Scaphoid bone

The scaphoid bone /ˈskæfɔɪd/ (from the Greek word scaphoides, boat-shaped) is one of the carpal bones of the wrist. It is situated between the hand and forearm on the thumb side of the wrist (also called the lateral or radial side). It forms the radial border of the carpal tunnel. The scaphoid bone is the largest bone of the proximal row of wrist bones, its long axis being from above downward, lateralward, and forward. It is approximately the size and shape of a medium cashew.

Structure

The scaphoid is situated between the proximal and distal rows of carpal bones. It is located on the radial side of the wrist, and articulates with the radius, lunate, trapezoid, trapezium and capitate. Over 80% of the bone is covered in articular cartilage.

Bone

The palmar surface of the scaphoid is concave, and forming a tubercle, giving attachment to the transverse carpal ligament. The proximal surface is triangular, smooth and convex, and articulates with the radius and adjacent carpal bones, namely the lunate, capitate, trapezium and trapezioid. The lateral surface is narrow and gives attachment 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 alongside the lunate with the head of the capitate bone.