632 - Prospective, Randomized Trial Comparing Lumbar Decompression with or w...

General Session: Innovative Technologies

Presented by: M. Rauschmann - View Audio/Video Presentation (Members Only)

Author(s):

M. Rauschmann(1), D. Adelt(2), J. Franke(3), S. Schmidt(4), S. Sola(5), G. Maislin(6), R. Davis(7)

(1) Orthopädische Universitätsklinik Friedrichsheim, Orthopaedic Spine, Frankfurt, Germany
(2) Ostseeklinik Damp, Damp, Germany
(3) Klinikum Dortmund, Dortmund, Germany
(4) University of Frankfurt, Frankfurt, Germany
(5) University of Rostock, Rostock, Germany
(6) Biomedical Statistical Consulting, Wynnewood, PA, United States
(7) Greater Baltimore Medical Center, Baltimore, MD, United States

Abstract

Background: Many clinicians are concerned that a simple microsurgical decompression may not be enough to relieve spinal stenosis symptoms long term evidenced by recent studies showing approximately 10% revision rate within 1 year follow-up. The complex presentation of degenerative lumbar spinal stenosis requires multiple validated patient reported outcomes (PROs) to reflect clinical benefit. However, the primary goal is to provide sustainability not requiring re-operations or further epidural interventions (ESI).

Purpose: The objective of this report is to present the two-year prospective, randomized, multicenter study comparing open microsurgical decompression alone (DA) to open microsurgical decompression and coflex® ILS (D + ILS) in patients with moderate to severe lumbar spinal stenosis, one or two contiguous levels at L3 to L5.

Methods: A prospective, randomized clinical trial was conducted at 6 clinical sites throughout Germany. Institutional approval was acquired at each site. The randomization was a 1:1 ratio for a total of 230 patient (115 investigational: 115 control) Randomization was not blinded however neither patients nor surgeons knew study treatment until time of surgery. All patients had a minimum of 3 months conservative therapy without improvement of symptoms, and required surgery. The major inclusion criteria were age greater than 40 years old, VAS back pain ≥ 50, and radiographic confirmation of clinical symptoms of at least moderate degenerative spinal stenosis, with constriction of the central spinal canal of one or two adjacent segments in the region L3 to L5 with the need for decompression. In addition the following was allowed but not required, hypertrophy of the facet joints and subarticular recess stenosis in the relevant segment or stenosis of the foramen in the relevant segment, and/or stable retrolisthesis up to grade I verified by flexion-/extension x-ray films. The main exclusion criteria was radiographic confirmation of translatory instability in the main segment as well as in adjacent segments (dynamic translatory instability ≤ 3 mm). PROs were assessed as ZCQ required success in >=2 of 3 ZCQ components. VAS back and leg pain success required >=20 mm improvement. To be an overall success, the patient needed to be a success in all parameters.

Results: At Month 24, primary clinical outcome success was achieved in 81.5% (70/87) D+ILS compared to 68% (66/97) DA trending towards statistical significance (p=0.055). Within patients who were a primary success, each additional PRO was evaluated. The compilation of the components that most accurately assess spinal stenosis provided an overall success showing a statistically significant difference between D + ILS and DA (p=0.032).

Conclusion: This study represents a significant advancement in the clinical understanding of the management of spinal stenosis showing superiority of D + ILS to standard decompression, and deserves consideration for patients with moderate to severe spinal stenosis.