When is spinal fusion needed for bone overgrowth?

If unstable: When bony overgrowth creates excessive motion in the spine and narrows the spinal canal, it will require surgery. If removal of the bony overgrowth causes destabilization of the spine, you have to fuse the spine.

Rarely: Spine fusion is reserved for when symptoms arise from spinal instability. Examples include unstable fracture, severe scoliosis, or symptomatic vertebral slip resulting in a pinched nerve. A symptomatic bone spur can almost always be removed without fusion. Like any surgery, fusion should be considered only when there is a clear benefit to offset inherent risks.