title: Assessment of trunk function in single and multi-level spinal stenosis: a prospective clinical trial.
abstract: OBJECTIVE
  To clarify the biomechanical indicators of single- and multi-level stenosis and to determine the biomechanical outcome of selective conservative decompression.
  
  
  METHODS
  This study is a prospective clinical trial examining trunk function in spinal stenosis patients operated using a conservative procedure in an orthopaedic clinic.
  
  
  BACKGROUND
  Although several clinical studies have examined the instability and motion characteristics of operated lumbar spinal canal stenosis, few if any studies have prospectively examined the biomechanical outcome of lumbar spinal canal stenosis surgery.
  
  
  METHODS
  Comprehensive pre- and post-operative trunk dynamometer strength and motion analysis tests were performed on 36 patients operated for lumbar canal stenosis. Surgical treatment efficacy was evaluated within a three variable crossed factorial design considering stenosis classification, number of operative levels, and changes in several trunk biomechanical outcomes from pre- to post-operative assessment. Patients were evaluated after a minimum one-year follow-up.
  
  
  RESULTS
  Pre-operatively there were no differential effects associated with stenosis classification or number of operated levels. There was a significant post-operative increase in isometric trunk extension torque and flexion-extension power and a return to a more normal trunk extension-flexion torque ratio. Patients with mixed, single level stenosis demonstrated greater trunk extension power both pre- and post-operatively compared to other patients.
  
  
  CONCLUSIONS
  Conservative surgical treatment of lumbar spinal stenosis produced a marked improvement in the functional mechanical status of the low back.
  
  
  CONCLUSIONS
  This study assists clinicians and researchers to understand trunk function following conservative surgical treatment of lumbar spinal stenosis.
authors.affiliation: Department of Mechanical Engineering, University of Vermont, 201 Votey Building, Burlington, VT 05405-0156, USA. keller@emba.uvm.edu
authors.forename: Tony S
authors.initials: TS
authors.lastname: Keller
authors.forename: Marek
authors.initials: M
authors.lastname: Szpalski
authors.forename: Robert
authors.initials: R
authors.lastname: Gunzburg
authors.forename: Kevin F
authors.initials: KF
authors.lastname: Spratt
mesh_terms: D019299:Decompression, Surgical / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007537:Isometric Contraction; D008297:Male; D008875:Middle Aged; D009068:Movement; D010808:Physical Examination / Q000379:methods*; D011182:Postoperative Care; D011300:Preoperative Care; D016059:Range of Motion, Articular; D020127:Recovery of Function / Q000502:physiology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013130:Spinal Stenosis / Q000145:classification / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery*; D019415:Torque; D016896:Treatment Outcome