title: Surgical Treatment Strategies for High-Grade Spondylolisthesis: A Systematic Review.
abstract: BACKGROUND
  HGS is a severe deformity most commonly affecting L5-S1 vertebral segment. Treatment available for HGS includes a range of different surgical options: full or partial reduction of translation and/or abnormal alignment and in situ fusion with or without decompression. Various instrumented or non-instrumented constructs are available, and surgical approach varies from anterior/posterior to combined depending on surgeon preference and experience. The aim of this systematic review was to review the literature on lumbosacral high-grade spondylolisthesis (HGS), identify patients at risk for progression to higher-grade slip and evaluate various surgical strategies to report on complications and radiographic and clinical outcomes.
  
  
  METHODS
  Systematic search of PubMed, Cochrane and Google Scholar for papers relevant to HGS was performed. 19 articles were included after title, abstract, and full-text review and grouped to analyze baseline radiographic parameters and the effect of surgical approach, instrumentation, reduction and decompression on patient radiographic and clinical outcomes.
  
  
  RESULTS
  There is a lack of high-quality studies pertaining to surgical treatment for HGS, and a majority of included papers were Level III or IV based on the JBJS Levels of Evidence Criteria.
  
  
  CONCLUSIONS
  Surgical treatment for HGS can vary depending on patient age. There is strong evidence of an association between increased pelvic incidence (PI) and presence of HGS and moderately strong evidence that patients with unbalanced pelvis can benefit from correction of lumbopelvic parameters with partial reduction. Surgeons need to weigh the benefits of fixing the deformity with the risks of potential complications, assessing patient satisfaction as well as their understanding of the possible complications. However, further research is necessary to make more definitive conclusions on surgical treatment guidelines for HGS.
  
  
  METHODS
  II.
authors.affiliation: Division of Spinal Surgery, Department of Orthopaedic Surgery, NYU Medical Center Hospital for Joint Diseases, NYU School of Medicine, New York City, New York, USA.
authors.forename: Peter G
authors.initials: PG
authors.lastname: Passias
authors.affiliation: Division of Spinal Surgery, Department of Orthopaedic Surgery, NYU Medical Center Hospital for Joint Diseases, NYU School of Medicine, New York City, New York, USA.
authors.forename: Caroline E
authors.initials: CE
authors.lastname: Poorman
authors.affiliation: Division of Spinal Surgery, Department of Orthopaedic Surgery, NYU Medical Center Hospital for Joint Diseases, NYU School of Medicine, New York City, New York, USA.
authors.forename: Sun
authors.initials: S
authors.lastname: Yang
authors.affiliation: Division of Spinal Surgery, Department of Orthopaedic Surgery, NYU Medical Center Hospital for Joint Diseases, NYU School of Medicine, New York City, New York, USA.
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Boniello
authors.affiliation: Division of Spinal Surgery, Department of Orthopaedic Surgery, NYU Medical Center Hospital for Joint Diseases, NYU School of Medicine, New York City, New York, USA.
authors.forename: Cyrus M
authors.initials: CM
authors.lastname: Jalai
authors.affiliation: Division of Spinal Surgery, Department of Orthopaedic Surgery, NYU Medical Center Hospital for Joint Diseases, NYU School of Medicine, New York City, New York, USA.
authors.forename: Nancy
authors.initials: N
authors.lastname: Worley
authors.affiliation: Division of Spinal Surgery, Department of Orthopaedic Surgery, NYU Medical Center Hospital for Joint Diseases, NYU School of Medicine, New York City, New York, USA.
authors.forename: Virginie
authors.initials: V
authors.lastname: Lafage
keywords: Complication; High-grade spondylolisthesis; Outcome; Reduction; comparative outcome; decompression; instrumentation; surgical treatment