The use of in vivo impact microindentation to measure bone material strength in postmenopausal women with recent atypical fractures may not have predictive value to identify fracture risk, according to study results published in the Journal of Bone and Mineral Research.
Researchers conducted a cross-sectional study of 153 postmenopausal women with recent atypical femoral or hip fractures, including women with and without long-term bisphosphonate use. Long-term use was defined as taking oral or intravenous bisphosphonates for >5 years. Investigators measured bone material strength via impact microindentation to ascertain whether cortical bone tissue features differed in patients with fractures.
After statistical analysis, investigators found that bone material strength index measures were comparable across all patients, with no differences seen in bisphosphonate users vs non-bisphosphonate users. In addition, strength index values were not altered with changes in duration of bisphosphonate treatment, age, or vitamin D level.
Primary study limitations included the cross-sectional design and small sample size.
“Our results do not support clinical use of impact microindentation to identify those at risk for atypical femoral fractures. This remains to be verified in larger studies,” the researchers wrote.
Further studies are needed to fully investigate the links among impact microindentation, bisphosphonate use, and fracture risk.
Popp KL, Caksa S, Martinez-Betancourt A, et al. Cortical bone material strength index and bone microarchitecture in postmenopausal women with atypical femoral fractures [published online October 3, 2018]. J Bone Miner Res. doi:10.1002/jbmr.3590