The value of sonography in the detection of osteomyelitis

Purpose. A retrospective study was carried out in order to determine the role of sonography in establishing the diagnosis in extremity osteomyelitis. Materials and methods. The imaging documents of 24 infants and children aged from 2 weeks to 13 years with osteomyelitis (acute 21, chronic 3) were reviewed. Sonograms and conventional radiographs were available in all patients. Additional skeletal scintigraphy had been performed in 13 patients and MRI in only 3. Special emphasis was put on the different ultrasound findings and their onset in the course of disease. Results. Intra-articular fluid collections (in 15 cases) and/or subperiosteal abscess formation (in 12) were the most frequent early sonographic findings, and preceded any radiographic changes by several days in 11 of these cases. Together with positive clinical signs of inflammation, they were usually sufficient to establish the correct diagnosis. In selected cases, fluid or abscess puncture for immediate microscopic and later bacteriological studies was carried out under sonographic control. In addition, sonography was also able to detect superficial cortical erosion and even an intramedullary focus in a very young patient. Conclusion. Ultrasonography is a very helpful tool for establishing the correct diagnosis in osteomyelitis and reducing the frequency of additional imaging studies.