增强可改善腰椎全椎间盘置换术人体尸体椎体的压缩力学性能。
Augmentation improves human cadaveric vertebral body compression mechanics for lumbar total disc replacement.
机构信息
Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA 19104, USA.
出版信息
Spine (Phila Pa 1976). 2010 Apr 20;35(9):E325-31. doi: 10.1097/BRS.0b013e3181cf7055.
STUDY DESIGN
Cadaveric biomechanical study.
OBJECTIVE
To quantify the effects of vertebral body augmentation on biomechanics under axial compression by a total disc replacement (TDR) implant.
SUMMARY OF BACKGROUND DATA
TDR is a surgical alternative to lumbar spinal fusion to treat degenerative disc disease. Osteoporosis in the adjacent vertebrae to the interposed TDR may lead to implant subsidence or vertebral body fracture. Vertebral augmentation is used to treat osteoporotic compression fracture. This study sought to evaluate whether vertebral augmentation improves biomechanics under TDR axial loading.
METHODS
Forty-five L1-L5 lumbar vertebral body segments with intact posterior elements were used. Peripheral quantitative computed tomography scans were performed to determine bone density, and specimens were block-randomized by bone density into augmentation and control groups. A semiconstrained keeled lumbar disc replacement device was implanted, providing 50% endplate coverage. Vertebral augmentation of 17.6% +/- 0.9% vertebral volume fill with Cortoss was performed on the augmentation group. All segments underwent axial compression at a rate of 0.2 mm/s to 6 mm.
RESULTS
The load-displacement response for all specimens was nonlinear. Subfailure mechanical properties with augmentation were significantly different from control; in all cases, the augmented group was 2 times higher than control. At failure, the maximum load and stiffness with augmentation was not significantly different from control. The maximum apparent stress and modulus with augmentation were 2 times and 1.3 times greater than control, respectively. The subfailure stress and apparent modulus with augmentation were moderately correlated with bone density whereas the control subfailure properties were not. The augmented maximum stress was not correlated with bone density, whereas the control was weakly correlated. The maximum apparent modulus was moderately correlated with bone density for both the augmented and the control groups.
CONCLUSION
Augmentation improved the mechanical properties of the lumbar vertebral body for compression by a TDR implant.
研究设计
尸体生物力学研究。
目的
通过全椎间盘置换（TDR）植入物量化椎体增强对轴向压缩下生物力学的影响。
背景资料概要
TDR 是治疗退行性椎间盘疾病的腰椎融合术的替代手术。插入的 TDR 相邻椎体的骨质疏松症可能导致植入物下沉或椎体骨折。椎体增强用于治疗骨质疏松性压缩性骨折。本研究旨在评估椎体增强是否改善 TDR 轴向加载下的生物力学。
方法
使用 45 个具有完整后元素的 L1-L5 腰椎椎体段。进行外周定量计算机断层扫描以确定骨密度，并通过骨密度将标本随机分组为增强组和对照组。植入半约束龙骨腰椎置换装置，提供 50%的终板覆盖。在增强组中进行 17.6% +/- 0.9%椎体体积填充的 Cortoss 椎体增强。所有节段均以 0.2mm/s 至 6mm/s 的速度进行轴向压缩。
结果
所有标本的载荷-位移响应均呈非线性。增强后的亚失效力学性能与对照组明显不同；在所有情况下，增强组都比对照组高 2 倍。在失效时，增强后的最大载荷和刚度与对照组没有显著差异。增强后的最大表观应力和模量分别比对照组高 2 倍和 1.3 倍。增强后的亚失效应力和表观模量与骨密度中度相关，而对照组的亚失效特性则没有。增强后的最大应力与骨密度无关，而对照组则呈弱相关。增强后的最大表观模量与骨密度呈中度相关，增强组和对照组均如此。
结论
增强改善了 TDR 植入物压缩下腰椎椎体的力学性能。
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