Medical Implant Technology Group (MEDITEG), Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor, Malaysia.
J Orthop Res. 2013 Sep;31(9):1447-54. doi: 10.1002/jor.22376. Epub 2013 May 2.
Posterior instrumentation is a common fixation method used to treat thoracolumbar burst fractures. However, the role of different cross-link configurations in improving fixation stability in these fractures has not been established. A 3D finite element model of T11-L3 was used to investigate the biomechanical behavior of short (2 level) and long (4 level) segmental spine pedicle screw fixation with various cross-links to treat a hypothetical L1 vertebra burst fracture. Three types of cross-link configurations with an applied moment of 7.5 Nm and 200 N axial force were evaluated. The long construct was stiffer than the short construct irrespective of whether the cross-links were used (p < 0.05). The short constructs showed no significant differences between the cross-link configurations. The XL cross-link provided the highest stiffness and was 14.9% stiffer than the one without a cross-link. The long construct resulted in reduced stress to the adjacent vertebral bodies and screw necks, with 66.7% reduction in bending stress on L2 when the XL cross-link was used. Thus, the stability for L1 burst fracture fixation was best achieved by using long segmental posterior instrumentation constructs and an XL cross-link configuration. Cross-links did not improved stability when a short structure was used.
后路内固定是治疗胸腰椎爆裂骨折的常用方法。然而，不同的交叉连接配置在改善这些骨折固定稳定性方面的作用尚未确定。使用 T11-L3 的三维有限元模型研究了不同交叉连接治疗假设的 L1 椎体爆裂骨折的短（2 个节段）和长（4 个节段）节段性脊柱椎弓根螺钉固定的生物力学行为。评估了三种交叉连接配置，施加 7.5 Nm 的力矩和 200 N 的轴向力。无论是否使用交叉连接，长结构都比短结构更硬（p < 0.05）。短结构在交叉连接配置之间没有明显差异。XL 交叉连接提供了最高的刚度，比没有交叉连接的刚度高 14.9%。长结构导致相邻椎体和螺钉颈部的应力减小，当使用 XL 交叉连接时，L2 的弯曲应力减少了 66.7%。因此，使用长节段后路内固定结构和 XL 交叉连接配置可实现 L1 爆裂骨折固定的最佳稳定性。当使用短结构时，交叉连接并不能提高稳定性。
