Wear particle induced osteolysis is a serious complication in total joint arthroplasty. The purpose of this study was to compare the preventive and mitigative effects of alendronate on particle induced osteolysis among particles using mouse calvarial model.

Seventy-two mice were randomized into sham group, Ti6Al4V group, CoCr- Mo group and Ultra High Molecular Weight Polyethylene (UHMWPE) group according to the particles treated to the calvarial tissues. Each group was divided into control subgroup which received no alendronate, preventive subgroup which received alendronate for 4 weeks after particle distribution and therapeutic subgroup which received alendronate for 3 weeks after 1 week delay from particle distribution. We evaluated the effects quantitatively using histomorphometry. Number of osteoclast, fibrous thickness, eroded bone surface area, bone thickness and bone volume were measured and compared.

Alendronate showed significant preventive and mitigative effects on osteolysis induced by Ti6Al4V particles and showed significant preventive and somewhat less mitigative effect on osteolysis by CoCrMo particles. On UHMWPE particles, alendronate showed no preventive and mitigative effects.

Alendronate may be useful in preventing osteolysis induced by metal particles but had no effect on ostelysis induced by UHMWPE particles.