Ultrasound's Pivotal Role in Diagnosing Pediatric Osteomyelitis After a Negative X-Ray: A Case Report

Acute osteomyelitis is a potentially severe bone infection that commonly affects children, and early diagnosis is essential to prevent complications. However, plain radiographs are often normal in the early stages, which can delay treatment. We report the case of a 9-year-old female who presented with acute pain, swelling, and tenderness over the distal right tibia. Initial plain radiographs showed no bony abnormalities, while ultrasound revealed a hypoechoic subperiosteal fluid collection with surrounding soft tissue oedema and increased vascularity on colour Doppler, consistent with early osteomyelitis. The patient was treated with antibiotics, and a follow-up radiograph obtained six weeks later demonstrated cortical destruction, periosteal elevation, and patchy osteolytic changes, confirming the diagnosis. This case highlights the value of ultrasound as a sensitive, accessible, and radiation-free tool for the early detection of acute osteomyelitis in children, especially in resource-limited settings where advanced imaging may not be readily available.