title: Long-term survival of the uncemented Balgrist total hip replacement cup.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the long-term clinical and radiographic outcomes of the Balgrist total hip replacement cup.
  
  
  METHODS
  We report the results of a retrospective review of 195 total hip prostheses with Balgrist cup implanted in 178 patients. There were 59 men and 119 women with a mean age at surgery of 52.3 years (range, 19-72). Cox regression was used to determine the influence of independent variables on the survivorship of the prosthesis.
  
  
  RESULTS
  There were 117 (66 %) of 178 patients, and 131 (67 %) of 195 hips available for assessment at a mean follow-up of 17.4 years. A total of 21 patients (22 hips) were lost from follow-up (12 %). A total of 25 patients (27 hips) required some type of re-operation during the follow-up period. Eight of 27 re-operations (30 %) were directly caused by the Balgrist cup failure due to fatigue fracture of the metallic shell (n = 5; 19 %), polyethylene wear (n = 2; 7 %) and aseptic loosening (n = 1; 4 %). The mean polyethylene wear rate was 0.068 mm/year (range, 0.008-0.230; SD = 0.043). The risk of re-operation for any reason was decreased with dysplastic hip as a primary diagnosis (hazard ratio; HR = 0.250; 95 % CI 0.086-0.725) and with greater age at the time of surgery (HR = 0.923; 95 % CI 0.880-0.969). The 19-year survivorship with re-operation for any reason was 75.6 % (95 % CI 67.0-84.2). The 19-year survivorship with re-operation for the Balgrist cup failure was 90.5 % (95 % CI 83.4-97.6).
  
  
  CONCLUSIONS
  The Balgrist cup continues to provide excellent clinical and radiological outcomes. This is associated at least in part with a low polyethylene wear rate. The main reason for the Balgrist cup failure is fatigue fracture of the metallic shell.
authors.affiliation: Department of Orthopaedics, Faculty of Medicine and Dentistry, Palacky University Olomouc, University Hospital, I. P. Pavlova 6, 77520, Olomouc, Czech Republic. jiri.gallo@volny.cz
authors.forename: Jiri
authors.initials: J
authors.lastname: Gallo
authors.forename: Jiri
authors.initials: J
authors.lastname: Lostak
authors.forename: Katerina
authors.initials: K
authors.lastname: Langova
mesh_terms: D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation*; D001843:Bone Cements; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006617:Hip Dislocation / Q000601:surgery*; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D006622:Hip Prosthesis; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000601:surgery*; D020959:Polyethylene; D016016:Proportional Hazards Models; D011474:Prosthesis Design; D011859:Radiography; D012086:Reoperation / Q000295:instrumentation / Q000706:statistics & numerical data; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D001843:Bone Cements; D020959:Polyethylene