Distal Extremity Articulation
The distal extremity of the radius, located closest to the wrist, is a significantly large and rectangular portion. It contains two articular surfaces that facilitate movement in the wrist. The carpal articular surface, with its smooth and triangular concave shape, interacts with the carpal bones of the hand. On the other hand, the ulnar notch, also concave and smooth, but narrower than the carpal region, allows for movement at the head of the ulna.
Non-Articular Surfaces of the Distal Radius
The distal end of the radius has three surfaces that are not involved in joint articulation. Understanding these surfaces is important for a comprehensive understanding of the anatomy. The dorsal surface, which refers to the top of the arm, is convex and features three distinct grooves. It is connected to the dorsal radiocarpal ligament. The first and third grooves are wide and shallow, while the second groove is narrow but deep. On the other hand, the volar surface, located on the palm side, has a rough texture and attaches to the volar radiocarpal ligament. Lastly, the lateral surface of the distal radius has a cone-like projection called the styloid process. This projection connects to multiple muscles, tendons, and ligaments, adding stability and support to the wrist joint.