Spondylolisthesis is a spinal condition that occurs when one of the vertebrae, the bones of the spine, slips out of place onto the vertebra below it. It is a condition involving spine instability, which means the vertebrae move more than they should. The word spondylolisthesis comes from the Greek words spondylos, which means "spine" or "vertebra," and listhesis, which means "slipping, sliding or movement". 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.

Symptoms of spondylolisthesis can include localized lower back pain and/or leg pain if there is associated nerve compression. Most patients with spondylolisthesis have few or no symptoms, and it is generally not a serious or dangerous condition. However, if patients develop associated symptoms due to nerve compression, disc degeneration, or osteoarthritis, it can become a concern.

Treatments for spondylolisthesis vary by individual case. Nonsurgical treatments may include activity reduction, a back brace, physical therapy, and/or corticosteroid injections. In severe cases, spine surgery may be required to alleviate chronic pain or nerve damage. Surgery for back pain due to spondylolisthesis typically involves spinal decompression, with or without fusion. Decompression alone is almost never done in isthmic spondylolisthesis. Studies show fusion with decompression may give better outcomes than decompression alone.

If you have symptoms of spondylolisthesis, your doctor may examine your back and run imaging tests to see if a vertebra is out of place. Your doctor may give you a grade based on how severe the spondylolisthesis is. Low-grade (I or II) is less serious and usually doesn’t need surger...