title: Periprosthetic bone mineral density with a cementless triple tapered stem is dependent on daily activity.
abstract: OBJECTIVE
  Periprosthetic bone loss around the femoral stem is frequently found after total hip arthroplasty. We have shown that periprosthetic bone mineral density (BMD) loss using the triple tapered stem is consistently much less in comparison with the straight type component. In this study, we compared periprosthetic BMD change with clinical factors.
  
  
  METHODS
  Postoperative dual-energy X-ray absorptiometry was evaluated at follow-up. BMD was determined based on seven Gruen zones. We further compared BMD with clinical examination: body mass index (BMI), age, Harris hip score (HHS) or University of California at Los Angeles (UCLA) activity rating score.
  
  
  RESULTS
  Periprosthetic BMD loss of the triple tapered stem was maintained. Especially, BMD in Gruen zone 1 which was maintained at 96% in comparison with the straight tapered stem. We compared the BMD change with clinical factors. There is no correlation between BMD and BMI, age or HHS. However, we found significant correlation between BMD and UCLA activity rating score in Gruen zones 1 and 2 of the triple tapered stem. Further, the correlation coefficient was increased at 48 months in comparison with 24 months.
  
  
  CONCLUSIONS
  The cementless triple tapered stem maintains periprosthetic bone mineral density. Activity may reflect improving periprosthetic bone quality after THA using a triple tapered stem.
authors: Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe, 650-0017, Japan.
authors: Shinya
authors: S
authors: Hayashi
authors: Takayuki
authors: T
authors: Nishiyama
authors: Takaaki
authors: T
authors: Fujishiro
authors: Noriyuki
authors: N
authors: Kanzaki
authors: Shingo
authors: S
authors: Hashimoto
authors: Masahiro
authors: M
authors: Kurosaka
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D018488:Bone Demineralization, Pathologic / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000209:etiology; D015519:Bone Density / Q000502:physiology*; D016723:Bone Remodeling; D002484:Cementation; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology; D006304:Health Status; D006621:Hip Joint / Q000503:physiopathology / Q000601:surgery; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D011474:Prosthesis Design; D011859:Radiography