Scintigraphic evaluation of bone healing after US stimulation

Bone defects were surgically induced in the radial cortical plates of 15 dogs. In each animal, one defect was exposed daily to 1 hour of US irradiation at 14-17.5 KHZ, the defect in the contralateral side serving as a control. The effects of US were assessed by radiographic, scintigraphic, and histologic techniques. Each dog was injected with 10 mCi of Tc-99m-MDP and three-phase bone scans were performed in both extremities. Healing was evaluated by two bone growth indicators, a point bone-growth indicator, which normalizes Tc-99m-MDP incorporation for a brief scoring period (80-500 sec), and a cumulative indicator, which expresses bone proliferation throughout the study. The authors found increased Tc-99m uptake at the edges and over the central area of the bone defects. Narrow-window imaging over the central area indicated that US stimulation facilitated bone healing