I've just injured my back - Do I need an MRI scan?

Aside from getting asked this question on a daily basis in clinic, recent press and media attention made me feel the need to give my point of view. 

MRI scans have in many ways revolutionised medicine and enhanced patient care. The newest systems provide detailed images of anatomy that even 5 years ago lacked true clarity. They've also become increasingly affordable to many, and even on Harley street it is now possible to get a scan for £200 if booked off peak. Unlike CT scans and XRays their direct action is safe, as they don't expose the patient to a dose of radiation. However, many respected voices in the medical world are warning that inappropriate use of MRI to get a low back pain diagnosis is actually harming the healthy (1). 

To understand the problem it's important to understand that most acute low back pain resolves within 4-8 weeks if good management advice and reassurance is given by a medical professional.

The guidelines are in essence:

1. Use non-steroidal anti-inflammatory medication

2. Refer to physical therapy/physiotherapy

3. Avoid early MRI unless exceptional cases involving red flags

4. Avoid habit forming medication

5. Avoid early referral for injections or surgery

Ok, so what's the problem? Well, point three of the guidelines isn't being followed and this is leading to "overdiagnosis" of simple back sprains (2). These sprains are given labels like "slipped disc" and "degenerative disc disease" when really the injury is as benign as an ankle sprain. Let me explain further. A recent study (1) showed that in a normal pain free group of people given an MRI scan, 90% had degenerative discs and 30-40% had disc bulges, joint degeneration, and bone spurs. Just to be clear this is the pain free, normal group. The group that had pain related to pathology was tiny at 1-2% of the population. 

So if a medical professional advises an MRI scan and it comes back with "degenerative disc disease" you now have a label, in fact you have just been told you have a disease. This feeds anxiety and fear, creating what's called a nocebo effect. This is the opposite of the placebo effect, and describes any case where putting someone in a negative state of mind has an adverse effect on their health.

This asks the wider question: what are the boundaries that define an illness or pathology? And what is in fact normal and not going to cause longstanding incapacity? If the data tells us that 98% of people with acute low back pain alongside structural changes on MRI have just suffered a sprain, then we clearly need a more careful interpretation of these results. Definitively, low back pain should never be diagnosed from a scan alone.

Overdiagnosis as a concept may sound counterintuitive and many, many peoples lives have benefitted from appropriate use of MRI, but this final statistic delivers the strongest message: In America, people referred for MRI for routine back pain are eight times more likely to have surgery. Now that's a statistic worth changing.

Tom Lowes B.Ost MSc (Sports Med)
Registered Osteopath - Sports Injury Rehabilitation

Twitter @SportsMedOsteo       

 

Here's a great link to a podcast on this subject: Ray Moynihan 

Thanks to Karim Khan @BJSM_BMJ

1. McCullough et al. Lumbar MR imaging and reporting epidemiology: do epidemiologic data in reports affect clinical management? Radiology. 2012 Mar;262(3):941-6. doi: 10.1148/radiol.11110618.

2. Mafi et al. Worsening Trends In The Management and Treatment of Back Pain, AMA Intern Med. 2013;173(17):1573-1581

Paracetamol: No better than a placebo for easing low back pain?

Most people who have experienced an episode of low back pain will have been told by their GP to take some paracetamol. A recent study in The Lancet Journal recommends that this very common prescription should no longer be given for helping reduce pain in this area.

The study involved 1,643 people with acute low back pain and directly tested paracetamol against a placebo. The subjects took their medicine for up to four weeks as prescribed, and were all given advice and reassurance that they would recover.

Their results showed that paracetamol did not reduce the subjects pain intensity, or improve their quality of sleep or recovery time (an average of 17 days). The researchers main message from this trial is that paracetamol shouldn't be the first line pain relieving medication for acute low back pain.

But this is only half of the story. In my opinion the more powerful message from this study is that the advice and reassurance given to the subjects in this group meant that they all recovered faster than those in other similar studies. This is incredibly important, as by removing the fear of low back pain it is far less likely to become longstanding. It is easy to understand how someone with acute back pain, no knowledge of how long it will take to recover or how to ease it, can make irrational judgements. The intensity of pain can cause deep anxiety in someone who doesn't know that most of the time if you follow the right advice, in a few days you'll be 50% better. For example most people become far less active, when all the evidence recommends you to stay as active as you can and avoid bed rest. Basic advice on the do's and don't's of movement, and how to manage the pain allow the injury to be rationalised.

Hopefully further research will be done to compare whether advice and reassurance is more effective than medication for acute low back pain. In my clinical experience good advice, appropriate medication and high quality rehabilitation is by far the most effective combination.

Watch this space.

Tom Lowes B.Ost MSc (Sports Med)
Registered Osteopath - Sports Injury Rehabilitation

Twitter @SportsMedOsteo