Controlled clinical trial on the efficacy of antibiotic addition in the prevention of deep infection after total primary knee arthroplasty

Total knee arthroplasty (TKA) is considered the gold standard treatment for osteoarthritis (OA) in advanced stage with severe joint involvement and has excellent clinical results with survival rates of more than 15 years. The number of TKA performed annually in the United States is approximately 1,000,000. The periprosthetic joint infection (PJI) is the second most common cause of failure in arthroplasty, ranging from 1% to 23% and it is one of the most devastating complications with great frustration for both the patient and the surgeon. Treatment of PJIs also has great economic impact ranging from 30 thousand to 50 thousand dollars. Several preventive strategies are used in order to reduce the rates of infection in TKA and the use of bone cement with antibiotic routinely persists to the present day as a controversial issue in clinical practice. The aim of this study was to evaluate the effectiveness of adding antibiotics to bone cement in primary TKA as a form of deep infection prevention. We conducted a prospective, randomized controlled trial with patients undergoing TKA in the Knee Specialized Care Center (CAE) of the National Institute of Traumatology and Orthopedics Jamil Haddad between 2010 and 2013. We included 286 volunteers, who were divided into two groups: "No ATB" (n = 158) that included those undergoing TKA with standard technique using prosthetic Press Fit condylar (PFC Sigma / DePuy-Synthes®) with conventional cement (DePuy-Synthes®) and the group "with ATB” (n = 128) which included patients underwent the same procedure, with the same implant, but using cement with the addition of the vancomycin at a ratio of 2g per 40g of cement. A mixture of the antibiotic cement was performed manually by the surgeon. Patients were followed for 24 months after surgery. The analysis of preoperative data showed that the random distribution of patients between the groups were homogeneous considering the age, gender surgical risk (ASA), diagnosis, BMI and levels of globulin and albumin. The time of surgery did not differ between groups. The overall percentage of infection was 2.09% (n = 6), with no difference (p = 0.466) between the group "with ATB" (n = 2 or 1.56%) and "without ATB" (n = 4 or 2.53%). In the "No ATB" group, the infection was related to Methicillin-resistant Staphylococcus aureus (n = 2), Methicillin Sensitive S. aureus (MSSA) (n = 1) and E. coli (n = 1). In group "With ATB" was related to Methicillin Sensitive S. aureus (n=1) and to P.mirabilis resistant to polymyxin B and tigecycline (n=1). The use of vancomycin impregnated bone cement in patients undergoing total knee primary arthroplasty, including those at high risk for infection, does not reduce the rates of deep infection, thus, should not be encouraged in TKA. We believe that our results may serve to direct the conduct of orthopedic surgeons at INTO and other hospitals with similar conditions and also contribute to the reduction of inappropriate antibiotic use.