Popliteal Pain

My father's doctors stage a suspicion he has osteomyelitis, but my knowledge on this iwith bone infection I guess he is in pain. It is apparently behind the knee. Considering what it's near a town I would have been well aware.
He had a bump on the back of this ares for ages and it rutured and doctors from a foreign body from which was diagnosed as a human bone. Thus, indicative of osteomyelitis.
He is obviously worried and is getting a bone scan on Friday and a cat scan
Can someone give me a head?

Osteo is often painful. Of course there are exceptions.

For the bone infection, it must have been penetration from the outside to an area close to the bone at some point.
According to the patient, it may take some time to progress.

Good luck.