Quantitative and qualitative assessment of the impact of osteoporosis on endplate layers

Abstract

The endplate (EP) is a composite structure made of osseous and cartilage components that separates the intervertebral disc from the vertebral body. As an intermediary link between rigid bone tissue and the flexible intervertebral disc, EP is affected by structural changes as well as changes in biomechanical properties of both these elements caused by pathological changes in the spine. One of the modern civilization hazards related to the skeletal system are osteoporotic changes. Although the influence of osteoporosis on vertebral bodies has been extensively researched, there is still a lack of information about its impact on the structure of the endplate itself. The aim of this study was to carry out a quantitative and qualitative assessment of the impact of osteoporosis on individual layers of EP.An animal model of the cervical and thoracic vertebrae was used. The analyses were conducted on two study groups: control (healthy sheep) and osteoporotic (with induced osteoporosis). Microstructural changes were analyzed using a micro-CT scanner, while mechanical parameters were analyzed using the microindentation test.There were no statistically significant differences in the analyzed parameters between cranial and caudal endplates. The performed tests showed significant changes in the trabecular microarchitecture of the endplate layer caused by osteoporosis. Despite the presence of morphometric changes in the osteoporotic group, no significant changes were observed in the mechanical properties of analyzed structures. A comparison of the mechanical parameters obtained for healthy endplates of the sheep model showed a high correlation with literature data for the human model.