title: Effectiveness of interspinous implant surgery in patients with intermittent neurogenic claudication: a systematic review and meta-analysis.
abstract: BACKGROUND
  Despite an increasing implantation rate of interspinous process distraction (IPD) devices in the treatment of intermittent neurogenic claudication (INC), definitive evidence on the clinical effectiveness of implants is lacking. The main objective of this review was to perform a meta-analysis of all systematic reviews, randomized clinical trials and prospective cohort series to quantify the effectiveness of IPDs and to evaluate the potential side-effects.
  
  
  METHODS
  Data from all studies prospectively describing clinical results based on validated outcome scales and reporting complications of treatment of patients with INC with IPD placement. We searched MEDLINE, EMBASE, Web of Science, Cochrane (CENTRAL), CINAHL, Academic Search Premier, Science Direct up to July 2010. Studies describing patients with INC caused by lumbar stenosis, reporting complication rate and reporting based on validated outcome scores, were eligible. Studies with only instrumented IPD results were excluded.
  
  
  RESULTS
  Eleven studies eligible studies were identified. Two independently RCTs and eight prospective cohorts were available. In total 563 patients were treated with IPDs. All studies showed improvement in validated outcome scores after 6 weeks and 1 year. Pooled data based on the Zurich Claudication Questionnaire of the RCTs were more in favor of IPD treatment compared with conservative treatment (pooled estimate 23.2, SD 18.5-27.8). Statistical heterogeneity after pooled data was low (I-squared 0.0, p = 0.930). Overall complication rate was 7%.
  
  
  CONCLUSIONS
  As the evidence is relatively low and the costs are high, more thorough (cost-) effectiveness studies should be performed before worldwide implementation is introduced.
authors.affiliation: Department of Neurosurgery, Leiden University Medical Center, Albinusdreef 2, 2300 RC, Leiden, The Netherlands. w.a.moojen@lumc.nl
authors.forename: Wouter A
authors.initials: WA
authors.lastname: Moojen
authors.forename: Mark P
authors.initials: MP
authors.lastname: Arts
authors.forename: Ronald H M A
authors.initials: RH
authors.lastname: Bartels
authors.forename: Wilco C H
authors.initials: WC
authors.lastname: Jacobs
authors.forename: Wilco C
authors.initials: WC
authors.lastname: Peul
mesh_terms: D006801:Humans; D007383:Intermittent Claudication / Q000209:etiology* / Q000601:surgery*; D008159:Lumbar Vertebrae / Q000601:surgery; D019736:Prostheses and Implants / Q000009:adverse effects / Q000592:standards*; D013123:Spinal Fusion / Q000379:methods*; D013130:Spinal Stenosis / Q000150:complications / Q000601:surgery*