(from the Greek to “step” or “slide”)
Spondylolysis results when there is a stress fracture in one of the vertebrae that makes up the spinal column. This is a condition in which one vertebra slips forward in relation to the vertebra below it and a loss of spinal column alignment results. The causes can be hereditary or due to structural defects, degenerative changes or injury. Some people can have spondylolysis without any symptoms, but others may experience pain and other nerve-related symptoms.
Spondylolysis is the most common cause of lower back pain in adolescent athletes. Some sports, including gymnastics, weight lifting, and football, put a great deal of stress on the lower back. They also require that the athlete constantly overstretch (hyperextend) the spine. This may result in a stress fracture on one or both sides of the vertebra. If the stress fracture weakens the bone to the point that it is unable to maintain its proper position, the vertebra can start to slip out of place. This condition is called spondylolisthesis. If too much shifting occurs, the bones may start to press on nerves, in which case surgery may be recommended.
Spondylolysis and spondylolisthesis are often present without any obvious symptoms. When there is pain, it usually spreads across the lower back and may feel like a muscle strain. In the case of spondylolisthesis, the condition can cause spasms that stiffen the back and tighten the hamstring muscles, which may result in changes to posture and gait. If the slippage is significant, it could compress the nerves and narrow the spinal canal. One form of spondylolisthesis is most common among older female patients, usually over 60 years of age, and is typically caused by "wear and tear" on the spine that breaks down vertebral components.
There may be a hereditary aspect to spondylolysis. Some individuals are born with thin vertebral bones that make them more vulnerable to this condition. Significant periods of rapid growth may lead to fractures as well.