According to WebMD, listhesis or spondylolisthesis is a slipping of the back bone or vertebra, usually occurring at the base of the spine. It is a fracture or defect of one or both of the wing-shaped bones of the vertebrae, resulting in it slipping backward, forward or over a lower bone.
WebMD notes many causes of spondylolisthesis. A vertebra can be defective from birth. It can also be broken by a stress fracture or other trauma. Vertebrae can also be broken down by disease or infection. Spondylolisthesis occurs most commonly in children or adolescents who are active in athletics like gymnastics.
WebMD states that the symptoms for spondylolisthesis include pain in the buttocks, muscle tightness or stiffness, lower back pain and pain radiating down the legs due to pressure on nerve roots. It is typically treated through physical therapy aimed at strengthening the supportive abdominal and back muscles. If patients continue to experience disability and severe pain after physical therapy, they may have the option of surgery to fuse the problem vertebra to the bone below it.
Wikipedia indicates that the types of spondylolisthesis include traumatic, degenerative, pathological and isthmic. Traumatic spondylolisthesis is rare and is the result of acute fractures. Degenerative spondylolisthesis occurs in older adults and is a result of joint remodeling due to arthritis. Pathological spondylolisthesis is a result of metabolic bone disease. Isthmic is the most common form of spondylolisthesis, occurring in five to seven percent of the United States population; this type occurs due to a latent slip or fracture of an intravertebral joint.