Spondylolysis is a defect of the bones that make up the spinal column, according to the American Academy of Orthopaedic Surgeons. Spondylolysis happens in any section of the spine but most often at the fourth or fifth lumbar vertebra, states Mayfield Clinic.
Spondylolysis results from a stress fracture in the pars interarticularis of the vertebral arch, according to Mayfield Clinic. As of 2015 the exact cause is unknown, but scientists have identified genetic predisposition and sports that require frequent hyperextension of the lumbar spine as key contributing factors, states the American Academy of Orthopaedic Surgeons. Treatment for spondylolysis includes some nonsurgical options during its initial stages, such as physical therapy and use of a back brace. Doctors employ surgical treatment if the slippage progressively worsens.