In clinic, we get a lot of questions about pain because it is the main reason people walk through the door. Today I am going to go through a brief review about pain and imaging. Imaging refers to radiographs (x-rays), MRI, and CT scans. These are typically used to help a medical provider determine what is causing the pain and the best intervention to resolve the problem.
What do we know?
• Numerous imaging studies ranging from knee to the low back show that the level of pathology cannot predict a person’s pain experience. We cannot predict pain, the level of disability or long term activity based upon an image.
• Individuals with chronic low back pain have been compared to those with no back pain. The findings on the imaging does not show consistent differences between these two samples. For example, a woman with nasty, limiting pain may show nothing with an x-ray and MRI while a pain free older woman could have an image that looks like they should be in a wheelchair.
• Another study design uses individuals with no pain. Radiologists are asked to identify any pathologies in the image without any other information. Most people will be diagnosed with an identifiable pathology despite having no pain.
Here are a couple things to consider:
• The use of MRI is increasing despite evidence showing it does not improve outcomes. The increase in MRI use has been correlated with the increasing rate of surgical intervention. This means people are getting surgery that is not improving long term outcomes.
• Knowledge of imaging abnormalities, like knowing you have a disc herniation, has been linked with fear avoidance behaviors but not improved long term outcomes. This means that you may become afraid of your own body for no reason. It hard to know what is normal and what is pathological. 90% of 60 years old without low back pain will have a degenerated or bulging disc. Is this pathological or just normal?
Imaging is a critical tool that we use in specific situations, but it is rarely the first tool we use in diagnosis.
When we refer for imaging, we use these guidelines:
• Progressive or severe neurological deficits. This can include loss of muscle, loss of reflexes, or changes in sensation
• Severe, persistent pain that is not responsive to treatment
• Specific pathologies that can be ruled out with imaging
• History of other non-orthopedic pathology like cancer
If you think an image is needed, please let us know so we can review the case with you.