Radiocarpien

Radiocarpien, or the radiocarpal joint, is the main wrist articulation between the distal radius and the proximal row of carpal bones, primarily the scaphoid and lunate. The ulna does not directly articulate with the carpal bones; stability on the ulnar side is provided by the triangular fibrocartilage complex (TFCC). The joint is classified as an ellipsoidal (condylar) synovial joint, enabling multi-axial movement while distributing load from the hand to the forearm.

Anatomy and surfaces: The distal radius presents an articular surface that faces the palm and articulates with the scaphoid and lunate. The triquetrum has minimal direct contact with the radius; its influence is mainly through the TFCC. The radiocarpal joint is reinforced by dorsal and volar radiocarpal ligaments and is complemented by the TFCC, which also stabilizes the ulnocarpal aspect and permits smooth carpal articulation.

Movement: The radiocarpien allows flexion and extension of the wrist, as well as radial deviation (abduction) and ulnar deviation (adduction). Combined motion enables circumduction and contributes to overall wrist mobility. Intercarpal joints between the carpal bones permit partial independent motion while sharing load with the radiocarpal joint.

Clinical relevance: Intra-articular fractures of the distal radius can disrupt radiocarpal congruity and increase the risk of post-traumatic osteoarthritis. Radiocarpal dislocations are uncommon but serious. Diagnosis relies on imaging, including X-rays and, when indicated, MRI to assess TFCC injury. Treatment aims to restore articular congruity and stability, with options ranging from immobilization to surgical fixation or, in chronic cases, joint-preserving procedures or fusion.