Hyperparathyroidism – Phalanges (Rad) Fig. 23.57 Primary hyperparathyroidism: Phalanges showing gross subperiosteal bone resorption (with appearance after healing for comparison). Bony changes are now evident radiologically in a minority of patients with primary hyperparathyroidism. Subperiosteal bone resorption is the earliest radiological sign and is specific for hyperparathyroidism. Generalised skeletal demineralisation is a late finding. The film (a) of the middle and distal phalanges of the index finger shows gross subperiosteal bone resorption of the shafts of the phalanges and also of the tip of the distal phalanx. The bone density is decreased and the texture of the cortex shows a ‘basket-work’ pattern with loss of definition of the normal corticomedullary junction.