The proximal ulna as an additional diagnostic feature of advanced rheumatoid arthritis

Rheumatoid arthritis (RA) is considered to be an uncommon condition in paleopathology, although several case studies have recently been published. These studies tend to focus on changes in the small joints of the hands and feet, which are the most diagnostic, though these skeletal elements are often poorly preserved in archaeological contexts. This study aims to highlight another common trait that has been observed in multiple cases of RA in the clinical and paleopathological record: erosive lesions on the proximal ulna. RA frequently affects the elbow in clinical cases, with erosions observable in the radial head, the proximal ulna, and the distal humerus, in the later stages of the disease. Lesions produced by RA in the proximal ulna demonstrate a remarkable consistency in appearance between paleopathological cases from different periods and places. Although overlooked, erosive lesions on the proximal ulna provide an important diagnostic indicator of RA and yields additional information concerning disease progression.