone, practice variations will not go away. Expansion of the research agenda will require not only the early evaluation of new technologies and new theories about the use of current technologies, but also the ongoing evaluation of existing practice," they write. Addressing this problem will require the work of academic medical centers, physicians, and national funding and regulatory agencies, such as the National Institutes of Health, Centers for Medicare & Medicaid Services and the Food and Drug Administration, they argue.

In addition to variation between rates in the U.S. and the rest of the world, the study shows "striking" variation in regions within the U.S. For example, in 2002, lumbar fusion was performed on 4.6 out of 1,000 Medicare patients in Idaho Falls, ID, while in cities such as Bangor, ME, Covington, KY, and Terre Haute, IN, an average of 1.0 patients per 1,000 underwent the procedure. Other regions with unusually high rates of the surgery included Missoula, MT, Mason City, IA, Bradenton, FL, and Casper, WY.

Reasons for the geographic variations internationally and nationally are not fully understood, but the authors suggest that "lack of scientific evidence, financial incentives and disincentives to surgical intervention, and difference in clinical training and professional opinion" are underlying causes.

Co-authors of the paper, "United States' Trends and Regional Variations in Lumbar Spine Surgery: 1992-2003" are Jon D. Lurie, MD, MS; Patrick R. Olson, MD; Kristen K. Bronner, MS; and Elliott Fisher, Ph.D. Findings were based on analysis of Medicare claims and enrollment data for Medicare beneficiaries over age 65 in each of the 306 US Hospital Referral Regions between 1992 and 2003.

More information about the Dartmouth Atlas of Health Care may be found at

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