Low back pain is a common symptom experienced by more than 540 million people at any one time (1). In most cases, nearly 99 percent, the cause of the low back pain is not medically serious and most people will see symptoms subside within 2 to 6 weeks.
Where does imaging come into play?
Lumbar imaging provides us with a snapshot of the current structural state of an individual’s spine. We cannot see pain on imaging. There are some situations where imaging may be warranted but for the vast majority of cases it is not. Here are some guidelines that may indicate imaging is warranted, which may be triggered by the presence of red flags during a clinical exam.
Some examples of red flags include, but are not limited to:
- Patient medical history (i.e was there trauma or a fall? Prolonged use of corticosteroids? A history of cancer?) [2].
- Lumbar or sacral dermatome changes (hypoesthesia, hyperesthesia or anesthesia) [3].
- Lower extremity weakness or hyporeflexia [3].
- Bowel and bladder changes [3].
These, or other components of a clinical assessment, may raise suspicion of pathological cause(s) of an individual’s low back pain. Some of these major conditions include, but are not limited to:
- Spinal fracture (1.8-4.3%)
- Malignancy (0.2%)
- Infection (0.01%)
- Cauda equina syndrome (0.04%)
Lumbar imaging will be warranted in particular cases, however, as stated previously, these incidents are rare (less than 1% of all low back cases) [2,3,4]. This information is not to suggest lumbar imaging is unnecessary. As stated in the guidelines, there are times where medical imaging will be warranted and advisable for those experiencing low back pain. Please seek out your local medical professional for proper advice.
References:
1) Hartvigsen J, Hancock MJ, Kongsted A, et al. What low back pain is and why we need to pay attention. The Lancet. 2018;391(10137):2356-2367. doi:10.1016/s0140-6736(18)30480-x
2) Henschke N, Maher CG, Refshauge KM, et al. Prevalence of and screening for serious spinal pathology in patients presenting to primary care settings with acute low back pain. Arthritis & Rheumatism. 2009;60(10):3072-3080. doi:10.1002/art.24853. 3) Baker SR, Rabin A, Lantos G, Gallagher EJ. The effect of restricting the indications for
lumbosacral spine radiography in patients with acute back symptoms. AJR Am J Roentgenol. 1987;149(3):535-538. 4) Bardin LD, King P, Maher CG. Diagnostic triage for low back pain: a practical approach for primary care. Med J Aust. 2017;206(6):268-273.