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# CMC vs MCP

# 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.

||| **Please take photos in the supplier app of the tissue as it is unwrapped/prior to processing. This allows JRF to collect feedback for recovery groups.**




![Figure 1: Right Hand/Wrist Bones Overview](https://storage.crisp.chat/users/helpdesk/website/45175be43c538400/hand-v3_893yg9.jpg)

**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.


![Figure 2: Palmer view (supine) of a processed right 1st (thumb) CMC Joint](https://storage.crisp.chat/users/helpdesk/website/45175be43c538400/right-1st-cmc_bgfjb1.jpg)


**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.

![Figure 3: Palmer view (supine) of a processed right 1st (thumb) MCP Joint](https://storage.crisp.chat/users/helpdesk/website/45175be43c538400/right-1st-mcp_1qkyjrv.jpg)