Subacute osteomyelitis-Epiphyseal Involvement

This is a case of 15 year old male with pain, swelling and on aspiration pus was noted. There are areas of altered marrow signal alteration involving the diapmetaphyseal region and extending across the physeal cartilage to involve the epiphysis with patchy areas of T1 hypointensity and T2 /STIR hyperintensity. There are areas of cortical tunneling and minimal fluid collection in the knee joint and suprapatellar bursa.  Findings likely indicate an infective etiology possibly subacute osteomyelitis, which may involve the epiphysis as well. Interconnecting subacute osteomyelitis of the epiphysis and metaphysis is readily explainable in infants younger than 18 months, when one considers that vascular communication between the epiphysis and metaphysis is present until age 18 months.  Epiphyseal lesions may also occur in older adolescents when the growth plate becomes attenuated and fails to provide a barrier to epiphyseal infection.