Lumbar Isthmic Spondylolysis/listhesis
Isthmic spondylolysis is a fracture that occurs in childhood but does not create much pain until a patient is in young adulthood. It is very common, occuring in 6% of the population and in most cases there are no symptoms. The fracture is usually due to cumulative stress, analogous to taking a paper clip and bending it multiple times. It will eventually break apart after enough stress.
Isthmic spondylolisthesis occurs when one vertebral body slips forward on the one below it because of a spondylolysis defect. This is most common at the L5-S1 level and can cause low back pain from instability and nerve compression. It has been estimated that 80% of people with a spondylolisthesis will never have symptoms, and if it does become symptomatic, only 15 to 20% will ever need surgical correction.
Spinal core strengthening and stabilization are very important in decreasing pain in these conditions.