[RWebb]

maybe you should see a doctor - and get a referral to a specialist

but first write down the entire history of this problem

I will bet that the initial injury did not fully heal (ankle injuries are under diagnosed and under treated - and this was esp. true long ago), and that there is some looseness of the "stuff" that binds it all together and makes a secure joint -- this has led to further injuries.

I'd also bet on some calcification in unwanted places.