This is a spinal disorder in which a vertebra slips forward onto the bone below it, pressing on the nerves and causing back or leg pain and numbness. The disease is graded by measuring the degree to which the vertebrae has slipped: Grade 1 indicates that 25% of vertebral body has slipped forward, while grade 5 means the vertebral body has completely fallen off. The more common causes of this condition are congenital spondylolisthesis, which is the result of abnormal bone formation at birth; isthmic spondylolisthesis, which results from spondylolysis, a condition that leads to small stress fractures, weakening the bone and causing it to slip; or degenerative spondylolisthesis, which is related to aging. Spondylolisthesis is more likely to occur in younger patients who participate in sports that involve hyperextension or overuse of the lumbar spine.
Some patients do not experience any symptoms; for those who do, the most common are a feeling of muscle strain that radiates into the buttocks or back of the thighs, or pain that worsens with activity and improves with rest. Muscle spasms that often occur as a result of this condition can also lead to back stiffness, tight hamstrings, and difficulty standing and walking. Risk factors for spondylolisthesis include playing physical sports that put stress on the bones in the lower back, such as gymnastics and football, and genetics.
The doctor will conduct a physical exam to determine areas of tenderness, limited range of motion, and muscle spasms or weakness. Imaging tests, like X-rays, magnetic resonance imaging (MRI), and computed tomography (CT) scans may also be required to provide a detailed view of the bones and soft tissue.
Treatment can include over-the-counter or prescription-strength pain relievers, or epidural steroid injections, which are inserted directly in the space surrounding the spine to reduce inflammation and ease pain. Physical therapy may also be warranted. Severe spondylolisthesis may require surgery, including spinal fusion, in which a portion of bone is transplanted and fused to the back of the spine to stabilize it.