This condition is a break of the radius bone at the wrist. The radius is the larger of the two bones that connect the wrist to the elbow. The other bone is called the ulna. The radius supports the majority of forces at the wrist joint with its large joint surface. A fracture of the distal end of the radius—the end nearest the wrist—is one of the most common types of fractures. It may be part of a complex injury that involves other tissues, nerves and bones of the wrist.