Evaluation of the size and density of osteocyte lacunae in metastatic bone cores

Bone is one of the most common sites of metastases, which contribute to the alteration of mechano-sensation and mechano-transduction regulated by osteocytes, the most abundant cell type in bone. Investigating the effects of metastases at the microstructural level and understanding the relationship between the dimension and distribution of osteocyte lacunae in bone cores extracted from bones with metastases can be useful to understand their role in the formation and development of blastic tissue. The aim of this study was to evaluate the size and distribution of osteocyte lacunae in cores extracted from bone with metastases. Nine bone cores were extracted from lumbar vertebrae affected by blastic metastases and micro-CT scanned to investigate at microstructural level the microstructural properties and the properties of the osteocyte lacunae. The results obtained from the microstructural analysis showed that trabecular thickness (Tb.Th) an trabecular separation (Tb.Sp) resulted to be lower in this study when compared to studies based on healthy human bone cores. Similarly, the number of lacunae (N.Lc) resulted to be lower in this study when compared to studies based on cortical bone cores extracted from healthy human bones. Moreover, the total volume of lacunae (Lc.TV) and the density number of lacunae (N.Lc/TV) resulted to be higher in this study compared to other studies with similar values of number of lacunae but with healthy human bones. These results indicate that, since osteocytes, which are responsible for mechanotransduction and mechanosensation, are formed from osteoblasts which create new bone tissue, osteocytes lacunae could have a fundamental role in the development of metastases. In conclusion, the outcomes of this study highlight the importance of investigating microstructural parameters of osteocytes lacunae in bone cores extracted from vertebrae with blastic tissue to understand their role in the formation and development of blastic tissue.