MRI of acute osteomyelitis in long bones of children: pathophysiology study

Introduction The classic pathophysiology of acute osteomyelitis in children described by Trueta has a metaphyseal infection as the starting point. This hypothesis was recently brought into question by Labbe’s study, which suggested a periosteal origin. Thus, we wanted to study this disease's pathophysiology through early MRI examinations and to look for prognostic factors based on abnormal findings. Material and methods This was a prospective, multicentre study that included cases of long bone osteomyelitis in children who underwent an MRI examination within 7 days of the start of symptoms and within 24 hours of the initiation of antibiotic therapy. We also collected clinical, laboratory and treatment-related data. Results Twenty patients were included, including one with a bifocal condition. The lower limb was involved in most cases (19/21). Staphylococcus aureus was found most frequently. Metaphyseal involvement was present in all cases. No isolated periosteal involvement was found in any of the cases. No prognostic factors were identified based on the various abnormal findings on MRI. Conclusion Our study supports the metaphyseal origin of acute osteomyelitis in children. Level of evidence II.