The nerves of your hand and wrist originate within the structure known as the brachial plexus which is located proximally in the basis of the neck and axillary region. Boutonniere Deformity: The MCP (metacarpophalangeal) joints as well as the DIP (distal interphalangeal) joints are impacted.  The key destruction would be to flexion https://www.theorthopaedicandpainpractice.com/what-are-the-different-bones-found-in-my-hand/