Differences in osteonal micromorphology between tensile and compressive cortices of a bending skeletal system: Indications of potential strain-specific differences in bone microstructure

Background: It has been hypothesized that bone has the capacity to accommodate regional differences in tension and compression strain mode and/or magnitude by altering its osteonal microstructure. We examined a simple cantilevered bone to determine whether regional differences in particular strain-related features are reflected in the microstructural organization of compact bone. Methods & Results: The artiodactyl (e.g., sheep and deer) calcaneus has a predominant loading condition which is typified by prevailing compressive and tensile strains on opposite cortices, and variations in strain magnitudes across each of these cortices. Microscopic examination showed osteon density and cortical porosity differences between tension (caudal) and compression (cranial) cortices, averaging 11.4% more osteons in the compression cortex (P < 0.01) and 80.2% greater porosity in the tension cortex (P < 0.01). There is 43.5% more interstitial bone in the compression cortex (P < 0.01). Osteons in the compression cortex also have smaller areas in contrast to the larger area per osteon in the tension cortex. Although no definite transcortical gradient in osteonal density or cortical porosity is found, fractional area of interstitial bone is largest and osteon population density is lowest in the endocortical regions of both tension and compression cortices. The endocortical regions also have greater porosity than their corresponding middle and pericortical regions (P < 0.01). Conclusions: These osteonal microstructure and cortical porosity differences may be adaptations related to regional differences in strain mode and/or strain magnitude. This may be related to the disparity in mechanical properties of compact bone in tension vs. compression. These differences may reflect a capacity of bone to process local and regional strain-related information. © 1994 Wiley-Liss, Inc.

1 This article is a US Government work and, as such, is in the public dotmain in the United states of America

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In vivo measurement of bone quality in the horse: Estimates of precision for ultrasound velocity measurement and single photon absorptiometry

The in vivo precision of ultrasound velocity measurement and single photon absorptiometry for the assessment of equine bone quality is discussed. In vivo precisions for ultrasound velocity measurements were less than 0.5 per cent, whereas cortical cross-sectional area, compact bone density and modulus of elasticity were around 1 per cent, and bone mineral content and density were just over 2 per cent. Except for ultrasound velocity, substantial improvements could be achieved by taking the mean of five readings for each measurement. The long-term precision of the techniques was also high, with all precision values being less than 3 per cent. The possible sources of variation in ultrasound velocity measurements were also investigated. The method for combining ultranonic and photon absorptiometric data for equine bone quality assessment has been proven to be highly accurate and precise. There appears to the no reason why the same principles cannot be applied with equal success to the noninvasive assessment of bone quality in humans.     

唑来膦酸联合椎体后凸成形治疗骨质疏松性压缩骨折：提高骨密度、预防椎体再骨折、远期疗效评价的Meta分析

文题释义：椎体后凸成形：采用椎体内置入气囊的方法通过扩张使椎体复位,在椎体内部形成空隙,减小骨水泥注入所需的推力,使骨水泥在椎体内不易流动,可有效解除或缓解疼痛、恢复病椎高度,但临床发现仍存在骨水泥渗漏等风险。 唑来膦酸：椎体后凸成形已被广泛应用于骨质疏松性压缩骨折的治疗,临床疗效显著,然而如何有效改善骨质疏松状况成为临床面临的重要问题。唑来膦酸是双膦酸盐类药物,可有效抑制骨吸收,降低再发骨折风险,改善骨折患者的功能评分。 背景：临床应用唑来膦酸治疗骨质疏松症缺乏系统的科学评价和循证学依据,因此目前对于唑来膦酸联合椎体后凸成形治疗骨质疏松性椎体压缩骨折的临床疗效尚无明确定论。 目的：系统评价唑来膦酸联合椎体后凸成形治疗骨质疏松性椎体压缩骨折的临床疗效。 方法：应用计算机检索公开发表在CNKI、万方、维普等中文数据库及CBM、PubMed、Cochrane等英文数据库中,有关唑来膦酸联合椎体后凸成形治疗骨质疏松性椎体压缩骨折的随机对照试验,试验组治疗方式为唑来膦酸联合椎体后凸成形,对照组治疗方式为椎体后凸成形,时间截止至2019年9月。由2位研究员独立进行文献筛选、数据提取,按Cochrane协作网标准对纳入随机对照试验逐个进行质量评价,采用RevMan 5.3软件对符合纳入标准的研究进行统计分析。 结果与结论：①最终纳入5篇文献,均为随机对照研究,试验组患者175例,对照组患者184例;②统计分析结果显示：试验组治疗后12个月的骨密度高于对照组[MD=0.12,95%CI(0.08,0.17),P < 0.000 01],治疗后6,12个月的目测类比评分低于对照组[MD=0.46,95%CI(0.18,0.75),P=0.002;MD=0.85,95%CI(0.20,1.50),P=0.01],治疗后1年的Oswestry功能障碍指数评分低于对照组[MD=6.59,95%CI(4.77,8.41),P < 0.000 01],骨水泥渗漏率、椎体骨折再发率低于对照组[OR=0.22,95%CI(0.08,0.59),P=0.003;OR=0.18,95%CI(0.07,0.50),P=0.000 8];两组椎体高度恢复、椎体后凸Cobb角比较差异无显著性意义[MD=0.65,95%CI(-0.27,1.56),P=0.16;MD=-0.60,95%CI(-2.45,1.25),P=0.53];③结果表明与单独应用椎体后凸成形相比,唑来膦酸联合椎体后凸成形在提高骨密度值、减少椎体骨折再发率、改善患者远期临床症状、预防骨水泥骨水泥渗漏等并发症方面具有显著优势,但后期仍需大量高质量的多中心随机对照研究提供更充足的证据。 ORCID: 0000-0001-8871-3539(李凯明) 中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程     

Analysis of CA/GT microsatellite polymorphism in IVS8 of the cystic fibrosis transmembrane conductance regulator (CFTR) gene: a study of Italian CF families

Forty-six CF Italian patients and their parents were screened for a highly polymorphic microsatellite consisting of a variable number of CA/GT repeats in intron 8 of the CFTR gene. A strong degree of association was found between alleles 2 and 6 and the CF mutation delta F508. Moreover, considering the haplotypes at the closely linked locus D7S23 and the microsatellite's alleles, a strong linkage disequilibrium was again found for delta F508 and also for non-delta F508 CF chromosomes and the eight commonest haplotypes (B2, B6, C7, A6, A7, B7, D2 and D7). These data, compared with those described in the Spanish population, further support the common origin of the delta F508 mutation in Southern European populations.