title: Risk factors for degenerative spondylolisthesis: a systematic review.
abstract: METHODS
  Systematic literature review.
  
  
  BACKGROUND
  Many authors have postulated on various risk factors associated with the pathogenesis of degenerative spondylolisthesis (DS), yet controversies regarding those risk factors still exist.
  
  
  OBJECTIVE
  To critically appraise and summarize evidence on risk factors for DS.
  
  
  METHODS
  Articles published before October 15, 2011, were systematically reviewed using PubMed and bibliographies of key articles. Each article was subject to quality rating and was analyzed by two independent reviewers.
  
  
  RESULTS
  From 382 citations, 30 underwent full-text review. Fourteen studies met inclusion criteria. All but two were considered poor quality. Female gender and higher facet joint angle were consistently associated with an increased risk of DS across multiple studies. Multiple studies also consistently reported no association between back pain and prolonged occupational sitting. Associations between age, parity, lumbosacral angle, lumbar lordosis, facet joint tropism, and pelvic inclination angles were inconsistent.
  
  
  CONCLUSIONS
  There appears to be consistent evidence to suggest that the risk of DS increases with increasing age and is greater for females and people with a greater facet joint angle.
authors.affiliation: Dwight D. Eisenhower Army Medical Center Fort Gordon, GA, USA.
authors.forename: John G
authors.initials: JG
authors.lastname: Devine
authors.forename: Jeannette M
authors.initials: JM
authors.lastname: Schenk-Kisser
authors.forename: Andrea C
authors.initials: AC
authors.lastname: Skelly