Isolated Coronal Shear Fracture of the Nonossified Humeral Trochlea in a 7-Year-Old Patient.

Coronal shear fractures of the nonossified humeral trochlea are extremely rare in skeletally immature children. This fracture is difficult to diagnose accurately on routine radiographs. In addition, the mechanism of injury and appropriate treatment methods are unknown. We present the case of a 7-year-old boy who sustained an isolated coronal shear fracture of the nonossified humeral trochlea. Internal fixation of the fracture was performed with 2 K-wires. Two and a half years after surgery, the patient had pain-free active range of motion of the elbow from 0° to 130° with full forearm rotation and magnetic resonance imaging showed healing of the chondral fragment of the trochlea. Hand surgeons should be aware of the possibility of this rare fracture in skeletally immature children. Magnetic resonance imaging and arthrography are helpful in establishing the correct diagnosis.