My grandmother died from osteomylitis cancer 10 years ago, and my my uncle has just been given 8 - 10 months to live from the same disease. The doctor has adviced the offspring (me) to get checked.

What are my chances of having this?
Is it hereditary?
Can I be healthy now, but have this in my system?
I am having pain in my knee and have had three leg operations (waiting for my fourth), would this increase my chances of this cancer developing?

Thank You for any help you have to offer