Instrumentation has been developed specifically to improve rates of successful spinal fusion. Because bone tends to fuse more effectively in an environment where there is little motion, instrumentation works by limiting the motion at the fused segment. Spine surgery instrumentation can be placed posteriorly in the lamina, spinal processes, or pedicles. Alternatively, anterior instrumentation can be placed.

Posterior thoracic instrumentation is used to hold the midback motion segments together so that they can fuse. It is used for treatment of thoracic disc herniation, degeneration, tumors and fractures, or thoracic deformities such as scoliosis and kyphosis.

Posterior (pedicle)
Pedicle screws provide a means of gripping onto a vertebral segment from posteriorly and limiting its motion. The screws are placed at two or more consecutive spine segments, and then a rod is used to connect the screws. The screws and rods are generally made with titanium. After the bone graft grows, the screws and rods are no longer needed for stability and may be safely removed with a subsequent back surgery. However, most surgeons do not recommend removal unless the pedicle screws cause discomfort for the patient (5% to 10% of cases).

Posterior (lamina or spinous process)
Fixation to the posterior processes of the spine can be obtained by passing wires under the lamina. Alternatively, hooks can be placed to hold onto the lamina. Rarely, wires can be placed in adjacent spinous processes to hold them together.

Anterior
Approaching the disc from the front allows almost all of the disc to be excised. Placing instrumentation in front also allows the disc space to be distracted (jacked open), and restoring its normal height. This is often important in the correction of deformity.

Screws can be placed in the vertebral bodies, and by attaching rods to the screws, correction of deformity can be accomplished. Additionally, cages can be placed in the disc space or to replace the vertebral bodies. Many different cage types are available including cylindrical and titanium mesh. The cylindrical cages can be made of titanium, carbon fiber, or composite material. Allograft (donor) bone can be shaped to replace the vertebral bodies also. The screws and rods can be inserted through an endoscope (a scope that allows the surgery to be done through several one-inch incisions.