title: Predictors of improvement in low back pain after lumbar decompression surgery: Prospective study of 140 patients.
abstract: BACKGROUND
  Lumbar decompression surgery is often used to treat neurological symptoms of the lower extremity as a result of lumbar disease. However, this method also leads to the improvement of the accompanying low back pain (LBP). We studied the extent of LBP improvement after lumbar decompression surgery without fusion and the associated preoperative factors.
  
  
  METHODS
  Patients (n = 140) with lumbar spinal stenosis (n = 90) or lumbar disc herniation (n = 50) were included. To evaluate the change in LBP, VAS scores and the Oswestry disability index scores were measured before surgery and 2 weeks, 3 months, and 6 months after surgery. The predictors of residual LBP were investigated using logistic regression analyses.
  
  
  RESULTS
  In total, 140 patients were examined. The VAS scores for LBP before surgery and 2 weeks, 3 months, and 6 months after surgery were 4.4 ± 3.0 (mean ± standard deviation), 1.1 ± 1.5, 1.3 ± 1.8, and 1.9 ± 2.2, respectively. LBP significantly improved 2 weeks after surgery (P < 0.001), stabilized between 2 weeks and 3 months after surgery, but was significantly aggravated 3-6 months after surgery (P < 0.001). At 6 months after surgery, 67 (47.9%) patients had a VAS score of >1. The predictors of residual LBP included severe preoperative LBP, degenerative scoliosis and the size of the Cobb angle. The independent predictors, determined by multivariate analysis were degenerative scoliosis and the size of the Cobb angle.
  
  
  CONCLUSIONS
  LBP was alleviated at 2 weeks after lumbar decompression surgery for lumbar disc herniation and lumbar spinal stenosis. The predictors of residual LBP after decompression included more severe LBP at baseline, degenerative scoliosis and the size of Cobb angle.
  
  
  METHODS
  Level 3.
authors.affiliation: Department of Orthopaedic Surgery, Shinshu University, School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan. Electronic address: oba1@hotmail.co.jp.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Oba
authors.affiliation: Department of Orthopaedic Surgery, Shinshu University, School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan. Electronic address: jtaka@shinshu-u.ac.jp.
authors.forename: Jun
authors.initials: J
authors.lastname: Takahashi
authors.affiliation: Department of Orthopaedic Surgery, Yodakubo Hospital, 2857 Nagawa Chiisagata-gun, Nagano 386-0603, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Tsutsumimoto
authors.affiliation: Department of Orthopaedic Surgery, Shinshu University, School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan.
authors.forename: Shota
authors.initials: S
authors.lastname: Ikegami
authors.affiliation: Department of Orthopaedic Surgery, Yodakubo Hospital, 2857 Nagawa Chiisagata-gun, Nagano 386-0603, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ohta
authors.affiliation: Department of Orthopaedic Surgery, Yodakubo Hospital, 2857 Nagawa Chiisagata-gun, Nagano 386-0603, Japan.
authors.forename: Mutsuki
authors.initials: M
authors.lastname: Yui
authors.affiliation: Department of Orthopaedic Surgery, Yodakubo Hospital, 2857 Nagawa Chiisagata-gun, Nagano 386-0603, Japan.
authors.forename: Hidemi
authors.initials: H
authors.lastname: Kosaku
authors.affiliation: Department of Orthopaedic Surgery, Yodakubo Hospital, 2857 Nagawa Chiisagata-gun, Nagano 386-0603, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Kamanaka
authors.affiliation: Department of Orthopaedic Surgery, Yodakubo Hospital, 2857 Nagawa Chiisagata-gun, Nagano 386-0603, Japan.
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Misawa
authors.affiliation: Department of Orthopaedic Surgery, Shinshu University, School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kato
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019299:Decompression, Surgical; D005260:Female; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000150:complications / Q000601:surgery*; D017116:Low Back Pain / Q000209:etiology / Q000601:surgery*; D008159:Lumbar Vertebrae; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013130:Spinal Stenosis / Q000150:complications / Q000601:surgery*; D016896:Treatment Outcome; D055815:Young Adult