Decompression with or without Fusion in Degenerative Lumbar Spondylolisthesis  — The International Society for the Study of the Lumbar Spine
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  2. SESSION #3 - SPONDYLOLISTHESIS
  3. Decompression with or without Fusion in Degenerative Lumbar Spondylolisthesis 

Decompression with or without Fusion in Degenerative Lumbar Spondylolisthesis  (#11)

Christian Hellum 1 , Ivar Austevoll 2 , Erland Hermansen 3 , Morten Fagerland 4 , kjersti Storheim 5 , Jens Ivar Brox 6 , Tore Solberg 7 , Frode Rekeland 2 , Eric Franssen 8 , Clemens Weber 9 , Helena Brisby 10 , Oliver Grundnes 11 , knut Algaard 12 , Tordis Bøker 13 , Hasan Banitalebi 14 , Kari Indrekvam 2
  1. Division of Orthopedic Surgery, Oslo University Hospital, Ullevål, Oslo, Norway
  2. Kysthospitalet in Hagevik Orthopedic department, Haukeland University Hospital , Bergen, Norway
  3. Orthopedic Department, Ålesund Hospital, Ålesund, Norway
  4. Research Support Services , the Oslo Center for Biostatistics and Epidemiology, Oslo, Norway
  5. the Research and Communication Unit for Musculoskeletal Health, Division of Clinical Neuroscience, oslo University Hospital, Oslo, Norway
  6. the Department of Physical Medicine and Rehabilitation , Oslo Universtity Hospital, Oslo, Norway
  7. Department of Neurosurgery , University Hospital of North Norway, Tromsø , Tromsø, Norway
  8. Orthopedic Department, Stavanger University Hospital, Stavanger, Norway
  9. Department of Neurosurgery, Stavanger University Hospital, Stavanger, Norway
  10. the Spine Surgery Team, Department of Orthopedics, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden , Gothenburg, Sweden
  11. Orthopedic Department , Akershus University Hospital , Oslo, Norway
  12. Radiology, Unilabs Radiology, Oslo, Norway
  13. the Department of Radiology and Nuclear Medicine , oslo University Hospital, Oslo, Norway
  14. the Institute of Clinical Medicine, University of Oslo, Akershus University Hospital, Oslo, Norway

INTRODUCTION

It remains uncertain whether decompression surgery is noninferior to decompression with instrumented fusion in patients with lumbar spinal stenosis and degenerative spondylolisthesis.

METHODS

In this open-label, multicenter, noninferiority trial, patients were randomly assigned to decompression or decompression with instrumented fusion. Patients were included with symptomatic lumbar stenosis that did not respond to conservative management for at least 3 months and 3 mm or greater single level spondylolisthesis, regardless of dynamic slippage of vertebral bodies. Patients with degenerative scoliosis more than 20 degrees, radicular pain related to an extensive foraminal stenosis, or previously operated at the level of spondylolisthesis were not included. The decompression group were operated with a midline-preserving decompression. The techniques used for decompression with instrumented fusion was at the discretion of operating surgeons. 

The primary outcome was an improvement of at least 30% on the Oswestry Disability Index (ODI; ranging from 0 to 100, with higher scores indicating more impairment) from inclusion to 2-year follow-up. The noninferiority margin was a between-group difference of 15 percentage points in the primary outcome. To declare noninferiorirty for decompression, noninferiority was required in the modified intention-to-treat analysis and the per-protocol analysis. Secondary outcomes included mean improvements in the ODI, the Zurich Claudication Questionnaire, the Numerical Rating Scale for leg and back pain, duration of surgery and hospital stay, and reoperation within 2 years.

RESULTS

In total 267 patients were randomized; 134 to decompression alone (mean [SD] age 66.0 [7.4] years and 133 to decompression and instrumented fusion (mean [SD] age 66.5 [7.9] years. In the modified intention-to-treat analysis with multiple imputation of missing data (n= 26), 95 of 133 patients (71.4%) in the decompression group and 94 of 129 patients (72.9%) in the instrumented fusion group met the primary outcome (difference 1.4 percentage points; 95% confidence interval [CI], -9.4 to 12.2). In the per-protocol-analysis 80/106 (75.5%) and 83/110 patients (75.5%) met the primary outcome (difference, 0.0; 95% CI -11.4 to 11.4). The both analyses demonstrated noninferiority. The mean between-group difference in ODI from baseline to 2-year follow-up was 0.7 (95% CI, -2.8 to 4.3). Decompression alone was associated with shorter operation time (104 vs 174 minutes; mean difference -70; 95% CI, -84 to -55) and shorter hospital stay (3.3 vs 5.0 days; mean difference -1.8; 95% CI, -2.4 to -1.2 days). The reoperation rate was 15 of 120 patients (12.5%) in the decompression group and 11 of 121 (9.1%) in the instrumentation group (mean difference, 3.4%-points; 95% CI, -4.6 to 11.5 %-points).

DISCUSSION

In this trial involving patients with primary surgery for single-level degenerative lumbar spondylolisthesis, without a deformity or an extensive foraminal stenosis, decompression alone was noninferior to decompression with instrumented fusion over 2 years.

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