Each individual metacarpal contains a foundation, shaft along with a head. The medial and lateral surfaces of the metacarpals are concave, allowing attachment with the interossei muscles. Boutonniere Deformity: The MCP (metacarpophalangeal) joints and the DIP (distal interphalangeal) joints are influenced.  The first harm is always to flexion of the proximal https://www.theorthopaedicandpainpractice.com/what-are-the-different-bones-found-in-my-hand/