21r-E/M + 21u-M   Monteggia equivalent

The Monteggia equivalent involves an ulnar fracture (often distal to the coronoid) with a radial head/neck fracture. The radial head remains in place and the radial shaft is displaced in the same direction as the ulnar shaft.

This combination leads to an unstable elbow.

The fracture of the proximal ulna may be an incomplete (‘greenstick’) or a complete fracture.