Monitoring of fracture calluses with color Doppler sonography

Purpose. Fracture callus formation is closely associated with vascular invasion, and the use of color Doppler sonography has been suggested as a means to monitor, earlier than gray-scale sonography, the first stages of the healing process. We report the findings in a series of patients with tibial fractures in whom both gray-scale sonography and color Doppler imaging were employed to monitor new bone formation at the fracture site. Methods. Twenty patients with tibial fractures treated with external fixator frames were examined sonographically about 10 days after surgery and then about every 25 days until radiographic demonstration of consolidation. Results. Eighteen of 20 patients had a well-developed callus, while the remaining 2 patients showed delayed fracture healing. In patients with normal callus development, color Doppler imaging demonstrated the progressive formation of new vessels until about 100 days from the surgery; at subsequent examinations, flow signals decreased, and bone remodeling was confirmed by conventional radiography and gray-scale sonography. The resistance indices in these patients tended to decrease in the early weeks after surgery and then slightly increased. In contrast, lack of development of flow signals and persistence of high resistance indices were observed in the 2 patients with delayed fracture healing. Conclusions. Color Doppler sonography seems to have the capability to predict whether the development of fracture calluses will be normal or delayed.