Facet arthropathy, often called facet joint osteoarthritis, is a form of arthritis affecting the small joints located in the spine. This condition involves the degeneration of the joints that link the vertebrae, leading to pain and stiffness in the back or neck. It is a common source of chronic spinal discomfort, frequently diagnosed among older adults.
Understanding Facet Joint Anatomy and Function
The spine is composed of stacked bones (vertebrae), which connect via two pairs of facet joints (zygapophyseal joints) located on the posterior side of the spinal column. These structures work like hinges, guiding movement and providing stability. The joint surfaces are lined with smooth cartilage and enclosed within a capsule containing lubricating synovial fluid.
These joints allow the spine to safely flex, extend, and twist while preventing excessive motion. In the lumbar spine, facet joints bear a portion of the vertical load and limit excessive rotation and forward sliding of vertebrae. The medial branch nerves innervate these joints, carrying pain signals from them.
Common Causes and Identifying Symptoms
Facet arthropathy is primarily caused by cumulative wear and tear over a lifetime, leading to osteoarthritis in these spinal joints. When protective cartilage wears away, the bones within the joint rub together, causing irritation, inflammation, and pain. Biomechanical factors, such as degenerative disc disease, also contribute by causing intervertebral discs to lose height, shifting greater stress onto the facet joints.
The characteristic pain is a deep, aching discomfort localized to the affected area of the spine. This pain often worsens with motions that compress the joints, such as bending backward (extension), twisting, or standing for long periods. Patients often report stiffness, particularly in the morning or after rest. While the pain is generally localized, it can sometimes radiate to the buttocks, hips, or the back of the thighs, but it rarely extends below the knee, distinguishing it from nerve root compression conditions like sciatica.
Confirming the Diagnosis and Management Strategies
Diagnosing facet arthropathy begins with a physical examination and a review of symptoms, focusing on movements that provoke pain. Imaging tests (X-rays, CT scans, or MRIs) can show structural changes like cartilage loss or bone spurs. However, these findings alone cannot confirm the joint as the source of pain, as many people show degeneration on imaging without symptoms.
The gold standard for confirmation is a diagnostic medial branch block. This minimally invasive procedure involves injecting a local anesthetic near the medial branch nerves using X-ray guidance. A significant, temporary reduction in pain immediately following the injection suggests the facet joint is the source of discomfort.
Treatment strategies start with non-surgical, conservative methods aimed at managing pain and inflammation. Initial steps include over-the-counter nonsteroidal anti-inflammatory drugs (NSAIDs), applying heat or ice, and physical therapy. Physical therapy strengthens core muscles, improves spinal flexibility, and reduces mechanical stress on the affected joints.
If conservative measures fail, interventional treatments are considered. Therapeutic facet joint injections deliver a corticosteroid and anesthetic mixture directly into the joint space, providing longer-lasting relief by reducing inflammation. For patients who respond well to the diagnostic nerve block, radiofrequency ablation (RFA) is often the next step. RFA uses heat energy to temporarily deactivate the medial branch nerves, preventing them from sending pain signals to the brain, with relief lasting several months to a couple of years.