Spondylolisthesis

The spine consists of vertebral bones stacked one on top of the other that surround and protect the spinal cord. Spondylolisthesis is a condition in which a vertebral bone slips out of place in relation to the one beneath it. This causes misalignment and narrowing of the spinal column, a condition called spinal stenosis, which can put pressure on the nerves, resulting in pain in the lower back, buttocks or legs with walking or standing.  As the spine tries to stabilize itself, the joints between the slipped vertebra and adjacent vertebrae can become enlarged, pinching the nerves as they exit the spinal column.