Pars defect, otherwise known as spondylolysis is a fracture within the pars interarticularis of the vertebral arch in the spinal column. To put it simply, the defect is a stress fracture of the bones of the lower spine that results in lower back pain. Rather than being in the center of the back, this back pain is usually on one side of the back. When a pars defect does not heal it can lead to spondylolysis which is a permanent pars fracture on both sides of the spine. When this occurs, the spine can slip backwards over time which would result in a more serious condition of what is commonly referred to as spondylolisthesis. This, then increases the possibility of a degenerative vertebra and further back conditions in adulthood. The good news that these back problems can be prevented with early diagnosis and treatment methods.