title: Decompression Surgery Alone Versus Decompression Plus Fusion in Symptomatic Lumbar Spinal Stenosis: A Swiss Prospective Multicenter Cohort Study With 3 Years of Follow-up.
abstract: METHODS
  Retrospective analysis of a prospective, multicenter cohort study.
  
  
  OBJECTIVE
  To estimate the added effect of surgical fusion as compared to decompression surgery alone in symptomatic lumbar spinal stenosis patients with spondylolisthesis.
  
  
  BACKGROUND
  The optimal surgical management of lumbar spinal stenosis patients with spondylolisthesis remains controversial.
  
  
  METHODS
  Patients of the Lumbar Stenosis Outcome Study with confirmed DLSS and spondylolisthesis were enrolled in this study. The outcomes of this study were Spinal Stenosis Measure (SSM) symptoms (score range 1-5, best-worst) and function (1-4) over time, measured at baseline, 6, 12, 24, and 36 months follow-up. In order to quantify the effect of fusion surgery as compared to decompression alone and number of decompressed levels, we used mixed effects models and accounted for the repeated observations in main outcomes (SSM symptoms and SSM function) over time. In addition to individual patients' random effects, we also fitted random slopes for follow-up time points and compared these two approaches with Akaike's Information Criterion and the chi-square test. Confounders were adjusted with fixed effects for age, sex, body mass index, diabetes, Cumulative Illness Rating Scale musculoskeletal disorders, and duration of symptoms.
  
  
  RESULTS
  One hundred thirty-one patients undergoing decompression surgery alone (n = 85) or decompression with fusion surgery (n = 46) were included in this study. In the multiple mixed effects model the adjusted effect of fusion compared with decompression alone surgery on SSM symptoms was 0.06 (95% confidence interval: -0.16-0.27) and -0.07 (95% confidence interval: -0.25-0.10) on SSM function, respectively.
  
  
  CONCLUSIONS
  Among the patients with degenerative lumbar spinal stenosis and spondylolisthesis our study confirms that in the two groups, decompression alone and decompression with fusion, patients distinctively benefited from surgical treatment. When adjusted for confounders, fusion surgery was not associated with a more favorable outcome in both SSM scores as compared to decompression alone surgery.
  
  
  METHODS
  3.
authors.affiliation: Department of Orthopedics and Neurosurgery, Spine Center, Schulthess Clinic, Zurich, Switzerland.
authors.forename: Nils H
authors.initials: NH
authors.lastname: Ulrich
authors.affiliation: Horten Centre for Patient Oriented Research and Knowledge Transfer, University of Zurich, Zurich, Switzerland.
authors.forename: Jakob M
authors.initials: JM
authors.lastname: Burgstaller
authors.affiliation: Horten Centre for Patient Oriented Research and Knowledge Transfer, University of Zurich, Zurich, Switzerland.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Pichierri
authors.affiliation: Horten Centre for Patient Oriented Research and Knowledge Transfer, University of Zurich, Zurich, Switzerland.|Division of General Internal Medicine, Bern University Hospital, Bern University, Bern, Switzerland.
authors.forename: Maria M
authors.initials: MM
authors.lastname: Wertli
authors.affiliation: Spine Division, Balgrist University Hospital, University of Zurich, Zurich, Switzerland.
authors.forename: Mazda
authors.initials: M
authors.lastname: Farshad
authors.affiliation: Department of Orthopedics and Neurosurgery, Spine Center, Schulthess Clinic, Zurich, Switzerland.
authors.forename: François
authors.initials: F
authors.lastname: Porchet
authors.affiliation: Horten Centre for Patient Oriented Research and Knowledge Transfer, University of Zurich, Zurich, Switzerland.
authors.forename: Johann
authors.initials: J
authors.lastname: Steurer
authors.affiliation: Horten Centre for Patient Oriented Research and Knowledge Transfer, University of Zurich, Zurich, Switzerland.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Held
mesh_terms: D019299:Decompression, Surgical / Q000009:adverse effects / Q000379:methods / Q000706:statistics & numerical data; D006801:Humans; D008159:Lumbar Vertebrae / Q000601:surgery*; D012189:Retrospective Studies; D013123:Spinal Fusion / Q000009:adverse effects / Q000379:methods / Q000706:statistics & numerical data; D013130:Spinal Stenosis / Q000601:surgery*; D013168:Spondylolisthesis / Q000601:surgery*; D016896:Treatment Outcome