The Effects Of Strontium-calcium Sulfate Compounds On Cancellous Bone Defect And Blood Rheology

Objective: To observe the effect of strontium-calcium sulfate compounds on cancellous bone defect, and the effect on blood rheology during the repairing process.Methods: After femur defect model was set, a total of 48 rabbits were randomly divided into 3 groups, including research group(strontium-calcium sulfate group, Sr CS group), control group(calcium sulfate group, CS group) and model group. Research group were locally implanted with 0.5% Sr CS in the bone defect area, and control group were implanted with CS, while the model group were not implanted any repair material. At postoperative 4 and 12 w, CT imaging was used to observe the repair of bone defects, and new bone radiographic score was made. At postoperative 8 and 12 weeks, rabbits were executed, and mechanical test was performed. At 2 and 4 w post surgery, fluorescent labeling for mineralized tissue was performed using Alizarin Red S and calcein, and samples were gained for histological examination at 8 w post surgery. Biochemical indicators and hemorheology were measured preoperatively and 2, 4, 12 w postoperatively.Results: Modeled by bone defect, serum alkaline phosphatase(ALP) were significantly higher(P <0.05); two weeks postoperatively, ALP in research group was significantly higher than that of the model group and the control group(P<0.05), while there were no significant differences in other biochemical indicators including aspartate aminotransferase, alanine aminotransferase, blood urea nitrogen, creatinine and uric acid(P>0.05). CT scans showed that bone defect local regional were filled with new bone tissue in research group at 12 w post surgery, while a small amount of implanted material debris could be found in local bone defects, in control group. At postoperative 4 w, imaging score of new bone formation of research group was significantly higher than that of control group(P<0.05). The compressive strength in Cr CS group was significantly higher than that in CS group at both 8 and 12 w post surgery(P<0.05). Morphological study showed that bone generation at week 2 and mineralization at week 4 after operation in research group were both significantly higher than that in control group post surgery(both P <0.01). The study of blood rheology indicated that whole blood blood viscosity, plasma viscosity and platelet aggregation were significantly higher after bone defect model was set(P <0.01), and at postoperative 8 w, whole blood blood viscosity(1/200 s), plasma viscosity and platelet aggregation in research group were all significantly lower than those in control group.Conclusion: 0.5% Cr CS showed better efficacy in repairing the cancellous bone defect than CS, and can also improve the abnormally elevation of whole blood viscosity, plasma viscosity and platelet aggregation rate caused by bone defects, which indicated that it could be applied in clinic in future.