title: Medium-term results of ceramic-on-polyethylene Zweymüller-Plus total hip arthroplasty.
abstract: BACKGROUND
  The need for better durability and longevity in total hip arthroplasty for patients with various hip joint diseases remains a challenge. This study aimed to obtain medium-term results at a follow-up of >10 years for Zweymüller-Plus total hip arthroplasty with ceramic-on-polyethylene bearing.
  
  
  METHODS
  A retrospective study was conducted to review the results after a minimum of 12.4 years of 207 consecutive total hip arthroplasties in 185 patients in Peking University People's Hospital in China using the Zweymüller SL-Plus stem in combination with the Bicon-Plus threaded cup and ceramic-on-polyethylene bearing between October 1994 and April 2000.
  
  
  RESULTS
  During the study period, two patients (2 hips) died and 25 patients (28 hips) were lost to follow-up. Two hips were revised for aseptic loosening of the Bicon-Plus cup. The mean clinical and radiological follow-up was 14.1 years (range, 12.4-16.5 years) for the remaining 156 patients (175 hips). The mean (standard deviation) Harris Hip score for the 175 hips increased significantly from 39.3 (3.8) preoperatively to 94.1 (2.5) postoperatively at a mean follow-up of 14.1 years (P<0.05). Focal osteolysis was observed in seven (4.0%) of 175 stems and three (1.7%) of 175 cups. The Kaplan-Meier survival with revision for any reason as the end-point was 99.03% (95% confidence interval, 95%-100%).
  
  
  CONCLUSIONS
  The high survival rate of the cementless Zweymüller-Plus system with ceramic-on-polyethylene bearing at mid-term follow-up makes this total hip arthroplasty system reliable for patients with various hip joint diseases.
authors.affiliation: Arthritis Clinic and Research Center, Peking University People's Hospital, Beijing, No.11 Xizhimen South Street, Xicheng District, Beijing, 100044, China.
authors.forename: H
authors.initials: H
authors.lastname: Li
authors.affiliation: Orthopaedic Department, Beijing Dongchengqu First People's Hospital, Beijing, 100075, China.
authors.forename: S
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Orthopaedic Department, Beijing Moslem Hospital, Beijing, 100054, China.
authors.forename: X M
authors.initials: XM
authors.lastname: Wang
authors.affiliation: Arthritis Clinic and Research Center, Peking University People's Hospital, Beijing, No.11 Xizhimen South Street, Xicheng District, Beijing, 100044, China.
authors.forename: J H
authors.initials: JH
authors.lastname: Lin
authors.affiliation: Arthritis Clinic and Research Center, Peking University People's Hospital, Beijing, No.11 Xizhimen South Street, Xicheng District, Beijing, 100044, China.
authors.forename: B L
authors.initials: BL
authors.lastname: Kou
mesh_terms: D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation* / Q000379:methods; D002516:Ceramics; D002681:China; D005260:Female; D005500:Follow-Up Studies; D006621:Hip Joint / Q000503:physiopathology; D006622:Hip Prosthesis / Q000706:statistics & numerical data*; D006801:Humans; D007592:Joint Diseases / Q000503:physiopathology / Q000601:surgery*; D059012:Lost to Follow-Up; D008297:Male; D008875:Middle Aged; D020959:Polyethylene; D011184:Postoperative Period; D011474:Prosthesis Design; D011475:Prosthesis Failure; D016059:Range of Motion, Articular; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D020959:Polyethylene
keywords: Hip prosthesis; Polyethylene; Prosthesis design; Survival analysis