To treat the Osteomyelitis, Treat the lesion overlying it!!
Once the biofilm has been established it is nearly impossible to treat with abx alone. At this point its classified as chronic OM and can only be treated with surgical debridement. At this point ortho involvement should already have been established.
Its often the case in diabetic foot patients where there is ulceration on the foot and there likely is some degree of OM present, however with good wound care and management of the overlying lesion this can be managed effectively. Good debridement, sanitation and dressing is key.