Overview
A boat-shaped bone, oriented oblique with its long axis aligned form the medial portion of hte distal radius. It is largest of the proximal row of carpal bones, located on the radial side of the lunate.
Structure
- Divided into proximal and distal poles, separated by a waist.
- The palmar surface is concave, forming a bony prominence on the lateral portion of the distal pole called the scaphoid tubercle. This gives attachment ot the transverse carpal ligament
- The lateral surface is narrow and gives attachement to the radial collateral ligament
- The medial surface has two facets: a flattened semi-lunar facet articulating with the lunate bone and an inferior concave facet, articulating with the lunate bone
- The inferior facet is concave, articulating with the lunate with the head of the capitate bone
- The dorsal surface of the bone is narrow, with a groove running the length of the bone and allowing ligaments to attach
- The scaphoid tubercle is a bony prominence on the ventral surface of the lateral portion of the distal pole.
Articulations
- Proximal surface: Radius
- Laterally: Trapezoid, trapezium
- Medially: Capitate, lunate
Arterial Supply
- Recurrent branch of radial artery – predominant supply
- Deep and superficial palmar arch – contributes
Notably, the proximal pole is perfused in a retrograde fashion, hence is vulnerable to avascular necrosis following fracture htrough the waist or tubercle
Ligamentous Attachments
- Dorsal surface: dorsal radiocarpal ligament
- Radial surface: radial collateral ligament
- Scapholunate ligament
- Radioscapholunate ligament
- Scaphocapitate ligament
- Transverse carpal ligament
Relations
- Superficially: Forms the floor of the anatomical snuffbox, thus radial artery, cephalic vein, superficial branch of the radial nerve, abductor pollicis longus and extensor pollicis longus.
Anatomical Variants
- Bipartite/tripartite scaphoid
- Coalition with neighbouring capral bones
- Scaphoid hypoplasia