What Patients and Referring Providers Need to Know

By Joseph H. Miller, MD, FAANS — Advanced Neurosurgery Associates, Northside Hospital Gwinnett

Ok you see your lumbar MRI report and are alarmed because it says “severe spinal stenosis.” Patients hear severe and assume the canal is collapsing and surgery is next. Referring colleagues see the same line and reasonably wonder how urgently — or how aggressively — does this need to be addressed. In reality, canal narrowing on an image is a description of space, not automatically a diagnosis of what is generating the patient’s pain. Radiographic stenosis is frequently asymptomatic. I do not operate an MRI… I operate on people!

If your spine surgeon gives you a measurement of your remaining spinal canal diameter and tells you that is why you need surgery – politely excuse yourself from the room and run! Don’t let that person operate on you. A measurement is not an indication for surgery. 

My approach to stenosis, like the rest of the work I do at Northside, starts from the same place: identify what’s actually generating the pain, exhaust the appropriate non-surgical options, and reserve surgery for the patients who absolutely require surgery.

What Is Spinal Stenosis?

Lumbar spinal stenosis is a narrowing of the space available for the spinal cord (which ends at about L1 or 2) and nerve roots. Spinal stenosis is normally caused by some combination of the disc, facet hypertrophy, ligamentum flavum thickening, and bone/osteophytes. You can also have narrowing from the shifting of the spine (spondylolisthesis or with traumatic fractures) or from other causes like infections or tumor. The central canal, the lateral recesses, and the foramina can each be involved, alone or together.

The Websteresque definition from The North American Spine Society (NASS) guideline defines spinal stenosis as “a condition in which there is diminished space available for the neural and vascular elements in the lumbar spine secondary to degenerative changes in the spinal canal.”  

Who Gets It: Onset and Demographics

Degenerative spinal stenosis is predominantly a condition of later middle age and beyond. The Spine Patient Outcomes Research Trial (SPORT) stenosis cohort — surgical candidates with at least 12 weeks of neurogenic claudication or radicular leg symptoms and confirmatory imaging, without degenerative spondylolisthesis — had a mean age of 65 years (Weinstein et al., NEJM 2008). Weinstein and colleagues also note that spinal stenosis is the most common reason for lumbar spine surgery in adults over 65, and that radiographic stenosis is frequently asymptomatic — which is why clinical correlation is so important.

A few patterns are worth knowing:

  • Neurogenic claudication is the classic presentation: buttocks or legs that complain on walking or standing that gets better with rest or flexion.
  • A single-level disc herniation in a 40-year-old is a different disease, even if the MRI report also says “stenosis.” The chance of a disc herniation spontaneously resorbing is higher than hypertrophied facet joints getting smaller.

It is not exclusively an “older person’s” MRI finding. A congenitally small canal can declare itself earlier (Peyton Manning’s older brother had this condition).

The Numbers Behind Spinal Stenosis

In medicine there are trials to see what works and what does not. The big trial for spine surgery is a trial known as the SPORT trial. This was a randomized trial and treatment was decompressive surgery versus usual nonsurgical care.

  • Crossover was high — which is the first thing to understand before anyone quotes “surgery works” or “surgery doesn’t.” At two years, 67% of patients randomized to surgery had undergone surgery, and 43% of those randomized to nonsurgical care had also undergone surgery.
  • The as-treated analysis, combining both cohorts and adjusting for confounders, showed a significant advantage for surgery by three months on all primary outcomes; those differences remained significant at two years. 
  • The as randomized analysis showed no effect

The honest reading of SPORT is: patients who actually underwent decompression improved more than those who did not.

Recognizing the Symptoms

Lumbar stenosis typically causes:

  • Activity-related buttocks or leg pain, heaviness, or fatigue that builds with walking or standing
  • Relief with sitting, resting, or flexion (the leaning over the shopping-cart sign is a cliché because it is real)
  • Variable low-back pain, which may or may not be the dominant complaint
  • Numbness or tingling that is often broader and less strictly dermatomal than a single-root disc herniation
  • Occasional focal weakness, more often after a long walk than first thing in the morning

Symptoms that warrant urgent evaluation rather than a routine stenosis work-up:

  • New bowel or bladder dysfunction, or numbness in the saddle region — this raises concern for cauda equina syndrome, a surgical emergency
  • Progressive or significant motor weakness
  • Rapidly declining walking tolerance that is no longer just “I have to sit on the bench”
  • Fever, unexplained weight loss, or a history of cancer or IV drug use, which shift the differential toward infection or malignancy
  • In the cervical spine: hand clumsiness, gait imbalance, hyperreflexia — that is myelopathy, not lumbar claudication

How We Diagnose Spinal Stenosis

Diagnosis starts with a thorough history and physical exam. I want to know how far the patient can walk, what stops them, what position relieves it, whether the pulses are intact, and whether the neurologic exam shows a consistent root or a more diffuse picture. A normal exam does not rule out the syndrome. An abnormal MRI does not confirm it.

