Is three-phase bone scintigraphy really obsolete? : a combined TPBS-CRP diagnostic method

Area of Science:

• Orthopedic Surgery
• Nuclear Medicine
• Diagnostic Imaging

Background:

• Periprosthetic joint infection (PJI) is a significant complication following arthroplasty.
• Three-phase bone scintigraphy (TPBS) is a recognized imaging technique for PJI diagnosis.
• Evaluating combined diagnostic strategies can improve PJI detection accuracy.

Purpose of the Study:

• To assess the diagnostic efficacy of combining TPBS with C-reactive protein (CRP) levels for PJI detection.
• To compare the performance of TPBS, CRP, and the combined TPBS-CRP method in diagnosing PJI.
• To analyze the impact of antibiotic therapy on diagnostic accuracy in PJI evaluation.

Main Methods:

• Retrospective analysis of 317 patients undergoing revision hip or knee arthroplasty.
• TPBS performed pre-operatively; PJI diagnosis based on 2013 Musculoskeletal Infection Society (MSIS) criteria.
• Evaluation of diagnostic performance metrics (sensitivity, specificity, AUC) for TPBS, CRP, and TPBS-CRP.

Main Results:

• In total knee arthroplasty (TKA), TPBS-CRP achieved 100% sensitivity and NPV for PJI exclusion, with 50% specificity.
• For total hip arthroplasty (THA), TPBS-CRP showed superior AUC (0.846) compared to TPBS and CRP alone.
• Antibiotic therapy impacted CRP accuracy more significantly than TPBS, but both TPBS and CRP showed higher accuracy in treated patients for TPBS-CRP.

Conclusions:

• The combined TPBS-CRP method synergizes imaging and inflammatory markers for superior PJI diagnostic accuracy.
• TPBS alone has limited specificity for differentiating PJI from aseptic loosening.
• Caution is advised for TPBS-CRP in patients with severe bone loss and prolonged symptoms due to potential false positives.