Aim: The aims of our study were to evaluate cases of extremity pain or swelling in paediatric patients using USG to diagnose acute osteomyelitis, and correlate USG findings with MRI findings. Material and methods: 18 paediatric patients with extremity pain or swelling were evaluated. After the clinical and laboratory work-up, imaging was done using radiographic examination, USG and MRI of the affected limb. Results: 5 patients (27.8%) out of 18 were diagnosed with acute osteomyelitis based on USG findings, confirmed by MRI and surgical drainage. The mean age of the patients with acute osteomyelitis was 8.2 years. Male children were more commonly affected as compared to female. The distal metaphysis of the femur was the most common site involved (80%). The right lower limb was more commonly affected. The most frequent presentation was pain at the affected site. On USG, deep soft tissue fluid collection around the bone was present in all cases (100%). Periosteal thickening or elevation with subperiosteal fluid collection was seen in 4 cases (80%). Increased vascularity within or around the periosteum on colour Doppler was seen in 4 cases (80%). Conclusions: Acute osteomyelitis is a common entity in the paediatric population, presenting with acute limb pain and swelling. Early diagnosis and management of acute osteomyelitis are essential to prevent serious complications. USG can play an important role in the early diagnosis of paediatric acute osteomyelitis, and should be incorporated into the treatment protocols followed in cases of suspected acute osteomyelitis. MRI should be reserved as problem-solving tool.

acute limb pain and swelling, paediatric acute osteomyelitis, ultrasound and colour Doppler, magnetic resonance imaging