Spinal Stenosis in the Absence of Spondylolisthesis: Can Interlaminar Stabilization at Single and Multi-levels Provide Sustainable Relief?

Background: In the absence of spondylolisthesis, fusion procedures are generally not recommended. However, decompression alone often does not provide long-term clinical success of intractable leg and back pain. Decompression with interlaminar stabilization (ILS) offers a new option within the clinical continuum of care by providing a nonfusion surgical alternative. The objective of this study is to examine the sustainability of decompression with ILS and to understand the clinical success at either 1 or 2 levels as a surgical treatment for nonspondylolisthesis patients with spinal stenosis.

Methods: Under an FDA-regulated investigational device exemption (IDE) study, a total of 322 patients were enrolled in the prospective, randomized trial. This investigation focuses only on the subset of patients (116 total) from this overall cohort who were treated with decompression plus ILS at 1 or 2 levels and who did not present with spondylolisthesis preoperatively. The patients were assessed before and after surgery up to 60 months.

Results: At 60-month follow up, there was no statistically significant difference in ODI ≥ 15 point improvement between patient populations (81.6% of 1 level, 90.3% of 2 level). At 60 months, 83.1% of 1 level and 86.3% of 2 level patients did not require a secondary surgical procedure. At 60 months, 94.7% of 1 level and 100% of 2 level reported ≥20 mm improvement in Visual Analogue Scale leg pain. Patients reported improvement in their physical state according to Short Form-12 scores (89.3% of 1 level, 88.9% of 2 level). Patient satisfaction at 60 months was 97.4% for 1 level and 93.3% for 2 level.

Conclusions: The therapeutic sustainability for the treatment of spinal stenosis without spondylolisthesis with ILS at 1 or 2 levels in the lumbar region has been shown to be safe and efficacious for patients who have failed conservative treatment.

Clinical Relevance: Decompression with ILS offers a nonterminal surgical option for the treatment of the symptomology of spinal stenosis, a progressive degenerative condition, that potentially can provide longer durability and stability than decompression alone.