Aspergillus niger as a rare cause of postarthroscopy knee septic arthritis in a healthy patient.

This case report outlines the diagnostic and therapeutic challenges encountered in a man in his 70s suffering from knee septic arthritis caused by Aspergillus niger It is the second published case in the literature with osteoarticular infection from A. niger and the first one in the last 40 years. Following knee arthroscopy, the patient experienced persistent pain, swelling and discomfort, prompting further investigation. Postoperative knee cultures were negative for infection, but symptoms were not ameliorated. Therefore, an arthroscopic debridement was performed that revealed severe joint inflammation and degeneration. Cultures from the synovial fluid and tissue samples identified infection from A. niger sp. Antimicrobial treatment with voriconazole finally led to significant clinical improvement and eradication of infection. This case highlights the intricacies involved in diagnosing and managing fungal osteoarticular infections in healthy patients without concomitant medical diseases or comorbidities.