Spinal fusion is a surgery that joins (fuses) two or more vertebrae together. Vertebrae are the 33 interlocking bones of the spinal column that are stacked on top of each other.

Methods of doing spinal fusion may include:

• Using bone that is harvested from elsewhere in the body or is obtained from a bone bank. Or sometimes human-made bone is used. This bone is used to make a "bridge" between adjoining vertebrae. This graft of bone stimulates the growth of new bone.
• Securing metal implants to the vertebrae to hold them together until new bone grows between the vertebrae.

The medical term for spinal fusion is arthrodesis.