What is spondylolisthesis?
Spondylolisthesis is a condition in which a vertebra in the lower spine slips forward over another. This slippage can narrow the spinal canal and put pressure on the spinal cord, causing pain and weakness. The condition is on the rise among children and adolescents who are active in athletics. In these patients, spondylolisthesis usually occurs between the fifth lumbar vertebra and the first bone in the sacrum. In adults, the slip usually occurs between the fourth and fifth lumbar vertebrae.
What causes spondylolisthesis?
Causes of spondylolisthesis vary based on age, heredity and lifestyle. The most common causes include:
- A congenital spine defect present at birth
- An accident or traumatic injury
- Small stress fractures in the vertebrae (a condition called spondylolysis) from injury or overuse
- Degenerative arthritis
- Bone disease, such as osteoporosis, or infection
What are the symptoms?
Symptoms of spondylolisthesis range from mild to severe and may include:
- Lower back pain
- Pain in the thighs and buttocks
- Muscle tightness or weakness in the legs
Pain generally occurs with activity and improves with rest. Neurological damage (leg weakness or changes in sensation) may result from pressure on nerve roots, causing pain that radiates down the legs.
How is spondylolisthesis diagnosed?
In addition to a complete physical exam and patient history, your doctor can use X-rays to determine if one of your vertebrae has slipped out of place. You might also have an MRI or CT scan to pinpoint the damage and help guide treatment.
Left, The pars interarticularis is found in the posterior portion of the vertebra. Center, Spondylolysis occurs when there is a fracture of the pars portion of the vertebra. Right,Spondylolisthesis occurs when the vertebra shifts forward due to instability from the pars defect.
-(Courtesy of John Killian, MD, Birmingham, AL)
This lateral X-ray of the lumbrosacral spine demonstrates the forward shift in the fifth lumbar vertebra on the sacrum (L5-S1 spondylolisthesis).
-(Courtesy of Texas Scottish Rite Hospital for Children)
What is the treatment?
Many patients with spondylolisthesis will improve with non-surgical measures. These include rest, non-steroidal anti-inflammatory medication, corticosteroids, epidural injections, a back brace or physical therapy.
Surgery may be needed if the slippage progressively worsens or if the pain does not respond to conservative treatment and begins to interfere with activities of daily living. The most common surgical treatment is a decompressive laminectomy and fusion. In this two-part procedure, the surgeon removes the bone that is pressing on the nerves and opens up the spinal canal. The vertebrae are fused together to provide stability. In some cases, rods or screws are used to hold the vertebrae firm as the fusion heals.
Two of the most advanced fusion techniques are transforaminal lumbar interbody fusion (TLIF) and extreme lateral interbody fusion (XLIF). During TLIF, surgeons approach the spine from the side of the spinal canal through a midline incision in the patient’s back, sparing nerves and muscles. XLIF is performed through the patient’s side, avoiding the major muscles of the back.
These state-of-the-art, minimally invasive procedures take a fraction of the ordinary surgical time and offer patients a host of benefits that speed recovery. Advantages include smaller incisions, less tissue and muscle damage, less pain and bleeding, and shorter hospital stays. However, not everyone is a candidate for the XLIF or TLIF procedure. A surgeon who is trained in these techniques is the best person to determine the most appropriate surgical option for the patient. A consultation with the proper surgeon is crucial in making that determination.