Spondylolisthesis occurs when one vertebra in the spinal column becomes fractured and the spine slips out of place, usually in the lumbar area. Back pain, numbness in the extremities, or sensory loss can be caused by nerve root compression as a result of the slippage. Related conditions include spondylosis which is arthritis of the spine, and spondylolysis which is a fracture of a vertebra without it coming out of alignment.
What is Spondylolisthesis?
Spondylolisthesis occurs if a vertebra shifts as a result of a widening fracture when the muscles and ligaments holding a vertebra in place become overworked; the vertebral body can then slide forward onto the vertebra below. The forward slip makes the spinal canal smaller, leaving less room for the nerve roots and often causing a pinched nerve. Teenagers sometimes develop a type of spondylolisthesis in which one vertebra slips forward and slides completely off the vertebra below.
Spondylolisthesis can also occur in the cervical spine and may result from a neck injury or rheumatoid arthritis. Cervical spondylolisthesis usually causes neck pain and stiffness.
Jeremy Steinberger, MD, explains the difference between spondylolisthesis, spondylosis, and spondylolysis.
What Causes Spondylolisthesis?
Spondylolisthesis can be caused by degeneration, trauma, or congenital defects. It most commonly occurs in the lowest lumbar vertebra on the bony ring formed by the pedicle and lamina bones, which protects the spinal cord and spinal nerves. The bone is weakest in the area, pars interarticularis, which joins the upper and lower joints. At first, the body can heal the damage produced by strain on the bone. However, if repeated strains occur faster than the body can respond, the bone will eventually fracture. This pars defect or fracture is called spondylolisthesis.
Spondylolisthesis is one of the most common causes of persistent back pain in children and adolescents but does not always cause discomfort. If you experiencing pain, it may stem from mechanical problems (certain activities, movements, or positions), or from within the moving parts of the spine. If compression of the spine pinches or irritates nerves, that can also cause pain. For example, a pinched nerve can produce pain in the back, sciatica, which is pain that radiates down to the foot. Spondylolisthesis can also cause numbness in the foot and weakness in the muscles supplied by the affected nerve. Mount Sinai specialists are highly skilled in diagnosing and treating spondylolisthesis.
Your physician will take your history, perform a physical exam, and will likely request an X-ray. X-rays are often all that are needed to diagnose a pars defect or forward slip of a vertebra. However, sometimes bone scans and computerized tomography (CT) scans are preferred.
Treatment for spondylolisthesis is similar to treatment for other causes of mechanical and compressive back pain. Doctors may prescribe rest during the acute phase, including avoidance of sports, to help relieve symptoms. Special braces, casts, or corsets may be used to help heal a stress fracture and to ease pain. We may also encourage you to work with a physical therapist. Specific exercises are important for rehabilitation and return to sports.
Surgical Treatment for Spondylolisthesis
If conservative treatments for spondylolisthesis fail to manage your pain, we may recommend surgery. Surgical treatment should relieve both mechanical and compressive pain as well as any pressure on spinal nerves. The surgical procedure for spondylolisthesis is known as decompressive laminectomy of the lumbar spine and will free up or decompress the affected nerves. The surgeon will remove a section of bone from the back of the spine (lamina) and/or a portion of the facet joints. Because the lamina and facet joints provide stability to the spine, removing them can cause the spine to become loose and unstable. When this occurs, we may also perform spinal fusion in the same procedure. In adolescents and children with spondylolysis only and no spondylolisthesis, we may perform direct repair of the pars defect without fusion.