Correlation of histological and microbiological findings in septic and aseptic knee implant failure

Abstract

Introduction The Musculoskeletal Infection Society (MSIS) has defined specific clinical and laboratory criteria for the diagnosis of periprosthetic joint infection (PJI). In this study we assessed the diagnostic utility of MSIS microbiological and histological criteria for PJI in 138 cases of septic and aseptic knee implant failure. Materials and methods Intra-operative samples from 60 cases of knee septic implant failure (SIF) and 78 cases of aseptic implant failure (AIF), defined on the basis of clinical, laboratory and operative findings/surgical management, were analysed microbiologically and histologically. Findings were correlated with the final clinical diagnosis and the specificity, sensitivity, accuracy, positive and negative predictive value of MSIS microbiological and histological criteria for knee PJI were assessed. Results 80% of SIF cases showed culture of the same organism from two or more samples (ie MSIS microbiological criteria for definite PJI); 8.3% grew an organism from one sample, and 11.7% showed no growth from any sample. 23.1% of AIF cases grew an organism from one sample and 76.9% showed no growth from any sample. MSIS histological criteria for PJI identified 96.7% of SIF cases. The sensitivity, specificity, accuracy and positive and negative predictive value of MSIS histological criteria for PJI were 96.7%, 100%, 98.6%, 100% and 97.5%, respectively. MSIS microbiological and histological criteria identified all AIF cases. Conclusions Knee PJI is more often identified by current MSIS histological than microbiological criteria. A significant proportion of SIF cases show either no growth or growth of an organism from only one sample. AIF is identified by both MSIS microbiological and histological criteria. Correlation of clinical, radiological and laboratory findings is required for the diagnosis of knee PJI.

Clinical and Histological Features of Prosthetic Joint Infections May Differ in Patients With Inflammatory Arthritis and Osteoarthritis

“…A histological diagnosis is very important in the assessment of possible PJI as it forms part of the minor MSIS diagnostic criteria at a threshold of 5 PMNs per HPF [ 16 ]. A study of prosthetic knee infection concluded that knee PJI was more often confirmed by MSIS histological than microbiological criteria; thus, histology aids in distinguishing between aseptic and septic cases [ 9 ]. The AAOS recognizes that 5 PMN per HPF confers a likelihood ratio of 13.82 (7.29, 26.19); however, 10 PMN/HPF in 5 fields confers a likelihood ratio of 56.5 (20.3, 157.2) [ 15 ].…”

Current Clinical Methods for Detection of Peri-Prosthetic Joint Infection

“…Inagaki et al [30] reported similarly high statistics for conventional culturing including one positive culture, producing 88.3% sensitivity, while two positive cultures decreased the sensitivity to 80%. Decreased sensitivity with two cultures could point to the presence of contamination and the inconsistency of relying on culturing to confirm PJI.…”

“…Further, although one might assume that low grade shoulder infections with pathogens such as C. acnes would produce fewer cell counts, they are, in fact, associated with high leukocyte levels [67]. Inagaki et al [30] found that almost every case of septic knee failure had 5+ neutrophils per 400x magnification in a high power field, indicating its utility visualizing both virulent and non-virulent infections. The 5+ neutrophils under histologic analysis of TKA produced 96.7% sensitivity and 100% specificity in detection of either bacterial or fungal PJI.…”

Application of [68Ga]Ga-citrate PET/CT for Differentiating Prosthetic Joint Infection from Aseptic Loosening After Joint Replacement Surgery

“…The diagnostic standards used in this study were based on the previous literature [4,12,18,20,21], as follows: PJI was diagnosed when the patient met the 2013 Musculoskeletal Infection Society (MSIS) criteria [22], or when at least one of three features was positive (intraoperative ndings including the occurrence of pus or purulent uid around the prosthesis, histological analysis, and surgical microbiological culture); AL was only diagnosed when the patient was excluded from the MSIS criteria and the intraoperative ndings, histological analysis, and microbial culture results were negative. Those who did not meet the MSIS criteria and were not con rmed to have AL through surgery were considered to have insu cient criteria for the diagnosis of AL and were excluded from our cohort.…”