 [ Symptoms ] i use crutches after injured ankle and foot becomes very red and purple and my foot begins to throb [ Disease ] hi from the severity of the symptoms it is less likely that this could be only a sprain a bone around the ankle may surely have been fractured get a repeat xray or a ct scan to confirm only using crutches will not help you should be getting a plaster boot applied with strict non weight bearing and leg elevation take anti inflammatory and analgesic fibrinolytic tablets like trypsin chymotrypasin serratiopeptidase thanks