Can an MRI show where it hurts?

“Free MRI review. Send your MRI today” (…and we will determine that you are a surgical candidate.)
This is a common marketing gimmick used by many spine surgery practices. But, can you really determine if a patient is a surgical candidate just by looking at an MRI?
This goes to the heart of another dilemma….can an MRI show a pain generator? Or more plainly put, can an MRI show where it hurts?
For years it has been widely known that MRI abnormalities (including herniated discs) do not correlate well with prevalence of back pain. More than 50% of people over the age of 50 will have abnormalities in their spine MRI, with only a fraction of those people suffering from persistent back or leg pain. Still, MRI abnormalities are still widely used as a deciding factor to recommend surgery of the spine. Physicians in general, and surgeons in particular, often assume that a disc herniation on an MRI is the direct cause of persistent low back pain or sciatica.
A new study (doi 10.1056/NEJMoa120950.) just published in the New England Journal of Medicine highlights the diagnostic limitations of spinal MRI scans:
A randomized controlled trial comparing surgical and non-surgical care for sciatica found no evidence that the presence of a disc herniation on an MRI scan had any relationship with persistent sciatica symptoms. In this study, MRI scans performed one year after treatment could not distinguish those with a favorable outcome and those with unfavorable outcome.
This new study questions (again) whether MRI scans have any useful role in determining the cause of pain for patients with persistent sciatica. One of the many reasons for the increased prevalence of “failed-back syndrome” patients is precisely that an MRI was used to determine the need for back surgery, and the levels to be performed at. The MRI could show a herniated disc, but the persistent pain could be coming from other nearby structures (tendons, ligaments, muscle fascia, facet joints, sacroiliac joint, etc)
Lesson to be learned here? Be extremely suspicious of any surgeon willing to operate on your spine based solely on MRI findings. We should be treating patients, not MRI scans.