Fig. 17. Humerus fractures as a consequence of traumatic birth.

Frontal radiograph of the left upper extremity in a 2-day-old infant demonstrates mid shaft fracture of the left humerus (a). Illustration (b) depicting chondro-epiphyseal separation at the distal humerus. Upon separation of the distal humeral epiphysis from the bone, it no longer lines up with the distal humerus (black arrow), as seen in figure parts c-d. 10-day-old male twin infant with history of traumatic delivery, presenting with decreased right arm movements. Right elbow radiograph (c) demonstrates fragmentation of the distal right humeral metaphysis, with mild periosteal new bone formation (arrow). Sagittal STIR MR image of the distal right humerus (d) demonstrates increased STIR signal and enhancement surrounding and involving the distal right humeral metaphysis and epiphysis, with mild posterior angulation of the distal epiphysis relative to the metaphysis (arrows), suggestive of distal humeral fracture with chondroepiphyseal separation