"Mirror hand", or ulnar dimelia, is a rare congenital anomaly characterized by doubling of the ulna, absence of the radius and the first finger of the hand, an excessive number of fingers, usually symmetrically located relative to the midline. Usually, limited movement in the elbow joint and rotational movements of the hand are visualized, since in these patients, instead of the head of the radius, the proximal part of the second ulna is involved in the elbow joint.