两种改良Goel技术治疗颅底凹陷症稳定性的有限元分析
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摘要
目的应用有限元分析评价C_2双皮质椎板螺钉和C_2椎弓根螺钉联合关节内Cage在寰枢固定中的生物力学差异。方法采集1名35岁正常男性上颈椎(C_(0～2))CT数据,通过Mimics10.01和Abaqus6.11软件建立C_(0～2)节段三维有限元完整模型并进行有效性验证。在失稳模型上分别建立后路C_1侧块螺钉+Cage+C_2双皮质椎板螺钉组成的钉棒系统模型(C_1 lateral mass screw+Cage+bicortical C_2laminar screw, C_1L+Cage+BC_2L)、后路C_1侧块螺钉+Cage+C_2椎弓根螺钉组成的钉棒系统模型(C_1 lateral mass screw+Cage+C_2pedicle screw, C_1L+Cage+C_2P)。在枕骨髁上施加40 N轴向压力模拟头颅重力,同时在枕骨上施加1.5 Nm力矩使模型产生前屈、后伸、侧弯、旋转运动,记录C_1L+Cage+BC_2L组及C_1L+Cage+C_2P组的应力云图及应力峰值,计算C_(1～2)节段活动度(range of motion,ROM)。结果在任何工况下C_1L+Cage+BC_2L组和C_1L+Cage+C_2P组的C_(1～2)节段ROM差异均小于0.1°,且两组内固定所有螺钉的应力分布和应力峰值无明显差异。在后伸工况下两组内固定Cage内植骨应力最小,存在明显应力遮挡,尤其是C_1L+Cage+C_2P组。结论对于BI的治疗,C_1L+Cage+BC_2L内固定系统的稳定性与C_1L+Cage+C_2P相当,与C_2P技术相比,BC_2L技术简单、易行,同时能有效避免椎动脉和脊髓的损伤。为了避免内固定失效和应力遮挡,术后患者应避免颈部后伸运动。
Objectives To determine the biomechanical differences between C_2 pedicle screw and bicortical C_2 laminar screw with intra-articular Cage in C_(1～2) fixation by finite element analysis. Methods A validated three-dimensional finite element model of the upper cervical spine(C_(0～2)) was established, and an unstable model was also established after removing the transverse ligament. Two different implanted models:C_1 lateral mass screws+Cage+C_2 pedicle screw(C_1L+Cage+C_2P) and C_1 lateral mass screws+Cage+bicortical C_2 laminar screw(C_1L+Cage+BC_2L) were integrated at the C_(1～2) segment into the unstable model. To study the biomechanics, vertical load of 40 N was applied in the inferior direction on the occipital condyles, to simulate head weight and 1.5 Nm torque was applied to the occiput to simulate flexion, extension, lateral bending, and rotation. Results There was no significant difference in the range of motion between C_1L+Cage+BC_2L and C_1L+Cage+C_2P implanted models( <0.1° for all loading cases),and also there was no significant difference in stress distribution and maximum stress between the 2 implanted models. Bone graft stress of the 2 implanted models, especially the C_1L + Cage + C_2P fixation model, were minimum under extension loading condition.Conclusions Our results indicate that the C_1L+Cage+BC_2L fixation offers similar stability to C_1L+Cage+C_2P for the treatment of basilar invagination. Compared to C_2P technique, the BC_2L is an easy, effective technique and it can avoid vertebral artery and spinal cord injury. To avoid the instrumentation failure and stress shelter, neck extension movement should be restricted or banned after surgery.
