THE IMPORTANCE OF THE HEMATOMA FOR FRACTURE-HEALING IN RATS

In 3 groups of rats, bilateral femoral fractures were produced. The fr acture hematoma was removed on one side after 30 min, 2 days and 4 day s in the 3 groups, respectively. The fractures were mechanically teste d at 4 weeks. When the fracture hematoma was removed early, callus pro duction, bending moment, and fracture energy were decreased. Removal o f the hematoma at Day 2 or 4 impaired fracture healing even more, as b oth bending moment, bending rigidity and fracture energy were greatly decreased compared to the control fractures. We conclude that the frac ture hematoma favors healing; removal of the hematoma after some days is more harmful to healing than when the hematoma is removed in the in itial phase.