Spondylolisthesis is a subluxation of the lumbar vertebrae and usually occurs during adolescence. It often develops as a result of congenital defects in the interarticular part of the vertebral column – spondylolysis.
Spondylolisthesis is usually fixed. L3-L4, L4-L5 and L5-S1 vertebrae are most commonly affected.
Spondylolisthesis often develops in adolescents and young people who are engaged in sports and have suffered even minimal injury; the reason is that the congenital pathology weakens the lumbar vertebrae in the interarticular area (spondylolysis). Fractures can easily occur at the site of the defect; the separation of the resulting bone fragments leads to subluxation. Spondylolisthesis can develop after minimal injury in patients > 60 years of age with osteoarthritis.
Mild to moderate (subluxation ≤ 50%) spondylolisthesis, especially in young people, may be accompanied by mild pain or remain asymptomatic. Spondylolisthesis may predispose to spinal stenosis. Spondylolisthesis associated with significant trauma may cause spinal cord compression or other neurological disorders; such conditions are rare.
Spondylolisthesis is classified according to the degree of displacement of bodies of adjacent vertebrae:
Stage I: 0-25%
Stage II: 25-50%
Stage III: 50-75%
Stage IV: 75-100%
Spondylolisthesis can be detected on a normal lumbar spinal X-ray. Side-projection radiographs are usually used to determine stage. Projections in the flexion and extension stage can be used to detect instability.
Treatment is most commonly symptomatic. Physiotherapy with exercises to strengthen the lumbar area may be useful.