Salter-Harris I fracture of the distal humerus in a neonate: imaging appearance of radiographs, ultrasound, and arthrography.

Neonatal Salter-Harris I fractures of the distal humerus are a rare injury. This injury can be easily mistaken for a posterior elbow dislocation, creating a delay in diagnosis. We present a case of a neonate with a distal humerus Salter-Harris I fracture secondary to trauma during delivery. The patient presented with pseudoparesis of the left arm following birth. Posterior displacement of the elbow was identified on radiographs. Ultrasound of the elbow was performed after a gentle closed reduction of the left elbow was unsuccessful. A transphyseal supracondylar distal humerus fracture was identified on ultrasound. The patient subsequently had an intraoperative left elbow arthrogram to assist in visualization of the supracondylar fracture during closed reduction and percutaneous pinning. At 2-month follow-up, the patient was neurologically intact with full passive range of motion and had normal alignment of the capitellar ossification center and distal humerus on follow-up radiographs.