Flöter Michelle, Bittar Cíntia Kelly, Zabeu José Luis, Carneiro Ana Carolina
Orthopedics Department, Faculty of Medical Sciences, Pontifical Catholic University of Campinas, Brazil.
Acta Reumatol Port. 2011 Oct-Dec;36(4):327-35.
To assess the utility of quantitative ultrasound (QUS) of the calcaneus for diagnosing osteoporosis compared to the gold standard, bone densitometry using dual-emission X-ray absorptiometry (DXA), according to published reports.
In this systematic review, the Medline/PUBMED, Medline Ovid and Journals@Ovid, and Wilson General Sciences Full Text database were used. The search strategy involved use of the following MeSH descriptors: [osteoporosis AND (densitometry OR ultrasonography)], and 39 articles published between 2001 and April 2010 were assessed. However, only six articles met the inclusion criteria: sensitivity and specificity of QUS, sample (women or men with no treatment or other disease likely to change bone mass index), devices used, comparative T-score between QUS of the calcaneus and DXA. The GE-Lunar Achilles and Hologic Sahara devices were used in most of the tests reported and were effective.
All studies assessed compared QUS of the calcaneus to DXA of the lumbar spine or femoral neck, as the gold standard. QUS sensitivity ranged from 79% to 93% and specificity ranged from 28% to 90% when at the lower threshold. It is a controversial parameter, because the gold-standard threshold (T-score < -2.5, DXA) could not be used for QUS without errors in osteoporosis diagnosis. All studies had a threshold determined by the authors’ criteria, with a variability of -1.7 (pDXA T--score) and -2.4 for QUS, leading to the same prevalence of osteoporosis, and a T-score of < -3.65 for QUS was equivalent to a T-score < -2.5 for DXA.
Based on the analysis of seven studies, we conclude that QUS of the calcaneus still cannot be used to confirm diagnosis of osteoporosis by comparing the results to those of patients who had already received such a diagnosis based on DXA. However, further research should be conducted in this area, because it is possible to improve the number diagnoses by varying the cutoff T-score. Furthermore, using QUS of the calcaneus was a helpful tool for assessing pathological fractures, whether or not they were associated with osteoporosis.
根据已发表的报告，将跟骨定量超声（QUS）与使用双能X线吸收法（DXA）的骨密度测定这一金标准相比较，评估其在诊断骨质疏松症方面的效用。
在本系统评价中，使用了Medline/PUBMED、Medline Ovid和Journals@Ovid以及Wilson General Sciences全文数据库。检索策略涉及使用以下医学主题词描述符：[骨质疏松症AND（密度测定法或超声检查）]，并评估了2001年至2010年4月期间发表的39篇文章。然而，只有6篇文章符合纳入标准：QUS的敏感性和特异性、样本（未接受治疗或无其他可能改变骨量指数疾病的女性或男性）、使用的设备、跟骨QUS与DXA之间的比较T值。在大多数报告的测试中使用了GE-Lunar跟腱仪和Hologic Sahara设备，且它们是有效的。
所有评估的研究都将跟骨QUS与作为金标准的腰椎或股骨颈DXA进行了比较。当处于较低阈值时，QUS敏感性范围为79%至93%，特异性范围为28%至90%。这是一个有争议的参数，因为在骨质疏松症诊断中，金标准阈值（T值＜-2.5，DXA）不能无误地用于QUS。所有研究都有由作者标准确定的阈值，pDXA T值的变异性为-1.7，QUS为-2.4，导致骨质疏松症患病率相同，且QUS的T值＜-3.65等同于DXA的T值＜-2.5。
基于对七项研究的分析，我们得出结论，跟骨QUS仍不能通过将结果与已根据DXA确诊的患者结果相比较来确诊骨质疏松症。然而，该领域应进一步开展研究，因为通过改变截断T值有可能增加诊断数量。此外，无论是否与骨质疏松症相关，使用跟骨QUS都是评估病理性骨折的有用工具。
