Locally delivered minocycline microspheres do not impair osseointegration of titanium implants in a rat femur model.

BACKGROUND

The purpose of this study was to determine whether intramedullary administration of extended-release minocycline microspheres would affect osseointegration.

METHODS

Twenty-two rats were randomized to minocycline or saline femoral intramedullary injection followed by implantation of titanium alloy rods. Following euthanasia at four-weeks, pushout testing was performed and bone-volume-fraction assessed.

RESULTS

Pushout strength was marginally greater in minocycline-treated implants (122.5 ± 39.1 N) compared to saline (96.9 ± 26.1 N) (P = 0.098). No difference was observed in energy to maximum load, mean stiffness, or peri-implant bone-volume-fraction (P > 0.05).

CONCLUSIONS

Peri-implant minocycline administration did not impair implant fixation strength or peri-implant bone-volume, supporting its potential utility as an adjunct to intramedullary implants.