The effects of high-dose, long-term alendronate treatment on microarchitecture and bone mineral density of compact and trabecular bone in the proximal femur of adult male rabbits.
BACKGROUND
Despite the widespread use of bisphosphonates, its effects on normal bone microarchitecture of the proximal femur are still poorly studied. The purpose of this study was to determine the effects of long-term high-dose treatment of alendronate on microstructure and bone mineral density of cancellous, cortical compact and subchondral compact bone of the femoral head and neck region in normal adult male rabbits.


METHODS
Thirty-two adult, male rabbits were randomized into and were treated with either alendronate or placebo for 6 and 12 months. Micro-QCT measurements were taken in the (1) trabecular region, (2) cortical region of the femoral neck and (3) the subchondral region of the femoral head.


RESULTS
In the trabecular region of the femoral head, alendronate treatment significantly increased vBMD at 6 and 12 months (+21.0%, p < 0.05 and +26.8%, p < 0.05, respectively) and BVF (29.6%, p < 0.05 and 35.6%, p < 0.05, respectively) with significantly altered bone microarchitecture when compared with their placebo group; 6- and 12-month alendronate treatment significantly increased the vBMD and thickness and decreased the porosity of the subchondral bone in the femoral head.


CONCLUSIONS
High-dose alendronate treatment led to significant and differential changes in bone microarchitecture in trabecular, cortical and subchondral bone of the proximal femur of adult male rabbits.
Hofstaetter
Jochen G
JG
Department of Orthopedic Surgery, Children's Hospital and Harvard Medical School, Boston, MA 02115, USA. jochen.hofstaetter@osteologie.at
Wang
Jinxi
J
Hofstaetter
Stefan G
SG
Glimcher
Melvin J
MJ
D000367:Age Factors; D019386:Alendronate / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D015519:Bone Density / Q000187:drug effects*; D050071:Bone Density Conservation Agents / Q000008:administration & dosage / Q000494:pharmacology*; D005270:Femur Head / Q000033:anatomy & histology*; D008297:Male; D011817:Rabbits; D013997:Time Factors
D050071:Bone Density Conservation Agents; D019386:Alendronate