title: Grade 2 spondylolisthesis at L4-5 treated by XLIF: safety and midterm results in the "worst case scenario".
abstract: Spondylolisthesis is one of the most common indications for spinal surgery. However, no one approach has been proven to be more effective in treating spondylolisthesis. Recent advances in minimally invasive spine technology have allowed for different approaches to be applied to this indication, notably extreme lateral interbody fusion (XLIF). The risk, however, of using XLIF in treating grade II spondylolisthesis is the ventral position of the lumbar plexus, particularly at L4-5.
  
  
  OBJECTIVE
  This study reports the safety and midterm clinical and radiographic outcomes of patients with grade II lumbar spondylolisthesis treated with XLIF.
  
  
  METHODS
  63 patients with grade II spondylolisthesis and spinal stenosis were treated with XLIF and were available for 12-month followup. Of those, 61 (97%) were treated at L4-5. Clinical (VAS, complications, and reoperation rate) and radiographic (anterolisthesis, disk height, and fusion) parameters were assessed.
  
  
  METHODS
  Data were collected via a prospective registry and analyzed retrospectively.
  
  
  RESULTS
  Sixty-three patients were available for evaluations at least one year postoperatively. Average pain (visual analog scale) decreased from a score of 8.7 at baseline to 2.2 at 12 months postoperatively. Average anterior slippage was reduced by 73% and was well maintained. Average disk height (4.6 mm pre-op and 9.0 mm post-op) nearly doubled after surgery. Slight settling (average 1.3 mm) occurred over the twelve-month follow-up period. There were no neural injuries and no nonunions noted.
  
  
  CONCLUSIONS
  XLIF is a safe and effective minimally invasive treatment alternative for grade II spondylolisthesis. Real-time neurological monitoring and attention to technique are mandatory.
authors.affiliation: Spine Midwest, Inc., Suite 301, 200 St. Mary's Medical Plaza, Jefferson City, MO 65101, USA.
authors.forename: W B
authors.initials: WB
authors.lastname: Rodgers
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Lehmen
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Gerber
authors.forename: Jody A
authors.initials: JA
authors.lastname: Rodgers
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011859:Radiography; D012189:Retrospective Studies; D013131:Spine / Q000000981:diagnostic imaging / Q000601:surgery; D013168:Spondylolisthesis / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D016896:Treatment Outcome