Too Much Weight Placed on Imaging to Diagnose Lumbar Spinal Stenosis

Pauline Anderson

January 15, 2010

January 15, 2010 — Surgeons are relying too heavily on imaging to diagnose lumbar spinal stenosis and to determine the need for surgery to correct this condition, a new commentary suggests.

In the article, appearing in the January 6 issue of the Journal of the American Medical Association, Andrew J. Haig, MD, professor of physical medicine and rehabilitation at the University of Michigan, Ann Arbor, and colleague Christy C. Tomkins, PhD, challenge North American Spine Society (NASS) guidelines that call for imaging when conservative treatments, such as physical therapy, steroid injections, and lifestyle changes, have failed.

"I'm definitely questioning whether MRI [magnetic resonance imaging] can positively make the diagnosis," Dr. Haig told Medscape Neurology. "In other words, I'm questioning whether a doctor should look at a photograph and make any decisions about whether that person has the problem."

MRI is "never conclusive," he said. "Arriving at a decision for surgery should be an iterative process rather than some simple cut-and-paste answer."

Minds Made Up

Too often, he said, "surgeons look at a bunch of films and when they walk in to see the patients they've already made up their mind" to do surgery, which probably leads to unnecessary operations. Each year, 90 of 100,000 older Americans undergo lumbar fusion surgery with a diagnosis of lumbar spinal stenosis being an "important driver" for the "exponential increase" in this procedure, said Dr. Haig.

An alternative for diagnosing spinal stenosis, he said, is electromyography (EMG), a procedure that allows physicians to check the health of muscles and nerves and can help determine causes of nerve pain. "EMG is very exciting because when EMG is positive for spinal stenosis, you can be pretty sure the person has it," said Dr. Haig.

In his commentary, Dr. Haig cited several articles, some of them his own, to support his assertion that imaging techniques such as MRI are not a reliable method for diagnosing spinal stenosis.

Compromised Methods

However, Thomas J. Gilbert, MD, a spine radiologist who was diagnosis/imaging chair of the NASS Clinical Guidelines Committee that wrote the lumbar spinal stenosis guidelines, believes these arguments are based on "severely compromised" methods.

"If he [Dr. Haig] wants to prove that an EMG would improve our selection process for surgery, I think that's worthy of study, but he needs to do the studies and prove that assertion. I don't think the literature we have right now nor his studies support that assertion."

Dr. Gilbert pointed out that to have a diagnosis of lumbar spinal stenosis, a patient not only has to have pain that worsens with walking and eases with resting or sitting but also a narrowing of the spinal canal. He agreed with Dr. Haig that patients should first attempt conservative therapies, but he defended the use of an MRI when these have been exhausted.

"If the patient has failed conservative therapy and has significant pain and disability, then you do an MRI or CT [computed tomography] to see if there's a narrowing that can be decompressed by surgery, because if there's nothing that can be decompressed then surgery is not an option," he added.

Key Steps

In his editorial, Dr. Haig said there are 3 key steps to evaluate older patients with suspected spinal stenosis. The first is to find and treat what is not stenosis. "The presence of leg pain does not necessarily mean that the clinically most relevant symptoms are the result of nerve root compression," he writes. Patients with diabetic neuropathy or peripheral vascular disease may be misdiagnosed as having spinal stenosis, and those with back pain may have reversible disorders, such as depression or obesity, that may exacerbate pain.

Another step should be to define and treat the effects of stenosis. Older patients respond well to such things as exercise, counseling, and lifestyle changes, said Dr. Haig.

A third step is to treat presumed stenosis without a definitive diagnosis. Noninvasive approaches, such as physical therapy (including lumbar flexion, body weight–supported treadmill walking, and muscle coordination training), pain-relieving approaches (including heat, ice, electrical stimulation, massage, and ultrasonography), and epidural steroid injections, should be considered. Medications should also be considered, although these increase the risk of falls, cognitive deficits, and bladder dysfunction in older patients.

Time, too, can be an important treatment for stenosis. Treatment choices should be based on current pain and disability "not on anticipation of future pain or complications," said Dr. Haig.

Dr. Gilbert believes all these steps are perfectly appropriate. "The assertion that you should not use imaging alone to make a decision about surgery is absolutely correct; you need to have a clinical syndrome and you need to fail conservative therapy, and only then do you do imaging to select who might benefit from surgery."

Not Rushed To Surgery

For his part, James Bean, MD, past-president of the American Association of Neurological Surgeons, now in private practice in Lexington, Kentucky, said he, too, agrees that symptoms can be treated with exercise, weight loss, physical therapy, and other approaches. But the commentary, he said, "is assuming everyone who gets a scan and sees a surgeon is rushed off to surgery, and that's wrong."

And although he agreed that the number of lumbar fusion surgical procedures is increasing, Dr. Bean disagreed with the reason for this cited by Dr. Haig. "I don’t disagree with the exponential increase for fusions; I do disagree that fusion is the treatment for stenosis."

He said that most fusion procedures treat lumbar degenerative disk disease and that lumbar stenosis is mostly treated with lumbar decompression.

Factors that affect referrals from primary care physicians to neurosurgeons include fear of "overlooking something" and being held liable for it and patient demand for surgery, Dr. Bean added. "People want to know what’s wrong; they don’t want doctors to just guess."

Dr. Haig reports that through Rehabilitation Team Assessments LLC, a company he formed, he consults with hospitals and healthcare systems on rehabilitation program development, including BlueCross/Blue Shield of Michigan and the Center for Healthcare Research and Transformation. Other outside interests include consulting with Best Doctors Inc and other groups on case reviews, and he advises in the development of a muscle stimulator for Mainstay Medical. Dr. Christy C. Tompkins has disclosed no relevant financial relationships.

JAMA. 2010;303:71-72.

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