title: Impaction bone grafting with hydroxyapatite: increased femoral component stability in experiments using Sawbones.
abstract: BACKGROUND
  Substantial bone loss and bone defects increase the amount of allografting required in hip revision surgery. Thus, the use of a synthetic material to limit the amount of allograft tissue required for impaction grafting is desirable. We evaluated the potential of hydroxyapatite (HA) mixtures to provide initial mechanical stability to a polished tapered femoral stem.
  
  
  METHODS
  We determined the initial stability of a polished tapered femoral stem after reconstructing a cavitary femoral bone defect by impaction bone grafting with cement in Sawbones composite femurs. Three types of graft material were tested for their ability to improve initial rotational stability. The graft materials investigated were pure allograft, a mixture of 50% allograft and 50% hydroxyapatite (HA), and pure HA.
  
  
  RESULTS
  We found a statistically significant difference between the three groups as regards torsional micromotion and failure load.
  
  
  CONCLUSIONS
  Our findings suggest that reconstruction of femoral bone defects with pure HA or a mixture of allograft and HA provides adequate initial stability for femoral revision arthroplasty using impaction grafting.
authors.affiliation: Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, Japan. taka2446@yg8.so-net.ne.jp
authors.forename: Takaaki
authors.initials: T
authors.lastname: Fujishiro
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Nishikawa
authors.forename: Takahiro
authors.initials: T
authors.lastname: Niikura
authors.forename: Satoshi
authors.initials: S
authors.lastname: Takikawa
authors.forename: Takayuki
authors.initials: T
authors.lastname: Nishiyama
authors.forename: Kiyonori
authors.initials: K
authors.lastname: Mizuno
authors.forename: Shinichi
authors.initials: S
authors.lastname: Yoshiya
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kurosaka
mesh_terms: D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D001696:Biomechanical Phenomena; D018786:Bone Substitutes; D016025:Bone Transplantation / Q000379:methods*; D005269:Femur / Q000601:surgery; D006801:Humans; D006882:Hydroxyapatites; D011475:Prosthesis Failure; D012086:Reoperation; D014182:Transplantation, Autologous; D014183:Transplantation, Heterologous
chemical_list: D018786:Bone Substitutes; D006882:Hydroxyapatites