The thoracic spine is the longest portion of the spine. It connects the cervical spine above to the lumbar spine below, running from the base of the neck down to the abdomen. The thoracic spine is the only spinal region attached to the rib cage.
The thoracic spine consists of vertebrae T1-T12 with soft spinal discs providing cushioning between the vertebrae. The thoracic spine has two important roles: to protect the spinal cord and to anchor the rib cage, which protects vital organs such as the heart and lungs.
Because the thoracic spine is less mobile than the cervical or lumbar sections, it doesn’t suffer the number of disc herniations as those spinal sections. For that reason, spinal fusion in the thoracic region is much less common than in the cervical or lumbar spine.
What Is Thoracic Fusion?
Thoracic spine fusion occurs in the T1-T12 vertebrae portion of the spine. In fusion, the spinal disc is removed, which has usually herniated, and replaces it with bone grafting material. The two vertebrae above and below the herniated disc are then fastened together using a plate or rods and screws. This precludes any movement while the bone graft material works to fuse the two vertebrae together. As the graft grows, it eventually grows over the titanium rods and screws and the two vertebrae become a single piece.
Why Would A Person Need Thoracic Spine Fusion?
Disc herniation is much less common in the thoracic spine compared to either the cervical spine or the lumbar spine. That’s because the thoracic spine doesn’t move to the degree of the other sections, and it doesn’t bear the loads of the lumbar spine. The goal of fusion in any section of the spine is to eliminate movement between the two vertebrae, as this movement is leading to contact with either the spinal nerve roots exiting the spinal cord or with the spinal cord itself.
These are different conditions that could lead to a thoracic fusion:
- Degenerative disc disease — This is the degeneration of our spinal discs that is the result of normal wear and tear and aging.
- Disc herniation — When a spinal disc herniates, force has caused the inner gel of the disc to push through the outer annulus. The disc gel then pushes outwards and can affect nearby nerves.
- Radiculopathy — This is the term for compression of the nerve roots exiting the spine. This can occur due to disc herniation or to the formation of bone spurs on the foramen, the hole where the nerve roots exit the vertebra.
- Spinal stenosis — Stenosis is a narrowing of the spinal canal to the degree where the spinal cord or the nerve roots are being compressed. This can occur due to osteoarthritic changes in the vertebrae, disc height deterioration, disc herniation, and other reasons.
- Kyphosis — When looked at from the side of our body, our spine naturally has curves in it. When those curves become too large in the normal outward curve in the mid-back region, this is kyphosis. This can be congenital or due to degenerative disc disease.
- Scoliosis — Adult scoliosis would involve an abnormal curve of the spine to the right or the left after a person has finished growing. Scoliosis is common in adolescents, but typically doesn’t merit surgery. However, if the discs and spinal anatomy deteriorate due to the curve as the person reaches adulthood, fusion could be necessary.
- Thoracic vertebrae fracture — Spinal fractures often come from trauma, such as a car crash or a fall from height. They can also occur in later life due to osteoporosis.
How Is Thoracic Fusion Performed?
Various techniques for spinal fusion is used, depending on the location of the vertebrae being fused and the reason for the fusion. They may approach the spine from the front in anterior spine fusion or from the back in posterior spine fusion. In anterior fusion, a plate is usually used to fasten the two vertebrae together. In posterior fusion, rods and screws are used.
The patient is under general anesthesia for this surgery. Regardless of the method, this is the basic procedure.
- Making the incision — To gain access to the vertebrae to be fused, an incision is made either in the back directly over the spine (posterior), on either side of your spine, or in your abdomen (anterior). Necessary muscle and tissue are moved aside to access the spine.
- Disc removal and graft placement — The disc is removed between the two vertebrae to be fused. Often this disc has herniated and is pushing on the adjacent spinal cord or nerve roots. The disc is replaced with bone graft material. This material will grow and fuse the two vertebrae into one. The graft may come from a bone bank, your body (usually your pelvis), or may be synthetic.
- Fusion — The bone graft material will fuse the two vertebrae together permanently, but to provide support to keep the vertebrae together while the graft grows, the two vertebrae are bound to each other with either a plate and four screws or with a pair of vertical metal rods and screws. This completely stabilizes the spine to allow the graft to grow effectively.
What Is Recovery Like After Spinal Fusion Surgery?
After your fusion surgery you’ll be in the hospital for usually two to three days. You’ll have some pain and discomfort, but this is manageable with pain medications. We’ll take spinal x-rays before discharge, just to make sure everything looks good before sending you home. Your stitches will come out in about 10 days. From there, you’ll have follow-up appointments in about 4-6 weeks, 6 months, one year and two years.
Your recovery will take some commitment and work on your part. It can take up to 6 months to a year for your back to fully heal. Physical therapy is important and ongoing. For the first 6 months, you’ll need to avoid twisting, bending, and any heavy lifting (that means anything over a gallon of milk).
What Can I Expect for My Results After Thoracic Fusion Surgery?
Fusion is typically effective treatment for fractures, deformities, or instability in the spine. It is most effective when the source of your back or leg pain is identifiable, and a specific site can be pinpointed.
This procedure will usually provide relief from your symptoms, but it doesn’t prevent you from developing more back pain in the future. That’s especially the case if osteoarthritis or degenerative disc disease are the issues behind your spinal deterioration.
Fusion, by immobilizing the two vertebrae in question, can also create additional stress and strain on the surrounding vertebrae above or below the fused section. This can speed degeneration in those areas in some patients.