metakarpalbasen

The metacarpal base, or metakarpalbasen, refers to the proximal end of each metacarpal bone. There are five metacarpal bases, corresponding to the five metacarpals in the hand. Each base articulates with the distal row of carpal bones to form the carpometacarpal joints, enabling the hand’s movements and contributing to the stability of the palm.

Anatomy and articulation: The bases are generally broader than the distal ends and carry articular surfaces on their palmar (volar) and dorsal aspects for contact with the carpal bones. The exact pattern of articulation varies by metacarpal: the first metacarpal base primarily articulates with the trapezium; metacarpals II–V articulate with carpal bones in a way that involves the trapezium, trapezoid, capitate, and hamate to differing extents. These articulations form a series of carpometacarpal joints, which are important for the range of motion and grip.

Relationships and function: The metacarpal bases anchor the proximal ends of the metacarpals and contribute to the hand’s transverse and longitudinal arches. They serve as attachment sites for ligaments and soft tissues that stabilize the carpometacarpal joints and help distribute axial load transferred from the fingers to the wrist.

Clinical relevance: Injuries to the metacarpal bases, such as fractures or dislocations, can disrupt carpometacarpal joint stability and may require radiographic assessment and appropriate management. Treatment depends on the degree of displacement and the specific metacarpal involved.