Low back pain is extremely common. Three quarters of people will report at least one episode of back pain in their life time. Back pain is often excruciating, leading to withdrawal from activity, time off work and decreased productivity while at work. So given this, it would make sense to get an X-ray, CT or MRI to work out the cause of your back pain, right? Actually, for most people this is not the case.
- Most results seen on scans do not relate to pain and symptoms and are likely to be part of normal aging
- Scan results can create more anxiety about your pain – it may make it more likely that you will have surgery
- In rare circumstances, scans are still important, but your practitioner can help assist you on this decision.
1. Imaging doesn’t improve outcomes
One large study compared people who had usual care (staying active, hot pack, over the counter medication) for low back pain against people who received early imaging. They found no difference between the groups for measures of pain, function and quality of life. There are a few reasons why this might be the case.
- Firstly, the prognosis for acute low back pain is good, with most people seeing significant improvements in the first month after onset, so imaging is unlikely to speed this up.
- Secondly, there is a poor correlation between what we see on scan and people’s symptoms. One study scanned 67 people who had never had back pain in their life and found almost 90% of them had either bulging or degenerative discs. So really, most findings on scans are so common, they could be viewed as normal signs of aging.
2. Harms of imaging
The harms of imaging for low back pain are twofold. There are the obvious direct harms of things like radiation, especially with CT scans. And also the direct costs of the scans themselves to the patient and health care system. Harms that people are often not aware of are the indirect harms of things such as “labelling”, or unnecessary treatment procedures that are performed due to imaging results.
Labelling refers to when a patient is told they have a condition they were not previously aware. As noted before, imaging will often find things like disc bulges or degenerative discs, even in people that don’t have back pain. So when people with back pain have medical imaging they are told that their back is “damaged”, often with things that most likely have nothing to do with their problem. Labelling cause’s people to adopt a “sick role” and to see themselves as fragile. We now understand that this sense of fragility can be a pathway to chronic back pain.
The association between imaging and surgery is strong. One study found that an MRI in the first month after onset of back pain lead to an 8 times greater risk of surgery, and 5 times greater medical costs compared to people who did not have an MRI. A scary thought given those imaging findings may not be related to why people have pain!
Appropriate use of imaging
Medical imaging may not always be a bad idea. For example, when a person presents with worsening nerve symptoms, or there is a thought that a serious underlying condition such as cancer or fracture may be the cause of their back pain. These signs are called “red flags”. Red flags are uncommon, but a physio will always check if any of these are present before deciding if imaging is appropriate. Red flags for back pain include:
- Bowel or bladder dysfunction or numbness in the saddle region
- Signs of fracture (traumatic incident, or history of osteoporosis)
- Signs of inflammatory disease (night pain, long periods of morning stiffness)
- Signs of infection (fever, history of IV drug use)
- Signs of cancer (unremitting pain, unexplained weight loss)
Unless these red flags are present, imaging for back pain is not really required. As usual, your physio will be the best person to guide you on this decision and the best treatment plan for you.
If you have any questions please don’t hesitate to make an appointment at the clinic by calling 98882 2020 or emailing me at firstname.lastname@example.org/csc
Boden, S. D., Davis, D. O., Dina, T. S., Patronas, N. J., & Wiesel, S. W. (1990). Abnormal magnetic-resonance scans of the lumbar spine in asymptomatic subjects. A prospective investigation. J Bone Joint Surg Am, 72(3), 403-408.
Webster, B. S., & Cifuentes, M. (2010). Relationship of early magnetic resonance imaging for work-related acute low back pain with disability and medical utilization outcomes. Journal of Occupational and Environmental Medicine, 52(9), 900-907.