VIDEO
CONTENT
QUIZ
MATERIALS
Quick Facts
Key Features
Ossification
Variations
Clinical Correlates
Quick Facts:
- Location: Situated in the hand.
- Bone Type: Classified as a short bone.
- Key Features: Features palmar and dorsal surfaces; has articular facets for the trapezium, scaphoid, and capitate bones.
- Articulations: Connects with the trapezium, scaphoid, capitate, and second metacarpal bones.
- Arterial Supply: Received from the dorsal carpal branch of radial and ulnar arteries.
The trapezoid bone, with its unique shape and articulations, plays a vital role in the mobility and stability of the hand. Its small size belies its importance in the complex functioning of the carpal structure, and its rarity in clinical issues such as fractures makes it a unique study in hand anatomy.
Key Features & Anatomical Relations:
- Shape and Position: Quadrilateral-shaped, smallest bone in the distal row of carpal bones.
- Surfaces: Includes palmar and dorsal surfaces.
- Landmarks: Articular facets for the trapezium, scaphoid, capitate, and second metacarpal.
- Location Relative to Other Bones: Proximal to the second metacarpal, distal to the scaphoid, medial to the trapezium, and lateral to the capitate.
- Joints Formed: Participates in forming the trapeziotrapezoidal, scaphotrapezoid, trapeziocapitate, and carpometacarpal joints.
Ossification:
- Ossification Center: Develops from one ossification center appearing around the fourth to fifth years of life.
- Complete Ossification: Occurs during early to middle adolescence.
Variations:
- Bipartite Condition: In some individuals, it may be divided into two parts.
- Accessory Bone: The presence of an os centrale between the scaphoid, capitate, and trapezoid bones is a variation.
Clinical Correlates:
- Fractures: Fracture of the trapezoid bone is extremely rare.
