Has anyone ever heard of bone marrow that is practically petrified? During a total knee replacement my surgeon had to drill out the bone marrow. Yet neither the pathologist who examined the bone fragments, nor the hematologist who I saw can find any evidence of a bone, bone marrow, or a blood disorder. They say I happen to have very hard bones. I do drink mostly milk and quite a bit of it; I do not drink coffee nor many soft drinks.