Gull Wings and Mouse Ears

The recognition of the various patterns of arthritic destruction and the specific target areas involved, in each arthritic disorder, are the key factors used by the radiologist to make the correct diagnosis. The 1980 paper by William Martel and colleagues ¹ discussed the specific patterns of destruction that differentiate psoriatic arthritis (PA) from erosive osteoarthritis (EOA). Martel and his colleagues, at the University of Michigan, reported the findings in 84 patients who had either psoriatic arthritis or erosive osteoarthritis. The erosions on the distal surface of the distal interphalangeal joints (in patients with PA) have a characteristic appearance which suggests ‘mouse ears’ (Figure 1). Figure 1 Radiograph showing erosions of psoriatic arthritis (‘mouse ears’) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003076568/34c29fd5-5662-4e8f-b58c-badd7fa5d724/content/fig37_1_B.jpg"/>