Capitate

Original Editor- Mande Jooste

Top Contributors - Mande Jooste, Kim Jackson, Leana Louw, Nina Myburg and Carina Therese Magtibay

Description

Latin: "Os capitatum"

Capitate (derived from the latin word caput that means 'head') is the largest and most central carpal bone, that forms the wrist.

Structure/location

The capitate can be found in the distal row of carpal bones, where it articulates with the bases of the 2nd and 3rd metacarpal bones forming part of the common carpometacarpal joint.

The carpal bones are connected with inter carpal ligaments and the superiorly the capitate is covered by the flexor retinaculum.

Function

Articulations

The capitate articulates with seven other bones:

• Proximal surface: Scaphoid and Lunate
• Distal surface: base of 2nd and 3rd metacarpal; variably the capitate can also articulate with the base of the 4th metacarpal bone.
• Lateral surface: Trapezoid
• Medial surface: Hamate

Muscle attachments

M.adductor pollicis; oblique head

Clinical relevance

Due its anatomical location, isolated capitate injuries are uncommon. Fractures can be seen in association with scaphoid fractures, distal radius fractures or lunate injuries.

The capitate, similar to the scaphoid have limited blood flow, vascular necrosis should be ruled out post-injury.

Clinical features

Patient will complain of dorsal wrist pain, which will correspond with tenderness on palpation of the dorsal aspect. Pain can be increased with axial load of the 3rd metacarpal.