While spondylolisthesis involves the movement of vertebrae, spondylolysis is characterized by a crack or fracture in a spinal vertebrae.
Other differences between these two conditions:
The diagnosis of one of these conditions does not guarantee the diagnosis of the other.
Spondylolisthesis is much more common than spondylolysis in adults.
One shared quality between these two conditions is that symptoms progress downward and typically originate in the lower back.