Osteomyelitis of the Acetabulum in a Child: A Case Report of an Unusual Localization

Introduction: Acute haematogenous osteomyelitis (AHO) of the acetabulum is a rare condition in children. Presentation of case: We report a rare case in a ten-year-old child who had an acute presentation with new-onset hip pain and fever evolving for one week. The standard radiograph was without abnormalities. Emergency MRI showed osteoarthritis of the hip, with a 15 mm internal acetabular subchondral lacuna. Therefore, the child had antibiotic therapy. Pain relief and radiological improvement was obtained after 3 months of antibiotic treatment. At a two-year follow-up, the X-ray was normal. Discussion: Diagnosis is delayed because of the deep-seated location. Staphylococcus aureus is the most common causative organism. In the event of strong clinical-radiological suspicion, empirical treatment must be started rapidly, in order to obtain satisfactory results. Conclusion: Because of the atypical location of acute osteomyelitis of the acetabulum, diagnosis can be delayed. In some cases, treatment may be based on antibiotics therapy alone.