Evaluation of Modulus of Elasticity, Mineral Composition and Bone Mineral Density of Trabecular Bone L3- Vertebrae Samples Extracted From Mexican Men

Abstract

Extracted samples of L3 vertebrae, the healthy, osteopenic and osteoporotic from Mexican men, were fixed to carry out measurements of the modulus of elasticity (ME) and the minerals content, on the trabecular zone to study their behavior as a function of age.To determine the ME the immersion ultrasonic method (IUM) was used, X-ray dispersion was applied to know the chemical element concentration (Ca++, Na++, P, and Mg++) and computerized axial tomography (CAT) to obtain bone mineral density (BMD).The samples were organized in four groups by decade. The samples in the range of 30-39 years revealed: a normal BMD and a concentration [% w/w] between pairs of Ca++/P, Ca++/Mg++, P/Mg++ and Mg++/ Na ++ with correlation positive due to the strong dependence between them.The average ME results were: 2.79±0.326, 2.68±0.45, 2.66±0.43 and 2.70±0.397 [GPa] for each decade respectively. The ME profiles show a nonlinear behavior as a function of age, indicating a minimum value in the third decade, similar behavior is observed in the Ca++. An exponential behavior between ME and T-score was obtained. The plotted Ca++ and ME as a function of area showed a homogeneous distribution for the first and a non homogeneous for the second.

Biomechanical analysis of detachable duet screw to resist intraoperative screw loosening.

“…Multiple studies have elucidated a correlation between the mechanical characteristics of bone and the strength of screw xation, indicating that patients with lower bone density are at a heightened risk for screw loosening [8][9][10] . The mechanical characteristics of the vertebrae exhibit variability among individuals, particularly in those with osteoporosis [11] . Consequently, the utilization of screws for spinal correction surgery poses a formidable obstacle due to compromised bone quality.…”