Anaerobic infection after total hip replacement. Report of three cases.

In a series of 387 consecutive total hip replacements there were nine infections (2.3% infection rate). Three of the infections were caused by an anaerobic gram positive cocci, Peptococcus. This is an increased incidence of infection for this previously rare pathogen. The anaerobic infections occurred despite prophylactic antibiotic coverage with Keflin. No causative factors such as hospital, operating time, operating personnel, medical disease, or blood loss could be associated with the observed anaerobic infections. Two of the anaerobic infections appeared late. This is consistent with other reports of anaerobic infections in implants. Drainage after total hip arthroplasty operation must be cultured for anaerobes as well as aerobes, especially late infections in patients on prophylactic antibiotics. Drainage which is sterile to aerobic culture should alert the physician to a possible anaerobic infection.