Thyroid acropachy: hand radiograph showing periosteal reaction and clubbing.
The coned view (b) of the thumb and first metacarpal better demonstrates the characteristic lace-like appearance of the periosteal reaction. Besides the typical involvement of the first metacarpal, periosteal new bone formation may also occur along the shafts of other metacarpals and the proximal phalanges. In this patient, a slight periosteal reaction is also present along the shaft of the proximal phalanx of the thumb.
