Healing of a tibial double osteotomy is modified by clodronate administration.

We studied the healing of tibial double osteotomies in rats during clodronate administration 10 mg/kg daily subcutaneously for 6 weeks. Clodronate treatment did not inhibit the endochondral bone formation in callus or in the epiphyseal plate. The differentiation of osteoblasts into mature osteocytes was disturbed, and the bone structure around the osteocytes was not normal. In the clodronate-treated group, the amount of newly formed bone matrix seemed increased, but mineralization of the bone matrix was delayed. The bundle bone trabeculae in callus were not so spatially well organized as in the controls. No delay in the union of the bone segment by new bone was seen during clodronate administration.