Spondylolisthesis is a condition of the spine in which a vertebra slips out of alignment, moving forward on the vertebra below. The condition is usually caused by degenerative disease, such as arthritis. Other causes include bone diseases, trauma, and stress fractures.
A decompression laminectomy removes bony spurs in the spinal canal, freeing up space for the nerves and spinal cord. Spinal fusion is a technique in which two vertebrae (back bones) are fused together. This provides stronger support for the spine