In early rheumatoid arthritis, inflammation leads to synovial hypertrophy and increased vascularity, causing periarticular osteopenia due to increased local bone resorption. Additionally, soft tissue swelling reflects active synovitis and joint effusion. These changes occur before overt joint space narrowing or erosions, making them key early radiographic signs. Other findings like joint space widening, osteosclerosis, or subchondral cysts appear in later stages or different conditions. Detecting these early signs facilitates prompt diagnosis and management to prevent joint destruction.

Reference: Rheumatology, Hochberg MC et al., 6th Edition.