While this may seem like a simple question without knowing a lot of additional details I can only speak in general terms. There are 2 major bones that make up the ankle joint (tibia and fibular). One or both of these bones can be fractured. Depending on the severity of the facture it could be treated with casting and/or surgery which of course impacts healing time. All of these and many other factors (what ligaments may have been torn) play a role in the amount of time you must wear a brace. For a minor fracture involving the tip of the fibula you might only need a brace for 4-6 weeks. For complex fractures involving both bones and several ligaments bracing may be required for 3-4 months. Pretty much all ankle fractures also require physical therapy for strengthening and flexibility which can also impact the amount of time necessary to wear a brace.
P. Gunnar Brolinson, DO