Spondylolisthesis is a Greek term meaning "slippage of the bones in the spine". It presents as the slippage (usually forward) of one vertebra relative to another. It is most commonly found at the fourth and fifth lumbar levels (L4-5) and is more common in women. Overall, 5% of women have this condition, likely related to the force placed on the spine due to women's pelvic anatomy.
Spondylolisthesis can have multiple causes. The most common type of spondylolisthesis, degenerative, is likely caused by a combination of aging and wear weakening the disc. In addition, because of anatomic differences needed for child-bearing, the L4-5 disc of women has more force across it than discs at other levels and discs in men. Another type of spondylolisthesis, isthmic, results from a defect in the pars, a part of the arch of the spinal column. This defect typically occurs without symptoms in teenagers from repetitive extension activities, such as football or gymnastics. Traumatic spondylolisthesis can occur as a result of a fracture. Finally, congenital spondylolisthesis results from anatomical abnormalities present at birth.
Most cases of spondylolisthesis produce no symptoms and people are unaware of the condition. However, spondylolisthesis can cause hip and leg pain due to spinal stenosis that results from the spondylolisthesis. Spondylolisthesis can also cause back pain due to the slippage of bones. X-rays are the best way to diagnose spondylolisthesis.
Most patients with spondylolisthesis will find relief from non-surgical measures such as anti-inflammatory medicines, physical therapy, or epidural injections. Physical therapy exercises aim to strengthen abdominal and back muscles to decrease the motion of the spondylolisthesis. The exercises learned in physical therapy should be performed for at least six weeks to fully assess their effectiveness. Epidural injections of steroids around the spondylolisthesis will frequently decrease inflammation of the nerves and provide pain relief if a patient has leg pain.
Over 85% of patients whose symptoms do not disappear with non-operative treatments have excellent results and experience pain relief from surgical intervention. Generally, spinal fusion is necessary to correct the slip and prevent further slippage. Spinal fusion is combined with decompression, or lumbar laminectomy, to correct the spondylolisthesis and stenosis. Without fusion, the spondylolisthesis is likely to progress over time and symptoms may recur.