What IS IT ?

Spondylolysis refers to a defect in one of the vertebra in the lower back, usually the last vertebra of the lumbar spine. The area of the vertebra called the pedicle is affected. The pedicle is part of the bony ring that protects the spinal nerves, and is the portion that connects the vertebral body to the facet joints. When a spondylolysis is present, the back part of the vertebra and the facet joints simply are not connected to the body - except by soft tissue. It is almost as if the back portion had been broken off and tried to heal, but never did. Football linemen and gymnasts seem to be affected the most. It is thought that the spondylolysis is probably a stress fracture that never completely healed


Spondylolysis results from a weakness in a section of the vertebra called the pars interarticularis, the thin piece of bone that connects the upper and lower segments of the facet joints. The facet joints link the vertebrae directly above and below to form a working unit that permits movement of the spine. The exact cause of the weakness of the pars interarticularis is unknown. Many theories point to genetics as a factor, suggesting some people are born with thin vertebrae, placing them at a higher risk for fractures. Other theories suggest that repetitive trauma to the lower back, like being tackled or falling, can weaken the pars interarticularis.

Spondylolysis is especially common in adolescents who overtrain in activities such as tennis, diving, martial arts and gymnastics. Linemen in football are also at risk due to their bending over at the line. It has been proposed that the pars interarticularis is especially vulnerable when the spine is in an extended position, and a force suddenly presses the vertebrae together, such as when landing on one's feet after a hop. This pressure acts like a nut-cracker on the pars interarticularis and can fracture it in susceptible individuals.


Many people with spondylolysis have no symptoms and don’t even know they have the condition. When symptoms do occur, low back pain is the most common. The pain usually spreads across the lower back, and might feel like a muscle strain. The pain is generally worse with vigorous exercise or activity.  If the spondylolysis is not correctly identified and managed, there is a chance that the affected area may heal incorrectly, resulting in the possibility of continued stress that can lead to the slippage of spondylolisthesis and recurrent low back pain.


For active spondylolysis, you may be given a brace to immobilize the spine for a short while to allow the pars interarticularis to heal. Modalities will be used as necessary to reduce pain and begin to strengthen muscles. Stretching, beginning with gentle hamstring stretches and progressing over time, and strengthening will be used to stabilize the spine by strengthening the back and abdominal muscles. Once the fracture has begun to heal successfully, your therapist will help you return to normal active function and back to your sport.