Jaiman Ashish, Sabat Dhananjaya, Arora Sumit, Hafez Mahmoud A
Assistant Professor, Central Institute of Orthopaedics, Vardhman Mahavir Medical College & Associated Safdarjung Hospital, New Delhi 110029, India.
Assistant Professor, Department of Orthopaedics, Maulana Azad Medical College & Associated Sushruta Trauma Centre, Delhi 110054, India.
J Clin Orthop Trauma. 2013 Mar;4(1):11-4. doi: 10.1016/j.jcot.2013.01.010. Epub 2013 Feb 6.
Bone is a dynamic tissue. It remodels, thereby maintaining serum calcium, repairing micro damage and maintaining strength. A reduction in the strength of bone leads to osteoporosis that may manifest clinically as low energy vertebral and non-vertebral fractures. The bone strength, in turn, is determined by its material, structural properties and on its remodeling potential. Commonly, osteoporosis is objectively evaluated by 'T' and 'Z' scores and these are the indicators of bone density as determined by Dexa scan; these scores correlate inversely with the fracture risk. Quite often, we forget that Dexa scan results are not the only factors determining bone strength and the association between bone density and bone strength is not fixed, and is exemplified by the example of "osteopetrosis". The same issue is happening with the prolonged use of bisphosphonates (BP's).
骨骼是一种动态组织。它会进行重塑,从而维持血清钙水平、修复微损伤并保持强度。骨骼强度降低会导致骨质疏松症,临床上可能表现为低能量椎体和非椎体骨折。而骨骼强度又由其材料、结构特性以及重塑潜力所决定。通常,骨质疏松症通过 “T” 和 “Z” 评分进行客观评估,这些评分是双能X线吸收法(Dexa)扫描所测定的骨密度指标;这些评分与骨折风险呈负相关。我们常常忘记,Dexa扫描结果并非决定骨骼强度的唯一因素,骨密度与骨骼强度之间的关联也不是固定不变的,“骨硬化症” 就是一个例证。长期使用双膦酸盐(BP)也存在同样的问题。