22u-D/2.1   Ulna, greenstick

A greenstick fracture is a combination of a complete fracture on the tension (convex) side and plastic deformity on the compression (concave) side.

The periosteum is disrupted on the convex side and remains intact on the concave side.

Greenstick fractures occur mostly in young children.

Note: In all cases of an isolated ulnar fracture, it is important to confirm the normal alignment of the radiocapitellar joint and specifically exclude a Monteggia lesion.