Skeletal remineralization after surgery for primary and secondary hyperparathyroidism.

Bone mineral was measured by photon absorptiometry before and after parathyroid surgery in patients with primary or secondary hyperparathyroidism (HPT). The mean bone mineral density of lumbar vertebrae was 0.82 +/- 0.04 (SEM) gm/cm2 in primary HPT (n = 7) and 0.86 +/- 0.05 gm/cm2 in secondary HPT (n = 11). These values are significantly lower than for age-matched normal subjects. After successful parathyroid surgery, the bone mass of the distal radius and lumbar vertebrae increased by approximately 10% within 3 months after operation and then remained stable during the first postoperative year. In conclusion, parathyroid surgery is followed by a significant increase of bone mass in primary and secondary HPT. The substantial increase in bone mass in parts of the skeleton consisting predominantly of trabecular bone, as well as in sites with predominantly cortical bone, indicates that remineralization after operation involves a generalized increase in bone mass.