Facet Joint Syndrome
Facet joint syndrome is a condition resulting from degeneration of the facet joints in the vertebral column. The facet joint syndrome commonly affects the facet joints in the cervical spine or the lumbar spine. The patients suffering from facet joint syndrome may complain of neck pain or low back pain. The pain may be localized to the involved area or may radiate to other parts of the body.
The facet joints provide stability to the vertebral column and aid in the movement of the spinal column. Each vertebra has two pairs of facet joints, one pair facing upwards connecting with the vertebrae above and the other pair facing downwards, connecting with the vertebra below. The facet joints through sliding and gliding motion, help in bending, extending, and twisting the spine.
The facet joint like some other joints in the body are synovial joints which are covered by a joint capsule. The ends of the bones forming the facet joints are covered with a protective tissue known as the articular cartilage. The capsule of the joint secretes a watery thin fluid called synovial fluid to lubricate and nourish the joint.
With advancing age the intervertebral disk between the adjoining vertebrae loses water content that may lead to small tears in the disk. The loss of water content of the disk leads to loss of disk height. The instability from loss of disk height may lead to additional stress on the facet joints leading to facet joint degeneration.
The wear and tear of the joint leads to loss of articular cartilage and thinning of the joint capsule. The inner synovial lining of the joint capsule gets inflamed causing pain. The degeneration of the facet joint leads to the rubbing of the bones and the resulting instability may result in the formation of bone spurs. The bone spurs may impinge the exiting nerve roots and cause radiculopathy.
Facet joint degeneration may also occur in patients who are involved in excessive movements of the spine. The repetitive bending, extending, and twisting motions on the facet joint may lead to wear and tear of the facet joints. The wear and tear are especially common in the lumbar spine as the lumbar spine is the major weight-bearing part of the spine.
Cervical spine facet joint syndrome may result from traumatic neck injuries such as whiplash injury. The mid-back known as the thoracic spine is rarely affected by facet joint syndrome as the segment has little movement secondary to the attachment of the ribs.
The symptoms of facet nerve syndrome result from irritation of the joint during motion as the bones devoid of the cartilage rub against each other. The irritated and inflamed joint sends a signal to the brain via the medial branch nerve causing the sensation of pain.
The pain is usually a dull ache located in the segment of the involved spine. The pain gets worse after periods of inactivity and may be associated with stiffness. The pain may refer to the buttocks or upper thighs in the case of lumbar facet joint syndrome. In the case of cervical facet joint syndrome, the pain may refer to the upper back and shoulders. The pain gets worse on activities such as bending backward and twisting movements.
The patients may experience relief on activities that offload the weight from the joint such as bending forward and sitting. The bone spurs may impinge upon the nerve roots and cause symptoms of radiculopathy. The radiculopathy symptoms consist of shooting pain down the leg/foot in case of lumbar involvement and shooting pain down the arm/hand in case of cervical involvement.
Diagnosis & Management
The diagnosis of facet joint syndrome is made by a spine orthopedic surgeon after a detailed history and examination. The physician will extract a detailed history of the symptoms and the events leading to them. Various physical examination tests are done to localize the segment of the spine involved and rule out other causes of pain.
A detailed neurological examination is done to look for any motor sensory loss and signs of radiculopathy. Radiological tests are usually followed in the form of an X-ray and an MRI. The facet joints along with any bone spurs are usually visualized on an X-ray. The MRI allows detailed visualization of soft tissue structures.
A diagnostic facet nerve injection test may be done in patients with facet joint syndrome. The procedure involves the injection of a mixture of lidocaine (a numbing medication) and cortisone (a steroid medication) in the facet joint under fluoroscopic guidance. If the patient experiences immediate relief due to the action of lidocaine, a diagnosis of facet joint syndrome is likely.
The facet joint injection also serves as a therapeutic tool in such patients. Multiple injections may be administered over time leading to prolonged periods of relief. The cortisone in the injection reduces inflammation in the joint and the surrounding tissues leading to relief.
Conservative management in the form of medications such as NSAIDs and muscle relaxants, heat and cold therapy, and physical therapy are usually the first line of treatment in the management of facet joint syndrome. The physical therapy is directed towards posture training and muscle strengthening exercises. Physical therapy along with medications provides significant relief in the vast majority of the patients.
Surgical management is reserved for patients who are unable to benefit from conservative management. The initial surgical options include facet nerve injections and radiofrequency ablation of the medial branch nerve. Surgeries such as lumbar fusion are rarely performed in patients in whom all other treatment options have been tried and failed.