Biomechanical analysis of the reconstruction method following total spondylectomy.

只有少数研究调查了重建方法的生物力学特性后，全脊椎切除术的脊柱恶性肿瘤。生物学骨融合是维持脊柱稳定性所必需的，患者的预期寿命较长。最新的重建技术包括填充自体骨的钛网融合器作为前支柱。在全脊椎切除术后的重建中是否需要额外的前路内固定，后路椎弓根螺钉和棒是有争议的。在以前的研究中，生物力学应力是骨重建和融合所必需的。因此，将机械应力传递到钛网内的移植骨必然是融合和重塑的重要因素。没有发表的报告比较全脊椎切除术后不同重建方法的载荷分配特性。本有限元分析的目的是比较两种重建方法，后路内固定与前路/后路内固定，在全脊椎切除术后通过钛网融合器分担载荷的效果。本实验表明，从应力遮挡的角度来看，采用后路椎弓根螺钉附加前路内固定的重建方法，应力屏蔽钛笼的程度大于单独使用后路螺钉固定的系统。无前路固定的重建方法应提供足够的应力，用于钛网融合器内骨移植物的重建。

Only a few studies have investigated the biomechanical properties of the reconstruction method following total spondylectomy for spinal malignant tumors. Biological bony fusion is required for the maintenance of spinal stability in patients with long-term life expectancy. The most recent reconstruction techniques include a titanium mesh cage filled with autologous bone as an anterior strut. The need of additional anterior instrumentation with posterior pedicle screws and rods in the reconstruction following total spondylectomy is controversial. It has been well defined, in previous studies, that biomechanical stress is necessary for bone remodeling and fusion. Therefore transmission of mechanical stress to the grafted bone inside the titanium mesh cage must be an important factor for fusion and remodeling. No published reports comparing the load-sharing properties of the different reconstruction methods fllowing total spondylectomy exist. The purpose of this finite element analysis was to compare the effect of two reconstruction methods, posterior instrumentation versus anterior/posterior instrumentation, on load sharing through a titanium mesh cage following total spondylectomy.This experiment shows that from the viewpoint of stress-shielding, the reconstruction method using additional anterior instrumentation with posterior pedicle screws, stress shields the titanium cage to a greater degree than does the system using posterior prdicle screw fixation alone. A reconstruction method with no anterior fixation should provide adequate stress for remodeling of the bone graft inside the titanium mesh cages.