Bacterial Culture Study of the Hip Joint Fluid during Primary Total Hip Arthroplasty

Han, Chang Dong; Sohn, Joon Seok; Choe, Wahn Sub; Yoo, Joo Hyung

Abstract

Infection in primary total hip arthroplasty may cause catastrophic results and is the major reason for implant failure. The purpose of this study was to evaluate the utility of the hip joint fluid culture as a method of predicting the possibility of a hip joint infection by calculating the sensitivity, specificity and accuracy. We performed 628 primary total hip arthroplasty and aerobic and anaerobic bacterial cultures for hip joint fluid between January 1989 and June 1996. The hip joint fluid culture was routinely performed to evaluate the utility of the femoral head for bone banking. Thirty-two cases out of the 628 hips showed positive intraoperative culture and 596 cases showed negative intraoperative culture. The isolated organisms from 32 positive cultures were 11 for Staphylococcus aureus, eight for Staphylococcus coagulase negative, seven for Enterococcus, three for E.coli and one each for Enterobacter, Acinetobacter and Pseudomonas. Anaerobic culture was negative in all cases. In the positive intraoperative culture cases, none had delayed infection during the follow-up period. But in the negative intraoperative culture cases, one case had acute infection and two cases had delayed infection. In the case with acute infection, Staphylococcus aureus was isolated and on two cases with delayed infection, Enterococcus and Staphylococcus coagulase negative were isolated, respectively. All 32 positive culture cases were fa~lse positive and 595 negative culture cases were true negative and one negative culture case was fa~lse negative. The sensitivity of the hip joint culture was 0%, the specificity was 94.9% and the accuracy was 0%. The specificity of hip joint fluid culture in primary total hip arthroplasty was high, hut the sensitivity score was zero. Therefore, the hip joint fluid culture should not be used for a routine check of infection status in primary total hip arthroplasty. We recommend the hip joint fluid culture in revision arthroplasty or hips in which infection is clinically suspected.