title: Meta-analysis of randomised controlled trials comparing unipolar with bipolar hemiarthroplasty for displaced femoral-neck fractures.
abstract: OBJECTIVE
  Unipolar and bipolar hemiarthroplasty (HA) are used to treat displaced femoral-neck fractures. However, which type is best for treating displaced femoral-neck fractures in elderly patients remains a subject for debate. Our aim was to review randomised controlled trials to establish which type provides superior clinical outcome for this patient population.
  
  
  METHODS
  We searched PubMed, Embase and Cochrane Register of Controlled Trials databases and Web of Science for randomised controlled trials (RCTs) comparing unipolar with bipolar HA to treat femoral-neck fracture in the elderly. Risk ratios (RRs) and mean differences (MDs) from each trial were pooled using random-effects or fixed-effects models depending on study heterogeneity. Analysis was performed using RevMan5.2 from the Cochrane Collaboration.
  
  
  RESULTS
  A total of 1,100 patients from nine studies were assessed in this meta-analysis. Results showed no significant differences in function score [MD = -0.14, 95% confidence interval (CI) -2.42-2.13], mortality (RR = 0.97, 95% CI 0.65-1.46), dislocation (RR = 1.33, 95% CI 0.53-3.34), deep infection (RR = 0.79, 95% CI 0.35-1.79), acetabular erosion (RR = 1.99, 95% CI 0.61-6.52), operating time (MD = 2.14, 95% CI -9.85 to14.14), blood loss (MD = 13.40, 95% CI -49.60 to 76.39) and length of hospital stay (MD = 0.12, 95% CI -0.49 to 0.73) between unipolar and bipolar HA.
  
  
  CONCLUSIONS
  Unipolar and bipolar HA achieved similar clinical outcomes in patients with displaced femoral-neck fractures.
authors.affiliation: Department of Orthopaedics, The First Affiliated Hospital of Harbin Medical University, No. 23 You Zheng Street, Harbin, 150001, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Xueqiang
authors.initials: X
authors.lastname: Tao
authors.forename: Pei
authors.initials: P
authors.lastname: Wang
authors.forename: Zheng
authors.initials: Z
authors.lastname: Zhang
authors.forename: Wenlong
authors.initials: W
authors.lastname: Zhang
authors.forename: Quan
authors.initials: Q
authors.lastname: Qi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005265:Femoral Neck Fractures / Q000601:surgery*; D005500:Follow-Up Studies; D062785:Hemiarthroplasty / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data; D061646:Operative Time; D017063:Outcome Assessment, Health Care; D016032:Randomized Controlled Trials as Topic; D016896:Treatment Outcome