Ring and long digit radiograph in a patient with psoriatic arthritis. There is loss of the tuft to the ring finger (arrow), so called acroosteolysis. The long finger shows soft tissue swelling (asterisk) with severe joint space loss and erosions at the proximal interphalangeal (PIP) joint. The bone density is increased involving the proximal and middle phalanx to the long finger (ivory phalanx) related to periostitis, a characteristic feature of psoriatic arthritis. (Courtesy of Dr. A. Donovan)
