A Picture is Worth How Many Words?
I recently had a patient I was helping rehab after a total knee replacement. She was having a very hard time navigating her post-operative state as the process was more difficult than she had imagined it would be. One of the first things she told me was that she was dreading having her other knee done. This prompted me to ask her what difficulties she was experiencing in her other knee to which she responded, “well, nothing. I have no pain but my doctor told me that the x-rays show it’s bone-on-bone.”
This is one of many anecdotes that help pain the picture of just how complex pain is. How can someone have such a terrible looking image but not be experiencing symptoms that hypothetically should match it? Turns out that this is a very normal phenomenon. Imaging findings have less to do with pain presentations than you might guess.
One study found that cervical spine disc bulges occurred in 87.6% of asymptomatic individuals and spinal cord compression in 5.3%.
Asymptomatic rotator cuff tears are very prevalent in the general population and the risk of a tear increases with age. Not only that, but there is a high likelihood that if you are receiving treatment for a rotator cuff pathology that you also have an asymptomatic pathology on your non-painful side.
One study found that hip labral tears occurred in 68.1% of asymptomatic individuals who underwent an MRI.
In the late 80s, a group of asymptomatic individuals had an MRI of their lumbar spines and 31% demonstrated pathology. At a seven year follow-up, there was no indication that these images predicted future low back pain. Another study found that physical job characteristics and psychological status were better predictors of future symptoms than an MRI.
You are more likely than not to have a disc bulge show up on an MRI of your lumbar spine even if you have no back pain or associated leg pain.
Does this mean your image doesn’t matter? Of course not. It does means that what matters more to me as a physical therapist is how you feel and how you move. There’s a common phrase in the PT world: you get wrinkles on the outside, you get wrinkles on the inside. Just because something shows up as abnormal on your images doesn’t necessarily mean it’s your pain generator. Part of the job of a physical therapist is to make sure the imaging findings actually match your pain presentation. Pain is a highly complex phenomenon and there is so much more to it than what an image can show (reread the part above about psychological state being a better predictor of low back pain).
Don’t get me wrong. Imaging is absolutely necessary in a lot of cases and I’m so glad we have it at our disposal. That said, we don’t utilize imaging in this country in a way the evidence suggests we should.
It may seem like ignorance is bliss here, which in many cases might be true. However, in some conditions, such as a rotator cuff tear, partaking in physical therapy might not be a bad idea as that shoulder may become symptomatic down the line without intervention. That being said, I could get into all the nitty-gritty of pain science here and ponder whether or not the power of suggestion is what causes these asymptomatic tears to become symptomatic down the line, but I’ll save that for another ramble.
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