title: Does Obesity Affect Outcomes After Decompressive Surgery for Lumbar Spinal Stenosis? A Multicenter, Observational, Registry-Based Study.
abstract: OBJECTIVE
  To evaluate the association between obesity and outcomes 1 year after laminectomy or microdecompression for lumbar spinal stenosis (LSS).
  
  
  METHODS
  The primary outcome measure was the Oswestry Disability Index (ODI). Obesity was defined as body mass index (BMI) ≥ 30. Prospective data were retrieved from the Norwegian Registry for Spine Surgery.
  
  
  RESULTS
  For all patients (n = 1473) the mean improvement in ODI at 1 year was 16.7 points (95% CI 15.7-17.7, P < 0.001). The improvement in ODI was 17.5 points in nonobese and 14.3 points in obese patients (P = 0 .007). Obese patients were less likely to achieve a minimal clinically important difference in ODI (defined as ≥ 8 points improvement) than nonobese patients (62.2 vs. 70.3%, P = 0.013). Obesity was identified as a negative predictor for ODI improvement in a multiple regression analysis (P < 0.001). Nonobese patients experienced more improvement in both back pain (0.7 points, P = 0.002) and leg pain (0.8 points, P = 0.001) measured by numeric rating scales. Duration of surgery was shorter for nonobese patients for both single- (79 vs. 89 minutes, P = 0.001) and 2-level (102 vs. 114 minutes, P = 0.004) surgery. There was no difference in complication rates (10.4% vs. 10.8%, P = 0.84). There was no difference in length of hospital stays for single- (2.7 vs. 3.0 days, P = 0.229) or 2-level (3.5 vs. 3.6 days, P = 0.704) surgery.
  
  
  CONCLUSIONS
  Both nonobese and obese patients report considerable clinical improvement 1 year after surgery for LSS, but improvement was less in obese patients. Obese patients were less likely to achieve a minimal clinically important difference.
authors.affiliation: Department of Neurosurgery, St. Olavs University Hospital, Trondheim, Norway; Department of Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway. Electronic address: charalampis.giannadakis@ntnu.no.
authors.forename: Charalampis
authors.initials: C
authors.lastname: Giannadakis
authors.affiliation: Department of Neurosurgery, St. Olavs University Hospital, Trondheim, Norway; Department of Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Ulf S
authors.initials: US
authors.lastname: Nerland
authors.affiliation: Department of Neurosurgery, St. Olavs University Hospital, Trondheim, Norway; Department of Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway; National Advisory Unit in Ultrasound and Image-Guided Surgery, Trondheim, Norway.
authors.forename: Ole
authors.initials: O
authors.lastname: Solheim
authors.affiliation: National Advisory Unit in Ultrasound and Image-Guided Surgery, Trondheim, Norway; Department of Neurosurgery, Sahlgrenska University Hospital, Gothenburg, Sweden.
authors.forename: Asgeir S
authors.initials: AS
authors.lastname: Jakola
authors.affiliation: Department of Surgery, Ålesund Hospital, Ålesund, Norway; Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Michel
authors.initials: M
authors.lastname: Gulati
authors.affiliation: National Advisory Unit on Spinal Surgery Center for Spinal Disorders, St. Olavs University Hospital, Trondheim, Norway; Department of Neurosurgery, Stavanger University Hospital, Stavanger, Norway.
authors.forename: Clemens
authors.initials: C
authors.lastname: Weber
authors.affiliation: Department of Neurosurgery, St. Olavs University Hospital, Trondheim, Norway; Department of Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway; National Advisory Unit on Spinal Surgery Center for Spinal Disorders, St. Olavs University Hospital, Trondheim, Norway.
authors.forename: Øystein P
authors.initials: ØP
authors.lastname: Nygaard
authors.affiliation: Department of Neurosurgery, University Hospital of Northern Norway, Tromsø, Norway; The Norwegian National Registry for Spine Surgery, University Hospital of Northern Norway, Tromsø, Norway.
authors.forename: Tore K
authors.initials: TK
authors.lastname: Solberg
authors.affiliation: Department of Neurosurgery, St. Olavs University Hospital, Trondheim, Norway; Department of Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway; National Advisory Unit on Spinal Surgery Center for Spinal Disorders, St. Olavs University Hospital, Trondheim, Norway; Norwegian Centre of Competence in Deep Brain Stimulation for Movement Disorders, St. Olavs University Hospital, Trondheim, Norway.
authors.forename: Sasha
authors.initials: S
authors.lastname: Gulati
mesh_terms: D000368:Aged; D019299:Decompression, Surgical; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D007796:Laminectomy; D008136:Longevity; D017116:Low Back Pain / Q000628:therapy; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures; D009765:Obesity / Q000150:complications*; D011183:Postoperative Complications / Q000453:epidemiology; D011379:Prognosis; D011446:Prospective Studies; D012042:Registries; D013130:Spinal Stenosis / Q000150:complications* / Q000601:surgery*; D016896:Treatment Outcome
keywords: Neurosurgical procedures; Obesity; Quality of life; Spinal stenosis; Spondylosis