title: Mid term results of total hip arthroplasty using polyethylene-ceramic composite (Sandwich) liner.
abstract: BACKGROUND
  Ceramic-on-ceramic (COC) couplings are an attractive alternative bearing surfaces that have been reported to eliminate or reduce problems related to polyethylene wear debris. However, the material in total hip arthroplasty (THA) remains one of the major concern regarding the risk of fracture. The present study aims at reporting the fracture rate of bearings in a series of COC THAs with the use of a sandwich liner and attempt to detect the relative risk factors, the possible cause and assess the clinical results.
  
  
  METHODS
  We retrospectively evaluated 153 patients (163 hips) using the sandwich liner COC THA between 2001 and 2009. Patient assessment was based on demographic factors, including age, weight, gender and body-mass index (BMI). All patients were evaluated clinically and radiographically or using computed tomography viz-a-viz dislocation, osteolysis, periprosthetic fracture, infection, loosening and implant fracture.
  
  
  RESULTS
  Three ceramic sandwich liners fracture (1.84%) were observed at an average of 7.3 years' followup. The factors which were found to be non-significant to the ceramic liner fracture, included age (P = 0.205), weight (P = 0.241), gender (P = 0.553), BMI (P = 0.736), inclination (P = 0.199) and anteversion (P = 0.223). The overall survival was 91.4% at 12-year with revision as the endpoint. Other complications included osteolysis in 4 (2.45%), dislocation in one and periprosthetic fracture in one. In no hip aseptic loosening of the implants was seen.
  
  
  CONCLUSIONS
  Our experience with the ceramic-polyethylene sandwich liner acetabular component has been disappointing because of the high rate of fracture and osteolyis. We have discontinued the use of this device and recommend the same.
authors.affiliation: Department of Orthopaedics, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, Jiangsu 215006, P. R, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Wang
authors.affiliation: Department of Orthopaedics, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, Jiangsu 215006, P. R, China.
authors.forename: Jun-Ying
authors.initials: JY
authors.lastname: Sun
authors.affiliation: Department of Orthopaedics, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, Jiangsu 215006, P. R, China.
authors.forename: Guo-Chun
authors.initials: GC
authors.lastname: Zha
authors.affiliation: Department of Orthopaedics, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, Jiangsu 215006, P. R, China.
authors.forename: Sheng-Jie
authors.initials: SJ
authors.lastname: Dong
authors.affiliation: Department of Orthopaedics, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, Jiangsu 215006, P. R, China.
authors.forename: Xi-Jiang
authors.initials: XJ
authors.lastname: Zhao
keywords: Arthroplasty; Fracture; hip; hip prosthesis; osteolysis; replacement; sandwich liner; total hip arthroplasty