Skeletal effects of failed parathyroidectomy.

BACKGROUND: Parathyroidectomy improves bone mineral density and decreases risk for fracture in patients with primary hyperparathyroidism. The aim of this study was to determine skeletal consequences of failed parathyroidectomy.

METHODS: A retrospective, cohort study of patients with biochemically confirmed primary hyperparathyroidism within a vertically integrated health system was performed (1995-2014). Failed parathyroidectomy was defined by hypercalcemia within 6 months of initial parathyroidectomy. Time-varying Cox regression was used to estimate the risk for any fracture and hip fracture in 3 comparison groups: observation, successful parathyroidectomy, and failed parathyroidectomy. Bone mineral density changes also were compared.

RESULTS: The cohort included 7,169 patients, of whom 5,802 (81%) were observed, 1,228 underwent successful parathyroidectomy (17%), and 137 underwent failed parathyroidectomy (2%). The adjusted risk for any fracture (hazard ratio, 1.28; 95% confidence interval, 0.85-1.92) and hip fracture (hazard ratio, 1.63; 95% CI, 0.77-3.45) associated with failed parathyroidectomy was similar to that associated with observation. Successful parathyroidectomy was associated with a decrease in any fracture (hazard ratio, 0.68; 95% confidence interval, 0.57-0.82) and hip fracture (hazard ratio, 0.43; 95% confidence interval, 0.27-0.68) compared with observation. Bone mineral density changes in the failed parathyroidectomy group paralleled those associated with observation.

CONCLUSION: Failed parathyroidectomy is associated with a high risk for fracture similar to that seen with observation.