Hulsen D J W, Geurts J, van Gestel N A P, van Rietbergen B, Arts J J
Department of Orthopaedic Surgery, Research School CAPHRI, Maastricht University Medical Centre, Maastricht, The Netherlands; Department of Orthopaedic Biomechanics, Faculty of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands; MICT Department, Jeroen Bosch Ziekenhuis, ׳s-Hertogenbosch, The Netherlands.
Department of Orthopaedic Surgery, Research School CAPHRI, Maastricht University Medical Centre, Maastricht, The Netherlands.
J Biomech. 2016 May 3;49(7):1121-1127. doi: 10.1016/j.jbiomech.2016.02.047. Epub 2016 Feb 26.
Bioactive Glass (BAG) granules are osteoconductive and possess unique antibacterial properties for a synthetic biomaterial. To assess the applicability of BAG granules in load-bearing defects, the aim was to compare mechanical behaviour of graft layers consisting of BAG granules and morselized cancellous bone allograft in different volume mixtures under clinically relevant conditions. The graft layers were mechanically tested, using two mechanical testing modalities with simulated physiological loading conditions: highly controllable confined compression tests (CCT) and more clinically realistic in situ compression tests (ISCT) in cadaveric porcine bone defects. Graft layer impaction strain, residual strain, aggregate modulus, and creep strain were determined in CCT. Graft layer porosity was determined using micro computed tomography. The ISCT was used to determine graft layer subsidence in bone environment. ANOVA showed significant differences (p<0.001) between different graft layer compositions. True strains absolutely decreased for increasing BAG content: impaction strain -0.92 (allograft) to -0.39 (BAG), residual strain -0.12 to -0.01, and creep strain -0.09 to 0.00 respectively. Aggregate modulus increased with increasing BAG content from 116 to 653MPa. Porosity ranged from 66% (pure allograft) to 15% (pure BAG). Subsidence was highest for allograft, and remarkably low for a 1:1 BAG-allograft volume mixture. Both BAG granules and allograft morsels as stand-alone materials exhibit suboptimal mechanical behaviour for load-bearing purpose. BAG granules are difficult to handle and less porous, whereas allograft subsides and creeps. A 1:1 volume mixture of BAG and allograft is therefore proposed as the best graft material in load-bearing defects.
生物活性玻璃（BAG）颗粒具有骨传导性，作为一种合成生物材料还具有独特的抗菌性能。为了评估BAG颗粒在承重缺损中的适用性，本研究旨在比较在临床相关条件下，由BAG颗粒和松质骨同种异体碎骨组成的移植层在不同体积混合比例下的力学行为。使用两种模拟生理负荷条件的力学测试方式对移植层进行力学测试：高度可控的受限压缩试验（CCT）和在猪尸体骨缺损中更接近临床实际的原位压缩试验（ISCT）。在CCT中测定移植层的冲击应变、残余应变、聚合模量和蠕变应变。使用微型计算机断层扫描确定移植层孔隙率。ISCT用于确定移植层在骨环境中的下沉情况。方差分析显示不同移植层组成之间存在显著差异（p<0.001）。随着BAG含量的增加，真实应变绝对降低：冲击应变从-0.92（同种异体骨）降至-0.39（BAG），残余应变从-0.12降至-0.01，蠕变应变分别从-0.09降至0.00。聚合模量随着BAG含量的增加从116MPa增加到653MPa。孔隙率范围从66%（纯同种异体骨）到15%（纯BAG）。同种异体骨的下沉最高，而对于1:1的BAG-同种异体骨体积混合物则非常低。单独作为材料使用时，BAG颗粒和同种异体骨碎块在承重方面均表现出不理想的力学行为。BAG颗粒难以操作且孔隙较少，而异种异体骨会下沉和蠕变。因此，建议将BAG和同种异体骨1:1的体积混合物作为承重缺损中最佳的移植材料。
