ABSTRACT
The radius and ulna are longitudinally stabilized by the interosseous membrane, which in many ways can be viewed as a single bicondylar joint with a rotational axis between the centres of the proximal radioulnar joint and the distal radioulnar joint. The membrane serves as a hinge about which the ulna rotates around the radius; it has the following components: The radius has a 12 bow, convex laterally, and the ulna has a varus bow of approximately 9. Thompson's dorsal approach is an extensile approach to the radius. The abductor pollicis longus and extensor pollicis brevis cross obliquely over the mid-dorsal radius, and must be mobilized proximally or distally following incision of their inferior and superior borders, to access the middle third. Distally, incising between extensor pollicis longus and extensor carpi radialis brevis provides direct access to the radius. Extensor policis brevis Abductor policis brevis Pronator teres. The ulna is palpable subcutaneously throughout its entire length from olecranon to ulnar styloid.
