Perioperative Testing for Persistent Sepsis Following Resection Arthroplasty of the Hip for Periprosthetic Infection

What is the Diagnostic Accuracy of Aspirations Performed on Hips With Antibiotic Cement Spacers?

“…Although the MSIS criteria are considered the best standard we have for diagnosing acute and chronic periprosthetic joint infections in total joint arthroplasties, it was not designed to address joints with antibiotic-eluting spacers. There are limited studies that have evaluated methods to determine whether the periprosthetic joint infection has been effectively treated before the second-stage surgery [11,15,16,26]. No previous studies, of which we are aware, have examined the utility of preoperative hip aspirations with or without saline lavage for diagnosing persistent infection in hips with antibiotic cement spacers, and no cutoff values for WBC count and PMN percentage have been established.…”

“…Mont et al [18] reported that cultures from preoperative aspirations before reimplantation reduced the rate of recurrent infection after the second-stage surgery by allowing clinicians to identify patients with persistent infections. Along with synovial fluid cultures, the synovial fluid WBC count and PMN percentage are useful tests for identifying persistent infections at the time of the second-stage surgery for infected THA [26]. Shukla et al [26] reported on patients with hip spacers who had intraoperative aspirations during the second-stage surgery and found the WBC count sensitivity, specificity, and accuracy to be 78%, 96%, and 94%, respectively, and PMN percentage sensitivity, specificity, and accuracy of 78%, 82%, and 82%, respectively.…”

“…Along with synovial fluid cultures, the synovial fluid WBC count and PMN percentage are useful tests for identifying persistent infections at the time of the second-stage surgery for infected THA [26]. Shukla et al [26] reported on patients with hip spacers who had intraoperative aspirations during the second-stage surgery and found the WBC count sensitivity, specificity, and accuracy to be 78%, 96%, and 94%, respectively, and PMN percentage sensitivity, specificity, and accuracy of 78%, 82%, and 82%, respectively. The lower sensitivities reported in our study and by Shukla et al [26] may be attributable to a high false negative rate owing to the antibiotic spacer elution, which can elute antibiotics for up to 8 weeks [2].…”

“…The MSIS guidelines' thresholds have not been validated in the diagnosis of persistent infection after stage-one revisions in THA where antibiotic cement spacers are used. To aid in diagnosis, aspirations also may be done before the second-stage reimplantation to determine if there is a persistent infection [16,18,26]. Despite the assistance of fluoroscopic guidance, hip aspiration can be complicated by a lack of accessible synovial fluid or a ''dry tap'' [4].…”

CORR Insights®: Are Frozen Sections and MSIS Criteria Reliable at the Time of Reimplantation of Two-stage Revision Arthroplasty?

“…Prior work from our center [5,6], for example, suggests that there is no ideal ''cut-off'' value for the erythrocyte sedimentation rate or C-reactive protein that predicts persistent infection prior to reimplantation. Further, these same laboratory values do not need to be normal prior to safely proceeding with the second stage reimplantation.…”