title: Learning from the learning curve in total hip resurfacing: a radiographic analysis.
abstract: BACKGROUND
  Operation of hip resurfacing prosthesis is a technically demanding procedure accompanied by a learning curve. To our knowledge no objective data on this learning curve are available in the literature.
  
  
  METHODS
  For the first 40 resurfacing hip prostheses implanted by a single-surgeon radiographic 'learning curve' analysis was performed. Optimal implant positioning on preoperative digital templating was compared with the eventual implant position postoperatively, measured by six establishes radiographic parameters and compared for four chronological cohorts of patients.
  
  
  RESULTS
  A learning curve was clearly present and an optimal result was established in the last cohort. Pitfalls were a relatively steep cup position initially and a stem position in the posterior 1/3 of the collum. Besides marginal medialization a fully anatomic reconstruction of the center of rotation was achieved.
  
  
  CONCLUSIONS
  In total hip resurfacing one should recognize the presence of a learning curve. This learning curve appears to be acceptable and a reproducible optimal implant positioning can be achieved quickly.
authors.affiliation: Department of Surgery and Orthopaedics, Rijnstate Hospital, 6800 TA Arnhem, The Netherlands.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Witjes
authors.forename: José M H
authors.initials: JM
authors.lastname: Smolders
authors.forename: Paul E
authors.initials: PE
authors.lastname: Beaulé
authors.forename: Pieternel
authors.initials: P
authors.lastname: Pasker
authors.forename: Job L C
authors.initials: JL
authors.lastname: Van Susante
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D019644:Arthroplasty, Replacement, Hip / Q000592:standards*; D002983:Clinical Competence; D005260:Female; D006621:Hip Joint / Q000000981:diagnostic imaging* / Q000601:surgery*; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D017755:Prosthesis Fitting; D011859:Radiography; D016896:Treatment Outcome