Lumbar Facet Joint Blocks
A facet injection is a minimally invasive procedure that can temporarily improve neck or back pain caused by inflamed facet joints. The procedure has two purposes: it can be used as a diagnostic test to see if the pain is coming from your facet joints and it is used as a treatment to relieve inflammation and pain caused by facet joints. The effects of facet injections tend to be temporary - providing relief for days or months. The goal of facet injection is to reduce pain to improve your activities of daily living and to help you start a physical therapy program.
What is a facet injection?
During facet injection long-lasting corticosteroid such as methylprednisolone and a numbing agent such as lidocaine are injected into the painful facet joint(s) or next to the nerves that carry pain from the facet joint (medial braches of dorsal rami). Corticosteroid injections reduces inflammation and pain relief can last from days to years, allowing you to improve your function with physical therapy and an exercise program. Facet injections provide diagnostic information. If only short term relief is obtain from this diagnostic injection, then facet rhizotomy may increase duration of pain relief to months and years.
Who is a candidate?
If you have neck, arm, low back, or leg pain stemming from inflammation of the facet joints you may benefit from a facet injection. Typically, it is recommended to try conservative treatments, such as oral anti-inflammatory medication, rest, back braces or physical therapy prior to considering injection therapy. Facet injections may be helpful in treating inflamed facet joints caused by:
· Spinal Stenosis
· Herniated Discs
· Facet Joint Arthritis
· Postoperative Pain
Facet injections is NOT performed on people who have an infection, are pregnant, or have bleeding problems. It may slightly elevate the blood sugar levels in patients with diabetes, blood pressure and may cause short term fluid retention.
What happens before treatment?
The doctor who will perform the injection will review your medical records and imaging studies to plan for the best location for these injections. Patients who are taking aspirin or blood thinners may need to stop taking the several days before the facet injection, doctor will provide specific instructions. Discuss any medications with your doctors, including the one who prescribed them and the doctor who will perform the injection. The injection is usually performed in an outpatient procedures suite that has access to fluoroscopy. You will need make arrangements to have someone drive you to and from the office or outpatient center the day of the injection.
What happens during treatment?
Before your injection, you will be asked to sign consent forms, list medications you are taking, and list any allergies to medications. Procedure may last 15-30 minutes followed by a recovery period. Patients remain awake for these procedures. Sedatives can be given to help lessen anxiety. The patient will be lying face down on the table, will receive a local anesthetic, which will numb the skin before the injection is given. If IV sedation is used, your blood pressure, heart rate and breathing will be monitored during the procedure. With the aid of a fluoroscope (a special X-ray), the doctor will direct a hollow needle through the skin and muscles of your back into the facet joints or next to the sensory nerves that carry pain away from the inflamed facet joints. Fluoroscopy allows the doctor to watch the needle in real-time on the fluoroscope monitor to make sure that the needle goes to the specific facet joint. Contrast agent may be injected into the facet joints to confirm correct needle position. Some discomfort may occur, but patients typically feel more pressure than pain. After the needles are confirmed to be in correct position, the doctor will inject mixture of local anesthetic and corticosteroid medication into your facet joint. The needle is then removed.
What happens after treatment?
Most patients can walk immediately after the procedure. After being monitored for a short time, you can usually leave the office or suite. Someone must drive you home. Typically patients will resume full activity the next day. If soreness around the injection site is present the following day, it may be relieved by using ice and taking mild pain medications such as Tylenol. The doctor’s office may want to follow up with you 7 to 14 days after the procedure to assess you response to this injection. You may be provided a diary to record you response to this procedure. You may notice a slight increase in pain after the numbing medicine wears off and before the corticosteroid medication starts to take effect. If the facet joints are the source of pain, you may begin to notice pain relief in two to five days after the injection. If there is no improvement after 10 days, a second injection may be given. If after three injections you experience no or a little pain relief, then it is unlikely that you will benefit from more injections. Additional diagnostic tests may be needed to accurately diagnose your pain.
What are the results?
About 50% of patients experience some degree of pain relief . The pain may be relieved for several days to several months. If previous injections provide long term pain improvement and you experience a recurrence of pain, the procedure can be repeated up to 3 times a year. If you experience recurrence of back pain after a short period of time and you've experienced good pain relief with facet injections, you may be a candidate for a procedure that uses a radiofrequency probe to destroy some of the nerve fibers causing pain - radiofrequency rhizotomy.
What are the risks?
The potential risks associated with inserting the needle include bleeding, infection, allergic reaction, headache, and nerve damage (rare), corticosteroid medication induced side effects such as weight gain, water retention, flushing (hot flashes), mood swings or insomnia, and elevated blood sugar levels in diabetics. These usually resolve within 3 days. Patients who are being treated for chronic conditions (e.g. heart disease, diabetes, rheumatoid arthritis, or those who cannot temporarily discontinue anti-clotting medication) should consult their personal physician for a risk assessment. With few risks, facet injections are considered an appropriate nonsurgical treatment for some patients.
1. Bani A, Spetzger U, Gilsbach JM. Indications for and Benefits of Lumbar Facet Joint Block. Neurosurg Focus 13(2), 2002.