Biomechanical analysis of the reconstruction method following total spondylectomy.

只有少数研究对脊柱恶性肿瘤全脊椎切除术后重建方法的生物力学特性进行了研究。对于长期预期寿命的患者，生物骨融合是维持脊柱稳定性所必需的。最新的重建技术包括填充自体骨作为前支柱的钛网笼。后路椎弓根螺钉和棒在全椎体切除后重建中是否需要额外的前路内固定是有争议的。在以前的研究中，已经很好地定义了生物力学应力是骨重建和融合所必需的。因此，机械应力传递到钛网笼内的移植骨必须是融合和重塑的重要因素。目前尚无文献报道比较全椎体切除后不同重建方法的负荷分担特性。该有限元分析的目的是比较两种重建方法，后路内固定和前/后路内固定对全椎体切除后钛网笼载荷分担的影响。本实验表明，从应力遮挡的角度来看，后路内固定加后路椎弓根螺钉重建方法对钛笼的应力遮挡程度比仅使用后路椎弓根螺钉固定的系统更大。无前路固定的重建方法应能为钛网笼内植骨的重建提供足够的应力。

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.