Spondylolisthesis is essentially when parts of the spine become out of place. In most cases, the part of the back affected most is the lower back and this condition can cause extreme pain if a nerve is pinched when the spine bone slips out of place, according to the Cleveland Clinic.
There are six types of spondylolisthesis; three of them being very rare. These include congenital, isthmic, degenerative, traumatic, pathological and post-surgical, as stated by the Cleveland Clinic. Spondylolisthesis affects teenagers the most because the slipping out of place seems to happen more frequently when they are in their growth spurt.