Which joints in the hand and wrist are usually affected by Rhemuatoid Arthritis?
RA tends to involve the proximal joints of the hand and wrist. One should pay close attention to the ulnar styloid to evaluate for erosions or subjacent soft tissue swelling, which may indicate presence of tenosynovitis of the extensor carpi ulnaris tendon.
Whereas OA commonly involves the DIP joints, RA tends to involve the metacarpophalangeal (MCP) and PIP joints, as well as the radiocarpal and carpal joints.
Advanced changes include joint malalignment such as ulnar deviation at the MCP joints.
A swan neck deformity may occur due to tendon retraction causing extension at the PIP joint with simultaneous flexion at the DIP joint.
The reverse of this (i.e., flexion at the PIP joint and simultaneous extension at the DIP joint) may alternatively be seen, which is the so-called boutonnière (or buttonhole) deformity. End stage disease may present with carpal joint ankylosis (loss of joint spaces with bone fusion).
