if swelling continue even after draining the joint
it could be allergy esp nickel. I had that problem, blood work confirmed nickel allergy and another surgery had to be done.
On another note in spite of two surgeries and two and half year , I am in more pain and much worse situation withe my knee. have sharp pain at lower part of knee. It feels like insert is not the right size. Consulted few surgeons but no diagnose of pain. According to them my Xray is fine so there is no problem.
Any suggestions /advise will be helpful. Don't know what to do