The goal of a spinal fusion is usually a solid fusion (solidification) of the curved part of the spine. A fusion is achieved by operating on the spine, adding bone chips and allowing the vertebral bones and bone chips to slowly heal together to form a solid mass of bone called a fusion.
The bone chips (bone graft) may come from your hip (iliac crest) or from the hospital's bone bank. Often the spine is partially straightened with metal rods and hooks or wires (instrumentation). The rods, brace, or cast hold the spine in place until your fusion has a chance to heal.
Once the fusion has healed (usually 3 to 12 months) the abnormal section of the spine cannot curve more. The instrumentation can usually be left in your back without causing any problems.
Posterior fusion with instrumentation is the most common operation done for idiopathic scoliosis. In the posterior fusion the spine is operated on from behind with an incision straight down the back.
Various types of instrumentation are used to partially straighten the spine and hold it secure while the bone fusion occurs.
For most operations for idiopathic scoliosis, no brace or cast is used postoperatively.
- In congenital scoliosis or spondylolisthesis the posterior fusion is usually done without instrumentation, and a cast or brace is needed postoperatively.
Anterior fusion is used in special instances of idiopathic scoliosis, and commonly in congenital scoliosis, kyphosis, or myelomeningocele.
An incision is made along a rib and/or down the front of the abdomen to obtain access to the front of the spine. Bone graft from hip, rib or bone bank is used for the fusion. Screws and washers attached to a rod may be used to straighten the spine.
Fusions of this type usually require a postoperative brace.
Anterior and posterior fusion
Some special cases of spinal deformity require both an anterior (front) and posterior (back) operation. Usually these can be done on the same day, but sometimes must be done at separate operations spaced 1-2 weeks apart.