The most important joint connecting the wrist to the metacarpus, osteoarthritis of the TMC is a severely disabling condition; up to twenty times more common among elderly women than in average.

If the first metacarpal fails to sit well 'on the saddle', for example because of hypoplasia, the first CMC joint tends to be subluxated (i.e. slightly displaced) towards the radius.

[1] The capsule is sufficiently slack to allow a wide range of movements and a distraction of roughly 3 mm, while reinforcing ligaments and tendons give stability to the joint.

[7] The interosseous ligaments consist of short, thick fibers, and are limited to one part of the carpometacarpal articulation; they connect the contiguous inferior angles of the capitate and hamate with the adjacent surfaces of the third and fourth metacarpal bones.

The movements permitted in the second through fifth carpometacarpal joints most readily observable in the (distal) heads of the metacarpal bones.

The second and third joints are however almost essentially immobile and can be considered to have zero degrees of freedom in practice, but capable of anteroposterior gliding (translation) movements.

[8] The function of the finger carpometacarpal joints and their segments overall is to contribute to the palmar arch system together with the thumb.

Together, these arches allow the palm and the digits to conform optimally to objects as we grasp them (so-called palmar cupping).

The deep transverse metacarpal ligament stabilises the mobile parts of the palmar arch system.

The stability of these two carpometacarpal joints is a functional adaptation that enhances the efficiency of these muscles at the midcarpal and wrist.

Occasionally, the joint between the hamate and the fourth and fifth metacarpal bones has a separate synovial membrane.