General Session: Innovative Technologies I - Hall F

Presented by: A.T. Brecevich

Author(s):

A.T. Brecevich(1), C. Dowe(1), F.P. Cammisa Jr.(1), C. Abjornson(1)

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

Abstract

Background: After conservative treatment has failed, surgical intervention for symptomatic lumbar spinal stenosis (LSS) is common. However, LSS is rarely a discreet issue and often presents with spondylolisthesis, deformity, or other degenerative changes. Although decompression surgery is considered the standard treatment, trends indicate spine fusion surgery has disproportionately increased despite it being the more invasive approach. Interlaminar stabilization (ILS) is an evidence-based and less invasive alternative to fusion that is non-terminal and motion preserving. The purpose of this study was to compare the efficacy of decompression + ILS (D+ILS) to decompression plus posterolateral fusion (D+PLF) in patients aged ≤ 65 years with LSS with or without grade 1 spondylolisthesis.

Methods: A cohort from the original multi-center, randomized controlled Investigational Device Exemption clinical trial was examined with 5-year follow-up. The cohort included 181 patients with 131 in the D+ILS group and 50 in the (D+PLF) group. Intraoperative data, including length of hospital stay (LOS), estimated blood loss (EBL), and operative time were recorded. Pain management surveys and patient-reported outcomes were collected including Oswestry Disability Index (ODI), Short Form Surveys (SF-12), Zurich Claudication Questionnaire (ZCQ), and Visual Analog Scale (VAS) for back and leg pain and were completed preoperatively and out to 60 months postoperatively. Composite Clinical Success (CCS) was defined as a ≥ 15 point improvement of ODI plus the absence of reoperations, neurological deficits, and major device-related complications.

Results: Patient follow-up at 60 months for the D+ILS group and D+PLF groups were 88.2% and 86.7% respectively. Mean length of hospital stay was 1.79 days in the D+ILS group and 3.06 days in the D+PLF group (p< 0.001). A statistically significant difference was noted in mean EBL with 112cc for D+ILS and 337.8cc for D+PLF (p< 0.001). D+ILS patients experienced a significantly shorter surgery than D+PLF patients with a mean operative time of 96.5 minutes for D+ILS and 153.3 minutes for D+PLF (p< 0.001). Radiographic findings show preservation of foraminal height and disc height out to 5 years in D+ILS. At 60 months in the D+ILS group, narcotic and NSAID/ASA/Acetaminophen usage decreased from preoperative values by 17% and 20%, respectively. At 60 months, there was no statistically significant difference in the CCS between treatment groups. There were no differences in patient-reported outcomes.

Discussion: At 5-year follow-up, D+ILS has been shown to be a durable and efficacious treatment option in a younger spinal stenosis population with or without grade 1 spondylolisthesis. Decompression + ILS surgery is significantly less invasive for the patient as measured by shorter operative times, decreased blood loss, and shorter length of stay. As hospital costs are of growing concern, these substantial differences should be strongly considered. As a cohort of a non-inferiority study design, patient-reported outcomes showed no differences between the groups. However, in this younger and more physically active patient population, a safe and effective non-terminal surgery should be considered before more invasive fusion surgery.