Objectives To determine the biomechanical differences between C_2 pedicle screw and bicortical C_2 laminar screw with intra-articular Cage in C_(1～2) fixation by finite element analysis. Methods A validated three-dimensional finite element model of the upper cervical spine(C_(0～2)) was established, and an unstable model was also established after removing the transverse ligament. Two different implanted models:C_1 lateral mass screws+Cage+C_2 pedicle screw(C_1L+Cage+C_2P) and C_1 lateral mass screws+Cage+bicortical C_2 laminar screw(C_1L+Cage+BC_2L) were integrated at the C_(1～2) segment into the unstable model. To study the biomechanics, vertical load of 40 N was applied in the inferior direction on the occipital condyles, to simulate head weight and 1.5 Nm torque was applied to the occiput to simulate flexion, extension, lateral bending, and rotation. Results There was no significant difference in the range of motion between C_1L+Cage+BC_2L and C_1L+Cage+C_2P implanted models( <0.1° for all loading cases),and also there was no significant difference in stress distribution and maximum stress between the 2 implanted models. Bone graft stress of the 2 implanted models, especially the C_1L + Cage + C_2P fixation model, were minimum under extension loading condition.Conclusions Our results indicate that the C_1L+Cage+BC_2L fixation offers similar stability to C_1L+Cage+C_2P for the treatment of basilar invagination. Compared to C_2P technique, the BC_2L is an easy, effective technique and it can avoid vertebral artery and spinal cord injury. To avoid the instrumentation failure and stress shelter, neck extension movement should be restricted or banned after surgery.
引文
[1]Menezes A H,Vangilder J C,Graf C J,et al.Craniocervical abnormalities:a comprehensive surgical approach[J].J Neurosurg,1980,53(4):444-455.
[2]Goel A.Progressive basilar invagination after transoral odontoidectomy:treatment by atlantoaxial facet distraction and craniovertebral realignment[J].Spine,2005,30(18):E551-E555.
[3]张宝成,蔡贤华,黄卫兵,等.颅底凹陷症的分型及治疗进展[J].中国脊柱脊髓杂志,2014(07):660-663.
[4]Goel A.Treatment of basilar invagination by atlantoaxial joint distraction and direct lateral mass fixation[J].J Neurosurg Spine,2004,1(3):281-286.
[5]Chandra P S,Kumar A,Chauhan A,et al.Distraction,compression,and extension reduction of basilar invagination and atlantoaxial dislocation:a novel pilot technique[J].Neurosurgery,2013,72(6):1040-1053.
[6]Ma X,Yin Q,Wu Z,et al.C2 Anatomy and Dimensions Relative to Translaminar Screw Placement in an Asian Population[J].Spine,2010,35(6):704-708.
[7]蔡贤华,王威,王志华,等.不同前路内固定方式治疗枢椎椎体横行骨折合并Hangman骨折稳定性的有限元分析[J].中国脊柱脊髓杂志,2014,24(03):257-260.
[8]Li S,Ni B,Xie N,et al.Biomechanical evaluation of an atlantoaxial lateral mass fusion cage with C1-C2 pedicle fixation[J].Spine(Phila Pa1976),2010,35(14):E624-E632.
[9]Cai X,Liu Z,Yu Y,et al.Evaluation of biomechanical properties of anterior atlantoaxial transarticular locking plate system using threedimensional finite element analysis[J].Eur Spine J,2013,22(12):2686-2694.
[10]Zhang H,Bai J.Development and validation of a finite element model of the occipito-atlantoaxial complex under physiologic loads[J].Spine(Phila Pa 1976),2007,32(9):968-974.
[11]陈金水,倪斌,陈博,等.寰枢椎脱位三维非线性有限元模型的建立和分析[J].中国脊柱脊髓杂志,2010,20(09):749-753.
[12]王建华,尹庆水,夏虹,等.颅底凹陷症的分型及其意义[J].中国脊柱脊髓杂志,2011,21(4):290-294.
[13]Ni B,Zhou F,Guo Q,et al.Modified technique for C1-2 screw-rod fixation and fusion using autogenous bicortical iliac crest graft[J].Eur Spine J,2012,21(1):156-164.
[14]Panjabi M,Dvorak J,Crisco J R,et al.Effects of alar ligament transection on upper cervical spine rotation[J].J Orthop Res,1991,9(4):584-593.
