X-Wrist

Normal Anatomy

The wrist is made up of a number of complex joints. 
Some key structures: 

• Radiocarpal joints; articulation between the radius and the first row of carpal bones (carpalia). 
• Distal radioulnar joint (DRU joint); articulation between the distal radius and the distal ulna. 
• The triangular fibrocartilaginous complex (TFC complex), comprising the articular disc. This structure separates the radiocarpal joint from the DRU joint. 

Via the lunate fossa and the scaphoid fossa, the radius connects to both the lunate and scaphoid bones (fig. 9).
The DRU joint (together with the proximal radioulnar joint) facilitates the pronation and supination movement of the arm. The convex joint surface at the lateral side of the ulna communicates with the concave sigmoid notch on the radius (fig. 9).