Hello
Mam, I understand that you were operated upon in 2016.The bones should have united by now. Excess strain can cause soft tissue swelling.
You have also mentioned that you have excessive swelling and pain in the ankle. Did you twist your ankle or did you sustain any slip mam?
Next Steps
Would advice you to keep your leg elevated. Kindly move your toes and ankle(if it permits). Keep ice packs mam. If it does not subside within two days,kindly visit an Ortho and take an Xray.