CMC vs MCP Joints

This Job Aid is available to help with identifying hand/wrist grafts that are sent for processing already dissected, and to help guide the dissection for tissue sent as whole hand/wrist en-blocs.

Carpometacarpal (CMC) Joint

• The five joints in the wrist that articulate the distal row of carpal bones and the proximal bases of the five metacarpal bones.
• Where the wrist meets the hand
• Note the knobby/club-like shape of the metacarpal head (figure 2). This is distinct from the more trochlear/condylar shape ​of the proximal phalanx head found at the most distal component of the MCP graft (figure 3).
• Note the articular surface of the trapezium bone.
• The most commonly requested CMC joint is that of the thumb (1st digit). This graft comes from the thumb-pad area of the palm of the hand and the wrist.

Metacarpophalangeal (MCP) Joint

• Situated between the metacarpal bones and the proximal phalanges of the fingers.
• Where the fingers meet the hand
• Note the trochlear/condylar shape of the proximal phalanx head (figure 3). This is distinct from the more knobby/club-like shapes of the metacarpal heads found at the most distal component of the CMC graft (figure 2).
• The MCP Joint is centered around the first knuckle of the target digit. This graft will include the bones proximal (metacarpal) and distal (phalange) to that first knuckle.

Updated on: 13/01/2022