title: [A biomechanical study on polyethylene liner cementing into a fixed acetabular shell in revision total hip arthroplasty].
abstract: OBJECTIVE
  To evaluate the strength of polyethylene linercement interface when cementing a new liner into a fixed acetabular cup in revision.
  
  
  METHODS
  Twenty-five pairs of metal acetabular cups with polyethylene liners were randomly divided into 5 groups: 1 group with standard locking device as control group (group A), other liners were cemented into acetabular cups as 4 experimental groups. According to different intersection angles of metal acetabular cups with polyethylene liners and the polyethylene liners with or without metal ball, the 4 experimental groups were no ball 0 degrees group (group B), 0 degrees group (group C), 10 degrees group (group D), and 20 degrees group (group E), metal acetabular cups intersected with polyethylene liners without metal ball in group B, with metal ball in groups C, D, and E, respectively. The lever-out biomechanical test reproduced in vivo failure mechanism was then performed to evaluate the lever-out failure strength of liner-cement-metal cup interface.
  
  
  RESULTS
  The values of liver-out failure force were (626.68 +/- 206.12), (915.04 +/- 197.49), (449.02 +/- 119.78), (814.68 +/- 53.89), and (1 033.05 +/- 226.44) N in groups A, B, C, D, and E, respectively, showing significant differences for comparison among groups (F = 8.989, P = 0.000). The values of liver-out failure force in groups B and E were significantly higher than that in group A (P < 0.05), but no significant difference was found between groups C, D and group A (P > 0.05).
  
  
  CONCLUSIONS
  Cementation of polyethylene liner into a malposition shell meeting within 20 degrees can provide enough fixed strength.
authors.affiliation: Department of Orthopedics, the Third Affiliated Hospital of Southern Medical University, Guangzhou Guangdong, 510630, P.R. China.
authors.forename: Weijie
authors.initials: W
authors.lastname: Lu
authors.forename: Dadi
authors.initials: D
authors.lastname: Jin
authors.forename: Zhichen
authors.initials: Z
authors.lastname: Li
authors.forename: Yi
authors.initials: Y
authors.lastname: Chen
authors.forename: Dongfeng
authors.initials: D
authors.lastname: Chen
authors.forename: Nansheng
authors.initials: N
authors.lastname: Yu
mesh_terms: D000077:Acetabulum / Q000601:surgery; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation / Q000379:methods; D001696:Biomechanical Phenomena; D001843:Bone Cements; D002484:Cementation; D006622:Hip Prosthesis; D008670:Metals; D020959:Polyethylene; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012086:Reoperation; D013314:Stress, Mechanical; D054159:Torsion, Mechanical
chemical_list: D001843:Bone Cements; D008670:Metals; D020959:Polyethylene