Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The Radial carpal collateral ligament is a short, thick fibrous band that crosses from the tip of the radial styloid process to the scaphoid bone. The radial styloid process is a projection of bone on the lateral surface of the distal radius bone. It extends obliquely downward into a strong, conical projection. The tendon of the brachioradialis attaches at its base, and the radial collateral ligament of the wrist attaches at its apex. The lateral surface is marked by a flat groove for the tendons of the Abductor pollicis longus and Extensor pollicis brevis. Breakage of the radius at the radial styloid is known as a Chauffeur''s fracture; it is typically caused by compression of the scaphoid bone of the hand against the styloid.