Infection of
biomaterial implants is an expensive and devastating complication of orthopaedic surgery historically ranging from less than 1% in primary
total knee arthroplasty (TKA) to 10% in revision TKA. An in vivo animal model was developed to test the efficacy of
innovative therapies for the prevention of
biomaterial centered
infections caused by methicillin-resistant Staphylococcus aureus bacteria (MRSA). Twenty-two New Zealand White rabbits were used in this study. After proper
anesthesia, a
stainless-steel screw with a high molecular weight
polyethylene (
UHMWPE) washer was cemented in a defect created in the intra-articular, non-articulating portion of the lateral femoral condyle of each knee. After closure of the joint capsule, each knee was inoculated with 0, 10(2), 10(3), or 10(4) colony forming units (CFU) of MRSA. Animals were sacrificed after 7 days at which time joint aspirate, tissues and
biomaterial samples were examined for evidence of
infection. A total of 42 knees were used for analysis. When saline was injected into the knee, 0/10 of the knees demonstrated evidence of
biomaterial centered
infection (with the contralateral knee receiving 10(4)CFU MRSA). Four of 10 knees developed a
biomaterial centered
infection when 10(2)CFU MRSA was introduced. Seven out of 10 knees developed a
biomaterial centered
infection when either 10(3) or 10(4)CFU MRSA was injected. No evidence of
septicemia (positive blood cultures) was found in any animal. This rabbit knee model utilizes commonly employed inexpensive orthopaedic implant materials in an in vivo milieu and provides an effective method for the evaluation of treatments for
biomaterial centered
infections.