The facet joints are small stabilizing joints that are located in pairs between and behind each adjacent vertebra at every level of the spine except at the uppermost two levels. They are weight bearing structures and are subject to mechanical stress.
Functioning with the vertebral body and intervertebral disc the facet joints allow you to bend and twist via a sliding motion of the two joint surfaces.
Facet joints have cartilage and are lubricated with synovial fluid that is kept within the joint by a capsule which surrounds the joint. The facet joints have a rich nerve supply (medial branches) that allows it to perceive pain when injured.
Mechanical stress can lead to injury of the facet joint. Common causes of such stress include aging, loss of disc height, injury or repetitive abnormal loading of the joints over time.
The joint will show changes of thinning or loss of the articular cartilage, reduction or loss of the synovial fluid or lubricant, roughening and overgrowth of bone, inflammation in the bone adjacent to the joint space, overgrowth of the joint and, at times, cysts can develop in the bone adjacent to the joint space. These arthritic changes may or may not produce spine pain. This condition may also be referred to as "facet joint syndrome."
Patients with facet joint syndrome have pain and stiffness in their neck, mid-back or low back.
Facet joint pain in the low back causes low back pain, but pain can also be cause pain into the buttock, hips and thigh. It is often be provoked by motion or increased stress in the low back such as while standing or back bending.
Facet joint pain in the neck can cause neck pain, base of skull pain, headaches, upper back and shoulder blade pain, and is often most provoked by looking upward and rotating the head.
Facet joint pain in the mid back will cause back pain, shoulder pain and pain towards the ribs. Facet joint pain will not cause numbness or weakness in the arms or legs.
The diagnosis of facet joint syndrome usually begins with a complete history and physical exam.
X-rays can show arthritis in the joints but a CT scan or MRI usually shows greater detail of the joint’s anatomy.
A bone scan can occasionally be helpful to determine if there is substantial joint inflammation.
Radiology tests show the anatomy of the joint but cannot determine if the joint is the source of pain. This is because some people with arthritis or inflammation seen in these joints actually have no pain at all. The best method to determine if the facet joint is causing pain is to perform diagnostic injections of anesthetic under x-ray (fluoroscopic) guidance, numbing the nerve supply to the joint via Medial Branch Blocks.
The joint itself can be injected with anesthetic, but is not as specific or accurate as medial branch blocks to diagnose facet joint pain.
The first treatments should be non-invasive and include such methods as postural correction, activity alteration, improving muscle flexibility, strengthening, restoring normal joint motion and medications to reduce inflammation.
Commonly, such treatments are performed by physical therapists, manual medicine providers, and massage therapists. Acupuncture can also help some patients.
If these conservative treatments are not adequate, then fluoroscopically guided injections will be considered.
One option may be facet joint injections, which involve placing anti-inflammatory corticosteroid agents into the joint to reduce joint inflammation and pain. If relief is obtained, then therapeutic exercise programs are often resumed in order to improve the spine’s biomechanics.
Decreasing the degree of joint strain can prevent or delay the recurrence of pain and inflammation, and keep it from returning to the same intensity of pain as prior to the injection.
A multi-faceted treatment approach very often works better than utilizing treatments in isolation.
If facet injections fail to provide long enough relief of facet joint pain, then medial branch blocks can be performed to determine if the facet joints are causing a predominant degree of pain, and the results will determine if one is a candidate for a radiofrequency neurotomy.
Radiofrequency neurotomy (aka radiofrequency ablation or RFA) involves treating the medial branches so one no longer feels pain from the facet joint.
The pain signals are essentially short circuited or blocked for a long period of time (e.g. 10 months or longer).
If the nerves regenerate and the pain signals are restored, then radiofrequency neurotomy can be repeated to often reinstate pain relief.