title: What is the rate of lumbar adjacent segment disease after percutaneous versus open fusion?
abstract: OBJECTIVE
  Adjacent segment disease (ASD) requiring treatment or re-operation is a common problem after surgery on the lumbar spine. The hypothesis of this retrospective study was that ASD occurs less often following lumbar spine fusion in patients who undergo percutaneous minimally invasive (MIS) instrumentation than in those in whom open instrumentation is used.
  
  
  METHODS
  A case-control study was performed on consecutive patients who had undergone staged single or two level anterior lumbar interbody fusion for degenerative conditions followed by open or MIS instrumentation from 2002 to 2005 in our institution. ASD was defined as that necessitating additional procedures for new symptoms related to an adjacent lumbar dermatome.
  
  
  RESULTS
  One hundred and seventeen patients met the inclusion criteria. Of these, 53 had been followed up by chart or medical record review for longer than one year. There were 23 patients in the MIS group and 30 in the open group. Of the 30 patients in the open group, 9 had developed ASD (30%). Of the 23 patients in the MIS group, 7 had developed ASD (30%). This difference is not statistically significant (P = 1.00).
  
  
  CONCLUSIONS
  Contrary to our hypothesis, there was no significant difference in incidence of ASD in patients who had underwent open versus percutaneous instrumentation following anterior lumbar interbody fusion.
authors.affiliation: Department of Orthopaedic Surgery, Rothman Institute, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania, PA, USA.
authors.forename: Kristen E
authors.initials: KE
authors.lastname: Radcliff
authors.forename: Christopher K
authors.initials: CK
authors.lastname: Kepler
authors.forename: Motasem
authors.initials: M
authors.lastname: Maaieh
authors.forename: D Greg
authors.initials: DG
authors.lastname: Anderson
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Rihn
authors.forename: Todd
authors.initials: T
authors.lastname: Albert
authors.forename: Alex
authors.initials: A
authors.lastname: Vaccaro
authors.forename: Alan
authors.initials: A
authors.lastname: Hilibrand
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000009:adverse effects / Q000379:methods; D012008:Recurrence; D012086:Reoperation; D012189:Retrospective Studies; D013123:Spinal Fusion / Q000009:adverse effects* / Q000379:methods*; D055009:Spondylosis / Q000209:etiology / Q000601:surgery*; D016896:Treatment Outcome
keywords: Adjacent segment disease; Minimally invasive fusion; Percutaneous screws; Reoperation