Objective. To evaluate the effectiveness of surgical treatment of degenerative lumbar spondylolisthesis based on the comparative analysis of clinical and spondylometric parameters.

Materials and methods. The clinical and X-ray anatomical parameters of patients with degenerative spondylolisthesis of the lumbar vertebrae operated on by various methods of surgical treatment were studied.

Results. The best indicators of quality of life and intensity of pain in the late postoperative period were achieved using posterior decompression of the spinal canal, supplemented by fusion. While comparing bilateral point decompressions from a unilateral approach with laminectomy and decompression-stabilizing operations, there was no statistical difference in efficiency (p>0.05). A new parameter for assessing the degree of ventral dislocation of the superposed vertebra was proposed — the mean linear dislocation calculated as the arithmetic mean between the linear dislocation in the functional positions of flexion, extension and in the neutral position. While the application of isolated decompression without fixation in 62.8 % of cases, progression of the linear dislocation of the superposed vertebra was observed in the long-term period.

Conclusion. While combination of the degenerative lumbar spondylolisthesis with spinal canal stenosis decompression-stabilizing operations demonstrated higher efficiency compared to isolated laminectomy without fixation. Proposed in the study parameter for assessing the degree of ventral dislocation of the superposed vertebra (mean linear dislocation) showed a statistically significant, direct, moderate relationship with the Oswestry index and pain intensity. This fact confirms the diagnostic significance of the new parameter and the need for its use in the course of preoperative planning as a criterion for segmental instability.