Review Question - QID 2906

The radiographs show a transphyseal separation of the distal humerus. This injury pattern is a result of a rotatory shear mechanism and has a high association with child abuse.

Arthrograms may be of assistance to confirm the diagnosis of a transphyseal separation and to rule out other conditions including a very distal supracondylar fracture, lateral condyle fracture, and elbow dislocation. In the child with a visible ossification center at the capitellum, a true elbow dislocation will have disruption of the radiocapitellar line and transphyseal separation of the distal humerus will not.

Transphyseal separations of the distal humerus are treated with closed reduction and percutaneous pin fixation similarly as to a supracondylar humerus fracture.

DeLee et all looked at sixteen patients with fracture-separations of the distal humeral epiphysis. All sixteen patients revealed posteromedial displacement of the distal humeral epiphysis on the initial roentgenogram. Child-abuse was documented or suspected as a cause in six of the sixteen fractures (38%).

Akbarnia et al performed a Level 4 review of 6 infants that underwent an arthrograph because their elbow injuries were not clearly identified from the plain radiographs. They found that in over 75% of cases the management changed as a result of the arthrograph information. Salter-Harris I fractures were the most common injury pattern diagnosis. Child abuse was confirmed or suspected in 4 of 6 cases (66%).

Illustrations A and B show radiographs of the contralateral limb which can be a helpful tool when assessing for the presence of a transphyseal fracture.