Partially reversible osteopenia after surgery for primary hyperparathyroidism.

Bone mineral content of the radius in 30 patients with primary hyperparathyroidism was determined by single-photon absorptiometry before and one year after the removal of a parathyroid adenoma. When compared with normal age- and sex-matched subjects, preoperative bone mineral content was decreased by more than 1 SD in 24 patients 3 cm from the styloid apophysis (distal site) and in 23 patients 8 cm from the styloid apophysis (proximal site). The decrease at the distal site, where there is more trabecular bone, was significantly greater than at the proximal site (74% +/- 13% of the normal mean vs 79% +/- 13%). Bone mineral content values were not different in the female and male populations. One year after surgery, the bone mineral content was significantly increased but was still lower than normal at both sites (81% and 84% of the normal mean, respectively). In some patients, seen up to three years after surgery, the bone mineral content remained lower than normal. We conclude that primary hyperparathyroidism causes an osteopenia that affects both cortical and trabecular bone and that is only partially reversible, even in the long term.