The vertebrae are the bones that make up the spinal column, which surrounds and protects the spinal cord. The intervertebral discs are soft tissues that sit between each vertebrae and act as cushions between vertebrae, and absorb energy while the spinal column flexes, extends, and twists. Nerves from the spinal cord exit the spinal column between each vertebra.

Spinal fusion may be recommended for:

• Abnormal curvature of the spine: (scoliosis or kyphosis)
• Injury to the spinal vertebrae
• Protrusion of the cushioning disc between vertebrae (slipped disc, herniated nucleus pulposus)
• Weak or unstable spine caused by infections or tumors

While the patient is deep asleep and pain-free (using general anesthesia), an incision is made over the spinal area to be treated. Different incisions are made depending on the area to be treated.

The lower spinal vertebrae are repaired through an incision directly over the spine (posterior lumbar approach). The upper spinal vertebrae are repaired through an incision in the back or side of the neck (cervical spine). The middle spinal vertebrae are repaired through an incision made in the chest and abdomen (anterior thoracic spine). The abnormal or injured vertebrae are repaired and stabilized with bone grafts, metal rods, or both.

Spinal fusion results in a decreased mobility of the spinal column. Physical therapy is usually necessary post-operatively to optimize mobility.