 [ Symptoms ] what kinds of infections may occur in tkr 13 mons ago knee aspirations been bloody for past 5 months serious cure  orthopedic surgeon thinks i have an infection but lab test always negative he also thinks i may be allergic to the metal he wants to perform another replacement but i think we should do something first to determine why as much as 25cc of blood comes out every 5 6 wks when i have my knee aspirated please help me i am very worried that the toxins are doing damage to my leg i have had ct scan mri & a nuclear bone scan dr admitted he is not certain what to do maybe use ceramic [ Disease ] anaerobic bacteria do not need oxygen to grow they are generally associated with periodontal disease