This is really old news, but it came up in my personal life recently, so I’m putting it out there once again.
An article was published in the New England Journal of Medicine, in July, 1994, titled “Magnetic resonance imaging of the lumbar spine in people without back pain.”
They took 98 people who didn’t have low back pain and looked at their low backs with MRI scans. 36% had normal discs at all levels. 52% had a bulge at one or more levels (with 38% having more than one disc involved). 27% had a disc protrusion, and 1% had a disc extrusion. They noted that the prevalence of bulges increased with age.
- “On MRI examination of the lumbar spine, many people without back pain have disk bulges or protrusions but not extrusions. Given the high prevalence of these findings and of back pain, the discovery by MRI of bulges or protrusions in people with low back pain may frequently be coincidental.” (emphasis is mine)
Some definitions might come in handy. In this study,
- A disc bulge is defined as a circumferential symmetric extension of the disk beyond the interspace
- A disc protrusion is defined as a focal or asymmetric extension of the disk beyond the interspace
- A disc extrusion is defined as a more extreme extension of the disk beyond the interspace
These definitions are very basic, fairly vague, and non-universal. The people who read MRI’s don’t have a universal language, so what one radiologist might call a protrusion another might call a herniation, someone else might call a prolapse, and yet another might call a rupture. More information than even I want to read about the naming of this kind of radiographic finding can be found here.
I did find an article that gives a pretty balanced look at when it’s time to see the surgeon. Take a look if you are considering this option.
And, that said, if you are experiencing pain that you cannot get away from (no position of comfort), if you are experiencing loss of bowel or bladder control, if you have foot drop . . . get evaluated sooner (like, now), not later.