title: Outcomes of posterior facet versus pedicle screw fixation of circumferential fusion: a cohort study.
abstract: OBJECTIVE
  To compare single-level circumferential spinal fusion using pedicle (n = 27) versus low-profile minimally invasive facet screw (n = 35) posterior instrumentation.
  
  
  METHODS
  A prospective two-arm cohort study with 5-year outcomes as follow-up was conducted. Assessment included back and leg pain, pain drawing, Oswestry disability index (ODI), pain medication usage, self-assessment of procedure success, and >1-year postoperative lumbar magnetic resonance imaging.
  
  
  RESULTS
  Significantly less operative time, estimated blood loss and costs were incurred for the facet group. Clinical improvement was significant for both groups (p < 0.01 for all outcomes scales). Outcomes were significantly better for back pain and ODI for the facet relative to the pedicle group at follow-up periods >1 year (p < 0.05). Postoperative magnetic resonance imaging found that 20 % had progressive adjacent disc degeneration, and posterior muscle changes tended to be greater for the pedicle screw group.
  
  
  CONCLUSIONS
  One-level circumferential spinal fusion using facet screws proved superior to pedicle screw instrumentation.
authors.affiliation: Midwest Spine Institute, 1950 Curve Crest Blvd, Stillwater, MN, 55082, USA, butte011@umn.edu.
authors.forename: Glenn R
authors.initials: GR
authors.lastname: Buttermann
authors.forename: Tague M
authors.initials: TM
authors.lastname: Thorson
authors.forename: William J
authors.initials: WJ
authors.lastname: Mullin
mesh_terms: D000328:Adult; D001863:Bone Screws; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000601:surgery; D008297:Male; D019060:Minimally Invasive Surgical Procedures; D010149:Postoperative Pain / Q000209:etiology; D011446:Prospective Studies; D013122:Spinal Diseases / Q000601:surgery; D013123:Spinal Fusion / Q000009:adverse effects / Q000379:methods*; D016896:Treatment Outcome