The effect of prednisolone on the sensitivity of Technetium 99m-methylene diphosphonate ( 99m Tc-MDP) scintigraphy to detect simulated closed fracture in the rat tibia

Introduction: The purpose of the present study was to evaluate the effect of prednisolone on the sensitivity of bone scanning to detect the simulated closed fracture in the rat tibia.  Methods: A total number of forty eight adult, male NMRI rats randomly assigned into two parts, one part for 4 and other for 8 weeks experiments. Each part has been divided into four groups, one group not receiving prednisolone (control group) and the other groups receiving 5, 10 and 20 mg/kg prednisolone respectively. After four and eight weeks of experiments a simulated closed fracture was created in the tibia approximately 1 cm near knee joint. .The scintigraphy imaging has been performed on second and fifth day after tibial bone fracture and the ratio of the activity of tibia bone fracture to the contra lateral healthy side was calculated (R factor). Results: All scintigraphy images showed the rat tibia bone fracture. Statistically significant difference in the R factors have been observed, when scintigraphy images were performed in fifth day after injury. Conclusion: Bone radionuclide scanning by 99mTc-MDP is very sensitive for detection of occult fracture.  In order to enhance bone scan sensitivity, it may be reasonable to postpone 99mTc-MDP scintigraphy imaging at least 2 to 3 days after suspected trauma in patients receiving glucocorticoid medication.