What is spondylolisthesis?
Spondylolisthesis is a condition that occurs when one of the bones of your spine (the vertebrae) shifts out of its normal alignment and winds up pressing onto the vertebra – and often the nerves – below it. Although it can occur in any part of the spine, it most commonly occurs in vertebrae in the lower spine, or lumbar region. The term “spondylolisthesis” comes from two Greek words, one meaning “spine” and one meaning “to slide or slip.”
What causes spondylolisthesis?
Your vertebrae stay in alignment partly thanks to the connective tissues that surround them and partly due to the tiny joints, called facet joints, between each pair of vertebrae.
Spondylolisthesis occurs when a problem arises in these joints. The causes of these joint issues include:
- congenital defects in the joints (that is, defects that have been present since birth)
- injury to a joint due to an accident
- joint damage due to arthritis or infection
- stress fractures in the vertebrae, commonly caused by overuse injuries
Being significantly overweight may also contribute to spondylolisthesis by placing extra strain on the back muscles that help support the spine and keep the vertebrae in alignment.
What are the symptoms of spondylolisthesis?
When the slippage is relatively minor, there may be no symptoms at all. But in most cases, spondylolisthesis causes symptoms such as:
- back or neck pain that often feels like a pulled or strained muscle
- pain that radiates down the leg or arm
- tingling, numbness or weakness that radiates into the leg or arm
- muscle spasms in the leg, especially in the back of the thigh
- problems walking, usually to compensate for pain in the back or leg
- incontinence in extreme cases, when the nerves of the bladder or bowel are involved
How can the doctor tell if I have spondylolisthesis?
A physical exam that includes range-of-motion exercises provides the first evidence that spondylolisthesis could be occurring, and an x-ray or other imaging procedure can confirm that a vertebra has slipped out of its normal alignment. Computed tomography (CT) scans of magnetic resonance imaging (MRI) scans might be indicated in some cases to determine which nerves are involved.
Based on the results of the images, a radiologist can grade the extent of slippage, which can help the doctor determine treatment:
- Grade I includes slippages from one to 25 percent out of alignment
- Grade II includes slippages from 26 percent to 50 percent
- Grade III includes slippages from 51 percent to 75 percent
- Grade IV includes slippages from 76 percent to 100 percent
How is spondylolisthesis treated?
Treatment for spondylolisthesis can vary based on factors like overall health, age and the severity of the symptoms. In most cases, the first approach is conservative management, including rest from strenuous activity like sports or heavy lifting, combined with pain and anti-inflammatory medications to provide relief for symptoms. Over-the-counter medications are sufficient for many patients, but in some cases, a prescription medication may be needed, at least in the initial stages, to reduce swelling and irritation. Other patients may benefit from epidural injections of corticosteroids. Aside from medications and rest, physical therapy to strengthen back and abdominal muscles and stabilize the spine may also play an important part of conservative management.
When these approaches don’t provide enough relief, surgery may be considered. For most patients, surgical treatment involves one or both of these approaches:
- laminectomy removes a portion of the vertebrae to relieve nerve pressure or impingement responsible for symptoms of pain and muscle weakness
- spinal fusion which uses a bone graft to join the affected sections of the spine together to provide extra stability and prevent motion and friction between the vertebrae