Does Percutaneous Core Biopsy Grant Higher Diagnostic Value in Periprosthetic Infections in Large Joints? A Prospective Superiority Study.

Abstract

Existing diagnostic approaches in periprosthetic joint infections (PJIs) are primarily based on joint aspiration, with a reported sensitivity of 40% to 86%. "Dry taps," occurring in up to 40% of aspirations, reduce diagnostic accuracy. Core biopsies, which enable minimally invasive tissue sampling, are widely used across various medical specialties and represent a promising tool for application in orthopaedics. Can the inclusion of core biopsy analysis, as opposed to a sole joint aspiration, enhance diagnostic accuracy for PJI in large joint (hip, knee, and shoulder) arthroplasties? In this prospective superiority study, 175 patients with painful large arthroplasties were recruited between September 2020 and September 2023. All patients underwent joint aspiration and core biopsy, leading to 181 primary data sets, of which 111 were excluded from final analysis for not reaching the primary endpoint or because of unrelated death, protocol breach, or a dry tap, which occurred in 33% (34 of 104) of examined joints. Diagnostic accuracy was assessed for sensitivity and specificity against the 2018 Musculoskeletal Infection Society criteria. Subsequent revision surgery, septic or aseptic, along with the microbiological evaluation of the explanted, sonicated prosthesis, serving as the gold standard for definitive proof of PJI, constituted the primary endpoint. Core biopsy showed superior diagnostic performance compared with joint aspiration, with sensitivity and specificity of 96% (95% confidence interval [CI] 82% to 99%) and 97% (95% CI 87% to 99%), respectively, versus 79% (95% CI 60% to 92%) and 70% (95% CI 55% to 84%). The statistical difference, using the paired McNemar test for sensitivity and specificity, was p = 0.006 and p = 0.004, respectively. The area under the receiver operating characteristic curve was 0.77 (95% CI 0.65 to 0.88) for joint aspiration and 0.97 (95% CI 0.94 to 1.00) for combined aspiration plus core biopsy. Core biopsy enhances the accuracy of PJI diagnosis through higher sensitivity and specificity compared with joint aspiration, reducing the impact of dry taps and offering a more reliable PJI assessment. Incorporating it into the standard workflow could lead to earlier and more accurate diagnoses. Level II, diagnostic study.