Rationale for bisphosphonate use in patients with endoprosthesis.

Total joint replacement is accompanied by dramatic changes in the biomechanics of the adjacent bone. Under these conditions the phenomenon of stress-shielding is responsible for localized but significant bone atrophy. Another important and inevitable result of total joint arthroplasty is the production of wear debris particles, which recruit macrophages. These cells are present in abundance in osteolytic lacunae filled with pseudo-membranes, which are the cause of aseptic loosening of the implants. Bisphosphonates are an osteotrophic class of drugs that have been demonstrated to inhibit osteoclast-induced osteolysis. They are widely applied in bone pathologies in which osteoclastosis plays an important role, e. g. osteoporosis, Sudeck's bone dystrophy, Paget's bone disease, and many others. The routine administration of bisphosphonates in patients recovering from joint replacements seems to be fully justified. There is considerable evidence from both animal and human studies supporting the view that the suppression of osteoclastic activity is beneficial for the bone adjacent to metal implants. We have observed decreased joint pain in the early stages of aseptic loosening and stabilization of the x-ray picture of the bone adjacent to joint replacements after prolonged bisphosphonate treatment.