Lower Back Pain: The Big 5: Part 1

Dr Dan Bates MSCC

The first of the “Big Five” is facet joint pain. The facet joints sit at the back part of the spinal column and are the source of back pain in at least 30 per cent of people. When people speak about having arthritis in their back, this is probably the part that is affected. However, arthritis in backs is common and in most cases doesn’t actually hurt. As you get older is it more likely back pain is coming from facet joints, however, on MRI’s of people aged 80 with NO PAIN, 83 per cent had facet joint arthritis. Just because it is on the scan, doesn’t mean it hurts. 

The symptoms of facet joint pain are non-specific and overlap with other structures from the back. As a rule of thumb, the pain is an ache above the belt line, tennis ball or larger in size, and commonly more to one side or the other. The pain can radiate down the leg as far as the calf and very regularly gets labelled as “Sciatica”, but is it not. The pain is generally worse with bending backwards, and in the morning is associated with stiffness that improves as you warm up over 10-30 minutes. If you are being examined by a doctor they may try to reproduce your pain by pushing over the facets and doing a test called the Quadrant Test. This is done by bending backwards and toward the side of pain, trying to reproduce the “usual” pain. Interestingly, if you have no pain when doing this it makes it unlikely the pain is coming from your facets. 

Confirming that facets are the source of the pain is done either with facet joint injection or by blocking the nerves that supply the facets. This is known as a medial branch block. Although, you would think injecting the facet directly would be a good test, it turns out it isn’t because of leakage out of the joint. As a result doctors tend to avoid these injections and perform medial branch blocks. Medial Branch blocks use a very small amount of local anaesthetic to numb the nerves that supply the joints. It is performed on two separate occasions and if the pain goes away both on occasions, it is highly likely the facets are responsible for the pain. 
To be able to “fix” the joint would be great, but at the moment, there is no such solution. 
Treatment is aimed at decreasing the pain arising from the joints rather than “fixing” them. This is done utilising multiple techniques including medications, rehab and exercise. In addition, the pain signal can be disrupted from getting from the facet joint to your brain by a process known as radiofrequency ablation. 

This process heats the same nerves we blocked during medial branch blocks. Radiofrequency ablation is effective in 60-90 per cent of people, and results in 60-90 per cent decrease in pain for nine to 18 months. In many people, when the nerve regenerates the pain does not return, however if it does, it can be repeated with expectation of getting a similar period of pain relief. With regards to stem cells, there has been some reports in the media about their success, but nothing has yet published, to my knowledge, in the scientific literature. It is certainly an area that may be effective and in the future Melbourne Stem Cell Centre will likely look at performing a study using cells in people with confirmed facet joint pain that have failed normal treatment. 

Part 2 coming soon...