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What Is Spondylolysis?

Spondylolysis is a fracture (crack or break) in a vertebra (bone in the spine). It can happen from repetitive stress or injuries to the spine. Some kids are born with spondylolysis (spon-duh-LOL-uh-sis).

Spondylolysis is a very common cause of lower back pain in kids, teens, and young adults. It usually heals with rest and physical therapy. Surgery usually isn't needed.

How Does Spondylolysis Happen?

The spine (or backbone) has 33 bones called vertebrae (VER-tuh-bray). Nine vertebrae are fused together to form the tailbone, and the other 24 are in the back. The lumbar vertebrae are in the lower back (closest to the tailbone), and are where spondylolysis usually happens.

Spondylolysis is a fracture in the part of the vertebra called the pars (or pars interarticularis). Each vertebra has two pars, one on the left side and one on the right. A spondylolysis, also called a pars defect or stress fracture, can happen on one or both sides of this bone.

What Are the Signs & Symptoms of Spondylolysis?

Lower back pain is the most common symptom of spondylolysis. It usually gets worse during exercise or other physical activity, especially those where someone leans back a lot. Spondylolysis also can cause buttock and leg pain, and tight hamstrings.