Replicating a Colles fracture in an excised radius: revisiting testing protocols.
Replicating a Colles fracture in an excised radius: revisiting testing protocols.
复制标题
在切除的桡骨中复制科尔斯骨折：重新审视测试方案。
DOI：
10.1016/j.jbiomech.2012.01.014
复制
发表时间：
2012
影响因子：
2.4
通讯作者：
Beaupre,GaryS
中科院分区：
文献类型：
--
作者：
Wagner,DavidW;Lindsey,DerekP;Beaupre,GaryS
中老年人的桡骨远端骨折通常被认为是骨质疏松的前哨指标。身体标本的力学测试经常被用来量化骨骼强度，并为体内测量与骨折力的关系提供洞察力。使用完整前臂的机械测试方案在复制Colles骨折方面已经成功，然而，基于完整前臂测试方案的切除隔离半径方案并不成功。我们实验室复制了一种最初设计用于复制伸展的手摔倒的生理条件的方案，但令人惊讶的是，在标本中产生的桡骨远端骨折模式并不一致，也没有观察到具有Colles骨折特征的远端骨折的背侧角度。这项研究的目的是对切除的半径加载方案进行基于力学的分析，以量化对半径施加的力和内力。理想的截骨骨梁模型显示，在发生Colles骨折的桡骨远端区域，骨外表面99.99%的最大应变是纯压缩载荷的结果。这种加载条件与公认的Colles骨折的力学特征形成了直接的对比，Colles骨折的特征是干骺端弯曲骨折，掌侧皮质因张应力而失效，背侧皮质表现为压缩和粉碎性。结果表明，要用切除的桡骨力学测试方法可靠地复制临床骨折类型，需要进行更多的研究，特别是与克服可靠地支撑和施加力于桡骨远端的困难有关的研究。
A distal radius fracture in middle-age and older adults is often considered a sentinel indicator of osteoporosis. Mechanical testing of cadaveric specimens is often used to quantify bone strength and develop insight for relating in-vivo measures to fracture force. Mechanical testing protocols using an intact forearm have been successful at replicating a Colles fracture, however, excised isolated radius protocols based on the intact forearm testing protocol have not been as successful. One protocol originally designed to replicate the physiological condition of a fall on an outstretched hand was reproduced in our laboratory, yet surprisingly the produced distal radius fracture patterns were not consistent among specimens nor was dorsal angulation of the distal fragment that is characteristic of a Colles fracture observed. The purpose of this study was to perform a mechanics-based analysis of the excised radius loading protocol in order to quantify the imposed and internal forces on the radius. An idealized beam model of the excised radius revealed that in the area of the distal radius where Colles fractures occur, 99.99% of the maximum strain on the bone outer surface was the result of pure compressive loading. This loading condition is in direct contrast to the accepted mechanics of a Colles fracture, which is characterized as a metaphyseal bending fracture with the volar cortex failing due to tensile stresses and the dorsal cortex exhibiting compression and comminution. The results suggest that additional research, particularly related to overcoming the difficulties of reliably supporting and applying a force to the distal end of the radius, is necessary for clinical fracture patterns to be reliably reproduced with an excised radius mechanical testing protocol.