hi Stephanie May,
which seen over ankle definitely leads to some sub dermal hemorrhage means some vessels may crush and blood came out,why it shown at ankle because the site where damage formed is maybe loosely arranged skinned area or fat tissue area .
Due to gravitational force this blood which came out from vessels move to dependable area and settled there at ankle so no need to apply anything over ankle area.
may not be there but some tissue trauma which cannot be seen by x ray
is developed there
if bruises is not increasing no need to worry about the vessel damage.
if pain persist take some anti inflammatory medicines with the help of your doctor
i am an ayurveda doctor i have no right to say about that for clarification contact