Necessity of Fusion Following Decompression Surgery in Patients With Single-level Lumbar Stenosis

Inclusion Criteria: * age of patients from 45 to 75 years; * stenosis C or D according to Shizas et al. according to MRI at the level of L2-L3, L3-L4, L4-L5 or L5-S1; * clinical manifestations of lumbar stenosis (neurogenic claudication syndrome and/or radiculopathy); * lack of effect from conservative therapy within 3 months; * Informed consent to take part in the study. Exclusion Criteria: * spondylolisthesis more than 3 mm; * spinal instability according to functional radiography; * sagittal imbalance (type 4 according to C. Barrey); * bone density of the vertebrae at the level of the operation is less than 100 HU; * clinically significant spinal stenosis at 2 or more levels; * previously performed surgeries on the spine; * risk of anesthesia 4 or 5 according to ASA; * inability to take part in control examinations within 2 years after the operation; * participation in other clinical trials related to surgical or conservative treatment of diseases of the spine.