Hi, thanks for writing to HCM.
Foul smell coming out of a wound indicates purulent infection inside. This definitely sounds bad but nothing to panic.
If the pus is deep seated, it may need a surgical drainage
followed by an appropriate course of antibiotics and antiinflammatory medications. The quicker you act, the better will be the outcome.
There is no role for self care measures in your case.
I suggest you to immediately consult an orthosurgeon for further management.
Hope this information is helpful. Good day