An exploratory study of loading and morphometric factors associated with specific failure modes in fatigue testing of lumbar motion segments
An exploratory study of loading and morphometric factors associated with specific failure modes in fatigue testing of lumbar motion segments
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DOI：
10.1016/j.clinbiomech.2005.10.001
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发表时间：
2006-03-01
影响因子：
1.8
通讯作者：
Burr, D
中科院分区：
文献类型：
--
作者：
Gallagher, S;Marras, WS;Burr, D
背景目前很少有关于使用疲劳失效模型的运动节段失效的特定模式相关的因素的信息。使用脊柱压缩和剪切载荷对36个人体腰椎运动节段进行疲劳测试，这些载荷模拟在三个躯干屈曲角度（0度、22.5度和45度）下举起9 kg重量。在10，000次最大循环之前，25个节段因疲劳失效。对这些样本进行目视检查和解剖，以便确定失效模式。失效模式包括终板骨折（分为9种）、椎体骨折和/或关节突关节断裂。进行逻辑回归分析以确定某些形态测量变量、运动节段屈曲量、椎间盘退变评分和/或负荷特征是否与特定失效模式的发生相关。结果表明，星状终板骨折后的剪切力增加（P < 0.05），椎间盘退变减少（P < 0.01）。横向穿过终板的骨折与体积较大的运动节段相关（P < 0.01）。终板凹陷在较小的标本中更常见（P < 0.01），以及那些经历后部剪切力增加的标本（P < 0.05）。中立位更易发生关节突关节损伤（P < 0.01）。这些结果表明，故障模式的预测（例如，特定的终板骨折模式）是可能的（至少对于较老的样本），只要知道脊柱载荷沿着腰椎的某些特征。爱思唯尔有限公司出版
Background. There is currently little information regarding factors associated with specific modes of motion segment failure using a fatigue failure model.Methods. Thirty-six human lumbar motion segments were fatigue tested using spinal compressive and shear loads that simulated lifting a 9 kg weight in three torso flexion angles (0 degrees, 22.5 degrees, and 45 degrees). Twenty-five segments failed via fatigue prior to the 10,000 cycle maximum. These specimens were visually inspected and dissected so that the mode(s) of failure could be determined. Failure modes included endplate fractures (classified into nine varieties), vertebral body fractures, and/or zygapophysial joint disruption. Logistic regression analyses were performed to determine whether certain morphometric variables, amount of motion segment flexion, disk degeneration scores, and/or loading characteristics were associated with the occurrence of specific failure modes.Findings. Results indicated that stellate endplate fractures were associated with increased posterior shear forces (P < 0.05) and less degenerated discs (P < 0.01). Fractures running laterally across the endplate were associated with motion segments having larger volumes (P < 0.01). Endplate depression was more common in smaller specimens (P < 0.01), as well as those experiencing increased posterior shear force (P < 0.05). Zygapophysial joint damage was more likely to occur in a neutral posture (P < 0.01).Interpretation. These results suggest that prediction of failure modes (e.g., specific endplate fracture patterns) may be possible (at least for older specimens) given knowledge of the spinal loads along with certain characteristics of the lumbar spine. Published by Elsevier Ltd.