Spondylolysis

Spondylolysis is a stress fracture which occurs to the pars interarticularis, or pars for short, which is a bony projection from the vertebra located between the inferior and superior articular processes of the facet joint. Spondylolysis is frequently seen at the L5 vertebra and is the most common cause of low back pain in the active adolescent population. Pronounced (spon-de-low-lye-sis) the stress fracture is often seen in sports that involve repetitive hyper extension like gymnastics, football, soccer, baseball and tennis. There may be a heredity aspect that is involved as some individual bones are thinner which may make them more vulnerable to stress injury. Repetitive injury can weaken the bone so much that it is unable to maintain its proper position and the vertebra shifts out of place. This progression of vertebral slippage is called spondylolisthesis.

Spondylolisthesis

Spondylolisthesis is a condition in which the vertebra slides forward out of its proper position and over the bone below it. This most often occurs in the lower spine. In some cases, this may lead to the spinal cord or nerve roots being squeezed. In adults, the most common cause of spondylolisthesis is abnormal wear on the cartilage and bones, such as with arthritis.

The word spondylolisthesis comes from the Greek words spondylos, which means “spine” or “vertebrae,” and listhesis, which means “to slip or slide.” Thus, the condition is often characterized by the term slipped vertebrae.

Types of Spondylolisthesis

There are different types of spondylolisthesis.

Congenital spondylolisthesis. Congenital (which means “present at birth”) spondylolisthesis is the result of abnormal bone formation. In this case, the abnormal arrangement of the vertebrae puts them at a greater risk for slipping.

Isthmic spondylolisthesis. This type occurs as the result of spondylosis, which leads to small stress fractures (breaks) in the vertebrae. These fractures weaken the bone to the degree that it slips out of place.

Degenerative spondylolisthesis. This is the most common form of the disorder. With aging, the discs (cushions between the vertebral bones) lose water, becoming less spongy and less able to resist movement between the vertebrae.

Displastic spondylolisthesis. Occurs over time when the pars heals in an elongated position and it is unable to maintain its normal positioning.

Pathologic spondylolisthesis. Are associated with tumors of the spine.

Spondylolisthesis Symptoms

Symptoms of spondylolisthesis may include any of the following:

• Lower back pain
• Muscle tightness (tight hamstring muscle)
• Pain, numbness or tingling in the thighs and buttocks
• Stiffness
• Tenderness in the area of the vertebra that is out of place
• Weakness in the legs

Treatment for Spondylolisthesis

Non-surgical treatment for spondylolisthesis includes:

• Physical therapy (such as strengthening exercises for trunk and abdomen)
• Possible anti-inflammatory medications or cortisone injections for pain
• Rest

If non-surgical methods are inadequate, surgery may be indicated. This is usually a decompression (also called a laminectomy) followed by spinal fusion. Spinal fusion surgery for degenerative spondylolisthesis is generally quite successful. Upwards of 90 percent of patients experience improvement in their function and a substantial decrease in their pain.