Lunate

Function

Moon-shaped centrepiece of the proximal carpal row. Sits in the wrist's cockpit, cradling the capitate's head and transferring forearm load through the radiolunate joint — the fulcrum of wrist motion.

Landmarks

• Concave facet for the capitate head
• Palmar and dorsal horns

Articulations (joints)

• Radius
• Scaphoid
• Triquetrum
• Capitate
• Hamate

Clinical relevance

Kienbock disease — idiopathic avascular necrosis of the lunate — causes progressive wrist collapse in young manual workers. Lunate dislocation (volar, the 'spilled teacup' sign) is the end stage of the perilunate injury spectrum.