Hi, thanks for writing to HCM.
As your xrays are negative for a fracture, the other possibilities for the swelling could be INFLAMMATION or INFECTION.
Infective causes tend to produce Fever and the swelling will result in suppuration (pus formation) if left untreated. In your case this is unlikely as it has been more than 2 months.
So the other possibility is a inflammatory cause. The common causes for inflammatory
arthralgia are
Rheumatoid arthritis, Gout and
pseudogout, Reactive arthralgia,
tuberculosis etc.
You need a detailed evaluation to establish the diagnosis.
I suggest you to consult an orthopedic surgeon or a
rheumatologist for further workup and management .
Hope this information is helpful. Good day