title: Flexion-distraction injuries of the thoracolumbar spine: open fusion versus percutaneous pedicle screw fixation.
abstract: OBJECTIVE
  Flexion-distraction injuries occur due to distractive forces causing disruption of the posterior and middle spinal columns. These fractures classically consist of a fracture line through the posterior bony elements; involvement of the posterior ligamentous complex is, however, common. Surgical treatment is often required for these unstable injuries to avoid neurological deterioration and posttraumatic kyphosis, and the surgery traditionally consists of an open posterior approach with instrumented fusion. Percutaneous pedicle screw fixation for these injuries, with the goal of minimal tissue disruption and preservation of normal anatomy while achieving adequate stabilization, has recently been reported in the literature, but to date, a direct comparative study comparing open and percutaneous fixation has not been reported. The authors report their experience treating these fractures with both techniques and review the available literature.
  
  
  METHODS
  Patients with flexion-distraction injury who were treated between May 2003 and March 2013 were prospectively followed. American Spinal Injury Association scores and degree of kyphotic angulation were recorded at admission, discharge, and follow-up. Data regarding intraoperative blood loss and operative time were obtained from a chart review. Patients treated with open versus minimally invasive procedures were compared.
  
  
  RESULTS
  The authors identified 39 patients who suffered flexion-distraction injuries and were treated at their institution during the specified period; one of these patients declined surgery. All had injury to the posterior ligamentous complex. Open surgical procedures with pedicle screw fixation and posterolateral fusion were performed in 27 patients, while 11 patients underwent minimally invasive pedicle screw placement. Overall, there was improvement in kyphotic angulation at the time of discharge as well as most recent follow-up in both the open surgery and minimally invasive surgery (MIS) groups. The authors found no significant difference in American Spinal Injury Association score or the degree of kyphotic angulation between the MIS and open surgery groups. There was a trend toward shorter operative time for the MIS group, and patients who underwent minimally invasive procedures had significantly less blood loss.
  
  
  CONCLUSIONS
  Minimally invasive percutaneous pedicle screw fixation appears to have similar efficacy in the treatment of flexion-distraction injuries and it allows for reduced blood loss and tissue damage compared with open surgical techniques. Therefore it should be considered as an option for the treatment of this type of injury.
authors.affiliation: Departments of Neurosurgery, University of Iowa, Iowa City, IA 52245, USA. andrew-grossbach@uiowa.edu
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Grossbach
authors.forename: Nader S
authors.initials: NS
authors.lastname: Dahdaleh
authors.forename: Taylor J
authors.initials: TJ
authors.lastname: Abel
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Woods
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Dlouhy
authors.forename: Patrick W
authors.initials: PW
authors.lastname: Hitchon
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001863:Bone Screws; D060826:Cementoplasty / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008159:Lumbar Vertebrae / Q000293:injuries / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D016059:Range of Motion, Articular; D012189:Retrospective Studies; D016103:Spinal Fractures / Q000473:pathology / Q000601:surgery*; D013123:Spinal Fusion / Q000379:methods*; D013904:Thoracic Vertebrae / Q000293:injuries / Q000601:surgery; D016896:Treatment Outcome; D055815:Young Adult