The facet joint, or zygapophyseal joint, is located between two adjacent vertebrae. facet ( facet) literally means one face of a polyhedral shape, for example a cube or a diamond. Vertebral bones are also complex, polyhedral. It has a cylindrical part called the body at the front and parts called the pedicle and lamina at the back. The back of the trunk contains the space between the pedicle and the laminae, where the spinal cord is located. The laminae have bony projections to connect the upper and lower vertebrae. The facet joints are located between these protrusions called the superior and inferior articular processes. As a classification, the planar type is synovial joints. This means that the inside of the joint is covered with the joint membrane called the synovial membrane, contains joint fluid and can slide. Bubbles formed in the synovial fluid of the facet joints are thought to be the source of the sound produced when cracking the spine.
The shape of the facet joints determines how each spine segment moves. For example, facet joints at the waist prevent the spine from bending forward, turning and sliding over each other. It does not have much effect on the side bending motion. It allows some rotational movement while preventing forward bending in the back area.
Facet Joint Diseases
The functions of the facet joints may deteriorate due to aging or excessive use (degeneration), rheumatism, trauma (fracture, dislocation, etc.) and surgery. Abrasions can cause a problem called facet joint arthritis. This is popularly known as calcification. Facet joint arthritis or facet arthropathy may be felt as blunt pain in the lower back. This condition, also called facet syndrome, is among the most common causes of low back pain.
Since facet joints are synovial joints, there is a layer of cartilage on the sides of the bones facing the joint. Due to aging, wear and rheumatism, the cartilage layer can be eroded or even completely lost. As a result, the bones directly touch and rub against each other. The resulting friction and damage cause inflammation (edema and inflammation). The result is pain.
As a reaction to the wear and tear of the facet joint and its failure to perform its normal function, osteoarthritis (calcification) causes spinous bone growth (osteophyte) and thickening of the ligaments. Even synovial cysts can occur.
Malnutrition, smoking, obesity, a past trauma (traffic accident, fall, sports injury, etc.) are risk factors for the development of facet syndrome.
Symptoms vary depending on which facet joint is involved and how much. The degree of wear on the facet joint is not always directly related to the severity of pain. Some people experience no pain at all, while others may develop chronic pain.
Facet joint pain does not conform to the distribution of a particular nerve root, so it is in a reflected pain pattern rather than a radicular one. When the facet joints are involved at the neck level , pain radiating to the neck, head and shoulders may occur. At the waist level, there may be pain radiating to the buttocks and legs. Pain usually increases with bending back (extension) from the waist. Walking or standing for long periods of time can also cause discomfort.
Because the facet joints are located under a thick muscle mass, a special diagnostic approach is required. Muscle aches, herniated discs , and pain radiating from internal organs may cause similar complaints. Special examination techniques are used to distinguish facet joint problems. One of them is the Kemp test. While standing or sitting, the person bends from the waist to the back and then to the side (extension, lateral flexion), then rotation (rotation) is performed and the pain is evaluated. Imaging methods such as direct radiography (X-ray), MRI (MRI), computed tomography are useful in excluding other possible problems and supporting the diagnosis. When pain relief local anesthetic injection is applied to the facet joint, pain relief can be used for diagnostic purposes.
Treatment of Facet Joint Problems
Manual therapy, physical therapy, exercise are the main treatment approaches. Corticosteroid injections may be given to suppress joint inflammation. Simultaneous imaging (fluoroscopy) is used to make sure the needle is placed in the correct place in the joint.