Twenty-seven cases with delayed union and nonunion were selected for the present study. Osteomedullograms were positive in 12 and negative in 15 cases. All the fractures with positive osteomedullograms united after conservative treatment. Fourteen of 15 fractures with negative osteomedullograms needed surgical treatment. Of 14, two are still in followup. One case with negative signs on osteomedullogram refused surgery.