MP joint arthritis is most common in the thumb and index fingers due to the stress of pinching. The different joints of the hand are shown in Figure 1. Arthritis means joint inflammation and is a word that is often used to describe pain or a problem at a joint.
Sep 02, 2010 · MP Joint. The MP joint of the thumb is the middle joint of the thumb, located between the CMC joint and the tip of the thumb. Break down the words in the name, metacarpophalangeal, and you get metacarpo-(hand bone) and phalangeal (finger bone). This joint moves a lot in some people and just a little in other people.
Metacarpophalangeal (MP) joint dislocations are rare injuries, which is primarily due to the strong connective tissue surrounding these joints and their basal location in the hand. 1 The index MP joint is most commonly affected, with the thumb MP joint ranking second in incidence. 2,3 Thumb MP dislocations usually occur in young, active individuals and the mechanism of injury in most cases is.
The fingers pinch and grip against the thumb which acts as a mechanical anatomic post. The thumb can forfill this function without a full range of motion. Therefore, a stiff thumb MP joint is not usually a functional problem. Even normal thumb MP joints can have an arc of motion that is les than 30 degrees.