Radius

Study entry

Parts

Proximal: head (disc that rotates on the capitulum and in the radial notch of the ulna), neck and radial tuberosity (insertion of the biceps). Shaft with interosseous border. Distal (broadened): styloid process of the radius, ulnar notch, dorsal tubercle and articular surface for the carpus.

Joints

Humeroradial, proximal and distal radioulnar, radiocarpal (with the scaphoid and the lunate).

Palpation

Head (rotating under the thumb in pronation and supination, below the lateral epicondyle), styloid process and dorsal tubercle.

Clinical

Fracture of the distal end (Colles) is the most common fracture in adults over 50: distal fragment displaced backward, the "dinner fork" deformity.

Source: cap. 3, «Huesos del antebrazo» y cuadro clínico

Clinical correlation

Fractures of the radius and ulna; Colles fracture

In children they are usually greenstick fractures. A direct blow breaks both bones at the same level, generally in the middle third. Because the interosseous membrane joins the two, a fracture of one bone tends to come with dislocation of the nearest joint. The Colles fracture is the most common of the forearm: a complete transverse fracture of the distal 2 cm of the radius, frequent after 50 and in women with osteoporosis, from a fall on the outstretched, pronated hand. The distal fragment (often comminuted) goes backward, the styloid process of the ulna may be torn off and, with the radius shortened, the styloid of the radius is no longer more distal than that of the ulna.

Related clinical cases

• Fractures of the radius and ulna; Colles fracture

Other structures in this region

• Clavicle
• Scapula
• Humerus
• Ulna
• Scaphoid
• Lunate
• Triquetrum
• Pisiform