Radiokarpalgelenks

The radiokarpalgelenks, or radiocarpal joint, is the synovial articulation between the distal radius and the proximal carpal row. It forms the main wrist joint and is separated from the distal radioulnar joint by the triangular fibrocartilage complex (TFCC), which extends to the ulnar side.

Anatomy and articulation: the distal radius presents articular facets that interact with the scaphoid and lunate bones. The scaphoid and lunate articulate directly with the radius, forming two primary radiocarpal articulations. The triquetrum does not directly contact the distal radius. The ulna does not form a true wrist joint with the carpus; the TFCC provides ulnar-sided stability and separates the ulna from the radiocarpal surfaces. The joint capsule is reinforced by extrinsic ligaments, including volar (anterior) and dorsal radiocarpal ligaments, as well as radiocarpal connections to the scaphoid and lunate.

Ligaments and stability: in addition to the radiocarpal ligaments, intrinsic carpal ligaments stabilize the proximal carpal row (notably scapholunate and lunotriquetral joints) and the TFCC contributes to ulnar-sided stability and the articulation with the distal radioulnar joint. Blood supply arises from carpal and radiocarpal arteries, and innervation by branches of the median, ulnar, and posterior interosseous nerves provides pain and proprioceptive information.

Function: the radiocarpal joint permits flexion, extension, and radial and ulnar deviation, enabling complex wrist movements and circumduction when combined with midcarpal joints. Clinically, it is involved in injuries such as distal radius fractures and ligamentous disruptions, as well as degenerative arthritis.

Overall, the radiokarpalgelenks is the primary hinge for wrist motion, providing essential stability and a wide range of hand positioning.