Carpometacarpal joint#Thumb

The carpometacarpal joint ( trapezometacarpal joint of the thumb, carpometacarpal joint of the thumb ray ) is the saddle joint between the large trapezium ( trapezium ) and the first metacarpal bone. Because the saddle-shaped joint has joint surfaces, it can be moved in two axes, wherein the combination of these two axes, a mobility similar to a ball joint enables.

The carpometacarpal joint is stabilized by numerous bands whose number is specified depending on the author 5-16. Extensors of the thumb saddle joint are the extensor pollicis longus, extensor pollicis brevis of, the abductor pollicis longus ( simultaneously abductor ). Flexors of the flexor pollicis longus, flexor pollicis brevis of, the abductor pollicis brevis are ( simultaneously abductor ), musculus adductor pollicis (simultaneously also adductor ) and the musculus opponens pollicis ( simultaneously abductor ).

Arthrosis of the thumb saddle joint is referred to as the first carpometacarpal joint.