This difficult word denotes a slippage of one vertebra on another, usually the one above being forward on the one below.  It can be caused by a bilateral defect in the part of the vertebra that connects to the facet joint. It can be a congenital defect not causing symptoms and it’s usually at the base of the spine, at L5/S1.  Sometimes in people with back and leg pain and spondylolisthesis a herniated disc is found to be the cause of pain.

Spondylolisthesis can be caused by heavy lifting or other trauma and if it limits work, can be treated with a fusion operation.  The bony defect without any slippage is called spondylolysis and is usually an incidental finding. With aging, sometimes the facet joints fail and a degenerative type of spondylolisthesis develops, also called pseudo-spondylolisthesis. That can cause spinal stenosis and if symptoms require an operation, a fusion may need to be done.