title: Unilateral Pedicle Screw Fixation is Associated with Reduced Cost and Similar Outcomes in Selected Patients Undergoing Minimally Invasive Transforaminal Lumbar Interbody Fusion for L4-5 Degenerative Spondylolisthesis.
abstract: METHODS
  Retrospective study of 24 patients who underwent either a bilateral or unilateral TLIF procedure for the treatment of degenerative spondylolisthesis.
  
  
  OBJECTIVE
  To analyze differences in cost and outcome between patients undergoing minimally invasive transforaminal lumbar interbody fusion (mi-TLIF) with unilateral or bilateral pedicle screw fixation for L4-5 degenerative spondylolisthesis.
  
  
  BACKGROUND
  Lumbar fusion surgeries, including the TLIF procedure, have been shown to be an effective treatment for leg and low back pain caused by degenerative spondylolisthesis. Some studies have shown TLIF surgeries to be cost-effective, but there is still a paucity of data and no consensus. Unilateral TLIFs can provide the same benefits as bilateral TLIFs, but come with additional benefits of a less invasive surgery.
  
  
  METHODS
  We retrospectively analyzed a consecutive series of patients with L4-5 degenerative stenosis and spondylolisthesis who either received a unilateral or bilateral mi-TLIF, paying particular attention to hospital cost and clinical outcome. Of the 33 patients eligible for analysis, we were able to obtain appropriate clinical and radiographic follow-up data on 24 patients (72.7%), 14 patients who underwent unilateral fixation, and 10 patients who underwent bilateral fixation.
  
  
  RESULTS
  The cohorts were similar with regard to age, comorbidities, and demographics. Most patients reported good or excellent results, and there were no significant differences between the cohorts with regard to clinical outcome. There was one interbody graft extrusion in the unilateral cohort that required explantation, but no other hardware failures. Hospital cost was significantly lower in the unilateral cohort, and hardware savings accounted for only part of the difference.
  
  
  CONCLUSIONS
  Unilateral pedicle screw fixation is an acceptable surgical strategy in patients with stable L4-5 degenerative spondylolisthesis undergoing mi-TLIF. In our series, unilateral fixation led to significant hospital cost savings without compromising clinical or radiographic outcomes.
authors.affiliation: Department of Neurosurgery, Tufts University School of Medicine ; Wellman Center for Photomedicine and Department of Dermatology, Massachusetts General Hospital/ Harvard Medical School.
authors.forename: Philip
authors.initials: P
authors.lastname: Eliades
authors.affiliation: Department of Neurosurgery, Tufts Medical Center.
authors.forename: Jason P
authors.initials: JP
authors.lastname: Rahal
authors.affiliation: School of Medicine, Tufts University.
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Herrick
authors.affiliation: Department of Neurosurgery, University of Florida Health.
authors.forename: Brian M
authors.initials: BM
authors.lastname: Corliss
authors.affiliation: Department of Neurosurgery, Tufts Medical Center.
authors.forename: Ron
authors.initials: R
authors.lastname: Riesenburger
authors.affiliation: Department of Neurosurgery, Tufts Medical Center.
authors.forename: Steven
authors.initials: S
authors.lastname: Hwang
authors.affiliation: Department of Neurosurgery, Tufts Medical Center.
authors.forename: James T
authors.initials: JT
authors.lastname: Kryzanski
keywords: cost; degenerative spondylolisthesis; tlif; transforaminal lumbar interbody fusion