Facet joint injections for long-term back pain
BMJ Group Medical Reference
This information is for people who have long-term back pain. It tells you about facet joint injections, a treatment used for long-term back pain. It is based on the best and most up-to-date research.
Do they work?
We don't know. There's not much research on this treatment. We do know that facet joint injections can have side effects.
What are they?
Doctors inject an anaesthetic (which numbs pain) or a steroid drug (which reduces inflammation) into the joints that link the small bones (vertebrae) of your spine together. These joints (the facet joints) are covered with cartilage and a lubricating fluid, but they get a lot of wear and tear and can become inflamed and sore. Your doctor may prescribe these injections to temporarily block the type of pain that stops you from moving around.
How can they help?
We don't know whether facet joint injections can help with long-term back pain. There's not much research. One study found no difference between steroid injections and dummy ( placebo) injections using salt water. 
How do they work?
Some doctors think that because anaesthetics relieve pain and steroids reduce inflammation, it may be useful to inject them into painful parts of your back.
Can they be harmful?
Having an injection in an area that is already very sore can be painful. Some research has found that the injections may cause rare but serious side effects, such as infection, bleeding, meningitis (inflammation of the fluid in the spinal canal), and possible damage to your nervous system. 
How good is the research on facet joint injections for long-term back pain?
There is not much research on whether facet joint injections will help you if you have long-term back pain.
The best review we found looked at the results from one study of 101 people. It found that the injections didn't help ease the pain or help people move around better.