The effect of calcium sulfate on fracture healing in rat tibial fractures

Abstract

Objectives: Calcium sulfate dihydrate (CSD) has been successfully used as an osteconductive biomaterial for bone defects since the last century. Osteoconductive biomaterials are also known to be useful in fracture healing. In this study the effect of CSD on fracture healing was evaluated. Methods: Forty-four male Wistar rats (mean weight 255 g; age range 4 to 6 months) were randomly and equally allocated to two groups. Right tibial diaphyseal fractures were induced under ketamine anesthesia in all rats. In the control group, the fractures were immobilized with the use of above-knee cast for semirigid fixation. In the second group, CSD was injected into the fracture hematoma followed by cast immobilization. The rats were sacrificed in the fourth and eighth weeks. Histologic evaluation was performed according to Huo et al. and radiologic findings were scored using the Lane and Sandhu’s system. Results: Both radiologically and histologically, callus formation was found to be significantly superior in the control group compared to that of the CSD group in the fourth and eighth weeks. These findings were also corroborated by manual examinations. A marked difference was noted between the two groups in the fourth week in the form of foreign body reaction occurring around the CSD bodies. Conclusion: Contrary to its credentials for osteoconductive properties, CSD exerted an undesirable effect on fracture healing by decreasing its rate. Foreign body reaction induced by CSD, as addressed by some researchers, may account for this delay in fracture healing.