[15]Panjabi M,Dvorak J,Crisco J R,et al.Flexion,extension,and lateral bending of the upper cervical spine in response to alar ligament transections[J].J Spinal Disord,1991,4(2):157-167.
[16]Li-Jun L,Ying-Chao H,Ming-Jie Y,et al.Biomechanical analysis of the longitudinal ligament of upper cervical spine in maintaining atlantoaxial stability[J].Spinal Cord,2014,52(5):342-347.
[17]Wright N.Posterior C2 fixation using bilateral,crossing C2 laminar screws:case series and technical note[J].J Spinal Disord Tech,2004,17(2):158-162.
[18]Dorward I G,Wright N M.Seven years of experience with C2translaminar screw fixation:clinical series and review of the literature[J].Neurosurgery,2011,68(6):1491-1499,1499.
[19]Park J S,Cho D C,Sung J K.Feasibility of C2 translaminar screw as an alternative or salvage of C2 pedicle screws in atlantoaxial instability[J].J Spinal Disord Tech,2012,25(5):254-258.
[20]Wang M Y.Cervical crossing laminar screws:early clinical results and complications[J].Neurosurgery,2007,61(5 Suppl 2):311-315,315-316.
[21]马向阳,尹庆水,吴增晖,等.枢椎椎板螺钉固定的解剖可行性研究[J].中国脊柱脊髓杂志,2006,16(1):48-51.
[22]Gorek J,Acaroglu E,Berven S,et al.Constructs incorporating intralaminar C2 screws provide rigid stability for atlantoaxial fixation[J].Spine,2005,30(13):1513-1518.
[23]Elliott R E,Tanweer O,Boah A,et al.Outcome comparison of atlantoaxial fusion with transarticular screws and screw-rod constructs:meta-analysis and review of literature[J].J Spinal Disord Tech,2014,27(1):11-28.
[24]Daniel R T,Muzumdar A,Ingalhalikar A,et al.Biomechanical Stability of a Posterior-Alone Fixation Technique After Craniovertebral Junction Realignment[J].World Neurosurg,2012,77(2):357-361.
[25]Cai X,Yu Y,Liu Z,et al.Three-dimensional finite element analysis of occipitocervical fixation using an anterior occiput-to-axis locking plate system:a pilot study[J].Spine J,2014,14(8):1399-1409.
[26]Oh C H,Ji G Y,Seo H S,et al.Repeated complication following atlantoaxial fusion:a case report[J].Korean J Spine,2014,11(1):7-11.
[27]Ordway N R,Lu Y,Zhang X,et al.Correlation of cervical endplate strength with CT measured subchondral bone density[J].Eur Spine J,2007,16(12):2104-2109.
[2]Goel A.Progressive basilar invagination after transoral odontoidectomy:treatment by atlantoaxial facet distraction and craniovertebral realignment[J].Spine,2005,30(18):E551-E555.
[3]张宝成,蔡贤华,黄卫兵,等.颅底凹陷症的分型及治疗进展[J].中国脊柱脊髓杂志,2014(07):660-663.
[4]Goel A.Treatment of basilar invagination by atlantoaxial joint distraction and direct lateral mass fixation[J].J Neurosurg Spine,2004,1(3):281-286.
[5]Chandra P S,Kumar A,Chauhan A,et al.Distraction,compression,and extension reduction of basilar invagination and atlantoaxial dislocation:a novel pilot technique[J].Neurosurgery,2013,72(6):1040-1053.
[6]Ma X,Yin Q,Wu Z,et al.C2 Anatomy and Dimensions Relative to Translaminar Screw Placement in an Asian Population[J].Spine,2010,35(6):704-708.
[7]蔡贤华,王威,王志华,等.不同前路内固定方式治疗枢椎椎体横行骨折合并Hangman骨折稳定性的有限元分析[J].中国脊柱脊髓杂志,2014,24(03):257-260.
[8]Li S,Ni B,Xie N,et al.Biomechanical evaluation of an atlantoaxial lateral mass fusion cage with C1-C2 pedicle fixation[J].Spine(Phila Pa1976),2010,35(14):E624-E632.
