Inadequacy of Joint Aspiration for Detection of Persistent Periprosthetic Infection During Two-Stage Septic Revision Knee Surgery

Abstract

Despite the lack of validation, synovial aspiration remains a common practice during 2-stage septic revision total knee arthroplasty (TKA). The goal of this study was to investigate the diagnostic validity of synovial polymethylmethacrylate (PMMA) spacer aspiration of temporary knee arthrodesis to detect persistent periprosthetic joint infection before TKA reimplantation. This retrospective cohort study included 73 consecutive patients who underwent 2-stage septic revision TKA according to a standard protocol. After explantation surgery, including temporary arthrodesis with an intramedullary stabilized PMMA spacer, all patients had synovial aspiration 2 weeks before reimplantation to exclude persistent periprosthetic joint infection. Patients had a 2-week antibiotic holiday before aspiration. Sensitivity and specificity of the synovial PMMA spacer joint aspiration for the detection of periprosthetic joint infection were determined and referenced against intraoperative microbiologic and histologic samples obtained at second-stage surgery. Sensitivity of the synovial PMMA spacer aspiration was 21%. Because of poor diagnostic validity, synovial PMMA spacer aspiration cannot be recommended for routine exclusion of persistent periprosthetic joint infection before TKA reimplantation. Therefore, exclusion of persistent periprosthetic joint infection should be supplemented by other diagnostic methods, and it is not necessary to delay TKA reimplantation for PMMA spacer aspiration. [Orthopedics. 2017; 40(4):231-234.].

Pros and Cons of Spacers in the Treatment of Late Periprosthetic Infections of the Hip

“…However, the fact that there is an effective level of antibiotic in the tissues at the time of the aspiration means that, in our opinion, the prognostic value of the whole aspiration procedure is overrated. This hypothesis is supported by the study of Preininger et al, for two-stage revisions of infected total knee arthroplasties, who found a sensitivity of only 21% for the aspiration of the spacer synovial fluid before reimplantation [48]. Moreover, in the study on 115 patients with two-stage revision hip or knee arthroplasties of Hoell et al, the sensitivity for synovial culture before reimplantation was only 5%, for white blood count in the synovial fluid 31.3% and for the CRP in serum 42.1% [49].…”

Twenty common errors in the diagnosis and treatment of periprosthetic joint infection

“…The duration of an antibiotic holiday seems to be less related with reinfection than the time the antibiotic cement spacer is implanted [75]. Joint aspiration before reimplantation is not recommended, as synovial markers do not correlate with reinfection rates, and the diagnostic accuracy is very low (sensitivity of 4.6% and 25.0% and specificity of 94.3% and 96.9% for synovial fluid and cell count, respectively) [75][76][77]. To date, there is no reliable marker to prove the eradication of infection at the time of reimplantation.…”

High cure rate of periprosthetic hip joint infection with multidisciplinary team approach using standardized two-stage exchange

“…None of our 18 episodes treated with a short interval had a recurrence of infection. We do not recommend waiting for CRP in serum to be normalized and an antibiotic-free period with joint aspiration before reimplantation, as cultures from synovial fluid and CRP seem to be uncertain parameters to exclude persistent infection [40–42]. Waiting for CRP to normalize and an antibiotic-free period with joint aspiration prior reimplantation can delay reimplantation unnecessary.…”