450 Formula Upper Extremity Practice Exam

Rheumatoid arthritis is an autoimmune inflammatory arthritis that most often targets the small joints of the hands and wrists in a symmetrical pattern. The ongoing inflammatory synovitis wears away cartilage and bone and pulls on ligaments and tendons, leading to characteristic deformities. In the wrist and fingers you see ulnar drift at the MCP joints, and finger deformities such as Boutonnière (PIP flexion with DIP hyperextension) and swan neck (PIP hyperextension with DIP flexion). The thumb’s CMC joint is also commonly involved, contributing to functional decline. This pattern—inflammatory, symmetric involvement of the hand and wrist joints with these specific deformities—distinguishes rheumatoid arthritis from wear-and-tear osteoarthritis, infectious arthritis, or conditions that primarily affect the spine. OA tends to be degenerative and focal; septic arthritis is an acute, rapidly destructive infection; and RA is a systemic inflammatory disease with prominent upper-extremity joint involvement.