title: Risk factors associated with the early failure of cannulated hip screws.
abstract: OBJECTIVE
  We report our experience with cannulated hip screws and analyse the risk factors associated with their early failure.
  
  
  METHODS
  All patients undergoing cannulated hip screws at a single UK Major Trauma Centre between November 2009 and November 2011 were retrospectively identified. Radiographs were analysed for fracture displacement, successful reduction, and screw configuration. Risk factors predicting early failure, defined as re-operation within 6 months, were identified using logistic regression models.
  
  
  RESULTS
  340 patients were included in the study, 70% were female and the mean age was 81 years. After six months 23% patients had undergone revision surgery. Initial fracture displacement (p = 0.02) and unsuccessful lateral reduction (p = 0.04) were significant predictors of early failure.
  
  
  CONCLUSIONS
  Initial fracture displacement and successful fracture reduction are the most important factors related to the risk of early re-operation. We found no evidence that screw configuration is an important predictor of outcome.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Jordan
authors.forename: Nick A
authors.initials: NA
authors.lastname: Smith
authors.forename: Edward
authors.initials: E
authors.lastname: Dickenson
authors.forename: Helen
authors.initials: H
authors.lastname: Parsons
authors.forename: Xavier
authors.initials: X
authors.lastname: Griffin
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001863:Bone Screws; D005260:Female; D005593:Fracture Fixation, Internal / Q000295:instrumentation*; D006620:Hip Fractures / Q000601:surgery*; D006801:Humans; D008297:Male; D011475:Prosthesis Failure; D012086:Reoperation; D012189:Retrospective Studies; D012307:Risk Factors