title: The Pritchard ERS total elbow prosthesis: lessons to be learned from failure.
abstract: BACKGROUND
  Documentation of the long-term effectiveness of 3-part unlinked elbow replacement is limited. The value of replacing the radial humeral articulation has not been addressed to any extent in the currently available literature.
  
  
  METHODS
  A retrospective study of patient charts and radiographs of 37 patients receiving 46 primary Pritchard ERS arthroplasties between 1983 and 1992 were reviewed. Thirty-two implants (70%) failed after an average of 83 months (range, 0-198). Causes of failure were analyzed in detail.
  
  
  RESULTS
  Kaplan Meier survivor analysis showed a 10-year survival of 54% (confidence interval: 40-71%). Main reasons for failure were instability, wear, and loosening. Immediate postoperative radiographs showed ulnohumeral malposition (valgus or varus) in 19 elbows, which directly correlated to subsequent failure. While this design has proven to be unsuccessful, it does document the need for precise technique and highlights the issue of replacing the radio/capitellar joint in future designs deserves further study.
  
  
  CONCLUSIONS
  An explanation of these disappointing outcomes resides both in an inadequate design and a poorly understood and executed surgical technique. The value of refined instrumentation to allow accurate and reproducible component implantation and soft tissue balancing is highlighted. These considerations are particularly relevant if the radial head component is to be used.
authors.affiliation: Mayo Clinic, Mayo Foundation, Rochester, MN 55906, USA.
authors.forename: Roger P
authors.initials: RP
authors.lastname: van Riet
authors.forename: Bernard F
authors.initials: BF
authors.lastname: Morrey
authors.forename: Shawn W
authors.initials: SW
authors.lastname: O'Driscoll
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000601:surgery; D019643:Arthroplasty, Replacement / Q000009:adverse effects* / Q000379:methods; D004551:Elbow Joint / Q000503:physiopathology / Q000601:surgery*; D019544:Equipment Failure Analysis; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007431:Intraoperative Complications / Q000453:epidemiology; D007593:Joint Instability / Q000453:epidemiology / Q000209:etiology; D007595:Joint Prosthesis; D053208:Kaplan-Meier Estimate; D008297:Male; D010003:Osteoarthritis / Q000601:surgery; D011336:Probability; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011859:Radiography; D011884:Radius / Q000000981:diagnostic imaging / Q000601:surgery; D012086:Reoperation / Q000706:statistics & numerical data; D012189:Retrospective Studies; D018570:Risk Assessment; D013997:Time Factors; D016896:Treatment Outcome