The Diagnostic Implications of Two Cases of Known Rheumatoid Arthritis from the CAL Milano Cemetery Skeletal Collection

Rheumatoid arthritis (RA) is the most common erosive arthropathy and is of particular interest to forensic sciences. However, its diagnosis on bones remains challenging. We examined two skeletons from the CAL Milano Cemetery Skeletal Collection diagnosed with the pathology during life, to test the validity of the diagnostic criteria on bones. The first showed typical lesions of RA described in the literature. The second exhibited secondary osteoarthrosis, suggesting long-standing RA. A differential diagnosis including all four seronegative spondyloarthropathies, erosive osteoarthritis, gout and neuropathic arthropathy was also considered. Both shared common features consistent with the literature: symmetric erosions of bones in the hands, wrists and elbows, sparing of the distal interphalangeal joints, and the absence of sacroiliac and spinal fusion. Given the paucity of studies on known RA skeletons, these results strengthen the criteria for diagnosis. This research is, to our knowledge, the first study on identified and known individuals with RA.