title: Grade 1 spondylolisthesis and interspinous device placement: removal in six patients and analysis of current data.
abstract: BACKGROUND
  In the treatment of patients with Grade 1 spondylolisthesis, the use of interspinous devices has been controversial for nearly a decade. Several authors have suggested that Grade 1 spondylolisthesis be considered a contraindication for interspinous device placement.
  
  
  METHODS
  We removed interspinous devices in six symptomatic Grade 1 spondylolisthesis patients and analyzed pertinent literature.
  
  
  RESULTS
  All six patients reported an improvement in symptoms following device removal and subsequent instrumented fusion. One patient who had not been able to walk due to pain regained the ability to walk. Several articles were identified related to spondylolisthesis and interspinous devices.
  
  
  CONCLUSIONS
  Regarding patients receiving interspinous devices for symptomatic lumbar spinal stenosis, several high-quality studies have failed to demonstrate a statistical difference in outcomes between patients with or without Grade 1 spondylolisthesis. Nevertheless, surgeons should have a high degree of suspicion when considering use of interspinous devices in this patient population.
authors.affiliation: Department of Neurosurgery, University of Kansas Medical Center, Kansas City, USA.
authors.forename: Parker E
authors.initials: PE
authors.lastname: Bohm
authors.affiliation: Department of Neurosurgery, University of Kansas Medical Center, Kansas City, USA.
authors.forename: Karen K
authors.initials: KK
authors.lastname: Anderson
authors.affiliation: Department of Mechanical Engineering, University of Kansas, Lawrence KS, USA.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Friis
authors.affiliation: Department of Neurosurgery, University of Kansas Medical Center, Kansas City, USA.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Arnold
keywords: Interspinous process device; X-STOP®; interspinous process spacer; lumbar spinal stenosis; neurogenic intermittent claudication; spondylolisthesis