Wüster Jonas, Hesse Bernhard, Rothweiler Rene, Bortel Emely, Gross Christian, Bakhtiyari Shima, King Andrew, Boller Elodie, Gerber Javier, Rendenbach Carsten, Fretwurst Tobias, Preissner Saskia, Heiland Max, Nelson Katja, Nahles Susanne
Department of Oral and Maxillofacial Surgery, Berlin Institute of Health, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany.
Xploraytion GmbH, Berlin, Germany.
Front Bioeng Biotechnol. 2023 Aug 25;11:1169385. doi: 10.3389/fbioe.2023.1169385. eCollection 2023.
Autologous bone transplantation is successfully used in reconstructive surgery of large/critical-sized bone defects, whereby the microvascular free fibula flap is still regarded as the gold standard for the reconstruction of such defects in the head and neck region. Here, we report the morphological and lacunar properties of patient-paired bone samples from eight patients from the jaw (AB; recipient site) and the fibula (FB; donor site) on the micron length-scale using Synchrotron µ-CT. Insights into differences and similarities between these bone structures could offer a better understanding of the underlying mechanism for successful surgical outcomes and might clear the path for optimized, nature-inspired bone scaffold designs. Spatial vessel-pore arrangements, bone morphology, fluid-simulation derived permeability tensor, osteocyte lacunar density, and lacunar morphology are compared. The orientation of the vessel system indicates a homogenous vessel orientation for AB and FB. The average mineral distance (50%) to the closest vessel boundary is higher in AB than in FB (the mean is 96 μm for AB vs. 76 μm for FB; = 0.021). Average osteocyte lacunar density is found to be higher in AB than in FB (mean 22,874 mm vs. 19,376 mm for FB; = 0.038), which might compensate for the high distance from the mineral to the nearest vessel. No significant differences in lacunar volume are found between paired AB and FB. A comparable vessel network and similar distribution of vessel porosity between AB and FB may allow the FB graft to exhibit a high regeneration potential when connected to AB, and this might correlate with a high osteoinductive and osteoconductive potential of FB when connected to AB. Since widely used and potent synthetic bone grafts exist, new insight into the bone structure of well-established autologous bone grafts, such as the free fibula flap, could help to improve the performance of such materials and therefore the design of 3D scaffolds.
自体骨移植已成功应用于大尺寸/关键尺寸骨缺损的重建手术，其中微血管游离腓骨瓣仍被视为头颈部此类缺损重建的金标准。在此，我们使用同步加速器μ-CT在微米长度尺度上报告了8例患者来自颌骨（AB；受区）和腓骨（FB；供区）的配对骨样本的形态和腔隙特性。深入了解这些骨结构之间的异同，有助于更好地理解手术成功的潜在机制，并可能为优化的、受自然启发的骨支架设计铺平道路。比较了空间血管-孔隙排列、骨形态、流体模拟得出的渗透率张量、骨细胞腔隙密度和腔隙形态。血管系统的方向表明AB和FB的血管方向均匀。AB中到最近血管边界的平均矿物质距离（50%）高于FB（AB的平均值为96μm，FB为76μm；P = 0.02）。发现AB中的平均骨细胞腔隙密度高于FB（FB的平均值为19376/mm²，AB为22874/mm²；P = 0.038），这可能补偿了矿物质到最近血管的高距离。配对的AB和FB之间在腔隙体积上没有显著差异。AB和FB之间可比的血管网络和相似的血管孔隙率分布可能使FB移植物在与AB连接时表现出高再生潜力，这可能与FB在与AB连接时的高骨诱导和骨传导潜力相关。由于存在广泛使用且有效的合成骨移植材料，对成熟的自体骨移植材料（如游离腓骨瓣）的骨结构的新见解，有助于提高此类材料的性能，从而有助于3D支架的设计。
