Facet joint injections can be used to diagnose the facet joints as the source of pain. When the facet joint is numbed, there should be pain relief. If the pain is not relieved, there could be another underlying issue that is causing the pain. Facet joint injections are mainly used as a therapeutic to relieve back pain caused by the facet joints. The numbing injection provides temporary relief and the anti-inflammatory mixture provides long term relief.
The patient lies face down on the table. The area of the spine that will be treated (lower back, mid back, upper back) is sterilely cleansed with an antibacterial solution using aseptic techniques. The antibacterial solution usually contains iodine and alcohol. A local anesthetic, like Bupivacaine, is injected into the area to numb the joint. The patient might feel a slight sting. Imaging guidance is used to direct the needle into the facet joint. The type of imaging system used depends on the preference of the doctor. It is usually fluoroscopy using CT or x-ray guidance. CT fluoroscopy increases the precision of the needle placement. Others may use ultrasound or magnetic resonance guidance. Contrast dye is injected into the facet joint to assure that the needle is in the correct place. Once confirmed, a mixture of an anesthetic and anti-inflammatory medication, is slowly injected into the joint. The anti-inflammatory medication is usually the steroid Celestone. The needle is then released. The injection can be used to treat any facet joint that is causing pain, so this procedure may need to be repeated for the adjacent facet joints.
IV sedation can be used for anxious patients to help them sit still. Doctors try to avoid this because it interferes with a patient’s pain response, which is needed to determine which facet joint is the source of the pain. The sedation uses a local anesthetic. If the patient chooses to have the sedation, they can’t eat or drink 4-6 hours prior to the procedure.
Examination of the evidence on the effectiveness of facet joint injection has suggested that it has little effect. In 2018 the Lancet published a series of papers by a group of many international experts on the extent of back pain and evidence for treatments. The authors were scathing about the widespread use of “inappropriate tests” and “unnecessary, ineffective and harmful treatments”. On facet joint injection it was stated that "Injecting facet joints with local anaesthetic can cause temporary relief of pain; however, the Framingham Heart Study (3529 participants) did not find an association between radiological osteoarthritis of facet joints and presence of low back pain." One of the authors, Prof. Martin Underwood at Warwick Medical School, said that facet joint injections "are very widely used in the public and private sectors. There is no evidence to support their use, but nevertheless the numbers done in the NHS go up year on year".
The UK National Institute for Health and Care Excellence (NICE) gives the official recommendation "1.3.1 Do not offer spinal injections for managing low back pain".