The object of investigation – displastic spondylolisthesis with stenosis of spinal canal. The methods of investigation: clinical, roentgenological, roentgenometrical, roentgencontrasting, computer and magnetic-resonance tomography, biomechanical and statistical. For the first time comparative analysis of roentgenometrical indexes in patients that are ill with displastic spondylolisthesis with and without stenosis of spinal canal was done; dependence between the value of displacement and other roentgenometric parameters, correlation between the severity of neurological deficit and roentgenometric criteria of the deformation of lumbar-sacral and LIV-LV segments or indexes of sagittal vertebro-pelvic balance were ascertained. The mechanisms of spinal canal stenosing in the case of displastic spondylolisthesis were ascertained in experimental and clinical- roentgenological studies for the first time. Specifically, the range of influence of value of anterior straight displacement, index of disc height andvalue of angle deformation on the stenosing of spinal canal in the case of no-lysis displastic spondylolisthesis, value of anterior straight shift, decrease of height of lumbar-sacral disc, value of retrolisthesis and segmental hyperextension in the case of spondilolysis displastic spondylolisthesis were ascertained. New methods of surgical treatment of stenosing variants of displastic spondylolisthesis were worked out and known ones were improved. The principles of choice of optimal method of surgical treatment were ascertained on the base of investigation, that was performed for the first time, of short-distance and long-distance outcomes of surgical treatment of stenosing variants of displastic spondylolisthesis. Obtained results of investigation assist to form proper notion at clinicians and research workers concerning clinical-roentgenological presentations of the stenosis of spinal canal in the case of displastic spondylolisthesis, as well as concerning mechanisms of stenosing of spinal canal at this diseases and, therefore, concerning adequate methods for stenosis elimination. Using of worked out methods of the treatment of displastic spondylolisthesis, as well as proposed principles of choice of optimal surgical means, provide the improvement of efficacy of patients’ treatment. Using of new knowledge about mechanisms of stenosing of spinal canal at displastic spondylolisthesis allows to forecast the development of stenosis in proper time, to avoid errors and complications at surgical treatment of displastic spondylolisthesis. Methods of surgical treatment of stenosing displastic spondylolisthesis, that were worked out, have been using in clinical practice of Sytenko Institute of Spine and Joint Pathology of Ukrainian AMS, can be recommended for using in specialized orthopedic and neurosurgical patient care institutions of Ukraine. In accordance with the them of thesis three invention were worked out: “The method of epidurography” (Declared patent №71113A of 15.11.04), “The method of surgical treatment ofspondylolisthesis” (Declared patent №32810A of 15.02.01) and “The method of surgical treatment of spondylolisthesis” (Declared patent of Ukraine №32810A). Traumatology and orthopedics.
