title: Effect of Obesity and Being Overweight on Disability and Pain After Lumbar Fusion: An Analysis of 805 Patients.
abstract: METHODS
  Prospective follow-up study.
  
  
  OBJECTIVE
  To investigate the influence of obesity and being overweight on disability and pain of patients undergoing lumbar spinal fusion.
  
  
  BACKGROUND
  Although spinal fusion surgery has been shown to relieve symptoms in several spinal disorders, the influence of obesity on the results remains controversial.
  
  
  METHODS
  Since January 1, 2008, all patients undergoing lumbar fusion in two hospitals have been invited to participate in a prospective follow-up database. At the end of 2014, the preoperative and 1-year follow-up data of 805 patients were available. Disability was evaluated using the Oswestry Disability Index and back and leg pain by the visual analogue scale. In addition, the working status, smoking, physical activity, duration of symptoms, and indication for surgery were captured. According to the World Health Organization classification of preoperative body mass index, patients were divided into three groups: normal weight (<25.0 kg/m), overweight (25.0-29.9 kg/m), and obese (≥30.0 kg/m).
  
  
  RESULTS
  Of the 805 patients, 204 (25.3%) were normal weight, 365 (45.3%) were overweight, and 236 (29.3%) were obese. The patients in the obese group exercised significantly less per week (P < 0.001). Preoperatively, the body mass index groups did not differ with regard to disability and pain. At the 1-year follow-up, the change in the Oswestry Disability Index was -25 in normal, -24 in overweight, and -23 in obese patients (P = 0.013), and disability was severe in 14.7% of the normal group, 17.0% of the overweight group, and 24.2% of the obese group (P = 0.0052). Back and leg pain improved more in the normal weight group compared with the overweight or obese groups (P < 0.05).
  
  
  CONCLUSIONS
  Although lumbar spine fusion is also effective in obese patients, the present large follow-up study demonstrates that their outcome results are slightly poorer than patients with normal weight at 1 year after surgery.
  
  
  METHODS
  3.
authors.affiliation: *Department of Orthopaedic Surgery, Japanese Red Cross Maebashi Hospital†Department of Orthopaedic Surgery, Gunma University Graduate School of Medicine, Maebashi, Japan‡Department of Orthopaedics and Traumatology, Tampere University Hospital§Department of Orthopaedics and Traumatology¶Department of Physical Medicine and Rehabilitation, Central Finland Central Hospital||Department of Health Sciences, University of Jyväskylä, Finland.
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Sorimachi
authors.forename: Marko H
authors.initials: MH
authors.lastname: Neva
authors.forename: Kimmo
authors.initials: K
authors.lastname: Vihtonen
authors.forename: Kati
authors.initials: K
authors.lastname: Kyrölä
authors.forename: Haku
authors.initials: H
authors.lastname: Iizuka
authors.forename: Kenji
authors.initials: K
authors.lastname: Takagishi
authors.forename: Arja
authors.initials: A
authors.lastname: Häkkinen
mesh_terms: D000368:Aged; D004185:Disability Evaluation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000175:diagnosis / Q000453:epidemiology* / Q000601:surgery*; D050177:Overweight / Q000175:diagnosis / Q000453:epidemiology / Q000601:surgery; D010147:Pain Measurement / Q000379:methods / Q000639:trends; D010149:Postoperative Pain / Q000175:diagnosis / Q000453:epidemiology*; D011446:Prospective Studies; D013123:Spinal Fusion / Q000009:adverse effects* / Q000639:trends