Why an x-ray or MRI may not reveal what's causing your back pain
About two years ago I wrote a column in the Kitsap Sun designed to be a public service announcement, highlighting several shortcomings of diagnostic imaging (like x-rays, MRIs, etc.) for back pain. ("When it comes to back pain, weigh imaging carefully," Feb. 24, 2022)
At the time I cited studies showing that specific imaging findings we associate with back pain are routinely found in people who have never had it. Since these findings, which include disc degeneration, disc bulges, stenosis and spondylolisthesis, aren’t always symptomatic, they can be innocent bystanders when found in people with back pain. Because of that, I suggested we should add the statement "Finding may be unrelated to symptoms, further investigation necessary" to x-ray or MRI reports.
In my conversations with medical professionals and the public over the past two years, I feel the need to reiterate what I outlined back then. Despite decades of research indicating the contrary, most people, regardless of their medical training, still believe that imaging provides the best way to determine the source of back pain.
And just like I stated in the first column, the imaging findings I am referring to aren’t those considered serious pathologies. Serious pathologies include fractures, cancer, and infections, to name a few, where there is a strong correlation between symptoms and imaging findings. Fortunately, these pathologies are rare, and imaging allows us to provide timely and even lifesaving interventions when they are discovered.
But what about other findings?
It’s natural to think that our most advanced forms of imaging should be able to pinpoint exactly what is causing back pain. After all, our technology has progressed to the level where the phone in your pocket has more processing power than the computers that first landed humans on the moon.
Despite these advances in other areas, pain is still not visible with imaging. We have yet to progress to the point where X-rays and MRIs come equipped with flashing red lights showing exactly where the pain originates. And since painful and painless findings look the same on imaging, it can be difficult to discern why someone hurts by just looking at a picture.
Take, for example, the finding of a disc herniation on MRI. Most people would assume that herniated discs would only be found in people with severe back pain or sciatica. Quite the contrary, as individuals who have never had these symptoms routinely show herniated discs on imaging. Numerous studies depict this, including a paper in The Journal Spine that compared the MRIs of people with sciatica to those of asymptomatic volunteers. Remarkably, this study found a 76% prevalence rate of disc herniations in the group without symptoms, indicating that this finding doesn’t mean someone will be in pain.
And to take this notion a step further, if disc herniations are so often asymptomatic, why can’t they remain so (and something else be the culprit) in someone who develops back pain or sciatica?
Another example would be scoliosis. Scoliosis is a sideways curve of the spine and a popular reason to blame for back pain. Interestingly, research has shown that back pain is as prevalent in people with scoliosis as it is in those without it. Because of this, there is no guarantee that scoliosis will either cause back pain or, when found, be the reason why someone’s back hurts. I should mention, though, that imaging is necessary for determining the size of someone’s scoliotic curve and monitoring its progression. But we are talking about pain.
Disc herniations and scoliosis are just two examples. There are dozens more, including disc height loss, facet degeneration, and Scheuermann’s disease. While their prevalences in the asymptomatic population differ, the same rules apply. The presence of these findings doesn’t ensure that someone will have back pain, and you can’t tell where symptoms are coming from by just looking at a picture.
This lack of correlation between imaging findings and symptoms is critical because the way an image is interpreted often directly impacts treatment, which subsequently determines the outcome.
For this reason, orthopedic surgeon Ron Donelson cautioned against over-interpreting X-rays and MRIs. In his book "Rapid Recoveries Without Surgery for Back, Neck, and Joint Pain: The Power of a Precise Diagnosis," Dr. Donelson wrote: "Imaging studies could even complicate your care and delay your recovery if a provider incorrectly attributes your pain to some unrelated finding."
And even if one of these findings is the actual source of symptoms, there’s another equally challenging issue: imaging doesn’t come with a list of instructions detailing how to correct the problem. Therefore, with everything I have outlined up to this point, something other than imaging is needed to help make treatment decisions in most cases.
Fortunately, imaging isn’t required to treat most conditions. Unless some invasive intervention (e.g. surgery or injection) is being contemplated, precise identification of the pain-generating tissue is unnecessary. Thankfully, methods of assessment that classify and treat patients based on signs and symptoms provide us with the information we need. For example, suppose we improve symptoms and range of motion with a specific intervention. In that case, this cause-and-effect feedback informs us that we are positively affecting the pain generator, even if we don’t know what it looks like on imaging.
While the names of the findings differ, the concepts I outline in this column can be applied to musculoskeletal imaging in any area of the body, whether for the neck, shoulder, knee, hip, etc. Once these ideas are grasped by medical professionals and the public alike, the assessment and treatment of most musculoskeletal conditions should dramatically improve.
Dr. Jordan Duncan was born and raised in Kitsap County and graduated from the University of Western States in 2011 with a Doctor of Chiropractic Degree. He practices at Silverdale Sport and Spine. He is one of a small handful of chiropractors in Washington state to be credentialed in the McKenzie Method.
This article originally appeared on Kitsap Sun: Why an x-ray or MRI may not reveal what's causing your back pain
