Prosthetic joint infections: radionuclide state-of-the-art imaging.

Area of Science:

• Nuclear Medicine
• Radiology
• Orthopedic Surgery

Background:

• Prosthetic joint replacement surgery is increasingly common, with 1-3% incidence of prosthetic joint infection (PJI).
• Differentiating PJI from aseptic loosening, the primary cause of prosthetic failure, is critical for appropriate treatment.
• Current diagnostic methods, including imaging, face challenges due to limitations like artefacts and lack of specificity.

Purpose of the Study:

• To review current imaging modalities for diagnosing prosthetic joint infection (PJI).
• To evaluate the effectiveness and limitations of various scintigraphic and emerging imaging techniques for PJI.
• To identify the most accurate imaging modality for PJI diagnosis.

Main Methods:

• Review of current literature on imaging techniques for PJI.
• Analysis of scintigraphy, including bone scintigraphy (BS), bone/gallium scintigraphy (BS/GS), and radiolabelled leucocyte scintigraphy.
• Evaluation of emerging techniques like positron emission tomography (PET) and hybrid SPECT/PET-CT.

Main Results:

• Radiographs and cross-sectional imaging (CT, MRI) are limited by artefacts and lack of specificity.
• Scintigraphy is preferred as it is not affected by prosthesis material.
• Combined in vitro labelled leucocyte/bone marrow scintigraphy (LS/BMS) shows approximately 90% accuracy and is considered the current imaging modality of choice for PJI.

Conclusions:

• Accurate differentiation of PJI from aseptic loosening remains a diagnostic challenge.
• While LS/BMS is the current gold standard, limitations exist, driving research into novel radiotracers and hybrid imaging techniques.
• Further development of infection-specific PET tracers and hybrid imaging (SPECT/CT, PET/CT) is needed for improved PJI assessment.