mrsa osteomyelitis

Does anyone know much about this? My husband is a paraplegic and it was to widespread to do anything about it except a hemicorporectomy. That was 6 years ago and he is still hanging on. He is on bactrim and flagyl. Has been for all this time. I worry that one day he will become septic all at once and it will be over. He doesnt feel bad and is never sick. But he does have a chronic decubitus that drains constantly from area that wound first started. He has to go and get I&D every so often due to abscess. Last MRI said it was in part of his spine now.