title: Does cross-linked polyethylene decrease the revision rate of total hip arthroplasty compared with conventional polyethylene? A meta-analysis.
abstract: BACKGROUND
  Although cross-linked polyethylene is resistant to wear in comparison to conventional polyethylene, it remains unknown whether it can decrease the wear-related revision rate of total hip arthroplasty.
  
  
  OBJECTIVE
  To determine whether cross-linked polyethylene decreases the wear-related revision rate of total hip arthroplasty compared with conventional polyethylene.
  
  
  METHODS
  Electronic databases, including PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials, were queried from inception to July 6, 2013.
  
  
  METHODS
  Randomized controlled trials (RCTs) comparing cross-linked polyethylene with conventional polyethylene were included. In addition, the standard 28-mm femoral head was used, and follow-up was performed for a minimum of 5 years. The primary outcome assessed was wear-related revision. The secondary outcome measures evaluated were the incidence of osteolysis, the linear wear rate, and the linear head penetration.
  
  
  RESULTS
  The Cochrane Collaboration's tool for assessing the risk of bias was used for quality assessment. Data from eligible studies were pooled using a random effects model.
  
  
  RESULTS
  Eight studies involving 735 patients were included in this study. Meta-analysis showed there was no significant difference between cross-linked and conventional polyethylene group in terms of osteolysis or wear-related revision. The pooled mean differences were significantly less for the linear wear rate and linear head penetration for cross-linked polyethylene than for conventional polyethylene.
  
  
  CONCLUSIONS
  The studies differed with respect to the cross-linked liner brands, manufacturing processes, and radiological evaluation methods. Moreover, the follow-up periods of the RCTs were not long enough.
  
  
  CONCLUSIONS
  The current limited evidence suggests that cross-linked polyethylene significantly reduced the radiological wear compared with conventional polyethylene at midterm follow-up periods. However, there is no evidence that cross-linked polyethylene had an advantage over conventional polyethylene in terms of reducing osteolysis or wear-related revision. Nevertheless, future long-term RCTs on this topic are needed.
  
  
  RESULTS
  Cross-linked polyethylene significantly reduced radiological wear but not osteolysis or wear-related revision in comparison to conventional polyethylene at midterm follow-up periods.
  
  
  METHODS
  Level I, systematic review of level I studies.
authors.affiliation: Department of Orthopedics, Affiliated Hospital of Guilin Medical College, 541001 Guilin, Guangxi, China. Electronic address: sc821@foxmail.com.
authors.forename: C
authors.initials: C
authors.lastname: Shen
authors.affiliation: Department of Orthopedics, Affiliated Hospital of Guilin Medical College, 541001 Guilin, Guangxi, China.
authors.forename: Z-H
authors.initials: ZH
authors.lastname: Tang
authors.affiliation: Department of Orthopedics, Affiliated Hospital of Guilin Medical College, 541001 Guilin, Guangxi, China.
authors.forename: J-Z
authors.initials: JZ
authors.lastname: Hu
authors.affiliation: Department of Orthopedics, Affiliated Hospital of Guilin Medical College, 541001 Guilin, Guangxi, China.
authors.forename: G-Y
authors.initials: GY
authors.lastname: Zou
authors.affiliation: Department of Orthopedics, Affiliated Hospital of Guilin Medical College, 541001 Guilin, Guangxi, China.
authors.forename: R-C
authors.initials: RC
authors.lastname: Xiao
authors.affiliation: Department of Orthopedics, Affiliated Hospital of Guilin Medical College, 541001 Guilin, Guangxi, China.
authors.forename: D-X
authors.initials: DX
authors.lastname: Yan
mesh_terms: D019644:Arthroplasty, Replacement, Hip / Q000706:statistics & numerical data*; D003432:Cross-Linking Reagents; D006622:Hip Prosthesis; D006801:Humans; D020959:Polyethylene; D011095:Polyethylenes; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012086:Reoperation / Q000706:statistics & numerical data; D016896:Treatment Outcome
chemical_list: D003432:Cross-Linking Reagents; D011095:Polyethylenes; D020959:Polyethylene
keywords: Cross-linked; Meta-analysis; Polyethylene; Total hip arthroplasty