Use and Implications of the Fracture Risk Assessment Tool in Primary Hyperparathyroidism

Although primary hyperparathyroidism (PHPT) increases the risk of osteoporotic fractures, estimation of fracture probability among patients with PHPT remains challenging. Use of the Fracture Risk Assessment Tool (FRAX) among these patients remains poorly characterized, and its utility in identifying patients who may experience fracture risk reduction following parathyroidectomy (PTX) remains unknown.

To examine the calibration of FRAX in adults with PHPT and to describe the association between estimated probability and differential fracture risk with PTX compared with nonsurgical management.

This retrospective cohort study was performed from January 1, 2000, to January 1, 2024, using the TriNetX electronic health record US dataset. Participants included adults aged 40 to 90 years with diagnosis or biochemistry findings consistent with PHPT, excluding those with missing or out-of-range FRAX parameters.

PTX vs nonsurgical management.

Observed major osteoporotic fracture (MOF) and hip fracture. Ten-year FRAX estimations of fracture probability were calculated without bone mineral density (BMD) findings.

Among 59 194 patients with PHPT (mean [SD] age, 65.9 [10.8] years; 44 540 [75.2%] female), 14 783 (25.0%) were treated with PTX. Observed MOF and hip fractures were slightly greater than estimated by FRAX for all deciles of risk, with an MOF calibration y-intercept of 2.0% and slope of 1.17 and hip fracture calibration y-intercept of 1.4% and slope of 1.02. Overall, PTX was associated with a 12% decrease in MOF (hazard ratio [HR], 0.88; 95% CI, 0.77-1.02) and a 13% decrease in hip fracture (HR, 0.87; 95% CI, 0.72-1.07). The MOF score above which PTX was associated with consistently lower MOF hazard was 1.2%, and the corresponding hip score above which PTX was associated with consistently lower hip fracture hazard was 2.7%. Of the cohort not meeting traditional guideline-based surgical criteria, 6522 (25.0%) met this hip score for consistent fracture reduction associated with PTX.

In this cohort study of US patients with PHPT, FRAX estimation exhibited acceptable performance. FRAX may effectively stratify fracture risk and inform surgical decision-making even in absence of BMD. A larger subset of patients than previously identified by guidelines may benefit from parathyroidectomy from the standpoint of fracture prevention.