The twelve vertebrae in the thoracic spine (commonly referred to as T1-T12) each have two thoracic facet joint sets – one set on the top and one set on the bottom – which are responsible for providing the middle back with the flexibility and strength it needs.
On the right side and left side of each thoracic vertebra, a thoracic facet joint surface faces upward and one faces downward. These joints interlock with joints on adjoining vertebrae to ensure the structural integrity of the middle back. Coated in cartilage and encapsulated with a thick lubricant called synovial fluid, these joints act as a flexible hinge – which, along with the intervertebral discs, give the middle spine its stability and limited range of motion.
The thoracic spine, unlike its counterparts in the cervical (upper) and lumbar (lower) spine, is not designed to be particularly flexible. Instead, the main goal of the middle back is to be a solid support structure for the ribcage. To facilitate this stability (while still providing some flexibility and extension), the T1-T12 facet joints fit together like puzzle pieces, effectively connecting the vertebrae together.
As the thoracic facet joints are not as active as the cervical facet joints (in the neck) or lumbar facet joints (in the lower back), the thoracic area of the spine isn’t quite as prone to damage, but this isn’t to say it’s immune from problems. Middle back pain or nerve-related problems can be caused by a number of sources, such as:
- Regular aging
- Trauma or other injury
- Degenerative disc disease
- Facet disease
- Spinal stenosis
- Bone spurs or tumor
- Facet joint osteoarthritis
- And more
The deterioration of a thoracic facet joint can cause middle back pain and stiffness, which can be extremely frustrating. Treatment of the symptoms can usually be accomplished with a conservative course that includes therapy, painkillers, and heat or ice application. Occasionally, elective surgery may be required to sufficiently treat the symptoms of a problematic thoracic facet joint.