[9]Cai X,Liu Z,Yu Y,et al.Evaluation of biomechanical properties of anterior atlantoaxial transarticular locking plate system using threedimensional finite element analysis[J].Eur Spine J,2013,22(12):2686-2694.
[10]Zhang H,Bai J.Development and validation of a finite element model of the occipito-atlantoaxial complex under physiologic loads[J].Spine(Phila Pa 1976),2007,32(9):968-974.
[11]陈金水,倪斌,陈博,等.寰枢椎脱位三维非线性有限元模型的建立和分析[J].中国脊柱脊髓杂志,2010,20(09):749-753.
[12]王建华,尹庆水,夏虹,等.颅底凹陷症的分型及其意义[J].中国脊柱脊髓杂志,2011,21(4):290-294.
[13]Ni B,Zhou F,Guo Q,et al.Modified technique for C1-2 screw-rod fixation and fusion using autogenous bicortical iliac crest graft[J].Eur Spine J,2012,21(1):156-164.
[14]Panjabi M,Dvorak J,Crisco J R,et al.Effects of alar ligament transection on upper cervical spine rotation[J].J Orthop Res,1991,9(4):584-593.
[15]Panjabi M,Dvorak J,Crisco J R,et al.Flexion,extension,and lateral bending of the upper cervical spine in response to alar ligament transections[J].J Spinal Disord,1991,4(2):157-167.
[16]Li-Jun L,Ying-Chao H,Ming-Jie Y,et al.Biomechanical analysis of the longitudinal ligament of upper cervical spine in maintaining atlantoaxial stability[J].Spinal Cord,2014,52(5):342-347.
[17]Wright N.Posterior C2 fixation using bilateral,crossing C2 laminar screws:case series and technical note[J].J Spinal Disord Tech,2004,17(2):158-162.
[18]Dorward I G,Wright N M.Seven years of experience with C2translaminar screw fixation:clinical series and review of the literature[J].Neurosurgery,2011,68(6):1491-1499,1499.
[19]Park J S,Cho D C,Sung J K.Feasibility of C2 translaminar screw as an alternative or salvage of C2 pedicle screws in atlantoaxial instability[J].J Spinal Disord Tech,2012,25(5):254-258.
[20]Wang M Y.Cervical crossing laminar screws:early clinical results and complications[J].Neurosurgery,2007,61(5 Suppl 2):311-315,315-316.
[21]马向阳,尹庆水,吴增晖,等.枢椎椎板螺钉固定的解剖可行性研究[J].中国脊柱脊髓杂志,2006,16(1):48-51.
[22]Gorek J,Acaroglu E,Berven S,et al.Constructs incorporating intralaminar C2 screws provide rigid stability for atlantoaxial fixation[J].Spine,2005,30(13):1513-1518.
[23]Elliott R E,Tanweer O,Boah A,et al.Outcome comparison of atlantoaxial fusion with transarticular screws and screw-rod constructs:meta-analysis and review of literature[J].J Spinal Disord Tech,2014,27(1):11-28.
[24]Daniel R T,Muzumdar A,Ingalhalikar A,et al.Biomechanical Stability of a Posterior-Alone Fixation Technique After Craniovertebral Junction Realignment[J].World Neurosurg,2012,77(2):357-361.
[25]Cai X,Yu Y,Liu Z,et al.Three-dimensional finite element analysis of occipitocervical fixation using an anterior occiput-to-axis locking plate system:a pilot study[J].Spine J,2014,14(8):1399-1409.
[26]Oh C H,Ji G Y,Seo H S,et al.Repeated complication following atlantoaxial fusion:a case report[J].Korean J Spine,2014,11(1):7-11.
[27]Ordway N R,Lu Y,Zhang X,et al.Correlation of cervical endplate strength with CT measured subchondral bone density[J].Eur Spine J,2007,16(12):2104-2109.