Today, we’re going to look at the use of scans in the diagnosis of back pain.
The trouble is, the kinds of spinal “abnormalities” which show up on scans are known to correlate very poorly with pain. Put another way, people with bulging or herniated discs or other spinal degradation very often experience no back at all. If you have these things they may not have anything much to do with the pain you are feeling.
When it comes to scans it’s not just this issue of false positives that creates problems. Once people get it into their heads that it’s some kind of structural abnormality that’s behind their back pain it’s unlikely that they will look for other solutions beyond medication and surgery. That’s a shame because there is good evidence that many forms of therapy can help a great deal even when scans show degenerative changes in the spine. These include soft tissue work, pain education, graded movement and appropriate exercise.
There is another consequence of being told by a doctor that evidence from scans shows permanent changes in the bones of the back. These patients recover less well from episodes of back pain than those who don’t have scans or who aren’t given scan results even when the structural issues are the same. Telling someone their vertebrae are crumbling or that they have bulging discs adds considerably to their distress and lowers their expectation of a good outcome. What people think is an important factor in pain experiences, especially in chronic pain, and negative beliefs and expectations are likely to lead to protective guarding and avoidance behaviours which can make pain worse or delay recovery.
When it comes to back pain, interpreting scans need to come with a health warning.