Spondylolysthesis is a spine condition that results when one of the vertebra slips forward or backward when compared to the vertebra adjacent to it. A forward slippage of the vertebra is called anterolisthesis, while a vertebra that slips backward is called retrolisthesis.
There are five types of spondylolisthesis:
Dysplastic spondylolisthesis: A congenital condition caused by a defect in the formation of part of the vertebra called the facet that allows it to slip forward.
Isthmic spondylolisthesis: A defect and slip that exists in a portion of the vertebra called the pars interarticularis. (If there is a defect without a slip the condition is called spondylolysis.) Isthmic spondylolisthesis can be caused by repetitive trauma and is more common in athletes exposed to hyper-extension motions including gymnasts and football linemen.
Degenerative spondylolisthesis: More common in older patients, degenerative spondylolisthesis occurs due to arthritic changes in the joints of the vertebrae due to cartilage degeneration.
Traumatic spondylolisthesis: Caused by direct trauma or injury to the vertebrae, such as a fracture of the pedicle, lamina or facet joints that allows the front portion of the vertebra to slip forward with respect to the back portion of the vertebra.
Pathologic spondylolisthesis: Caused by abnormal bone, such as from a tumor.
Spondylolisthesis is the most common cause of back pain in teens. Symptoms of spondylolisthesis often begin during the teen-age growth spurt. Degenerative spondylolisthesis occurs most often after age 40.
When symptoms occur, low back pain is the most common. The pain usually spreads across the lower back and might feel like a muscle strain. Spondylolisthesis can also cause muscle spasms in the hamstring muscles in the back of the thighs. Tight hamstrings can cause the person to walk with short strides and with the knees slightly bent. If the slipped vertebra is pressing on a nerve, pain might spread down the leg to the foot. The foot might also tingle and/or feel numb.
Spondylolisthesis can lead to a deformity of the spine as well as a narrowing of the spinal canal (central spinal stenosis) or compression of the exiting nerve roots (foraminal stenosis). Persistent pain associated with spondylolisthesis can lead to reduced mobility and inactivity. There is also a risk of permanent nerve damage if a slipped vertebra is pressing on a spinal nerve root.
An X-ray of the lower back can show a vertebra out of place. A CT or MRI scan might be needed to more clearly see the bones and nerves involved. The Bonati Spine Institute offers free MRI reviews. MRI and CT scans can be uploaded directly to our website, and a surgeon will review and provide feedback as soon as possible.
Sources: MedicineNet.com, ClevelandClinic.org