Clinical characteristics at the onset of peri-knee acute osteomyelitis in 56 children.

This study aimed to summarize the clinical characteristics of acute peri-knee osteomyelitis in children at onset. Fifty-six children (30 boys and 26 girls, aged 19 days to 15 years) diagnosed and treated from July 2017 to 2024 were enrolled, including 32 with distal femoral, 21 with proximal tibial, 2 with proximal fibular, and 1 with patellar involvement. Patients were grouped by epiphyseal involvement (32 epiphysis group and 24 nonepiphysis group), knee septic arthritis (19 arthritis group and 37 nonarthritis group), and methicillin‑resistant Staphylococcus aureus (MRSA) infection (16 MRSA group and 40 non‑MRSA group). Clinical data, including age, gender, onset duration, body temperature, and inflammatory markers, were compared among groups; receiver operating characteristic curve and logistic regression were used to analyze MRSA infection. The epiphysis group showed a higher rate of concurrent septic arthritis than the nonepiphysis group, and the arthritis group had a higher proportion of epiphyseal osteomyelitis. The MRSA group had significantly higher C‑reactive protein (CRP) levels, and CRP exhibited moderate diagnostic value for MRSA infection. Logistic regression identified CRP more than 92.785 mg/L as an independent risk factor for MRSA infection. Our study revealed that in peri-knee acute osteomyelitis, septic arthritis of the knee often occurs when epiphyseal osteomyelitis is present, and epiphyseal osteomyelitis is often present when there is septic arthritis of the knee. CRP levels were higher in MRSA-infected osteomyelitis. CRP above 92.785 mg/L was a high-risk factor for MRSA infection.