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.