Tardy displacement of traumatic radial head dislocation in childhood

The diagnosis of traumatic dislocation of the radial head, either isolated or as part of a Monteggia fracture-dislocation, was delayed in 10 of the 11 0 children treated with these injuries during the study period. In eight ch ildren, the dislocation was overlooked on the initial radiographs. In two c hildren, the radial head was reduced on the initial elbow radiographs, but it was dislocated 10 days later in one child and 21 days later in the other . The most likely explanation is that the radial head dislocated at the tim e of impact, spontaneously reduced by the time the first radiographs were o btained, and redislocated while the arm was in a cast. We conclude that rad iographic assessments of the radiocapitellar joint, by using the radiocapit ellar line, are required in children with elbow and forearm injuries at pre sentation and when the cast is removed.