The 99Tcm-Sn-polyphosphate scintimetric time course of human tibial fractures with delayed union or pseudarthrosis

In 17 fractures of the human tibia, showing delayed union or the development of pseudarthrosis, the amount of callus formed was assessed monthly by scintimetry following intravenous administration of 99Tcm-Sn-polyphosphate. The mean scintimetric time course of the group of fractures with the atrophic type of delayed union was statistically significantly lower between the fourth and fourteenth week than that of fractures with uncomplicated healing. Nearly two-thirds of the fractures showed scintimetric ratios below the lower normal confidence limit (2 s.d.). The mean scintimetric time course of the fractures with the hypertrophic type of delayed union showed a normal scintimetric time course up to the eighth week, but from the tenth week a statistically significantly higher scintimetric ratio than the fractures with uncomplicated healing was found. The scintimetric ratio after the fourteenth week was below 2.5 for fractures with the atrophic type of delayed union, and above 2.5 for fractures with the hypertrophic type. The scintimetric time course of fractures which developed pseudarthroses was not different from those showing delayed union. The scintimetric method allows early detection of a pathological course of fracture healing. It supplies information about the functional state of the healing process and serves as an indicator of the correct treatment.