Detection of Synchronous Foci of Infection using Positron Emission Tomography in Septic Patients Who Have a Periprosthetic Joint Infection.

Introduction: Periprosthetic joint infection (PJI) with sepsis is a life-threatening condition and identification of synchronous foci of infection is challenging. Positron emission tomography using ¹⁸F-fluorodeoxyglucose combined with computed tomography (¹⁸F-FDG-PET/CT) is useful to detect PJI in elective, non-septic patients. We hypothesized that in patients who have PJI and concomitant sepsis requiring intensive care, ¹⁸F-FDG-PET/CT could accurately identify synchronous foci of infection. We addressed the following questions: (1) How often were synchronous foci of infection detected? (2) What were the confirmation rates of these infection foci by other complementary state-of-the-art methods? (3) Did ¹⁸F-FDG-PET/CT findings result in surgical treatment? and (4) What is the risk of synchronous PJI in patients who have PJI and concomitant sepsis who have another indwelling arthroplasty?

Methods: We retrospectively analyzed mechanically ventilated septic PJI patients who underwent ¹⁸F-FDG-PET/CT between January 1, 2017, and December 21, 2022. The identified synchronous foci of infection were categorized into musculoskeletal, cardiovascular, pulmonary, or other infections and compared to results from tissue culture, histopathology, magnetic resonance imaging, or transesophageal echocardiography.

Results: We identified 17 eligible patients. The ¹⁸F-FDG-PET/CT revealed at least one additional infection focus in 88% (15 of 17) of patients with the following distribution: musculoskeletal (71%, 12 of 17), cardiovascular (18%, 3 of 17), pulmonary (77%, 13 of 17), and other infections (35%, 6 of 17). Synchronous foci of infection identified with ¹⁸F-FDG-PET/CT were confirmed by another state-of-the-art method in 100% (15 of 15) of the patients. Diagnoses with ¹⁸F-FDG-PET/CT led to additional surgery in 65% (11 of 17) of the patients.Of the patients, 59% (10 of 17) had another arthroplasty with a risk of 30% (3 of 10) of synchronous PJI.

Conclusion: We highlight the value of ¹⁸F-FDG-PET/CT in patients who have PJI and sepsis, emphasizing its role in the comprehensive evaluation of these patients for subsequent therapeutic decision-making.