Fractures of the 5th MT base, in association with an inversion injury of the ankle, are avulsion fractures at the insertion of the tendon of peroneus brevis.
They are normally treated symptomatically with either a supporting bandage or plaster and with or without crutches (depending on the patient's mobility). Only one study has adequately compared plaster and supporting bandaging (and even that study is not without problems). This suggests that there is no difference in pain or time to bony union, but that support bandaging significantly shortens the time to full activity and so is recommended [3].
Most fractures heal quickly but occasionally go to non-union. This only needs treatment if it is symptomatic.