皮质骨通道置椎弓根螺钉技术的研究进展  

Cortical bone trajectory for pedicle screws

作　　者：宣俊[1] 徐道亮[1] 王向阳[1] 

机构地区：[1]温州医科大学附属第二医院骨科,325027

出　　处：《中华骨科杂志》2016年第1期51-57,共7页Chinese Journal of Orthopaedics

基　　金：国家自然科学基金面上项目（81371988）;浙江省自然科学基金杰出青年项目（LR12H06001）

摘　　要：椎弓根螺钉内固定技术能贯穿脊柱前、中、后三柱，起到三维矫形和固定作用，目前已在脊柱外科中广泛应用。但是传统椎弓根螺钉置入时，为暴露骨性标志而对肌肉剥离的程度较大，尤其在下腰椎和骶骨进行操作时，则需更充分的暴露。经皮椎弓根螺钉内固定技术能在一定程度上弥补这一缺陷，但其不能同时行植骨及减压，需另取切口入路，且需反复“C”型臂X线机透视，故患者和手术医生承受辐射量均较大。另外，由于螺钉松动导致内置物稳定性下降是术后常见的并发症，如为骨质疏松患者，因骨量减少、骨组织结构退化而术后出现并发症的可能性则更大。通过改进螺钉设计以及注入强化椎体的材料，虽可提高骨．螺钉界面强度，但仍存在各自的缺陷：前者对于严重骨质疏松患者仍难以获得有效骨．螺钉把持力；骨水泥强化椎弓根螺钉可以显著提高螺钉的轴向拔出力，且明显增加固定节段脊柱的抗疲劳能力，但存在误注或溢出风险、易损伤神经组织、聚合产生高热及对人体有毒等弊端。经皮质骨通道置椎弓根螺钉技术采用的螺钉直径小、长度短，且螺纹排列更紧密，可充分与皮质骨集中区域接触，增加骨．螺钉界面强度；另外，其置钉点邻近峡部，对肌肉剥离程度较小，且自内而外、由下而上的钉道可降低血管、神经损伤的概率。因此，皮质骨通道置椎弓根螺钉技术为获得螺钉对椎体的有效固定强度、椎弓根螺钉在微创手术中的应用以及传统技术置入椎弓根螺钉失败后补救性置钉提供了一种新的思路。Pedicle screw fixation is widely used in spine surgery, which allows 3-dimensional fixation with a more rigid construct and permits a shorter fusion length. However, conventional pedicle screw fixation has some drawbacks, including significant muscle dissection for the exposure of bone marks. Although percutaneous pedicle screw technique can compensate for above defects, it requires an additional approach for decompression and bone graft insertion. Besides, the percutaneous pedicle screw technique depends on intraoperative muhiplanar fluoroscopy, which results in high risk of radiation exposure of the surgeons and patients. Screw loosening is a well-known complication, especially in osteoporosis patients. Several methods can enhance screw stability, for example, modifying screw design and augmenting vertebral bodies with reinforcing materials that can improve the structural capacity of the deteriorated tissue, however, they also have some disadvantages. Although we can enhance bone-screw by modifying screw design, it is not useful in severe osteoporosis patients. At the same time, bone cement can increase pedicle screw axial pullout strength and fatigue resistance, however, it is associated with a number of inherent disadvantages such as its high exothermic polymerizing temperature, toxicity of the monomer, and risk of leakage to the spinal canal. Santoni et al. introduced cortical bone trajectory （CBT） for lumbar pedicle screw with a new screw design that is shorter and smaller in diameter which has been proposed to maximize the thread contact with this higher density bone surface. In addition, the CBT technique follows a caudocephalad path sagittally and a laterally directed path in the transverse plane, engaging only cortical bone in the pedicle without the involvement of the vertebral body trabecular space. Finally, the screw insertion point of this technique locates around lateral pars, enabling less tissue dissection. Therefore, it can be an alternative approach to enhance screw fixation strength, and i

关 键 词：椎弓根螺钉技术 皮质骨 椎弓根螺钉内固定技术 通道 骨质疏松患者 椎弓根螺钉置入 强化椎弓根螺钉 脊柱外科 

分 类 号：R687.3[医药卫生—骨科学]