Imaging then confirms and localizes:

  • Standing plain radiographs, including flexion-extension when I am thinking about instability
  • MRI as the preferred noninvasive study to show central, lateral recess, and foraminal compromise and to exclude other neural compression
  • CT or CT myelography when MRI is contraindicated or inconclusive
  • Vascular studies when the story could just as easily be the arteries (vascular claudication)
  • EMG when the picture is mixed with neuropathy, or when I need to separate an old root injury from an active one

The single most important diagnostic principle, given NASS Grade I on MRI narrowing versus symptoms, is correlation. The imaging findings have to match the patient’s clinical presentation. Treating an MRI report in isolation is one of the most common ways patients end up with an operation they did not need.

Treatment: Why We Start Conservative

A large fraction of patients referred for a “stenosis surgery evaluation” improve without surgery. I see that outcome as a success! — not a missed surgical opportunity. I only operate on about 8% of patients that I see in my office.

  • Activity modification that keeps the patient moving — brief relative rest during a flare, not prolonged bed rest, which delays recovery
  • Physical therapy and strength training focused on flexion-biased walking tolerance, core and hip strength, and a realistic home program
  • Medications — NSAIDs as first-line when the gut and kidneys will tolerate them, short courses of a muscle relaxant when appropriate, and deliberate avoidance of long-term opioids for a mechanical, positional problem
  • Weight management and smoking cessation, which help the patient whether or not they ever have an operation
  • Interventional procedures — epidural steroid injections for a defined radicular complaint; they can be both diagnostically important (ie help us figure out where the pain is actually coming from) and therapeutic (help the patient)

SPORT’s nonsurgical arm was usual care, not a highly protocolized program, and many of those patients still improved. That is worth remembering when “failed conservative care” is framed as two weeks of a recumbent bike… while conservative that is not what I consider treatment.

When Surgery Enters the Conversation

Surgery is appropriate for a defined subset of patients: those whose clinical syndrome correlates with the imaging and who have failed an adequate trial of conservative care, those with a progressive neurologic deficit, and the patient with cauda equina syndrome.

When surgery is indicated, the usual operation is a decompression — laminectomy or laminotomy, open or minimally invasive — aimed at the levels that match the exam and the image. Fusion is not the default add-on for stenosis without instability. A coexisting degenerative slip is a separate decision, not an automatic instrumented construct.

The goal in every surgical discussion is matching the smallest effective intervention to the specific pathology — not decompressing five levels because the report listed five, and not offering surgery at all when the evidence points back toward continued conservative management.

A Note to Referring Providers and Patients

Know that a referral to my office does not default to a surgical recommendation. My role is to determine, together with you, whether a patient’s anatomy and clinical picture justify surgery — and when they don’t, I am glad to be a second set of eyes on the conservative plan rather than a detour around it. I am also happy to provide second opinions for a patient who has been recommended a multi-level decompression or a fusion for stenosis.

If you are a patient with questions about a stenosis diagnosis, or a colleague looking to discuss a referral, please reach out to our office at Advanced Neurosurgery Associates, Northside Hospital Gwinnett.

Joseph H. Miller, MD FAANS

Advanced Neurosurgery Associates

2200 Medical Center Blvd Ste 350

Lawrenceville, GA 30046

Phone: 678-312-2700

Selected Sources

  • Weinstein JN, Tosteson TD, Lurie JD, et al. Surgical versus nonsurgical therapy for lumbar spinal stenosis. N Engl J Med. 2008;358(8):794-810. PMID: 18287602.
  • Kreiner DS, Shaffer WO, Baisden JL, et al. An evidence-based clinical guideline for the diagnosis and treatment of degenerative lumbar spinal stenosis (update). Spine J. 2013;13(7):734-743. PMID: 23830297.