Greenwood C, Clement J G, Dicken A J, Evans J P O, Lyburn I D, Martin R M, Rogers K D, Stone N, Adams G, Zioupos P
Cranfield Forensic Institute, Cranfield University, Defence Academy of the UK, Shrivenham, UK.
Forensic Odontology, Melbourne Dental School, University of Melbourne, Melbourne, Australia.
Bone Rep. 2015 Oct 5;3:67-75. doi: 10.1016/j.bonr.2015.10.001. eCollection 2015 Dec.
Osteoporosis is clinically assessed from bone mineral density measurements using dual energy X-ray absorption (DXA). However, these measurements do not always provide an accurate fracture prediction, arguably because DXA does not grapple with 'bone quality', which is a combined result of microarchitecture, texture, bone tissue properties, past loading history, material chemistry and bone physiology in reaction to disease. Studies addressing bone quality are comparatively few if one considers the potential importance of this factor. They suffer due to low number of human osteoporotic specimens, use of animal proxies and/or the lack of differentiation between confounding parameters such as gender and state of diseased bone. The present study considers bone samples donated from patients (n = 37) who suffered a femoral neck fracture and in this very well defined cohort we have produced in previous work fracture toughness measurements (FT) which quantify its ability to resist crack growth which reflects directly the structural integrity of the cancellous bone tissue. We investigated correlations between BV/TV and other microarchitectural parameters; we examined effects that may suggest differences in bone remodelling between males and females and compared the relationships with the FT properties. The data crucially has shown that TbTh, TbSp, SMI and TbN may provide a proxy or surrogate for BV/TV. Correlations between FT critical stress intensity values and microarchitecture parameters (BV/TV, BS/TV, TbN, BS/BV and SMI) for osteoporotic cancellous tissue were observed and are for the first time reported in this study. Overall, this study has not only highlighted that the fracture model based upon BMD could potentially be improved with inclusion of other microarchitecture parameters, but has also given us clear clues as to which of them are more influential in this role.
骨质疏松症是通过使用双能X线吸收法（DXA）测量骨矿物质密度进行临床评估的。然而，这些测量并不总能提供准确的骨折预测，这可能是因为DXA无法处理“骨质量”问题，骨质量是微观结构、纹理、骨组织特性、既往负荷史、材料化学以及骨对疾病反应的生理状态等多种因素综合作用的结果。如果考虑到这个因素的潜在重要性，针对骨质量的研究相对较少。由于人类骨质疏松标本数量少、使用动物替代物和/或缺乏对诸如性别和患病骨状态等混杂参数的区分，这些研究受到了影响。本研究考虑了从股骨颈骨折患者（n = 37）捐赠的骨样本，在这个定义明确的队列中，我们在之前的工作中进行了断裂韧性测量（FT），该测量量化了其抵抗裂纹扩展的能力，直接反映了松质骨组织的结构完整性。我们研究了骨体积分数（BV/TV）与其他微观结构参数之间的相关性；我们研究了可能表明男性和女性骨重塑差异的影响因素，并比较了与FT特性的关系。至关重要的是，数据表明骨小梁厚度（TbTh）、骨小梁间距（TbSp）、结构模型指数（SMI）和骨小梁数量（TbN）可能为BV/TV提供替代指标。观察到骨质疏松松质组织的FT临界应力强度值与微观结构参数（BV/TV、骨表面积与体积比（BS/TV）、TbN、骨表面积与骨体积比（BS/BV）和SMI）之间的相关性，本研究首次报告了这些相关性。总体而言，本研究不仅强调了基于骨密度的骨折模型可能通过纳入其他微观结构参数而得到潜在改进，而且还为我们提供了关于其中哪些参数在这一作用中更具影响力的明确线索。
