Histological Findings in Infected and Noninfected Second Stage Revision Knee Arthroplasties

Abstract

Tissues from a periprosthetic joint infection (PJI) of the knee contain a heavy neutrophil polymorph (NP) infiltrate (> 5 NPs per high-powered field [HPF] by Musculoskeletal Infection Society [MSIS] criteria). PJI of the knee can be treated by a two-stage procedure and our aim was to determine whether the MSIS histological criteria for PJI diagnosis are valid in a second-stage revision knee arthroplasty. Periprosthetic tissues from 45 second-stage revision knee cases were analyzed histologically by hematoxylin–eosin and chloroacetate esterase (CAE) staining for the identification of NPs. The number of NPs was determined semiquantitatively and results correlated with the microbiological and clinical findings. In 9 of the 45 cases, an organism was cultured in two or more samples, meeting MSIS microbiological criteria for a definite diagnosis of PJI; histologically, seven of these cases contained > 5 per NPs per HPF on average, with the remaining two cases containing 1 NP and 2 NPs per HPF. In noninfected second-stage revisions, NPs were not seen in 30 cases with 6 cases showing less than 1 NP per HPF on average. The sensitivity, specificity, accuracy, and positive and negative predictive values of MSIS histological criteria (> 5 NPs per HPF) to diagnose PJI were 78%, 100%, 96%, 100%, and 95%, respectively. MSIS histological criteria for the diagnosis of PJI are valid for most but not all infected second-stage revision knee arthroplasties. Correlation of histology with clinical, microbiology and other laboratory findings is required to establish a diagnosis of PJI in second-stage revision knee arthroplasties.

Chloroacetate esterase reaction combined with immunohistochemical characterization of the specific tissue microenvironment of mast cells

“…The enzyme is found in much greater amounts in MC granules (Wong et al 1982 ; Atiakshin et al 2017 ). High resistance to formalin fixation, as well as to other fixatives, has led to the widespread use of ChAE as a MC marker in histological and pathomorphological studies (Michova and Fakan 1980 ; Hahn von Dorsche et al 1981 ; Lam et al 1985 ; Kashima et al 2015 ; Atiakshin et al 2017 ; Zushi et al 2018 ; Uchihara et al 2019 ). The efficiency of MC detection by detecting ChAE activity can be comparable or even exceed other methods for MC detection, including immunohistochemical methods (Atiakshin et al 2017 ; Wong et al 1982 ).…”