Five carpometacarpal joints are present in each hand. The first CMC joint or joint of the thumb is in the shape of a saddle and the rest four are synovial elliptical joints.
The articulation happens between the carpus and metacarpal bones, which are second to fifth.
The carpometacarpal joint also called trapeziometacarpal joint plays an important role in the normal activity of the thumb. It must be acknowledged that most of the human hand activity depends on the movements of the thumb and index finger. Thus, it can be said that this joint is very crucial for the functioning of the hand.
The three distinct ligaments, namely, lateral, anterior (Palmar), and posterior (Dorsal) hold the joints in place.
Lateral Ligament: It runs between the lateral side of the trapezium and the radial side of the metacarpal base.
Anterior and Posterior Ligaments: These are oblique bands that converge to the ulnar side of the metacarpal base.
In addition, we can also find a strong fibrous capsule that is known to add stability to this joint.