What is Posterior Thoracic Fusion?
Posterior thoracic fusion is a spinal fusion procedure performed through an incision on the back (posterior) of the patient in which two or more vertebrae of the thoracic spine (mid back) are joined together, eliminating any movement between them. This procedure is performed by placing bone grafts or bone graft substitutes in between the affected vertebrae to promote bone growth and eventually fuse the vertebrae into a single, solid bone. Spinal instrumentation or implants such as rods, plates, screws, and interbody devices may be used to stabilize the spine after fusion.
Thoracic Spine Anatomy
The thoracic spine is the central part of the spine. The spine consists of 33 vertebral bones stacked one on top of the other with cushioning discs lying between each vertebrae. It is divided into 7 cervical vertebrae (neck), 12 thoracic vertebrae (mid back), 5 lumbar vertebrae (lower back), 5 sacral bones, and 4 coccyx bones. The sacral and the coccyx bones are fused and do not provide any movement in the spine. The spine plays a key role in the smooth movement, stability, and protection of the delicate spinal cord, and giving symmetry and support to the body.
Indications for Posterior Thoracic Fusion
Posterior thoracic fusion surgery is recommended in certain conditions that cause persistent back pain even after conservative treatment. The surgery is indicated in the following conditions:
- Injury or fracture of the vertebrae
- Instability of the spine caused by infections or tumors
- Spondylolisthesis: slipping of one vertebra over another
- Abnormal spinal curvature (kyphosis)
- Degenerative disc disease
- Spinal stenosis (narrowing of the space within the spinal column)
Preparation for Surgery
You will have a preoperative assessment session before surgery. During your assessment, you must inform your doctor about any health conditions you may have, such as diabetes or bleeding disorders, and about any medications that you may be taking, such as blood thinners and over-the-counter medications. You may be asked to stop taking certain medicines for several days before the procedure.
Your doctor will explain the surgical procedure, its risks and benefits, and answer all your other surgery-related queries before the procedure. Blood tests, X-rays or other imaging tests may also be ordered to assess your medical condition.
Procedure for Posterior Thoracic Fusion
Posterior thoracic fusion is usually performed through a posterior approach under anesthesia with you lying face down. Your surgeon will make an incision over the affected vertebra, along the midline of the back. The back muscles are then retracted to gain access to the spine. This allows direct access to the spine, which allows the surgeon to achieve adequate decompression of nerves, access the facet joints, and create significant correction by mobilizing and removing the facet joints.
Next, the irregularities are corrected by manipulating the spine and its different parts to create a balance. After achieving the right balance, a bone graft or bone graft substitute is placed along the back of the spine to fuse the two vertebrae into one bone. The bone graft may be derived from the same patient (autograft) or from a donor (allograft). Artificial bone grafts may also be used. After completing the surgery, the muscles are reattached to the bone and the incision is closed.
Your surgeon may suggest a brace to be worn or perform internal fixation with plates, screws, and rods during the surgery to hold the spine still. Immobilization of the vertebrae after the surgery helps in the fusion process as well as to stabilize the vertebrae.
Postoperative Care following Thoracic Posterior Fusion
Following the surgery, you will be transferred to the recovery room. Patients are usually encouraged to move after a day of the surgery. You will be given pain medicines in the hospital and will be taught the right way to move and correct posture while sitting, standing, and walking. You may need to stay in the hospital for 3 to 4 days after surgery. You may have to wear a brace or cast when you leave the hospital. You can resume normal daily activities only after 2-3 weeks of rest, during which time the spine heals. You should schedule a follow-up visit with your doctor approximately 10 days after surgery. Follow your doctor’s instructions and maintain a healthy lifestyle to achieve the best outcomes, including:
- Refrain from smoking. Smoking slows down bone healing.
- Eat a healthy nutritious diet. Nutritious foods stimulate bone healing.
- Exercise as advised by your doctor. Physical exercise improves circulation of the blood and lymph and promotes healing.
- Ensure to get ample rest to promote healing.
Risks and Complications of Posterior Thoracic Fusion
As with any surgical procedure, posterior thoracic fusion involves potential risks and complications that may include:
- Infection
- Bleeding
- Persistent pain
- Pseudarthrosis, a condition in which there is not enough bone formed and is more likely in patients who smoke
- Nerve damage
- Formation of blood clots in the legs
