title: Analysis of differences in bone removal during femoral box osteotomy for primary total knee arthroplasty.
abstract: OBJECTIVE
  this study was conducted to compare the quantity of intercondylar bone removed during femoral box osteotomy for implantation of three contemporary posterior stabilized (PS) total knee arthroplasty designs: Sigma PS (DePuy), Vanguard (Biomet) and Persona (Zimmer).
  
  
  METHODS
  we compared the maximum volumetric bone resection required for the housing of the PS mechanism of these three designs. Bone removal by each PS box cutting jig was three-dimensionally measured. The differences between the three designs were analyzed by the Kruskal-Wallis test. The Mann-Whitney U-test was used for pairwise comparisons. The level of significance was set at p<0.05.
  
  
  RESULTS
  for small-size implants, the average box osteotomy volume of Persona was significantly smaller than the Vanguard and Sigma PS volumes (p=0.003). The mean difference between Vanguard and Sigma PS (p=0.01) was also significant. For medium size implants, the mean difference between Persona and Sigma PS (p=0.008) and the mean difference between Vanguard and Sigma PS (p=0.01) were statistically significant. For large size implants, the mean difference between Vanguard and Sigma PS (p=0.01) and the mean difference between Sigma PS and Persona (p=0.008) were statistically significant.
  
  
  CONCLUSIONS
  irrespective of implant size, the Persona cutting jig always resected significantly less bone than did Vanguard and Sigma PS.
  
  
  CONCLUSIONS
  although this study does not establish any clinical relevance of removing more or less bone at primary TKA, its results suggest that if a PS design is indicated, it is preferable to select a model which resects less distal femoral bone.
authors.affiliation: Orthopaedics Clinic, university of Catania, Italy.
authors.forename: Angelo
authors.initials: A
authors.lastname: Graceffa
authors.affiliation: Centro eccellenza Sostituzioni articolari toscana (CeSat), Orthopaedics Clinic, university of Florence, Italy -Fondazione Onlus "...In Cammino...", Fucecchio, Italy ; Breyer Center for Overseas Study, Stanford university in Florence, Italy ; Orthopaedics Clinic, university of Florence, Italy.
authors.forename: Pier Francesco
authors.initials: PF
authors.lastname: Indelli
authors.affiliation: Breyer Center for Overseas Study, Stanford university in Florence, Italy.
authors.forename: Kaitlyn
authors.initials: K
authors.lastname: Basnett
authors.affiliation: Centro eccellenza Sostituzioni articolari toscana (CeSat), Orthopaedics Clinic, university of Florence, Italy -Fondazione Onlus "...In Cammino...", Fucecchio, Italy ; Orthopaedics Clinic, university of Florence, Italy.
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Marcucci
keywords: bone resection; box osteotomy; cruciate substituting; posterior stabilized; total knee arthroplasty