Lumbar spine fusion, if the surgery is successful can last a lifetime. Lumbar fusion is the fusion of two diseased lumbar vertebrae into one vertebral body. As long as the fusion surgery is successful and the bone grows smoothly, the two vertebrae become one vertebral body through the bony connection and there is absolutely no mobility in between and no relative motion. The two vertebrae have actually become one vertebral body, and at this point the vertebral body is so secure that there will be no movement in the lumbar spine as long as there is no particularly pronounced, particularly violent injury. Therefore, as long as the lumbar fusion surgery is successful, it can last a lifetime after surgery.