Influence of hydroxyapatite on fracture healing in diabetic rats: biomechanical and radiographic studies

Patients with diabetes mellitus incur a high incidence of fractures. This suggests that the structural integrity of the skeletal system may be compromised. This study was conducted to evaluate the effects of hydroxyapatite (HA) on fracture healing in diabetic rats by biomechanical and radiographic methods. Twenty-four adult male rats were randomly divided into four identical groups. Diabetes was chemically induced in 2 groups by alloxan. After 2 weeks, all the rats were anesthetized and a transverse osteotomy of the right radius was performed under aseptic conditions. In one diabetic and one non-diabetic group, the osteotomy gap was filled with HA while the other 2 groups did not receive HA. Radiographs were taken at 0, 15 and 35 days post operation. All the rats were euthanized 5 weeks post operation, and the radial bones were harvested and prepared for the three-point bending test. Comparison between the HA treated groups (diabetic and non diabetic), demonstrated that diabetes significantly reduced the capacity of bone to loaded bending forces. The non-treated diabetic group showed fewer radiographic signs of union and remodeling of fractures in comparison with the other three groups. In conclusion the diabetic rats that did not receive HA exhibited inferior biomechanical properties and radiographic signs in comparison with the HA treated groups and the negative control group.