The thoracic facet joints are small joints located at the back of the thoracic spine. Together with the intervertebral discs, they help stabilize the spine while allowing controlled movement between the vertebrae.
Because the thoracic spine is supported by the rib cage, the facet joints experience less motion and stress than those in the cervical or lumbar spine. As a result, thoracic facet disorders are less common but can still be an important source of mid-back pain and stiffness.
Please review the Thoracic spine anatomy section for more information.
Thoracic facet joint disorders may result from normal aging, arthritis, injury, inflammation, spinal deformity, or previous spinal surgery. Some conditions produce only localized pain, while others contribute to nerve compression, spinal instability, or degeneration of nearby spinal structures.
Major Diagnosis Types
Degenerative facet problems are rare, all fall into the Minor category.
Minor Diagnosis Types
These terms are often encountered, but are either less often treated or described within one of the above diagnoses.
Thoracic Facet Arthritis
Thoracic facet arthritis is degeneration of the cartilage within one or more facet joints.
As the cartilage wears away, the joint surfaces become rough and inflamed. The body may respond by forming bone spurs or enlarging the joint.
Thoracic facet arthritis commonly develops from:
- Normal aging
- Repetitive mechanical stress
- Previous injury
- Degenerative disc disease
- Thoracic kyphosis
- Adjacent segment degeneration
Symptoms may include:
- Localized mid-back pain
- Morning stiffness
- Pain with twisting
- Pain after prolonged standing
- Reduced spinal flexibility
Many people have mild arthritic changes on imaging without experiencing symptoms.
Thoracic Facet Syndrome
Thoracic facet syndrome describes pain believed to originate from one or more thoracic facet joints.
The joint may become painful because of:
- Arthritis
- Joint inflammation
- Minor instability
- Capsular irritation
- Repetitive stress
- Previous trauma
Pain is typically:
- Localized to one side of the mid-back
- Worse with twisting
- Worse with extension
- Increased after prolonged standing
- Relieved by changing position
Unlike thoracic radiculopathy, facet syndrome usually does not cause numbness or weakness unless another condition is also present.
Thoracic Facet Hypertrophy
Facet hypertrophy refers to enlargement of a facet joint due to chronic degeneration.
As arthritis progresses, the joint may become thicker because of:
- Bone spur formation
- Cartilage loss
- Joint remodeling
- Thickening of supporting tissues
Facet hypertrophy may contribute to:
- Thoracic spinal stenosis
- Foraminal narrowing
- Reduced spinal motion
- Local pain
- Nerve root compression
The degree of enlargement seen on imaging does not always correspond to the severity of symptoms.
Thoracic Facet Joint Effusion
A facet joint effusion is an abnormal collection of fluid within a facet joint.
Fluid may develop because of:
- Joint inflammation
- Arthritis
- Minor instability
- Trauma
- Infection
- Crystal deposition disease
Small effusions are often incidental findings.
A larger effusion may indicate increased joint stress or inflammation and, in some cases, may be associated with abnormal spinal motion.
Thoracic Facet Joint Cysts
Thoracic facet cysts are fluid-filled sacs that arise from a degenerating facet joint.
These cysts are much less common than lumbar facet cysts because the thoracic spine has less motion.
A thoracic facet cyst may:
- Occupy space within the spinal canal
- Narrow the neural foramen
- Compress a nerve root
- Compress the spinal cord
Possible symptoms include:
- Mid-back pain
- Rib pain
- Numbness
- Weakness
- Balance difficulty
- Thoracic myelopathy
The significance depends on the size and location of the cyst rather than simply its presence.
Degenerative and Inflammatory Facet Disorders
Most thoracic facet disorders develop gradually through normal wear and aging.
Less commonly, facet joints may become inflamed because of inflammatory conditions such as:
- Rheumatoid arthritis
- Ankylosing spondylitis
- Psoriatic arthritis
- Crystal deposition disorders
- Septic facet joint infection
Inflammatory disorders often involve multiple joints and may progress differently than typical osteoarthritis.