I tore up my knee pretty bad in 1974, acl and miniscus removed, ligaments re-attached.
For years I would get a monthly injection of cortisone into knee, in 1984 I woke up in the middle of the night with a 105 degree temp and a knee that was swollen out to basketball size.
Was diagnosed during lenghty hospital stay as having a staph bug, doctor said that it could have come from a shot.