Spinal discs and jam doughnuts - a sticky problem

Disclaimer - this blog is not a substitute for individual advice from a qualified professional!

This is a common scenario: a patient arrives at my clinic, obviously in some pain and walking very gingerly. When we start talking about their back pain, they tell me that they’ve been told that they’ve “put a disc out” or “slipped a disc”. Sometimes they’ll have been to see a therapist who “popped the disc back in for me”, but now it’s “gone out again”, or “I’m nervous about doing anything in case it goes out”.

There are a whole stack of issues with this, so I’m going to grab a large mug of coffee and try to unpack them one at a time. I invite you to join me!

First of all, anyone who tells you that they’re going to pop your disc back in is either badly informed or ethically challenged. The body doesn’t work that way; if you look at what’s going on it doesn’t even make any sense. The treatment offered may still have an effect - but it’s definitely not working as advertised, and you should probably be a bit concerned about seeing a therapist who’s happy to sell you this story.

With that out of the way, let’s look a bit more closely at disc injuries and what they actually are. The spine is (very roughly speaking) a stack of bones (vertebrae) on top of each other, and in between the bones you have the spinal discs. These help to allow movement between the vertebrae, as well as acting as a shock absorber.

The story that therapists often tell to patients (and I’ve used it myself) is that the discs are a bit like jam doughnuts. They have a fibrous outer layer, and some squishy stuff in the middle. As long as the jam stays inside the doughnut, you’re fine - but if you squeeze the doughnut too hard, you might damage the outside, allowing the jam to leak out and cause problems.

This is a simple image that helps to explain what a prolapsed disc is, and why you can’t just pop it back in again; but at the same time, there’s a problem. It conveys the impression that discs are fragile and susceptible to damage if we do anything too strenuous, and that once your doughnut has been damaged you’re stuck with it (pardon the pun). As a result, people often become wary of straining their back and are convinced that avoiding too much movement or lifting is the best way to protect it. Manual handling courses often reinforce this idea too, by focusing on all the things that can go wrong.

To make matters worse, when people think of a “slipped” or “prolapsed” disc, what usually comes to mind are all the worst and most extreme examples. The relative they know who slipped a disc and was in chronic pain for years, or the google search results they’ve found, talking about people who had a herniated disc that needed surgery.

“Degenerative changes” to the spinal discs may sound alarming, but the reality is that they’re completely normal. Most of us get some change to our discs as we get older, and they’re common even in people who have absolutely no history of back pain. Occasionally, it’s true that a particularly severe injury can cause pressure on a nerve that may require more intervention, but this only occurs in a tiny minority of back pain cases. Unlike the jam doughnut, your body has the capacity to adapt to change.

The other thing to remember is: back pain is not very well correlated with damage. People may have quite a lot of disc damage and no pain, and others with severe chronic pain may have very little damage. Pain is complicated, and often there’s more going on than it’s possible to see on an MRI scan. One of the things that tends to make pain worse is anxiety about movement. If you’re worried that you might make things worse by moving, or if you think that the pain is a sign that something is being damaged, then that can interfere with your recovery. It may stop you from doing things that would strengthen your back and actually help to reduce back pain. Even everyday movement may become threatening - and the less you move, the more you find movement hurts; before you know it, you've found yourself in a vicious cycle. Therapists who talk about the disc or the spine being “out of place” or needing to be “realigned” may unthinkingly reinforce this way of thinking.

What’s the take home message? Going back to the patient at the beginning of the blog, I think that reassurance and education are crucial factors to helping that person rebuild their confidence in their movement, and that’s an important part of my job. We all like to send patients away feeling better, but a lot of recent evidence suggests that long term outcomes may depend as much on how we talk to our patients about what’s going on as on what we do.

The human body is much more resilient than we often give it credit for, as long as we don’t allow ourselves to be convinced otherwise!

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