Breaking strength and bone microarchitecture in osteoporosis: a biomechanical approximation based on load tests in 104 human vertebrae from the cervical, thoracic, and lumbar spines of 13 body donors

Abstract

Background The purpose of the study was to investigate associations between biomechanical resilience (failure load, failure strength) and the microarchitecture of cancellous bone in the vertebrae of human cadavers with low bone density with or without vertebral fractures (VFx). Methods Spines were removed from 13 body donors (approval no. A 2017-0072) and analyzed in regard to bone mineral density (BMD), Hounsfield units (HU), and fracture count (Fx) with the aid of high-resolution CT images. This was followed by the puncture of cancellous bone in the vertebral bodies of C2 to L5 using a Jamshidi™ needle. The following parameters were determined on the micro-CT images: bone volume fraction (BVF), trabecular thickness (Tb.Th), trabecular separation (Tb.Sp), degree of anisotropy (DA), trabecular number (Tb.N), trabecular pattern factor (Tb.Pf), and connectivity density (Conn.D). The axial load behavior of 104 vertebral specimens (C5, C6, T7, T8, T9, T12, L1, L3) was investigated with a servohydraulic testing machine. Results Individuals with more than 2 fractures had a significantly lower trabecular pattern factor (Tb.Pf), which also proved to be an important factor for a reduced failure load in the regression analysis with differences between the parts of the spine. The failure load (FL) and endplate sizes of normal vertebrae increased with progression in the craniocaudal direction, while the HU was reduced. Failure strength (FS) was significantly greater in the cervical spine than in the thoracic or lumbar spine (p < 0.001), independent of sex. BVF, Tb.Th, Tb.N, and Conn.D were significantly higher in the cervical spine than in the other spinal segments. In contrast, Tb.Sp and Tb.Pf were lowest in the cervical spine. BVF was correlated with FL (r = 0.600, p = 0.030) and FS (r = 0.763, p = 0.002). Microarchitectural changes were also detectable in the cervical spine at lower densities. Conclusions Due to the unique microarchitecture of the cervical vertebrae, fractures occur much later in this region than they do in the thoracic or lumbar spine. Trial registration Approval no. A 2017-0072.

Regional Variations in the Intra- and Intervertebral Trabecular Microarchitecture of the Osteoporotic Axial Skeleton with Reference to the Direction of Puncture

“…The Conn.D in the CC group was significantly higher in all quadrants of the CS than that in the TS or LS. This finding agrees with previous studies [ 8 , 24 ]. With the aid of a finite element model, Kinney und Ladd [ 25 ] investigated the association between connectivity density and the elasticity module of trabecular bone.…”

“…As the material properties of bone tissue are predetermined in the widest sense of the term, the dimensions of a vertebra may be viewed as a result of adjustments to internal and external forces acting on the vertebra. The load-bearing capacity of vertebrae increases with their size [ 24 ]. Indeed, the mere location of lumbar vertebrae causes them to be loaded to a greater extent because the effective physical load of the body acting on the vertebrae increases towards the caudal aspect [ 27 ].…”

MSCT-semiotics of vertebrae in patients with cervical spine stenosis

“…Изучение анатомии позвонков, их архитектоники, плотностных показателей крайне важно для решения вопроса о выборе метода лечения при любом характере хирургического вмешательства на позвоночнике, в том числе и при устранении стеноза шейного отдела позвоночника (СШОП). Определение качества кости имеет решающее значение для успеха лечения во многих случаях, но оно также является частью оптимальной хирургической подготовки к операции на позвоночнике [12,13].…”

“…Плотность кости, как важный фактор прочности, определяют различными методами, однако наиболее распространенным и универсальным является МСКТ с использованием стандартизированных единиц Хаунсфилда (HU), обеспечивая надежную оценку плотности кости, улучшая диагностические показатели [10,18,19]. Изучение анатомии, архитектоники, плотности позвонков проводят с промощью отдельных методов или комплексно, как в работе G. Schröder et al, где использованы микро-КТ и МСКТ [12]. Гистоморфометрическое исследование («золотой стандарт» изучения качества кости) в работе H.J.…”