Combination of conventional culture, vial culture, and broad-range PCR of sonication fluid for the diagnosis of prosthetic joint infection

We assessed the value of conventional culture, vial culture, and broad-range PCR of the sonication fluid (SF), individually or in combinations, for the diagnosis of prosthetic joint infection (PJI). We studied 114 consecutive patients (median age:72.5 years, males: 28.07%) undergoing removal of a total knee or hip prosthesis. By non-microbiologic criteria, 87 patients had aseptic failure, and 27 PJI. All patients had periprosthetic tissue culture, sonication of prosthesis, and study of SF by conventional and vial culture, and PCR. Compared to tissue culture, each test was significantly more sensitive and less specific. If only one test was positive, the sensitivity was 88.46% and specificity 64.29%. If all three SF tests were positive, sensitivity, and NPV were decreasing (34.6% and 80.23%), but specificity and PPV were increasing up to 98.57% and 90.9%, respectively, outperforming tissue culture. A triple negative test practically excluded PJI.