Magnetic resonance imaging (MRI) is frequently performed during follow-up in patients with known lumbar disc herniation and persistent symptoms of sciatica. The association between findings on MRI and clinical outcome is controversial.
Although lumbar disc disease may well be a cause of low-back pain, it is important to note that disc degeneration can occur in the absence of back pain or any other symptoms. Some researchers have found that in 35% of healthy male volunteers significant disc degeneration was demonstrated on MR imaging. In a series of 600 autopsy specimens others noted that 90% of all lumbar discs had evidence of degeneration in individuals by the age of 50 years.
This current study included nearly 300 people randomly assigned to receive either surgery or conservative care for their sciatic pain. All the patients had signs of disc herniation on their initial MRI. A follow-up MRI was done one year later, and the two MRIs were compared with patient results.
After a year, 84 percent of those in the study reported successful treatment. Follow-up MRIs showed that 35 percent of those with successful treatment still had disc herniation compared to 33 percent of those with unsuccessful treatment.
One of the researchers noted that seeing a problem on an MRI doesn’t necessarily confirm that that is the source of the pain as he saw a percentage of patients with disc herniation who did not have symptoms. He concluded it was necessary to treat the patient, not the MRI.
At Devonshire Osteopaths we see many patients with MRIs – which are often helpful. Sometimes the cause of patient pain is clear, but the study reminds us that we have to be prepared for those cases where clarity can be deceptive, and we have to treat the patient, not the MRI.
Reference: el Barzouhi, A., Vleggeert-Lankamp, C. et al (2013): Magnetic Resonance Imaging in Follow-up Assessment of Sciatica. N Engl J Med 368:999-1007March 14, 2013