INTEGRATED BIOMECHANICAL ASSESSMENT OF TRABECULAR BONE MICROARCHITECTURE AND MECHANICAL INTEGRITY IN TYPE 2 DIABETES MELLITUS

Abstract

Type 2 Diabetes Mellitus (T2DM) negatively impacts bone quality by modifying its microarchitecture and mechanical strength, resulting in an elevated fracture risk despite normal or increased bone mineral density (BMD). Traditional densitometric assessments frequently overlook these qualitative alterations. This work combines high-resolution micro-computed tomography (micro-CT) and biomechanical compression testing to thoroughly evaluate trabecular bone integrity in Indian persons with T2DM.

Micro-CT analysis was conducted on trabecular bone specimens from two healthy controls and three patients with type 2 diabetes mellitus. Quantitative morphometric metrics, such as trabecular thickness (Tb. Th), trabecular number (Tb. N), trabecular separation (Tb. Sp), structural model index (SMI), and degree of anisotropy (DA), were calculated utilising ImageJ and MATLAB. Samples from T2DM demonstrated diminished trabecular thickness (Tb.Th) and trabecular number (Tb.N), augmented trabecular separation (Tb.Sp) and degree of anisotropy (DA), alongside an enhanced structural model index (SMI), signifying a transition from plate-like to rod-like trabecular configurations and a decline in structural connectivity.

Complementary uniaxial compression tests were performed on cylindrical trabecular bone specimens from matched groups to assess yield strength. T2DM specimens exhibited a 24% decrease in average yield strength (3.66 ± 0.32 MPa) relative to healthy controls (4.8 ± 0.14 MPa). In the diabetic group, increased HbA1c and BMI levels were linked to diminished mechanical performance, indicating a robust association between microstructural degradation and impaired mechanical integrity.

The consolidated data affirm that T2DM induces microarchitectural deterioration and mechanical compromise of trabecular bone, which together result in diabetic bone fragility. These findings underscore that bone mineral