Using x-rays to see inside the body has been around since 1895 and chiropractors were amongst the first to use this wonderful new technology. The first x-ray machine to be installed in a chiropractic college was in 1910 in Davenport, Iowa. Since then x-ray use fallen in and out of favour in both medical and chiropractic circles. Everyone assumes that all x-rays pose a risk to health but latest research puts this to the test.
Recently NICE recommended against the routine use of x-rays for simple low back pain. As far back as 1976 studies(1) showed that ordinary x-ray films don’t show the cause of the pain. Further arguments showed that in most cases and doesn’t improve care or the clinical outcome. Whilst that may be true for medicine where the first treatment is medication and then, after a while, physiotherapy exercises, chiropractors use x-rays differently.
The 1976 study was limited to the 18-50 age group so the same conclusion cannot be drawn for older back sufferers. Chiropractors take films standing up which shows such things as leg length differences far more accurately than measuring the legs or eyeballing differences at the feet or ankles. Hospitals take back x-rays lying down which show disease but mask postural changes like spinal curvature (scoliosis) and disc compression with instability.
Chiropractors main form of treatment is manipulation or adjustment of the spine. Whilst this is a safe procedure in most people, if you have a hidden spinal birth defect, x-ray can show if it safe to adjust. Chiropractors feel for individual spinal bone movement and it is the loss of this movement which is thought to cause many forms of back pain. If there is a spinal defect where 2 vertebra have not grown properly and have fused, which is not uncommon, then that segment will move abnormaly. Without an x-ray a chiropractor might conclude that this was 2 bones locked together causing the pain and start treatment to unlock them. In a review of 847 x-rays form new borns to 85 year olds, 68 % had observable anomalies (2). These ranged from common wear-and-tear arthritis to tumours and fractures. It is good to know so that the right treatment can be applied.
Are X-rays Safe?
We are exposed to x-rays every day, about 2.4 mSv a year. In Cornwall the rock emits more radiation so it is bit higher here ( no Cornish jokes please). When we fly the exposure is higher still. It has been assumed that any exposure is harmful. This has not been based on research but an assumption that the effects are linear down to zero. This theory means that even small doses have a small adverse effect.
But is this true. In 2008 Rodgers and Holmes (3) went to Chernobyl to find out. Astonishingly they found that at small doses of up to 15 mSv, x-rays were actually beneficial! Up to this level people had lower levels of cancer than a normal un-exposed population. So x-rays are good for you, within reason. A set of 2 low back x-rays is about 1 mSv (4) and the maximum safe dose is 20 mSv a year (5).
The British Chiropractic Association insists on a strict code of practice to ensure even higher safety standards. Regular site inspections and equipment maintenance is carried out to make the best use of a valuable resource in the chiropractors diagnostic options.
1. Nachemson, A. L. (1976). The lumbar spine an orthopaedic challenge. Spine,1, 59-71.
2. Beck, R. W., Holt, K. R., Fox, M. A., & Hurtgen-Grace, K. L. (2004). Radiographic anomalies that may alter chiropractic intervention strategies found in a New Zealand population. Journal Manipulative Physiological Therapeutics, 27, 554-9.
3. Rodgers, B. E., & Holmes, K. M. (2008). Radio-adaptive response to environmental exposures at Chernobyl. Dose Response, 6, 209-21.
4. Wall, B. F., & Hart, D. (1997). Revised radiation doses for typical X-ray examinations. Report on a recent review of doses to patients from medical X-ray examinations in the UK by NRPB. National Radiological Protection Board. Br J Radiol, 70, 437-9.
5. World Nuclear Association (2009). Radiation and Nuclear Energy. Dec 2009 from http://www.world-nuclear.org/info/inf05.html