There are two facet joints at either end of a vertebral segment in the spine. In the lumbar spine, these joints help give stability to the spine and help guide its motion. Because of a back injury, arthritis or mechanical stress on the lumbar spine, there can be low back pain. One treatment of this type of pain is the lumbar facet injection. The relief of pain the person receives can help them participate in physical therapy in order to strengthen the back and keep it pain free.
Lumbar facet injections have two primary goals: the first is to help diagnose the cause and location of the low back pain and the other is to give pain relief. A facet joint injection can find the source of the pain by injecting the joint with an immediate relief anesthetic. If the pain is relieved at a particular facet joint, it is the likely source of the pain. This is especially true if complete relief is obtained.
The lumbar facet injection is also used for pain relief. Longer acting anesthetics and cortisone can be injected into the joint. The cortisone acts as an anti-inflammatory medication, killing the pain for up to three months or more. It can also help the patient begin a program of physical therapy to strengthen the back. This pain relief is called a facet block.
During a lumbar facet injection, an IV is started and medications for sedation or relaxation are given. The patient lies stomach down and the lumbar area is exposed. The area is cleaned well with a cleansing agent to sterilize the area and the affected area is numbed with a local anesthetic. Fluoroscopy or x-ray guidance is used to locate the facet joint so that a small needle can be inserted into the joint. Contrast die is included in the injecting agent so that x-ray can confirm that the facet joint has indeed been entered. Usually a mixture of cortisone and lidocaine can be injected at the same time. The injection is done slowly so as to avoid pain and to make sure the solution gets into the joint.
The injection takes just a few minutes; however, the patient must remain on the table in a resting position for twenty to thirty minutes before being asked to try and mimic the pain. If the injection was successful, there should be a decrease in the amount of pain the person feels although pain relief may not be felt for a few hours. If the joint was the wrong one, there may not be pain relief at all. Weakness on the side of the injection can happen for a few hours after the injection, and it is advised not to drive or do any strenuous activities on the day of the procedure.
A person who has received a lumbar facet injection will be asked to record the degree of pain for approximately a week after the injection. This will help the doctor know whether or not the injection was successful or whether another type of treatment plan is necessary. There can be a few days of pain relief from the lidocaine with an increase in pain until the cortisone begins to work. Ice can be applied to the site of injection so as to relieve pain in the first few days.
If the patient receives no pain relief after getting the injection, it can be inferred that the facet joint was not the source of the pain. It takes about ten days to see if pain relief occurs. If not, then further diagnostic testing may need to take place.