title: Prognostic significance of stability in slipped upper femoral epiphysis: a systematic review and meta-analysis.
abstract: OBJECTIVE
  To examine associations of major complications after surgical treatment of slipped upper femoral epiphysis (SUFE) with condition- and treatment-related risk factors.
  
  
  METHODS
  This systematic review and meta-analysis of observational studies used an electronic literature search of Embase and Medline supplemented by a manual search of bibliographies. The studies enrolled children and adolescents with SUFE, defined stable and unstable disease, and reported at least 3 primary endpoints: avascular necrosis (AVN), chondrolysis, and reoperation. Random-effects meta-regression analysis was performed when possible.
  
  
  RESULTS
  The weighted risk for AVN, derived from intercept-only meta-regression, was estimated as 5.3% (95% confidence interval [CI], 3.4%-7.2%). Patients with unstable slips had a 9.4-fold greater risk of developing AVN. Instability proved to be an independent predictor for AVN. The weighted risk of chondrolysis was 0.8% (95% CI, 0.2%-1.4%), associated with unstable slips and osteotomies. The risk of reoperation was estimated at 5.5% (95% CI, 1.7%-9.3%). Loss of fixation was the primary reason for reoperation.
  
  
  CONCLUSIONS
  Current evidence indicates that unstable slips are at a significantly higher risk for AVN than stable slips, regardless of the attempted surgical approach. Little clinical information is available regarding chondrolysis and reoperation in relation to the stability of the physis.
authors.affiliation: Academic Department of Trauma and Orthopaedics, Leeds General Infirmary, University of Leeds, Leeds, UK.
authors.forename: Theodoros
authors.initials: T
authors.lastname: Tosounidis
authors.forename: Dirk
authors.initials: D
authors.lastname: Stengel
authors.forename: George
authors.initials: G
authors.lastname: Kontakis
authors.forename: Brian
authors.initials: B
authors.lastname: Scott
authors.forename: Peter
authors.initials: P
authors.lastname: Templeton
authors.forename: Peter V
authors.initials: PV
authors.lastname: Giannoudis
mesh_terms: D000293:Adolescent; D002648:Child; D004839:Epiphyses, Slipped / Q000150:complications* / Q000453:epidemiology / Q000601:surgery*; D005269:Femur; D006621:Hip Joint; D006801:Humans; D007593:Joint Instability / Q000150:complications*; D019637:Orthopedic Procedures / Q000379:methods; D010020:Osteonecrosis / Q000453:epidemiology / Q000601:surgery; D011379:Prognosis; D012086:Reoperation; D012307:Risk Factors