Clodronate prevents prosthetic migration: a randomized radiostereometric study of 50 total knee patients.

In a double-blind study, we randomized 50 patients to receive peroral clodronate medication or placebo from 3 weeks before until 6 months after a total knee replacement with a cemented NexGen implant. Migration of the tibial components was measured by radiostereometry at 1 year. Clodronate reduced prosthetic migration, as measured by maximum total point motion, from 0.40 mm to 0.29 mm (p = 0.01). This confirms that the early postoperative migration is related to bone resorption and thus the biology of the bone bed. Since early migration is related to late loosening, 6 months of clodronate medication might reduce the risk of loosening.