Facet-joint injections are both a minimally invasive treatment for back pain caused by inflamed facet joints, and a diagnostic tool for determining whether facet-joint inflammation is a source of pain. Four facet joints connect each vertebra to the vertebra above and below it. A facet-joint injection, administered into either the joint capsule or its surrounding tissue, combines a long-lasting steroid and a local anesthetic.
Although the anesthetic provides only temporary pain relief, the steroid reduces inflammation, and can relieve pain for anywhere from a few days to a few years. Lasting pain relief is diagnostically significant because it confirms that the pain originated in the joint that received the injection.
Facet-joint injections can be repeated up to 3 times a year for those who have successful but short-term pain relief.
Candidates for Facet-Joint Injections
Patients with back pain (or pain thought to originate in the back) are candidates for facet-joint injections. Facet-joint pain can be the result of injury, spinal stenosis, sciatica or osteoarthritis. Although pain typically appears in the lumbar region, it can occur anywhere in the spine. When facet joints are inflamed, depending on the location of the inflammation, pain can be experienced in the following regions:
- Groin
- Buttocks
- Hips
- Shoulders or neck
- Legs or arms
Facet-joint injections are often recommended after anti-inflammatory medication, physical therapy or other conservative methods have failed to alleviate symptoms.
The Facet-Joint and Medical Branch Injection Procedure
A facet joint injection is not often done for therapeutic purposes except for acute injury such as a sports injury to the spine or whiplash to the neck. Instead, it is done for prognostic purposes to better predict if radiofrequency neurotomy. As an alternative to directly injecting the facet joint, the nerves to the joint known as medial branches are instead injected in a similar way to temporarily numb them. If the pain relief is >80% over the baseline back pain then the response is positive and the next step in the diagnosis is done. That next step is to repeat the prognostic blocks looking for the same response which is >80% relief over the baseline. If two positive response are obtained then radiofrequency neurotomy is considered to alleviate the pain for longer periods of time.
The needle is then inserted directly into the facet joint through the back; fluoroscopy, an imaging technique, is used to ensure precise placement. Once the needle is correctly positioned, a combination of anesthetic and cortisone is injected into the targeted joint. The procedure takes less than 30 minutes to perform.
The needles for these procedures are placed under x-ray control to precisely deliver small amounts of local anesthetic in to the joint or the medial branch. Steroid is only injected if the injection is done for treatment and not prognosis. The injection takes less than 30 minutes to perform. There may be mild pain at the injection site; it can be managed by taking Tylenol and applying ice.
Recovery from Facet-Joint Injections
A patient can return home shortly after receiving an injection(s), and can resume regular activities the next day. A follow-up visit to the doctor takes place in about a week; an evaluation is made of how effective the injection has been in lessening symptoms.
Results of Facet-Joint Injections
We will call you a few days after the procedure to see if you had relief from the injection and for how long it initially lasted if it was done for prognostic reasons. We ask you to keep a diary to record hourly pain scores for hours. If the injection was done for therapeutic reasons then a follow-appointment is made a month afterward to assess effectiveness.
Risks of Facet-Joint Injections
Although considered safe, there are risks involved with facet-joint injections. In rare cases, they can cause infection, allergic reaction, bleeding or nerve damage.
