As a saddle joint allows the biaxial movements bending / stretching and Abspreizen / Anwinkeln. The saddle (carpometacarpal or trapeziometacarpal) joint of the thumb is the body's least stable joint.
3 While CMC arthroplasty and fusion are options for patients, they may not be optimal. The trapezium bone is shaped like a saddle in the area of the thumb saddle joint.
The bone sitting on the saddle can move in an oval shape relative to the other bone, similar to a condyloid joint. The thumb saddle joint is formed by the trapezium bone and the base of the first metacarpal bone. This carpometacarpal joint of the human thumb makes it opposable and allows it to span across the …
The carpometacarpal joint of the thumb, also known as the first carpometacarpal joint, or the trapeziometacarpal joint (TMC) because it connects the trapezium to the first metacarpal bone, plays an irreplaceable role in the normal functioning of the thumb. It is located roughly 1 inch (2.54 cm) above the wrist at the base of the thumb, between the carpal bones and the metacarpal bones. Thumb carpometacarpal (CMC) joint osteoarthritis (OA) is the second most common form of hand OA, affecting between 20% and 30% of the general population. It is called a saddle joint because of the way the concave surface of the proximal head of the metacarpal articulates or sits on the convex surface of the trapezium bone, much like a rider setting an English saddle. A saddle joint is a type of synovial joint in which the articular surfaces are reciprocally concavoconvex and resemble a saddle on a horse's back. Isolated thumb carpometacarpal (CMC) dislocations without any other concomitant injury are rare and account for <1% of all hand injuries.
There are five carpometacarpal joints in each hand.
The only synovial joint in the body with the distinction of being considered a saddle joint is the carpometacarpal (CMC) joint in the thumb.
The carpometacarpal (CMC) joints are five joints in the wrist that articulate the distal row of carpal bones and the proximal bases of the five metacarpal bones. 3 While CMC arthroplasty and fusion are options for patients, they may … What is the thumb saddle joint? Functionally and medically, first carpometacarpal joint is the most essential carpometacarpal joint and for this reason described in detail latter. 4,15,16 Demographic radiographic studies show a 6:1 female-to-male incidence of arthrosis of the trapeziometacarpal joint, although this difference decreases with age, with the incidence in women and men at age 75 years of 40% and 25%, respectively. The joint of the thumb is described at its own separate page Carpometacarpal joint – The best-known example of the saddle joint is the carpometacarpal joint of the thumb formed by trapezium bone sitting on the first metacarpal.
The only synovial joint in the body with the distinction of being considered a saddle joint is the carpometacarpal (CMC) joint in the thumb. There are five CMC joints in total, out of which the carpometacarpal joint of thumb (trapeziometacarpal joint) is the most specialized and flexible.
Learn about five procedures used to treat joint damage and pain caused by thumb arthritis.
This particular shape of the trapezium bone allows for great mobility in the thumb. The first carpometacarpal joint (Joint of the Thumb) is a saddle shaped joint while the remaining four are all synovial ellipsoid joints. 3 The thumb CMC joint is stabilized by its joint capsule and the palmar oblique, first intermetacarpal, dorsal radial, and posterior oblique ligaments. Carpometacarpal joint.
Joint pain stemming from the 1st CMC joint is one of the most common areas in the hand to develop arthritis, which is inflammation and pain resulting from cartilage loss. The distal surfaces of the carpals of distal row articulate with all the bases of metacarpals. The bone sitting on the saddle can move in an oval shape relative to the other bone, similar to a condyloid joint. 1,2 Thumb CMC joint OA is more prevalent in females than males, increases with age, and has been associated with hand pain and loss of functional hand use. The carpometacarpal joints are plane type of synovial joints with the exception of the carpometacarpal joint of the thumb, that is a saddle joint. The CMC of the thumb differs significantly from the other four CMCs and is therefore described separately.
Because of its relative instability, this joint is a frequent site for osteoarthritis.
The articulation takes place between the carpus and second to fifth metacarpal bones.