title: Lower Total Knee Arthroplasty Revision Risk Associated With Bisphosphonate Use, Even in Patients With Normal Bone Density.
abstract: BACKGROUND
  Bisphosphonates (BPs) are associated with lower total knee arthroplasty (TKA) revision risk, but the effect of bone mineral density has not been evaluated.
  
  
  METHODS
  A cohort of 34,116 primary TKA patients was evaluated with revision surgery and periprosthetic fractures as end points. BP usage was the exposure of interest. Bone quality (normal, osteopenia, and osteoporosis) and patient age (<65 vs ≥65 years) were evaluated as effect modifiers of risk estimates.
  
  
  RESULTS
  Of the patients, 19.6% were BP users. In BP users, 0.5% underwent an aseptic revision; and 0.6%, a periprosthetic fracture. In non-BP users, 1.6% underwent aseptic revision; and 0.1%, a periprosthetic fracture.
  
  
  CONCLUSIONS
  Bisphosphonate use was associated with lower risk of revision in all bone quality categories in those older than 65 years. The risk of periprosthetic fractures was higher for patients on BP.
authors.affiliation: Southern California Permanente Medical Group, Irvine, California.
authors.forename: Robert S
authors.initials: RS
authors.lastname: Namba
authors.affiliation: Kaiser Permanente, Surgical Outcomes and Analysis, San Diego, California.
authors.forename: Maria C S
authors.initials: MC
authors.lastname: Inacio
authors.affiliation: Kaiser Permanente, Research and Evaluation, Pasadena, California.
authors.forename: T Craig
authors.initials: TC
authors.lastname: Cheetham
authors.affiliation: Southern California Permanente Medical Group, Downey, California.
authors.forename: Richard M
authors.initials: RM
authors.lastname: Dell
authors.affiliation: Kaiser Permanente, Surgical Outcomes and Analysis, San Diego, California.
authors.forename: Elizabeth W
authors.initials: EW
authors.lastname: Paxton
authors.affiliation: Southern California Permanente Medical Group, Los Angeles, California.
authors.forename: Monti X
authors.initials: MX
authors.lastname: Khatod
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects* / Q000706:statistics & numerical data; D015519:Bone Density; D050071:Bone Density Conservation Agents / Q000009:adverse effects*; D001842:Bone and Bones / Q000601:surgery; D004164:Diphosphonates / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D057068:Periprosthetic Fractures / Q000139:chemically induced*; D012086:Reoperation / Q000706:statistics & numerical data; D012307:Risk Factors
chemical_list: D050071:Bone Density Conservation Agents; D004164:Diphosphonates
keywords: bisphosphonates; bone density; revision; total knee