A Posterior View Of A Metacarpal Bone's Base

Description

Metacarpal base anatomy dominates this posterior (dorsal) view, emphasizing the broad proximal epiphysis that forms the carpometacarpal (CMC) articulation with the distal carpal row. The dorsal surface lies opposite the palmar aspect of the hand, with the metacarpal shaft extending distally and narrowing toward the neck and head beyond the frame. Along the proximal margin, the articular facets sit superiorly and proximally for the carpal bones, while smaller medial and lateral facets may be present for intermetacarpal joints with adjacent metacarpal bases, depending on which ray is represented. Dorsal tuberosity contours and roughened zones for capsuloligamentous attachment are readable in relief. Dorsal base morphology is a practical landmark in hand trauma and reconstructive planning because CMC fracture-dislocations often propagate through the base’s articular surface and destabilize the dorsal ligament complex before volar structures fail. Thumb-base injuries (Bennett and Rolando fracture patterns) hinge on the geometry of the first metacarpal base, whereas the second and third metacarpal bases provide rigid central pillar support at the index and long finger CMC joints, a common teaching point when contrasting mobility across the ulnar rays. Fine surface modeling helps you distinguish true articular cartilage boundaries from nonarticular dorsal roughening where dorsal CMC ligaments and, in specific rays, extensor carpi radialis longus or brevis and extensor carpi ulnaris insert. Orientation is unambiguous. Use this illustration in upper-limb gross anatomy labs to anchor CMC joint orientation, in orthopedic and hand-surgery teaching files discussing CMC instability and base fractures, and in medical publishing where a dorsal operative approach to the CMC region needs a precise bony reference. Anatomical accuracy verified by SciePro's Medical Advisory Board.