what is a broken spondylolisthesis
Spondylolysis is a breakdown or fracture of the narrow bridge between the upper and lower facets, called the pars interarticularis. It can occur on one side (unilateral) or both sides (bilateral) and at any level of the spine, but most often at the fourth or fifth lumbar vertebra (Fig. 2).ost believe it is due to a genetic weakness of the pars interarticularis. Both spondylolysis and spondylolisthesis can be present at birth or occur through injury. Repeated stress fractures caused by hyperextension of the back (as in gymnastics and football) and traumatic fractures are also causes.