CT evaluation of primary epiphyseal bone abscesses.

We reviewed the clinical, radiographic, and computed tomographic (CT) findings in eight children with a histologically proven diagnosis of epiphyseal or apophyseal osteomyelitis. In all cases the femur was involved: in five the osteomyelitis was localized in the femoral condyle, in two it was in the greater trochanter, and in one it was in the femoral head epiphysis. In four of the six cases of epiphyseal involvement there was associated joint effusion or septic arthritis. CT examination may demonstrate a serpentine tract, a sequestrum, cortical destruction or adjacent soft tissue swelling and can differentiate osteomyelitis from other epiphyseal lucent lesions, particularly chondroblastoma and osteoid osteoma. CT yielded important new diagnostic information in seven of the eight patients, failing to do so in only one. In one case, CT showed a wooden splinter in an abscess cavity, which had been mistaken for a sequestrum. When combined with accurate clinical and laboratory information and good quality plain radiographs, CT can lead to an early diagnosis of epiphyseal infection. Early diagnosis helps avoid delays in initiating antibiotic or surgical treatment caused by the unusual (epiphyseal or apophyseal) location of the bone abscess.