I would not be surprised if you are not dealing with mycoplasma synovitis (MS.) If you do have MS, which the vet could test for by culturing the joint fluid, I would not do anything else to the feet. Here is some reading about MS:
http://www.poultrydvm.com/condition/infectious-synovitis
https://www.merckvetmanual.com/poultry/mycoplasmosis/mycoplasma-synoviae-infection-in-poultry
http://www.poultrydvm.com/condition/infectious-synovitis
https://www.merckvetmanual.com/poultry/mycoplasmosis/mycoplasma-synoviae-infection-in-poultry