title: Epidemiological characteristics and outcome in elderly patients sustaining non-simultaneous bilateral hip fracture: a systematic review and meta-analysis.
abstract: OBJECTIVE
  The present study aimed to quantitatively and comprehensively conclude the epidemiological characteristics and outcome in elderly patients with non-simultaneous bilateral hip fractures.
  
  
  METHODS
  A search was applied to Medline, Embase and Cochrane central database (all up to February 2014). All the studies on non-simultaneous bilateral hip fractures in elderly patients without language restriction were reviewed, and qualities of included studies were assessed using the Newcastle-Ottawa Scale. All the data were carefully and independently abstracted by two reviewers, any disagreement was settled by discussion. Data were pooled and a meta-analysis completed.
  
  
  RESULTS
  A total of 23 studies (all were observational) including 2168 cases with bilateral hip fractures were identified, showing an accumulated incidence of 8.54%, and of them 71.4% were symmetrical. A total of 70.4% of cases occurred in the first 3 years, especially 36.3% in the first year. Results of meta-analyses showed that patients of female sex (odds ratio [OR] 1.48, 95% confidence interval [CI] 1.10-1.99), advanced age (standardized mean difference 0.25, 95% CI 0.15-0.36), initial trochanteric fractures (OR 1.15, 95% CI 1.01-1.32) and osteoporosis (Singh Index 1-3) (OR 10.02, 95% CI 5.41-18.57) were more likely to sustain a second contralateral hip fracture.
  
  
  CONCLUSIONS
  Non-simultaneous bilateral hip fracture accounts for a high proportion of hip fractures, and most of the second hip fractures occurred in the first 3 years. Patients of female sex, having initial trochanteric fractures, of more advanced age and having osteoporosis are more likely to sustain a second contralateral hip fracture, and risk-reduction strategies should be implemented.
authors.affiliation: Department of Orthopedic Surgery, the Third Hospital of Hebei Medical University, Shijiazhuang, Hebei, China.
authors.forename: Yanbin
authors.initials: Y
authors.lastname: Zhu
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.forename: Tao
authors.initials: T
authors.lastname: Sun
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhang
authors.forename: Song
authors.initials: S
authors.lastname: Liu
authors.forename: Yingze
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D014943:Global Health; D006620:Hip Fractures / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D008297:Male; D058866:Osteoporotic Fractures / Q000453:epidemiology*; D018570:Risk Assessment; D012307:Risk Factors; D012737:Sex Factors
keywords: bilateral hip fracture; elderly patients; epidemiological characteristics; meta-analysis; outcome