title: Postoperative outcome of lumbar spinal canal stenosis after fenestration: correlation with changes in intradural and extradural tube on magnetic resonance imaging.
abstract: OBJECTIVE
  To evaluate the serial changes in clinical results and the intradural and extradural spaces on magnetic resonance imaging (MRI) after bilateral fenestration in 48 patients with lumbar spinal canal stenosis (LSCS).
  
  
  METHODS
  A prospective interventional study was performed to study the clinical results, magnetic resonance imaging scans among patients who were followed up for more than 3 years.
  
  
  RESULTS
  All patients showed improvement in clinical symptoms after operation, but clinical results deteriorated in 9 (19%) patients. Postoperative MRI scans showed that poor dural tube expansion, grouping of the cauda equina, and decrease in the cross-sectional area of the dural tube were factors associated with poor outcomes. The cross-sectional area of the dural tube and images of the cauda equina observed by MRI, before and after fenestration and during follow-up, reflected changes in clinical symptoms involving decompressed segments.
  
  
  CONCLUSIONS
  Serial changes in the cross-sectional area of the dural tube and images of the cauda equina observed preoperatively, postoperatively, and on follow-up by MRI may be useful when evaluating patients' condition before and after operation. It is also useful for predicting outcomes.
authors.affiliation: Department of Orthopaedic Surgery, Iwate Medical University, 19-1 Uchimaru, Morioka 020-8505, Japan. yamaken@iwate-med.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Yamazaki
authors.forename: S
authors.initials: S
authors.lastname: Yoshida
authors.forename: T
authors.initials: T
authors.lastname: Ito
authors.forename: T
authors.initials: T
authors.lastname: Toba
authors.forename: S
authors.initials: S
authors.lastname: Kato
authors.forename: T
authors.initials: T
authors.lastname: Shimamura
mesh_terms: D000368:Aged; D019299:Decompression, Surgical; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery*; D008159:Lumbar Vertebrae / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology / Q000473:pathology*; D011446:Prospective Studies; D013130:Spinal Stenosis / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery*; D018709:Statistics, Nonparametric; D016896:Treatment Outcome