Higher RANK ligand osteoprotegerin ratio results in lower callus diameter and osteocalcin expression on the healing of femur fracture between diabetic and nondiabetic rats using intramedullary wire

Background: Diabetes with uncontrolled glucose level offer a significant risk of acute or chronic complications. One of the chronic complications is a decrease in bone mineral density which is regulated by RANKL and OPG balance. Diabetes is estimated to slow the healing process of fracture. Both are related to fracture risk and fracture healing process. Fracture healing is characterized by measurement of callus diameter and osteocalcin expression. Aim: This research aimed to find out the difference in RANKL/OPG ratio, callus diameter and osteocalcin expression on the fracture healing in diabetic and nondiabetic rats. Methods: This is an experimental randomized post-test only with 32 Wistar rats. The population was divided into two groups, the control group did not get treatment and the second group was the diabetes modeling. On the 7th day, both groups were examined for their ratio of RANKL/OPG using ELISA and fracture was performed. On the 28th day, the rats were sacrificed, and the effects were assessed using histopathology examination of callus diameter and immunohistochemistry examination of osteocalcin expression at the fracture area. Result: Higher median ratio of RANKL/OPG in diabetic than nondiabetic rats with p = 0,000 (p <0,05). The diameter of callus on the healing of femur fracture in the nondiabetic group was higher than the diabetic group with p = 0,000 (p <0.005). Osteocalcin levels in nondiabetic group were higher than diabetic group with p = 0,000 (p <0.005). There was a negative correlation between RANKL/OPG ratio with callus diameter and osteocalcin level with a correlation coefficient of -0.701 and -0.652 respectively with p = 0,000 (p <0,05). Conclusions: Level of RANKL/OPG ratio has a negative correlation with callus size and osteocalcin expression on healed femur fractures in diabetic rats model.