Simultaneous occurrence of knee septic arthritis and coronavirus disease 2019 (COVID-19): A case report

BACKGROUND: Coronavirus disease 2019 (COVID-19) pandemic is increasingly recognized as a serious, worldwide public health concern. Most of the patients with COVID-19 are asymptomatic or show mild symptoms. It is important to identify the unusual manifestations and their long-term complication. CASE PRESENTATION: A case of COVID-19 in 45 years old man with septic arthritis due to Staphylococcus aureus is presented. COVID-19 was diagnosed using real-time polymerase chain reaction without obvious clinical manifestation. The patient had no history of trauma or inflammatory arthritis and had progressive left knee pain and limitation of movement. Knee X-ray was normal. Aspiration of the knee joint fluid showed a cloudy and purulent appearance. The patient was admitted to hospital and immediately treated with vancomycin 1gr/12 hr. A polymerized chain reaction (PCR) test for COVID-19 was performed, which was positive 24 h after hospitalization. Staphylococcus aureus was reported in synovial fluid culture which was sensitive to vancomycin and ciprofloxacin, thus vancomycin was continued. On the 4th day of hospitalization the patient had cough, therefore underwent CT scan lungs and ground-glass opacities (GGO) characteristic of COVID-19 were noticed. Favipiravir and interferon were started. Patient’s knee aspiration was performed for 5 consecutive days. On the 6th day of hospitalization, joint fluid markedly decreased and the patient's oxygen saturation was 96%. One week after hospitalization, the patient was discharged and a month later knee examination was completely normal. CONCLUSIONS: Septic arthritis should be considered in the manifestations or co-morbidity of COVID-19 patients with joint pain, swelling or redness.