Spondylolisthesis is a condition in which a bone (vertebra) in the lower part of the spine slips forward and onto a 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 area. It is often due to a birth defect in that area of the spine.

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 stress fractures (commonly seen in gymnasts) and traumatic fractures. Spondylolisthesis may occasionally be associated with bone diseases.

Spondylolisthesis may vary from mild to severe. A person with spondylolisthesis may have no symptoms.

The condition can produce increased lordosis (also called swayback), but in later stages may result in kyphosis (roundback) as the upper spine falls off the lower spine.

Symptoms may include:

• Lower back pain
• Muscle tightness (tight hamstring muscle)
• Pain in the thighs and buttocks
• Stiffness
• 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.

The doctor will perform a physical exam. A straight leg raise may be uncomfortable or painful.

X-ray of the spine can show if a vertebra is out of place, and whether there are any fractures.

Treatment varies depending on the severity of the condition. Most patients get better with strengthening and stretching exercises combined with activity modification, which involves avoiding hyperextension of the back and contact sports.

Some health care providers also recommend a rigid back brace.

Surgery to fuse the slipped disc may be needed if you have severe pain that does not get better with treatment, a severe slip of the vertebra, or any neurological changes. Such surgery has a higher rate of nerve injury than most other spinal fusion surgeries. A brace or body cast may be used after surgery.

Conservative therapy for mild spondylolisthesis is successful in about 80% of cases.

When necessary, surgery leads to satisfactory results in 85 - 90% of people with severe, painful spondylolisthesis.

• Chronic back pain
• Nerve compression
• Temporary or permanent damage of spinal nerve roots, which may cause sensation changes, weakness, or paralysis of the legs

Call your health care provider if:

• The back appears to curve excessively
• There is back pain or stiffness
• There is pain in the thighs and buttocks

People with marked lordosis should avoid back hyperextension (leaning way back), weight lifting, and contact sports.

Lower back pain, although common in preadolescent and adolescent children, should be evaluated, especially in the presence of marked lordosis.

Spiegel DA, Hosalkar HS, Dormans JP. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 18th ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 678.