Spondylolisthesis occurs when one of the bones of the spine (vertebrae) slips out of place onto the vertebra below it. The symptoms that accompany a spondylolisthesis include pain in the low back, thighs, and/or legs, muscle spasms, weakness, and/or tight hamstring muscles.
Forward slippage of an upper vertebra on a lower vertebra is referred to as anterolisthesis, while backward slippage is referred to as retrolisthesis. Spondylolisthesis can lead to a deformity of the spine as well as a narrowing of the spinal canal or compression of the exiting nerve roots.
Spondylolisthesis usually develops in the spine’s lumbar region. The lumbar spine is exposed to directional pressures while it carries, absorbs, and distributes most of the body’s weight at rest and during activity. While your lumbar spine is carrying and absorbing body weight, it also moves in different directions as it rotates and bends. Sometimes, this combination causes excessive stress to the vertebra and/or its supporting structures, and may lead to a vertebral body slipping forward over the vertebra beneath.
Some people are symptom free and find the disorder exists when revealed on an x-ray. In advanced cases, patients may appear swayback with a protruding abdomen, exhibit a shortened torso, and present with a waddling gait.
Surgery may be needed if slippage progressively worsens or if back pain does not respond to nonsurgical treatment and begins to interfere with activities of daily living.