Imaging description

AP and lateral radiographs of the right lower extremity in a young infant demonstrated diffuse exuberant periosteal reaction, diaphyseal sclerosis, and metaphyseal irregularity with horizontal metaphyseal lucent lines (Fig. 87.1a,b), suggestive of bony changes of congenital syphilis. AP radiograph of the bilateral lower extremities in a different infant with congenital syphilis demonstrated irregular, focal lucencies of the medial proximal metaphyses of the bilateral tibiae, the Wimberger sign (Fig. 87.2). AP radiographs of bilateral upper extremities in another infant demonstrated metaphyseal lucencies and diaphyseal sclerosis (Fig. 87.3).

Importance

Congenital syphilis is transferred through the placenta in the second or third trimester in mothers with untreated or recently treated primary or secondary syphilis. The pathogenesis of this disease is transplacental migration of Treponema pallidum bacteria. Bony changes are thought to result mostly from trophic effects rather than direct osteomyelitis. There is inhibition of osteogenesis and disturbance of active endochondral ossification. Symmetric involvement of the sites of endochondral ossification leads to bony changes at the epiphyseal-metaphyseal junctions, costochondral junctions, and endochondral ossification sites in the sternum and spine. A baby born to a mother with untreated syphilis in the primary or secondary stage has a nearly 100% chance of acquiring the infection. Radiographic changes occur approximately six to eight weeks after initial infection, so that they may not be present at birth but only manifest subsequently. Direct clinical examination, treponemal tests, VDRL (venereal disease research laboratory [test for syphilis]), and rapid plasma reagin are used to confirm the diagnosis. Results are considered conclusive when the infant’s titer is at least four times higher than that of the mother.