Oral Posters: Thoraco-lumbar Degenerative

Presented by: S. Grinberg - View Audio/Video Presentation (Members Only)

Author(s):

S. Grinberg(1), R. Simon(1), C. Dowe(1), F. Cammisa(1), C. Abjornson(1)

(1) Hospital for Special Surgery, Integrated Spine Research Program, New York, NY, United States

Abstract

Background: Multi-level lumbar spinal fusion surgeries are generally more invasive and can be less successful than single-level procedures for the treatment of spinal stenosis. Recently, a less invasive procedure utilizing interlaminar stabilization (ILS) after microsurgical decompression has been shown to provide better clinical outcomes than those from instrumented fusion for the same indication. However, the clinical question that remains is whether ILS is able to sustain similar results when utilized in multi-level procedures when compared to single level procedures.

Purpose: The objective of this study is to examine the efficacy of 2-level ILS and fusion surgeries when compared to 1-level surgeries for lumbar spinal stenosis with or without spondylolisthesis.

Methods: Under FDA-regulated Investigational Device Exemption (IDE) study, a total of 322 patients from 21 sites in the US were enrolled between 2006 and 2010 in the prospective, randomized trial. All patients were diagnosed with spinal stenosis with or without spondylolisthesis. Of the 322 patients enrolled in this study, 215 patients underwent decompression with ILS and 107 patients underwent decompression with fusion. The ILS group consisted of 138 patients treated at 1-level and 77 patients treated at 2-levels. The fusion group consisted of 68 patients treated at 1-level and 39 patients treated at 2-levels. Composite clinical success (CSS) was determined using Oswestry Disability Index (ODI), the absence of reoperations or epidurals, the absence of persistent or new neurological deficits and the absence of major device-related complications. The data was recorded 60 months post-operation. The results of the different assessments were combined to calculate the percentage of patients achieving composite clinical success.

Results: There was no statistically significant difference between 1-level and 2-level ILS patients in regards to ODI ≥ 15 point improvement (p=0.172), the absence of reoperations or epidurals (p=0.911), the absence of persistent or new neurological deficits (p=0.195) and the absence of major device-related complications (p=0.262). Of the ILS patients, 46.3% of 1-level and 55.1% of 2-level patients met the criteria for CCS (p=0.246). There was no statistically significant difference between 1-level and 2-level fusion patients in regards to ODI ≥ 15 point improvement (p=0.085), the absence of persistent or new neurological deficits (p=0.662) and the absence of major device-related complications (p=0.654). However, the difference between 1 and 2-level fusion was statistically significant for the absence of reoperations or epidurals (p=0.012). 25.0% of 1-level and 48.7% of 2-level fusion patients had epidural injections or reoperations in the 60 months following surgery. CCS was achieved by 48.3% of 1-level and 36.4 of 2-level fusion patients (p=0.271). In comparing 2-level ILS to fusion, 55.1% of 2-level ILS patients and 36.4% of 2-level fusion patients met the CCS criteria (p=0.077).

Conclusions: The lower rate of reoperation and injections indicates that 2-level ILS procedures were more effective than 2-level fusion when compared with respective 1-level procedures.