Spondylolisthesis is a condition in which a vertebra (bone) in the lower part of the spine slips out of the proper position onto the bone below it.
In children, spondylolisthesis usually occurs between the fifth bone in the lower back (lumbar vertebra) and the first bone in the sacrum (pelvis) area. It is often due to a birth defect in that area of the spine or sudden injury (acute trauma).
In adults, the most common cause is degenerative disease (such as arthritis). The slip usually occurs between the fourth and fifth lumbar vertebrae.
Other causes of spondylolisthesis include bone diseases, traumatic fractures and stress fractures (commonly seen in gymnasts). Certain sports activities, such as gymnastics, weight lifting and football, put a great deal of stress on the bones in the lower back. They also require that the athlete constantly overstretch (hyperextend) the spine. This can lead to a stress fracture on one or both sides of the vertebra. A stress fracture can cause a spinal bone to become weak and shift out of place.
Spondylolisthesis may vary from mild to severe. Some individuals have no symptoms.
The condition can produce increased lordosis (also called swayback), and in later stages may result in kyphosis (roundback) as the upper spine falls off the lower spine.
Symptoms may include:
- Low back pain
- Muscle tightness (tight hamstring muscle)
- Pain in the thighs and buttocks
- Tenderness in the area of the slipped disc
Nerve damage (leg weakness or changes in sensation) may result from pressure on nerve roots and may cause pain radiating down the legs.
Your doctor will perform a physical exam, asking you to raise your legs straight up, which may be uncomfortable or painful.
An x-ray of the spine will determine if a vertebra is out of place and whether there are any fractures.
Treatment varies depending on the severity of the condition. Most patients improve with strengthening and stretching exercises combined with activity modification, which involves avoiding hyperextension of the back and contact sports.
Your doctor will try non-surgical treatment first, which may include:
- Anti-inflammatory medicines to reduce back pain
- A stiff back brace
- Physical therapy
You should take a break from activities until your symptoms improve. In most cases, you can resume your lifestyle slowly. Conservative therapy for mild spondylolisthesis is successful in about 80 percent of cases.
Surgery to fuse the slipped disc may be needed if you have severe pain that does not improve with treatment, a severe slip of the vertebra or any neurological changes. Spinal fusion is surgery to join together two vertebrae in the spine so that there is no longer movement between them.
In general, such surgery for spondylolisthesis has a higher rate of nerve injury than most other spinal fusion surgeries. A brace or body cast may be used after surgery.
When necessary, surgery leads to satisfactory results in 85 to 90 percent of people with severe, painful spondylolisthesis. Periodic x-rays can show whether the vertebra is changing position over time.
Source: National Institutes of Health