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

Necessity of Fusion Following Decompression Surgery in Patients With Single-level Lumbar Stenosis: Study Protocol for an Open-label Multicenter Non-inferiority Randomized Controlled Clinical Trial

Long-term clinical results of two methods of surgical treatment (spinal decompression with or without fusion) in patients with single-level lumbar stenosis will be compared. A clear framework for surgical treatment methods and standardized postoperative rehabilitation treatment will be set to obtain the maximum homogeneity of the patient groups.

This trial should provide the first level of evidence for the need for spinal fusion in patients with single-level lumbar stenosis, subject to the high homogeneous comparison groups. Additional results will allow comparing the economic aspects of different surgical treatments for 2 years after surgery.

The necessity of spinal segment fusion after decompression is one of the most controversial and unresolved issues in single-level lumbar spinal stenosis surgery. To date, only one trial carried out 15 years ago focused on this problem. The key purpose of the current trial is to compare the long-term clinical results of the two surgical methods (decompression vs. decompression and fusion) in patients with single-level lumbar stenosis.

This study is focused on the non-inferior clinical results of decompression compared with the standard fusion procedure. In the decompression group, the spinous process, the interspinous and supraspinous ligaments, part of the facet joints, and corresponding parts of the vertebral arch are to be preserved intact. In the fusion group, decompression is to be supplemented with transforaminal interbody fusion. Participants meeting the inclusion criteria will be randomly divided into two equal groups (1:1), depending on the surgical method. The final analysis will include 86 patients (43 per group). The primary endpoint is Oswestry Disability Index dynamics at the end of the 24-month follow-up compared to the baseline level. Secondary outcomes included those estimated using the SF-36 scale, EQ-5D-5L, and psychological scales. Additional parameters will include sagittal balance of the spine, fusion results, total cost of surgery, and hospital stay followed by two-year treatment. Follow-up examinations will be performed at 3, 6, 12, and 24 months Authors suggest that this study will improve the evidence for application of various surgical techniques for lumbar spine stenosis surgery and verify the existing protocol for surgical management.

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.