Bone Material Strength Index as Measured by Impact Microindentation is Low in Patients with Primary Hyperparathyroidism

Manuela Schoeb 1Elizabeth M Winter 1Maria A Sleddering 1Mirjam A Lips 1Abbey Schepers 2Marieke Snel 1Natasha M Appelman-Dijkstra 1

J Clin Endocrinol Metab. 2021 Jun 16;106(7):e2527-e2534. doi: 10.1210/clinem/dgab207.

PMID: 33780545 PMCID: PMC8266436 DOI: 10.1210/clinem/dgab207

Context: In primary hyperparathyroidism (PHPT) bone mineral density (BMD) is typically decreased in cortical bone and relatively preserved in trabecular bone. An increased fracture rate is observed however not only at peripheral sites but also at the spine, and fractures occur at higher BMD values than expected. We hypothesized that components of bone quality other than BMD are affected in PHPT as well.

Objective: To evaluate bone material properties using impact microindentation (IMI) in PHPT patients.

Methods: In this cross-sectional study, the Bone Material Strength index (BMSi) was measured by IMI at the midshaft of the tibia in 37 patients with PHPT (28 women), 11 of whom had prevalent fragility fractures, and 37 euparathyroid controls (28 women) matched for age, gender, and fragility fracture status.

Results: Mean age of PHPT patients and controls was 61.8 ± 13.3 and 61.0 ± 11.8 years, respectively, P = .77. Calcium and PTH levels were significantly higher in PHPT patients but BMD at the lumbar spine (0.92 ± 0.15 vs 0.89 ± 0.11, P = .37) and the femoral neck (0.70 ± 0.11 vs 0.67 ± 0.07, P = .15) were comparable between groups. BMSi however was significantly lower in PHPT patients than in controls (78.2 ± 5.7 vs 82.8 ± 4.5, P < .001). In addition, BMSi was significantly lower in 11 PHPT patients with fragility fractures than in the 26 PHPT patients without fragility fractures (74.7 ± 6.0 vs 79.6 ± 5.0, P = .015).

Conclusion: Our data indicate that bone material properties are altered in PHPT patients and most affected in those with prevalent fractures. IMI might be a valuable additional tool in the evaluation of bone fragility in patients with PHPT.

Keywords: Bone Material Strength index (BMSi); bone quality; fractures; impact microindentation (IMI); osteoporosis; primary hyperparathyroidism.

Scroll to Top

This website uses cookies to enhance the user experience. By using this site you agree to our privacy policy

This website uses cookies to enhance the user experience. By using this site you agree to our privacy policy