Low-energy fractures without low T-scores characteristic of osteoporosis: a possible bone matrix disorder.
Low-energy fractures without low T-scores characteristic of osteoporosis: a possible bone matrix disorder.
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DOI：
10.2106/jbjs.l.01281
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发表时间：
2013-10-02
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影响因子：
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通讯作者：
Pienkowski, David
中科院分区：
文献类型：
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作者：
Malluche, Hartmut H;Porter, Daniel S;Pienkowski, David
背景：骨质疏松性骨折通常发生在低能量创伤后的绝经后妇女，其骨量减少表现为低骨密度(BMD)。方法：在三组绝经前白人女性的横断面研究中，对骨质量和骨量进行了评估：(1)2 5例低能量骨折(S)，骨密度在正常范围(t评分和GT；(2)18例低能量骨折(S)和骨质疏松范围内的骨密度(t-Score？‰？-2.5)，以及(3)14名健康志愿者(对照组)。采用傅立叶变换红外光谱和组织形态计量学方法对所有受试者的髂骨标本进行骨质量评价；采用双X射线骨密度计量学和组织形态计量学方法评价骨量。结果：非低骨密度骨折组的骨胶原交联率比低骨密度骨折组高13%，比对照组高14%(p<；两者均为0.001)。有骨折的非低骨密度受试者的松质骨体积比低骨密度骨折受试者增加29%(p<；0.01)，骨小梁间距减少31%(p<；0.01)；非低骨密度受试者的这些值与对照组没有差异。骨转换在不同组之间没有差异，骨软化症在任何受试者中都不存在。因此，骨折的非低骨密度受试者维持了骨量，但作为骨质量参数的胶原交联率异常。相比之下，低骨密度骨折的受试者没有这种胶原交联异常，但确实有异常的骨量。结论：这项研究突出了低能量骨折和非骨质疏松性骨折患者的胶原交联异常。有报道指出，胶原蛋白的交联性改变与不正常的抗折能力有关。在低能量骨折患者中发现非骨质疏松性骨量将证明对骨材料质量的评估是合理的，这目前需要骨活检。需要进一步的研究来寻找可能的非侵入性测试来诊断异常的交联性。由于目前还没有针对异常胶原交联的特定疗法，还需要研究探索新的治疗方式来逆转潜在的胶原交联异常。证据水平：预后水平III。有关证据水平的完整描述，请参阅作者的说明。
BACKGROUND: Osteoporotic fractures commonly occur after low-energy trauma in postmenopausal women with reduced bone quantity documented by low bone mineral density (BMD). Low-energy fractures, however, have also been reported to occur in premenopausal women with normal or near-normal BMD, suggesting the existence of a bone quality abnormality.METHODS: Bone quality and quantity were evaluated in a cross-sectional study of three groups of premenopausal white females: (1) twenty-five subjects with low-energy fracture(s) and BMD in the normal range (t-scores > -2.0), (2) eighteen subjects with low-energy fracture(s) and BMD in the osteoporotic range (t-scores ≤ -2.5), and (3) fourteen healthy volunteers (controls). Bone quality was assessed with use of Fourier transform infrared spectroscopy and histomorphometry in iliac crest bone samples obtained from all subjects; bone quantity was assessed by dual x-ray absorptiometry and histomorphometry.RESULTS: The collagen crosslinking ratio in the non-low-BMD subjects with fractures was 13% greater than the ratio in the low-BMD subjects with fractures and 14% greater than the ratio in the controls (p < 0.001 for both). Cancellous bone volume was 29% greater (p < 0.01) and trabecular separation was 31% less (p < 0.01) in the non-low-BMD subjects with fractures than in the low-BMD subjects with fractures; the values in the non-low-BMD subjects did not differ from those in the controls. Bone turnover did not differ among the groups, and osteomalacia was not present in any subject. Thus, the non-low-BMD subjects with fractures maintained bone quantity, but the collagen crosslinking ratio, a parameter of bone quality, was abnormal. In contrast, the low-BMD subjects with fractures did not have this collagen crosslinking abnormality but did have abnormal bone quantity.CONCLUSIONS: This study highlights a collagen crosslinking abnormality in patients with low-energy fractures and nonosteoporotic t-scores. Reports have indicated that altered collagen crosslinking is associated with subnormal fracture resistance. A finding of nonosteoporotic bone mass in a patient with low-energy fractures would justify assessment of bone material quality, which currently requires a bone biopsy. Further studies are needed to search for possible noninvasive tests to diagnose abnormal crosslinking. Since no specific therapies for abnormal collagen crosslinking are currently available, studies are also needed to explore novel therapeutic modalities to reverse the underlying collagen crosslinking abnormality.LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.