Lightning Podiums: Smorgasboard - Room 802B

Presented by: C. Dowe


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

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


Background: Multiple studies have supported decompression with fusion over decompression alone for the surgical management of spinal stenosis with spondylolisthesis. More recently, level-1 evidence has supported microsurgical decompression with interlaminar stabilization (D+ILS) as an effective alternative.

Purpose: The purpose of this study was to compare microsurgical decompression with instrumented posterolateral fusion (DF) to D+ILS in patients who require surgical treatment for lumbar spinal stenosis with grade I spondylolisthesis at 5 year follow-up.

Study Design/Setting: This patient cohort was part of a prospective, randomized, multicenter Investigational Device Exemption (IDE) non-inferiority study with a 2:1 randomization ratio which enrolled a total of 322 patients from 21 sites in the United States between 2006 and 2010.

Patient Sample: Of the 322 patients enrolled in the original study, 150 patients were diagnosed with up to Grade 1 spondylolisthesis. Within the cohort, 99 patients enrolled received ILS (coflex®, New York, New York) and 51 received DF.

Outcome Measures: Efficacy was measured by Composite Clinical Success (CCS) scores. Patients achieved CCS if all four of the following outcomes were met: achieving a ≥ 15 point improvement from baseline Oswestry Disability Index (ODI), no reoperation or epidural injections, no persistent, new, or increasing neurological deficits, and no major device-related complications.

Methods: Data was collected pre-operatively, and then at 6 weeks, 3, 6, 12, 18, 24, 36, 48, and 60 months post-operatively. A patient had to be a success in all four components of CCS to achieve clinical success at the 60 month mark.

Results: Baseline demographic, clinical, or radiographic variables were similar for the two groups. Patient follow-up at 5 years was 88.9% ILS and 76.4% for DF groups. Intraoperatively, ILS patients experienced significantly shorter operative times (p < 0.0001), less estimated blood loss (p < 0.0001), and shorter length of stay (p < 0.0001) than DF patients. There was no difference between groups in patients who underwent a reoperation and/or post-operative epidural injection (p = 0.71). The percentage of patients achieving CCS in the D+ILS group was non-inferior to that in the DF group [ILS 44.3% (39/88); DF 53.8% (21/39); p = 0.48].

Conclusions: As designed, this study demonstrates non-inferiority of decompression with interlaminar stabilization versus fusion for a validated composite endpoint of safety and efficacy, including patient-reported outcomes for the treatment of spinal stenosis with grade I spondylolisthesis. ILS provides a durable and effective treatment option in a less invasive manner for the patient. For the healthcare system, it is a significantly more cost-effective treatment option at approximately half the operative time and almost 2 days shorter hospital stay. As a non-terminal procedure, ILS offers an opportunity for motion sparing while not limiting options if further surgical intervention is needed in the future.