Among the many structures in the back that can cause pain are the facet joints. There is a pair of facet joints between each pair of vertebrae in the neck and lower back, one on each side of the spinal cord. “The facet joints make the back flexible and enable us to bend and twist,” says Kaixuan Liu, MD, PhD and founder of Atlantic Spine Center. “When they are healthy, their movement is eased by cartilage that provides cushioning and synovial fluid that provides lubrication and reduces friction. But facet joints are subject to pressure overload, to injury, and to the wear and tear of osteoarthritis as we age. When the joints become swollen and inflamed, 'facet joint syndrome' may make it hard to turn your neck or straighten your back.”
Nerves exit the spinal cord and pass through neuroforamen, small openings on each side of spine, to different parts of the body. When the cartilage and fluid wear away, facets could become larger and grow bone spurs that often result in narrowing of the neuroforamen and compressing nerves. Consequently, patients feel pain, numbness, and muscle weakness, in different parts of the body depending on which nerves are affected. If the affected nerves are in the cervical spine, symptoms may be felt in the neck, shoulders, arms and hands. If the affected nerves are in the lumbar spine, symptoms may be felt in the buttocks, legs, and feet.
Facet joint injections are used both diagnostically and to relieve pain related to facet arthritis. “We diagnose facet joint syndrome with a complete history and physical exam and with imaging tests to detect abnormalities in the spine,” says Dr. Liu. “We may also inject a small amount of anesthetic to aid or confirm the diagnosis. If the patient's pain is immediately relieved after the injection of numbing medication, we know that the facet joint was the source of the pain and we can proceed with a therapeutic plan to treat the condition. That plan may include a procedure, called rhizotomy with deadening of pain nerve endings surrounding facet joints for longer-term pain relief.”
Conservative treatment for facet joint syndrome generally includes the application of ice to reduce swelling and physical therapy to improve mobility and strength. “But often, physical therapy isn't feasible until we can reduce the patient's pain,” says Dr. Liu. “One of the best ways to do that is with a facet joint rhizotomy with radiofrequency or endoscopic surgery.”
A facet joint block injection is mostly used to diagnose facet joint pain syndrome. Long term pain relief of facet pain often can be accomplished with rhizotomy, and in severe cases, maybe spinal fusions.
A facet joint block injection takes only a few minutes and is performed in the doctor's office or in an outpatient surgical center. The primary side effect is tenderness that can usually be relieved with the use of an ice pack several times a day. As pain is reduced, the patient is advised to resume normal activities and exercise gradually and in moderation.
“Facet joint syndrome is disabling for many people,” Dr. Liu concludes, “As it progresses, some patients experience muscle spasms that force the spine out of alignment. Successfully treating the condition with facet joint blocks will usually relax the spastic muscles and enable patients to stand up straight and to get up from a chair without pain and without help.”