What is the definition or description of: lumbar fusion?

A spinal fusion is a: Surgery to cause 2or more lower (lumbar) spine segments to be joined together through a growth of bone initiated by placement of bone tissue or graft taken from patient or from a donor source or even a manufactured source which could include: bone growth proteins and particulate structures that act as scaffolds for bone to grow on & may include implants or instrumentation to enhance healing rates.

Imobilizing : A lumbar fusion causes 2 or more bones to join together to make one large solid piece of bone. Think of gluing two blocks togther. The process may involve placement of screws or other pieces of material such as cages between the bones .Multilevel fusions can included metal rods screwed to the bones.