Spondylolisthesis is subluxation of lumbar vertebrae, usually occurring during adolescence. It usually results from a congenital defect in the pars interarticularis (spondylolysis).
Spondylolisthesis is usually fixed. It usually involves the L3-L4, L4-L5, or L5-S1 vertebrae.
Spondylolisthesis often occurs in adolescents or young adults who are athletes and who have had only minimal trauma; the cause is a lumbar vertebra weakened by a congenital defect in the pars interarticularis (spondylolysis). This defect is easily fractured; separation of the fracture fragments causes the subluxation. Spondylolisthesis can also occur with minimal trauma in patients who are > 60 and have osteoarthritis.
If mild to moderate (subluxation of ≤ 50%), spondylolisthesis, particularly in the young, may cause little or no pain. Spondylolisthesis can predispose to later development of spinal stenosis. If due to major trauma, spondylolisthesis can cause spinal cord compression or other neurologic deficits; these deficits rarely occur.
Spondylolisthesis is staged according to the percentage of vertebral body length that one vertebra subluxes over the adjacent vertebra:
Spondylolisthesis is evident on plain lumbar x-rays. The lateral view is usually used for staging. Flexion and extension views may be done to check for instability.
Treatment is usually symptomatic. Physical therapy with lumbar stabilization exercises may be helpful.