Better Osteoporotic Fracture Healing with Sintered Dicalcium Pyrophosphate (SDCP) Treatment: A Rat Femoral Fracture Model.

The aim of this study was to evaluate the effect of sintered dicalcium pyrophosphate (SDCP) on fracture healing in an osteoporotic rat model. Female Sprague-Dawley rats (8 weeks old) were randomly allocated into five groups: sham-operated group, and bilateral ovariectomized group treated with SDCP, alendronate, calcitonin, or no treatment. Rats were sacrificed at 6 or 16 weeks after fracture. Fracture sites were examined by microcomputed tomography (microCT), histology, and mechanical testing. The results showed that SDCP mildly suppressed callus remodeling at 6 weeks, but not at 16 weeks. The lamellar bone in the callus area and new cortical shell formation in SDCP-treated group were similar to that of the sham group at 16 weeks after fracture, indicating there was no delayed callus remodeling into lamellar bone. At both 6 and 16 weeks after fracture, ultimate stress and elastic modulus were similar between the SDCP and sham groups, and the mechanical strength in these groups was better than that in other groups. Finally, analysis of the serum bone markers CTX-1 and P1NP suggested that SDCP decreased the bone turnover rate and promoted proper fracture healing. The effect of SDCP is superior to that of alendronate and calcitonin in the healing of osteoporotic fractures.