facet joint syndrome
Facet syndrome is an articular disorder related to the lumbar facet joints and their innervations, and produces both local and radiating pain. Ghormley was the first who characterized the ‘facet syndrome’ by back and/or leg pain, as a result from mechanical irritation of a lower lumbar zygapophysial joints. This is more then 20 years ago, but the facet joint has been increasingly recognized as an important cause of low back pain.
Excessive rotation, extension, or flexion of the spine (repeated overuse) can result in degenerative changes to the cartilage of the joint and may involve degenerative changes to other structures including the intervertebral disc. Strain of the lumbar facet joint (FJ) is highest at end-range extension.[ Additionally, with a reduction of disc height, Facet joint mechanical loads will increase, which can also leads to degeneration of the Facet joints.
55% of facet syndrome cases occur in cervical vertebrae, and 31% in lumbar. This includes all the structures that are a part of the facet joint such as the fibrous capsule, synovial membrane, hyaline cartilage and bone.
Neck pain due to cervical facet joint involvement is known as cervical facet syndrome and low back pain due to lumbar facet joint involvement is known as lumbar facet syndrome.
Clinically Relevant Anatomy
The facet joints are joints in the posterior aspect of the spine. In each spinal motion segment there are two facet joints. Although these joints are most commonly called facet joints, they are more properly termed zygapophyseal joints (abbreviated as Z-joints; also commonly spelled as "zygapophysial joints"), a term derived from the Greek roots zygos, meaning yoke or bridge, and physis, meaning outgrowth. This “bridging of outgrowths” is most easily seen from a lateral view, where the Z-joint bridges adjoin the vertebrae. The term facet joint is a misnomer because the joint occurs between adjoining zygapophyseal processes, rather than facets, which are the articular cartilage lining small joints in the body (eg, phalanges, costotransverse and costovertebral joints). This joint is also sometimes referred to as the apophyseal joint or the posterior intervertebral joint.
Etipathology of facet joints syndrome
The hypothesis that disc degeneration and disc narrowing play a meaningful role in facet joint dysfunction via increased loading and subsequent osteoarthritis , is often cited, but has yet to be supported by sufficient evidence.
In rare cases, facet joint pain can occur secondary to a traumatic event, but more commonly, it is the result of repetitive stress and/or cumulative low-level trauma. Data from cadaveric studies have shown that anatomical changes occur more rapidly during sustained flexion than with repetitive movements. Although the studies provides a theoretical model of degeneration, cadavers cannot experience pain and the viscoelastic materials may have altered characteristics.
In the upper lumbar spine, the greatest amount of joint displacement and strain is associated with lateral-flexion or side-bending in the first three pairs of facet joints (L1-L2; L2-L3; L3-L4). The two lowest levels(L4-L5; L5-S1) experience the greatest strain during forward flexion. The resultant inflammation causes the joint to swell, leading to stretching of the capsule and subsequent pain generation. The swelling can also irritate the nearby spinal nerves, resulting in spasm of the deep postural paraspinal muscles (ex. M. Multifidus).
Predisposing factors for lumbar facet joint pain are spondylolisthesis, spondylolysis, degenerative disc disease and advanced age.
Zygapophyseal joint pain is felt locally as a unilateral back pain, which when severe can spread down the entire limb. The source of pain must be confirmed by clinical examination.
The joint capsule is more likely to generate pain than the articular cartilage or the synovium. All of the lumbar facet joints are capable of producing pain that can refer to the groin (this is more common with lower facet joint pathology).[
Cervical facet syndrome includes following symptoms:
- Axial neck pain (rarely radiating past the shoulders), most common unilaterally
- Pain with and/or limitation of extension and rotation
- Tenderness upon palpation
- radiating pain locally or into the shoulders or upper back, and rarely radiate in the front or down an arm or into the fingers as a herniated disc might.
Lumbar facet syndrome can be characterised by following symptoms:
- Pain or tenderness in lower back.
- Local tenderness/stiffness alongside the spine in the lower back.
- Pain, stiffness or difficulty with certain movements (such as standing up straight or getting up from a chair.
- Pain upon hyperextension
- Referred pain from upper lumbar facet joints can extend into the flank, hip and upper lateral thigh
- Referred pain from lower lumbar facet joints can penetrate deep into the thigh, laterally and/or posteriorly
- L4-L5 and L5-S1 facet joints can refer pain extending into the distal lateral leg, and in rare instances to the foot
Possible reasons for cervical and lumbar pain
- Cervical disc injuries
- Cervical discogenic pain syndrome
- Cervical radiculopathy
- Cervical spine sprain/strain injuries
- Lumbosacral Disc Injuries
- Lumbosacral Discogenic Pain Syndrome
- Lumbosacral Radiculopathy
- Lumbosacral Spine Acute Bony Injuries
- Lumbosacral Spine Sprain/Strain Injuries
- Lumbosacral Spondylolisthesis
- Lumbosacral Spondylolysis
- Piriformis Syndrome
- Sacroiliac Joint Injury
- Inflammatory arthritidies (ex. rheumatoid arthritis)
- Spondylarthropathies (ex. osteoarthrosis, synovitis)
Diagnostic facet block Procedures
Facet joint syndrome cannot be reliably clinically diagnosed (Jackson RP2 1992). The most used systems to diagnose this syndrome are X-ray, computed tomography (CT) scan of the spine or a magnetic resonance imaging (MRI) scan. Plain radiography does not provide information in establishing the diagnosis of facet joint syndrome, but it may help with the evaluation of the degree of degeneration. Once degeneration is visible on plain radiography it has already reached an advanced stage.
The working diagnosis of facet pain, based on history and clinical examination, may be confirmed by performing a diagnostic block. A positive indication is when the patient experiences a 50% pain reduction after a block has been performed. It involves injecting a medicine into or near the nerves that supply the facet joint. If the pain is not relieved by the injection, it is unlikely that the facet joint is the source of the pain. If these injections help to reduce the pain, we can suggest that the pain comes from the facet joint.