Bone Abstracts

Background: Primary hyperparathyroidism (PHPT) drives PTH-mediated bone loss, with osteoporosis being a primary indication for parathyroidectomy (PTx). While PTx improves bone outcomes, the utility and timing of adjunctive anti-resorptive treatment (ART) remain unclear. This study evaluated real-world bone mineral density (BMD) outcomes across four distinct management pathways: PTx with pre-operative ART, PTx with post-operative ART, PTx alone, and non-surgical management.

Methods: Retrospective data were collected from 808 patients with PHPT at a single tertiary centre (20122024). Analysis was restricted to 370 patients with repeat DXA data (219 surgical, 151 non-surgical). Standardised proforma captured demographics, BMD (GE-Lunar iDXA), and ART history. Baseline fracture risk was estimated using the FRAX algorithm. Statistical analysis was performed using Prism v10.2.3.

Results: Within the surgical cohort, 114 patients received no ART, 46 received ART pre-operatively and 61 post-operatively. In the non-surgical group, 78 received ART. Non-surgical patients were the oldest with the highest fracture risk (77.4±8.7y, FRAX MOF 21.8±9.1%, P 0.001), while non-ART surgical patients were the youngest and lowest risk (57.4±15.2y, FRAX MOF 7.4±5.1% P 0.001). Pre- and post-operative ART cohorts were age and risk-matched (67.8±9.5y, FRAX MOF 16.9±8.1% vs 69.8±10.4y FRAX MOF18.4±10.1% ). Baseline BMD at lumbar spine, total hip, and distal radius were lower in all ART-treated patients compared to the surgery only cohort (P 0.001). Longitudinal analysis showed lumbar spine BMD improved across all surgical groups, with the greatest gains in the pre-operative ART cohort (4.1%), followed by post-operative ART (3.1%) and surgery alone (2.1%). Non-surgical ART patients showed the smallest gains (1.9%). At the total hip, changes were modest, though non-surgical ART patients experienced a BMD decline (3.5%).

Conclusion: Parathyroidectomy seems to be the primary driver of lumbar spine BMD recovery, outperforming non-surgical management. Although the pre-operative ART cohort showed the greatest numerical gain, the data suggests that the timing of anti-resorptive initiation, either pre- or post-operatively, does not fundamentally alter the skeletal recovery achieved after surgical cure. Consequently, ART timing should be dictated by individual fracture risk and clinical logistics rather than concerns over timing-dependent efficacy.