Osteocytes are capable of remodeling their perilacunar bone matrix, which causes considerable variations in the shape and size of their lacunae. If these variations in lacunar morphology cause changes in the mechanical environment of the osteocytes, in particular local strains, they would subsequently affect bone mechanotransduction, since osteocytes are likely able to directly sense these strains. The purpose of this study is to quantify the effect of alterations in osteocyte lacunar morphology on peri-lacunar bone tissue strains. To this end, we related the actual lacunar shape in fibulae of six young-adult (5-month) and six old (23-month) mice, quantified by high-resolution micro-computed tomography, to microscopic strains, analyzed by micro-finite element modeling. We showed that peak effective strain increased by 12.6% in osteocyte cell bodies (OCYs), 9.6% in pericellular matrix (PCM), and 5.3% in extra cellular matrix (ECM) as the lacunae volume increased from 100-200 μm³ to 500–600 μm³. Lacunae with a larger deviation (>8°) in orientation from the longitudinal axis of the bone are exposed to 8% higher strains in OCYs, 6.5% in PCM, 4.2% in ECM than lacunae with a deviation in orientation below 8°. Moreover, increased lacuna sphericity from 0 to 0.5 to 0.7–1 led to 25%, 23%, and 13% decrease in maximum effective strains in OCYs, PCM, and ECM, respectively. We further showed that due to the presence of smaller and more round lacunae in old mice, local bone tissue strains are on average 5% lower in the vicinity of lacunae and their osteocytes of old mice compared to young. Understanding how changes in lacunar morphology affect the micromechanical environment of osteocytes presents a first step in unraveling their potential role in impaired bone mechanoresponsiveness with e.g. aging.

骨细胞能够重塑其腔周骨基质，这会导致其腔隙的形状和大小发生相当大的变化。如果腔隙形态的这些变化导致骨细胞的机械环境发生变化，特别是局部应变，它们随后会影响骨机械转导，因为骨细胞可能能够直接感知这些应变。本研究的目的是量化骨细胞腔隙形态改变对腔隙周围骨组织应变的影响。为此，我们将通过高分辨率显微计算机断层扫描量化的六只年轻（5 个月）和六只老（23 个月）小鼠腓骨中的实际腔隙形状与显微品系相关联，并通过显微分析进行了分析。有限元建模。我们发现峰值有效应变增加了 12。³至 500–600 μm ³. 与骨纵轴方向偏差较大 (>8°) 的腔隙与方向偏差低于 8° 的腔隙相比，OCY 的应变高 8%，PCM 的应变高 6.5%，ECM 的应变高 4.2%。此外，将腔隙球形度从 0 增加到 0.5 到 0.7-1，分别导致 OCY、PCM 和 ECM 的最大有效应变减少 25%、23% 和 13%。我们进一步表明，由于老年小鼠中存在更小和更圆的腔隙，与年轻小鼠相比，老年小鼠的腔隙及其骨细胞附近的局部骨组织应变平均低 5%。了解腔隙形态的变化如何影响骨细胞的微机械环境是解开它们在骨机械反应性受损（例如衰老）中的潜在作用的第一步。