Treatments of osteoporosis increase bone material strength index in patients with low bone mass

Abstract

Effects on bone material properties of two-year antiosteoporotic treatment were assessed using in vivo impact microindentation (IMI) in patients with low bone mineral density (BMD) values. Antiresorptive treatment, in contrast to vitamin D ± calcium treatment alone, induced BMD-independent increases in bone material strength index, measured by IMI, the magnitude of which depended on pretreatment values. Introduction Bone material strength index (BMSi), measured by IMI in vivo, is reduced in patients with fragility fractures, but there is no information about changes in values during long-term therapy. In the present study, we assessed changes in BMSi in patients receiving antiosteoporotic treatments for periods longer than 12 months. Methods We included treatment-naive patients with low bone mass who had a BMSi measurement with OsteoProbe® at presentation and consented to a repeat measurement after treatment. Results We studied 54 patients (34 women), median age 58 years, of whom 30 were treated with bisphosphonates or denosumab (treatment group) and 24 with vitamin D ± calcium alone (control group). There were no differences in clinical characteristics between the two groups with the exception of a higher number of previous fragility fractures in the treatment group. Baseline hip BMD and BMSi values were lower in the treatment group. After 23.1 ± 6.6 months, BMSi increased significantly in the treatment group (82.4 ± 4.3 vs 79.3 ± 4.1; p < 0.001), but did not change in the control group (81.5 ± 5.2 vs 82.2 ± 4.1; p = 0.35). Changes in BMSi with antiresorptives were inversely related with baseline values (r = − 0.43; p = 0.02) but not with changes in BMD. Two patients in the control group with large decreases in BMSi values sustained incident fractures. Conclusion In patients at increased fracture risk, antiresorptive treatments induced BMD-independent increases in BMSi values, the magnitude of which depended on pretreatment values.

Bone material strength index as measured by in vivo impact microindentation is normal in subjects with high-energy trauma fractures

“…Bone material strength index was measured in all patients by impact microindentation using the handheld microindenter device (OsteoProbe® RUO, Active Life Scientific, CA, USA) on the midshaft of the tibia as previously described [ 20 ]. In brief, the patient was placed in supine position with the tibia in external rotation to orient the flat surface of the medial tibia diaphysis in a horizontal position.…”

“…Each time the skin is pierced, the new first measurement is discarded. After at least five adequate measurements, five additional measurements were performed on a polymethylmethacrylate (PMMA) calibration phantom [ 12 , 20 – 23 ]. BMSi was calculated by the corresponding computer software.…”

Clinical Importance of Bone Matrix Damage Mechanisms for Fracture Prevention

“…OsteoProbe was recently used to assess the effect of ageing [ 17 ] and treatment [ 18 ] on the cortical bone matrix. In a study of cadaveric human tibia, 20 females ranging from 53 to 97 years were assessed and correlations between BMSi measures and cortical geometry ranged from very weak to very strong ( r 2 = 0.03 to 0.98) [ 17 ].…”

“…bisphosphonates or denosumab) versus a control group prescribed supplements (i.e. vitamin D) [ 18 ]. In the antiresorptive group, BMSi increased significantly from baseline to 2 years whilst the supplement group did not change.…”

Association between nanoscale strains and tissue level nanoindentation properties in age-related hip-fractures

“…It is better in examining localised bone properties at the microscale and the spatial heterogeneity of cross sections of bone considering that bone microstructural features are normally from a few tens to a few hundreds of μm (Rho et al, 1997(Rho et al, , 2002. It has also been used as a tool to determine the mechanical properties of bone, which result from the chemical quality of bone (Rho et al, 2002;Chevalier et al, 2007;Donnelly et al, 2010;Hengsberger et al, 2002) and in response to treatments (Karim et al, 2018;Schoeb, 2020). The diamond tip of the indenter interacts with bone to cause local yield by compression through a largely stable ductile loading mode which crushes bone and loads fibres by probably separating the fibril-fibril and mineral-fibril interfaces.…”