Title : Adult-onset stills disease rather than periprosthetic joint infection: A rare cause of fever after total hip arthroplasty
Abstract:
Objective: To highlight the clinical similarities between Adult-Onset Still’s Disease (AOSD) and Periprosthetic Joint Infection (PJI) after Total Hip Arthroplasty (THA), and to identify key diagnostic factors to prevent misdiagnosis and unnecessary surgery.
Methods: A case of a 37-year-old male who developed recurrent fever, rash, polyarthralgia, and elevated inflammatory markers after THA is presented. Diagnosis involved bacterial cultures, serological tests, imaging, and multidisciplinary consultation. AOSD was diagnosed per Yamaguchi criteria, while PJI was excluded using 2018 ICM criteria.
Results: The patient presented with high fever (Tmax 39.4°C), transient rash, sore throat, lymphadenopathy, and polyarticular pain. Inflammatory markers (WBC, CRP, ESR) were significantly elevated, but all bacterial cultures were negative. D-dimer was normal, and broad-spectrum antibiotics were ineffective. The patient met the Yamaguchi criteria by fulfilling 4 major criteria (fever, arthritis, rash, leukocytosis) and 4 minor criteria (sore throat, lymphadenopathy, abnormal liver function, negative RF/ANA), confirming AOSD. Symptoms resolved rapidly with intravenous dexamethasone. One-year follow-up showed good functional recovery without recurrence.
Conclusion: The systemic inflammation of AOSD can mimic PJI after THA. Key differentiating features include negative cultures, multisystem involvement (rash, pharyngitis), normal D-dimer, and antibiotic unresponsiveness. Clinicians should maintain high suspicion for AOSD in postoperative fever, include autoimmune evaluation, and utilize MDT collaboration with strict ICM criteria to avoid misdiagnosis and unnecessary revision surgery.
