what causes lumbar spinal stenosis
Also, other conditions may cause spinal stenosis, such as: 1  An abnormally narrow spinal canal, which can be an inherited condition. 2  Spondylolysis, which is a defect or fracture on one or both of the wing-shaped parts of a vertebra.3  Spinal fracture. 4  Cancer. 5  Fibrosis, which is excess, ropy tissue much like scar tissue.pinal stenosis usually happens gradually. Symptoms may start when the changes begin to squeeze the spinal cord or its nerve roots. These age-related changes often happen when you have certain disorders: 1  Arthritis of the spine wears away joint cartilage and causes bony growths (spurs).