Bisphosphonate remains highly localized after elution from porous implants.

Background: Local elution of zoledronic acid from a porous implant reportedly enhances periimplant bone formation and implant fixation. However, there is no information in the literature on the extent to which eluted bisphosphonate remains localized around the implant or becomes systemically distributed.

Questions/purposes: We ascertained to what extent eluted zoledronic acid remains local and whether there is systemic exposure after local elution from porous implants.

The Otto Aufranc Award: bone augmentation around and within porous implants by local bisphosphonate elution.

The bisphosphonate zoledronic acid chemically and physically was bound to hydroxyapatite-coated porous tantalum implants. The zoledronic acid elution characteristics in saline were determined as a function of time and the in vivo effects of elution were quantified at 12 weeks in a canine ulnar implant model. Intramedullary implants surgically were implanted bilaterally into the ulnae of a control group of five dogs and a zoledronic acid-dosed (0.