Primary Epiphyseal Osteomyelitis (PEO) in 18 Children: A Rare Entity With Atypical Features

Objectives: The purpose of this study is to discuss the natural history and management of primary epiphyseal osteomyelitis (PEO), to differentiate clinico-radiologic features of PEO caused by Mycobacterium and other organisms, and to discuss their intermediate-term outcomes. Methods: Between 2006 and 2017, 18 patients of PEO were managed at our center. Blood investigations, x-rays, and magnetic resonance imaging of affected part were carried out. Surgical drainage of lesions was done to retrieve infective fluid and tissue for examination. Antibiotics were administered for 1 year in Mycobacterial PEO and for 6 weeks in bacterial PEO. Average follow-up of patients was 5.5 years (range, 2 to 11 y). Results: Boys were more commonly affected (11/18). Distal femur was the most common site involved (12/18). Eleven patients had Mycobacterium tuberculosis as the causative organism, 6 were positive for Staphylococcus aureus, and 1 for Brucella. Swelling and limp were predominant in patients with Tubercular PEO, whereas pain was more common in bacterial PEO. Nine of 11 patients with Tubercular PEO had penetration into the joint, whereas none in bacterial PEO. All patients recovered completely without residual movement restriction or growth alteration. On follow-up magnetic resonance imaging, 4 patients with Tubercular PEO had thinning of articular cartilage. Conclusion: High index of suspicion is required for early diagnosis of PEO. It is important to differentiate Tubercular from other bacterial PEO as it has more subtle symptoms and poor prognosis if left untreated. Aggressive surgical treatment followed by antibiotic therapy of appropriate duration is required to avoid complications related to joint destruction. To our knowledge, this is the largest reported series with longest follow-up.