Alendronate did not inhibit instability-induced bone resorption. A study in rats.
Alendronate is a bisphosphonate that can decrease osteoclastic activity. It has been suggested as treatment for periprosthetic osteolysis. We used 48 rats, of which 32 had a plate implant on one tibia, to study the effect of alendronate on bone resorption at an unstable implant-bone interface. The plate has a handle on top, which can be grasped through the skin and turned, to create a sliding motion of a titanium surface against the underlying bone. This is known to result in bone resorption, which was studied by histomorphometry. Osmotic minipumps were used to administer alendronate at 0.063 mg/kg/day or saline. The systemic effect of the treatment was assessed by ashing the proximal metaphyses of the tibia of the contralateral unoperated leg. The ash-weight was increased in the alendronate-treated group by 43% (p = 0.0001), corresponding to histological changes in the metaphyseal bone. There was no inhibition of the instability-induced bone resorption at the test surface by alendronate: bone was being resorbed and replaced by a tissue similar to a loosening membrane.
Astrand
J
J
Department of Orthopedics, Lund University Hospital, Sweden. Jorgen.Astrand@ort.lu.se
Aspenberg
P
P
D019386:Alendronate / Q000627:therapeutic use*; D000818:Animals; D001860:Bone Plates / Q000009:adverse effects*; D001862:Bone Resorption / Q000188:drug therapy* / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology; D004195:Disease Models, Animal; D004353:Drug Evaluation, Preclinical; D007595:Joint Prosthesis / Q000009:adverse effects*; D008297:Male; D011475:Prosthesis Failure; D051381:Rats; D017207:Rats, Sprague-Dawley; D014025:Titanium
D014025:Titanium; D019386:Alendronate