Scaphoid Bone

Key Features & Anatomical Relations

The scaphoid bone (navicular bone) is one of the eight carpal bones of the hand. It’s boat-shaped and is the largest bone in the proximal row of carpal bones. It’s classified as a short bone and includes the following bony features:

- part: tubercle;

- surfaces: palmar and dorsal surfaces;

- landmarks: radial, lunate, capitate, trapezoid, and trapezium articular facets.

More information regarding these bony features can be found in the Parts, Surfaces and Landmarks tabs for this bone.

The scaphoid bone is located:

- proximal to the trapezoid and trapezium bones;

- distal to the radius;

- lateral to the lunate and capitate bones.

It articulates with the:

- radius at the radioscaphoid joint, contributing to the formation of the radiocarpal (wrist) joint;

- lunate bone at the scapholunate joint;

- capitate bone at the scaphocapitate joint;

- trapezoid bone at the scaphotrapezoid joint;

- trapezium bone at the scaphotrapezium joint.

Ossification

Ossification of the scaphoid bone occurs at one ossification center, which appears within the fourth to fifth years (Standring, 2016). Complete ossification occurs during early adolescence.

Variations

In some individuals:

- the scaphoid bone may be present in a bipartite condition (i.e., divided into two parts);

- an accessory bone, known the os centrale, may be present between the scaphoid, capitate and trapezoid bones (Tubbs, Shoja and Loukas, 2016).

Surface Anatomy

The following bony features of the scaphoid bone are relevant to surface anatomy:

- The dorsal surface of scaphoid bone can be palpated in the anatomical snuffbox, distal to the radial styloid process.

- The tubercle of scaphoid bone can be palpated proximal to the thenar eminence during extension of the wrist joint.

List of Clinical Correlates

- Fracture of scaphoid bone (most commonly fractured carpal bone)

- Avascular necrosis of scaphoid bone (secondary to fracture)

- Scaphoid aplasia

- Preiser’s disease

References

Standring, S. (2016) Gray's Anatomy: The Anatomical Basis of Clinical Practice. Gray's Anatomy Series 41st edn.: Elsevier Limited.

Tubbs, R. S., Shoja, M. M. and Loukas, M. (2016) Bergman's Comprehensive Encyclopedia of Human Anatomic Variation. Wiley.