Diseases And Conditions
Spinal facet arthritis
The facet joints are small joints, found at every spinal level, involved in stabilizing the spine. These joints allow the spine to twist without excessive motion. The facet joints also slide on each other to a certain degree, participating in the stability of the spine during flexion and extension. The facet joints also prevent forward slippage, or spondylolysthesis, of one vertebra over the other. Each facet joint has a capsule, containing a lubricant that allows the joints some motion without friction. There is also a rich nerve supply to each joint. The main nerve that provides sensation from the facet joint is the median branch nerve.
Facet arthritis is a degenerative condition of the facet joints of the spine. Because the facet joints are in constant motion they begin to wear out over time. The coating, or cartilage of the joint, becomes thin. Eventually there is bone to bone contact, resulting in friction. This can result in irritation and enlargement of the bones, causing more friction and even compression of the nerves traveling near the facet joint. When the facet joints are inflamed there may be spasm of the nearby muscles. This can result in a crooking back and abnormal posture, which can trigger more back pain.
Facet arthritis pain can be seen anywhere along the spine, including the neck and the upper or lower back. In the neck there can be tenderness to pressure over the joints, usually just off of the midline. The pain may radiate to the shoulder, upper back or may present as headache, just above the neck. In the upper back, facet pain can usually be felt as dull upper back pain, either in the middle or to one side. Sometimes the pain may radiate to the side of the upper back. The joints may or may not be felt, depending on the degree of muscle in the back. The facet joints in the low back can easily be felt as bony protuberances 1 inch to 1 and 1/2 inches from the midline, or middle of the back moving towards the side. With facet arthritis there is tenderness with pressing on these easy to feel joints. There is also pain with movement of these joints. Leaning back or standing presses the facet joints together, and can be felt as pain across the back if both joints are involved or pain on one side of the back if both joints are involved. Likewise, planting your feet and twisting your back can also stress the arthritic facet joint, causing similar pain.
The diagnosis of facet pain is usually made based on the patient’s symptoms. As described above, facet pain usually has a fairly typical presentation. To confirm the diagnosis a doctor may order an MRI of the spine. With advanced facet arthritis there are typical MRI findings. MRI will show enlarged and inflamed facets.
To confirm the diagnosis of facet arthritis, your doctor may want to perform a pain management procedure. Your doctor may perform a facet injection. In a facet injection procedure, the doctor injects an anesthetic into the joint, to see if this relieves pain. If pain is relieved, the doctor may perform a second procedure, a median branch block. In a median branch block, the nerves that control pain from the facet joint are anesthetized, relieving pain. If a facet median branch block is successful, a procedure to ablate, or to excise the facet nerves is performed. This is called a rhizotomy and is also done with a small needle. This procedure results in 3 to 6 months of pain relief.
