What are the skeletal ramifications of hyperparathyroidism?
Osteitis fibrosa cystica represents the classic skeletal sequelae of prolonged advanced hyperparathyroidism from any cause. It most commonly occurs in patients with hyperparathyroidism associated with end-stage renal disease and is diagnosed by x-ray findings that are most prominent in the hands. Subperiosteal resorption with a blurring of the cortical margins on the radial side of the phalanges is seen, accompanied by a decrease in bone diameter and resorption of the tufts of the distal phalanges ( Fig. 48.4 ). Diffuse osteopenia is common, and erosions may be seen in the joints of the hands, axial skeleton, and at the ends of the clavicles. Bone resorption may lead to reactive osteoid deposition at the vertebral sub-endplates resulting in sclerotic bands on spinal radiographs. The alternating sclerotic and radiolucent areas mimic the stripes of a rugby jersey ( rugger-jersey spine; most common in secondary hyperparathyroidism). Discrete lytic lesions due to focal aggregates of osteoclastic giant cells and fibrous tissue with decomposing blood may occur and are known as brown tumors (more common in primary and tertiary hyperparathyroidism). Spinal compression fractures are common.
