Spondylolisthesis

Spondylolisthesis (from Greek spondylos — vertebra and olisthesis — slipping, displacement) is the pathological displacement of the body of the upper vertebra in relation to the lower one in a horizontal plane. The disease leads to a disruption of the normal axis of the spine and gross deformation of the spinal canal.

Etiology and pathophysiology

In traumatology practice, traumatic types of displacement are most commonly encountered. It occurs in severe comminuted fractures of the articular processes or vertebral arch. In this scenario, the natural bony locking mechanism, which normally holds the segment securely, is completely destroyed.

Deprived of the posterior mechanical support, the vertebral column begins to slip forward or backward under the influence of gravity and strong muscular traction. The degree of anatomical displacement is strictly classified by physicians as a percentage of the total width of the body of the lower vertebra.

Clinical significance

Clinically, the pathology presents as persistent, unrelieved pain in the affected spinal region, changes in gait, and visible contour deformity of the back.

The main danger of this condition lies in the secondary narrowing of the spinal canal. The displaced vertebral arches act on the principle of a guillotine, inexorably compressing the spinal cord or nerve roots. The treatment of unstable forms of displacement requires a complex surgical repositioning (returning the vertebra to its anatomical position) and mandatory segment fixation.