Comparison of the effect of 99mTc-DPD and 99mTc-MDP on experimentally-induced osteoarthritis in the stifle joint of the dog

This study was designed to evaluate the effect of (99m)Technetium-dicarboxypropane diphosphonate ((99m)-Tc-DPD) and (99m)Technetium-methylene diphosphonate (Tc-99m-MDP) on bone scan image quality and time in dogs with osteoarthritis. The left cranial cruciate ligament (CrCL) in ten healthy adult Beagle dogs was transected under general anesthesia. The dogs. were assigned to Tc-99m-DPD-injected or Tc-99m-MDP-injected groups. Stifle joint scintigraphy was performed after intravenous injection of 10 mCi Tc-99m-DPD or Te-99m-MDP. Scintigraphy was conducted before CrCL transection and 2, 4, 6, 8, 10 and 12 weeks after the procedure. There were no significant differences in density, sensitivity and pathological foci between the Tc-99m-DPD and Tc-99m-MDP groups of experimentally-transected CrCL dogs. A comparison of the images obtained with Pinhole type and low energy general purpose type collimators of the stifle joint of normal dogs and after CrCL transaction revealed no significant differences in bone radioactivity. Scintigraphs were obtained 3 It after Tc-99m-MDP and 2 h after Tc-99m-DPD injection. In conclusion, application of Tc-99m-DPD and Tc-99m-MDP in experimentally-induced osteoarthritis of the stifle joint in dogs results in similar effects on radioactive uptake ratio and image quality. Tc-99m-DPD is more efficient than Tc-99m-MDP in reducing the overall time of scintigraphy.