In patients with chronic neck, mid, or upper back pain, the prevalence of facet joint arthropathy can range from 40- 60 percent. The prevalence of lumbar facet joint pain in the general population is 10-15 percent.
Causes of cervical facet pain include whiplash due rapid deceleration injuries. Causes of both cervical and facet joint pain can include repetitive strain and intervertebral disc degeneration. Chronic strain can cause fluid collection and joint distension. Other causes include inflammatory arthritis and pseudocysts. Facet arthropathy in conjunction with other spine pathology can lead to radicular pain. Inflammatory mediators such as prostaglandins, interleukin-6 and tumor necrosis factor-alpha can be found in facet cartilage. Leakage of these substances through the joint capsule can contribute to radicular pain.
Diagnosis of facet pain typically involves a physical exam by a qualified physician. X-rays are not usually very sensitive but may demonstrate degenerative changes such as sclerosis and hypertrophic overgrowth. CT and MRI scans are more sensitive and may reveal hypertrophic osteophyte growth, subchondral sclerosis, bone marrow edema, joint space narrowing or widening, effusions and periarticular soft tissue edema. The level of symptomology and radiographic findings do not always correlate. The most reliable method to establish the facet joint as the source of pain is with medial branch or intra-articular facet joint blocks, which are typically performed with fluoroscopic (live x-ray) guidance.
After establishing the diagnosis with either an intra-articular or medial branch block, radiofrequency denervation can be performed. Prior to denervation, sensory stimulation is usually performed. Medial branch denervation is achieved by placing the tip of the RF needle at the nerve. The duration of pain relief after denervation is typically 6 months to a year.