Facet Joint
What are facet joints?
Facet joints link the bones of the spine together in the posterior or back part of the spine. Two facet joints are present at each spinal segment. They are named for the spinal bones that they connect. For example, in the neck or cervical spine the facet joints between cervical #5 and cervical #6 are called C56. Likewise, in the lower back the facet joints between lumbar #5 and the sacrum are called L5 S1. Because there are two joints per level, there is a right and left joint.
What is the function of the facet joints?
The facet joints are important in restricting the motion of the cervical and lumbar spine. They allowed twisting, flexion and extension motions.
Why do facet joints cause pain?
Facet joints are possible sources of neck pain and lower back pain. The facet joint is innervated by a small nerve that branches out from a spinal nerve. Facet joints have been demonstrated to cause pain in studies in which healthy volunteers were subjected to injections of normal saline into the joint. Trauma, arthritic changes can cause the release of pain generating substances which sensitize nerve endings located in the joint.
What are some of the signs and symptoms of facet joint pain?
For patients with facet joint pain from the lower back, complaints usually consist of pain or tenderness in the lower back slightly over to one or both sides, pain with lower back extension, pain with twisting, radiation of pain to the buttocks or back of the thighs. For patients with facet joint pain from the neck, complaints are typically based on segment or level involved. Depending on the level involved, patients may have neck pain, headaches, shoulder pain, or scapular pain.
Does an x-ray or other test determined whether or not a facet joint is causing pain?
X-rays do not determine whether a facet joint is causing pain. However, x-rays may point out abnormalities such as osteoarthritis that may be significant in causing pain. A series of diagnostic blocks with local anesthetic are the only way to reliably determine whether in fact the facet joints are a source of pain.
What is a facet joint block?
A facet joint block involves the injection of a substance into or next to the facet joint. Typically, in a diagnostic block, local anesthetic is used. In most cases a corticosteroid is also injected. Radiographic control is mandatory in accurately and safely placing the needle. The purpose of facet joint blocks is twofold. Initially, it is a diagnostic block. If the patient receives 50% or greater pain relief for at least 2 hours, there is an increased likelihood that the facet joint is important in the patients pain syndrome. The block is then repeated to confirm the diagnosis. The second purpose of the facet block is to reduce pain. Corticosteroids can help reduce the pain secondary to inflammatory substances that sensitize nerve endings.
What is evidence in the medical literature to support the use of facet joint injections for diagnostic and therapeutic purposes?
There are numerous articles and appear reviewed medical journal supporting the use of facet injections. Below are listed referenced articles with short summaries.
1. Manchikanti, Laxmaiah et al. Evaluation of Role of Facet Joints in Persistent Low Back Pain in Obesity: A Controlled, Prospective, Comparative Evaluation. Pain Physician, vol. 4, No. 3, pp. 266 ? 272, 2001.
This is a controlled prospective study with 100 lower back pain patients that were divided into two groups, normal and obese. The prevalence of lumbar facet mediated pain was 40% and obese patients and 36% in normal weight patients.
2. Manchikanti, Laxmaiah et al. Effectiveness of Lumbar Facet Joint Nerve Blocks in Chronic Low Back Pain: A Randomized Clinical Trial. Pain Physician, vol. 4, No. 1, pp. 101 ? 117, 2001.
This study included 200 lower back pain patients evaluated with controlled diagnostic blocks for the presence of facet joint pain. 42% of the patients were determined to have lumbar facet joint mediated pain. These patients were then treated with a local anesthetic and corticosteroid or Sarapin (a weak neurolytic agent). After 4 to 6 months, 82% of the patients had reduction of pain > 50% following 1 -- 3 injections.
3. Schwarzer et al. Clinical Features of Patients with Pain Stemming from the Lumbar Zygapophyseal Joints. Spine, vol. 19, No. 10 pp. 1132 ? 1137.
This was a prospective cross-sectional analytic study. There were 176 consecutive patients with lower back pain investigated with screening zygapophyseal joint blocks using lidocaine and bupivacaine. Results indicate that 47% of the patients had significant relief following the first facet joint injection.
4. Manchikanti, Laxmaiah et al. Pain Physician, vol. 5, No. 3 pp. 243 ? 249 2002. Prevalence of Cervical Facet Joint Pain in Chronic Neck Pain.
This is a study of the 106 neck pain patients that were seen in an interventional pain practice in 2001. Results indicate a prevalence of 60% with a false positive rate of 40% after one block.
5. Aprill, Charles et al. Cervical Zygapophyseal Joint Pain Patterns II: A Clinical Evaluation. Spine, vol. 15, No. 6 1990.
This was a study conducted on 10 consecutive neck pain patients referred to the radiology practice for the investigation of possible zygapophyseal joint pain. All patients complained of neck pain with referring pain to the head, shoulders, upper limb. In 8/10 cases there was complete concordance in the predicted levels between the first and second observers.
6. Aprill, Charles et al. Cervical Zygapophyseal Joint Pain Patterns I: A Study in Normal Volunteers. Spine, vol. 15, No. 6 June, 1990.
This was a study in which neck pain patterns were evoked in normal volunteers by injecting contrast medium into the target joint. Specific referred pain patterns were generated depending on the joint injected.
Are facet joint blocks safe?
Yes. The risks of facet joint blocks are very low with the use of x-ray control. Patients may experience some small amount of injection site tenderness. This will use the result in several days. Risks such as headache, infection, or bleeding are extremely rare.
Do the injections hurt?
Patients undergoing facet joint injections all receive local anesthetic to anesthetize the skin and deeper tissues. The patients may elect to receive intravenous sedation consisting of a sedative and/or a narcotic medication.
How long does it take for the injections to work?
Typically, the local anesthetic will work within 10 minutes and last up to two hours. The corticosteroid usually takes longer for pain reduction. It usually takes anywhere from 1 – 5 days for pain relief to occur if the pain is coming from the joint.
When can I resume normal activities following the block?
Most patients can resume normal activity the next day. In some cases, patients may require an additional day.
Are facet joint injections covered by insurance?
The overwhelming number of insurance companies currently covers facet joint injections. They are covered by Medicare and other government funded insurance plans. However, coverage may vary depending on your specific plan and policy.
What if I don’t get any relief from the facet joint injections?
If you don’t get relief from the facet joint injections, it is unlikely that this is a source of your pain. You should then consider with your physician the other possible sources of your pain. This may include other diagnostic blocks or imaging studies.
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