后部不同结构切除对胸椎稳定性的影响

目的研究后部不同结构对胸椎脊柱稳定性中的作用。方法选用9具带有8 cm肋骨的湿润成人尸体胸椎标本(T7～T10),依次对同一标本T8～T9节段进行单侧小关节突关节及半椎板切除、单侧肋椎关节切除、后部韧带复合切除体及全椎板切除、双侧关节突关节切除、双侧肋椎关节切除共5种切除模型,对标本进行生物力学实验测试并记录各模型在5 N.m载荷下于前屈/后伸、左右侧弯、轴向旋转6个方向的运动范围(ROM),将各模型ROM值分别与完整标本ROM值进行配对t检验比较。结果与完整胸椎标本比较,单侧小关节突关节及半椎板切除后在前屈/后伸、左右侧弯、轴向旋转方向上的ROM值无显著性差异(P>0.05),但双侧小关节突关节切除后,前屈/后伸、左右侧弯、轴向旋转方向上的ROM值有显著性差异(P<0.05,P<0.01),后部韧带复合体切除后在前屈/后伸及轴向旋转方向上的ROM值有显著性差异(P<0.05,P<0.01),切除双侧肋椎关节后胸椎在6个方向上的ROM值均有显著性差异(P<0.01)。结论在胸椎,小关节突关节在前屈/后伸和轴向旋转功能稳定性上起到了重要作用,但单侧小关节突关节及半椎板切除后对稳定性的影响并不显著,后部韧带复合体在前屈/后伸时的稳定性中起到了控制作用,肋椎关节是胸椎脊柱功能单位机械性能中最为重要的后部稳定因素之一。     

保留棘突棘上和棘间韧带的全椎板减压术探讨

脊柱的后部结构对脊柱稳定性起重要作用。全椎板切开减压往往将棘突、棘上和棘间韧带，甚至小关节一并切除，但术后常常发生脊柱不稳、后突畸型，甚至椎体滑脱等。作者自１９９１年起对６６例患者采取保留棘突、棘上和棘间韧带的全椎板切除术，并对１０具男尸腰椎行体外生物力学测定，证实全椎板切除对脊柱稳定性有显著影响；但保留棘突、棘上和棘间韧带的全椎板减压术并不影响腰椎稳定性，且同样达到减压目的，值得在临床推广应用。     

保留棘突棘上和棘间韧带的全椎板减压术探讨

脊柱的后部结构对脊柱性起重要作用，全椎板切开减压往往将棘突，棘上和棘间韧带，甚至小关节一并切除，但术后常常发生脊柱不稳，后突畸形，甚至椎体滑脱等。作者自１９９１年起对６６例患者采取保留棘突，棘上和棘间韧带的全椎板切除术，并对１０具男尸腰椎行体生物力学测定，证实全椎板切除对脊柱稳定恶性循环 有显著影响。     

后部结构对腰椎扭转稳定性的实验研究

目的：探讨小尾寒羊L5／L6后部结构分级切除对腰椎扭转稳定性的影响。方法：利用改良的定位移生物力学测试方法，对小尾寒羊L5／L6后部结构依次分级切除：Ⅰ正常→Ⅱ全椎板减压→Ⅲ左侧关节突切除1／2→Ⅳ左侧关节突全部切除→V右侧关节突切除1／2→Ⅵ右侧关节突全部切除，Instron8874试验机依次测试标本左／右扭转椎间运动的变化，行单因素方差分析，检验水准α=0．05。结果：后部韧带及其骨性结构切除即出现左／右扭转失稳（P〈0．05）；关节突关节与扭转的稳定性特别是对对侧扭转的稳定性具有重要意义。结论：在保证手术视野的情况下，腰椎后路手术力求做到微创，尽量保留后部结构的完整性。     

脊柱后柱复合体对全椎板切除后脊柱稳定性的影响

目的探讨脊柱后柱复合体(棘上韧带、棘间韧带及棘突复合结构)对全椎板切除后脊柱稳定性的影响。方法观察27例无脊柱不稳的腰椎管狭窄患者行保留后柱复合体结构的全椎板切除减压术后脊柱稳定性情况,均随访3~10年。以White等标准对术后脊柱稳定性进行评价。结果本组27例患者均成功手术,随访期间均无脊柱不稳的表现。结论保留后柱复合体(棘上韧带,棘间韧带,棘突)结构完整的全椎板切除减压术对腰椎的稳定性不会产生影响     

椎弓切除对腰椎稳定性影响的三维运动研究

用８具新鲜成人男性尸体标本腰椎功能单位，通过脊柱三维运动实验机施加最大载荷为１０．０Ｎ．ｍ６种力偶，使脊柱前生前屈／后伸。左／右侧弯和左／右轴向旋转运动。经立体摄像计算机图像处理得到Ｌ１－２节段的运动范围（ＲＯＭ），中性区（ＮＺ）和弹性区（ＥＮ）等参数。后在同一节段切小关节和椎弓。将示本测量的结果为自身对照组。根据节段间的变化定量分析小关节和椎弓切除对腰椎三运动的影响。结果：全椎弓和全小关节切后５     

单节段腰椎小关节分级切除对腰椎稳定性影响的生物力学研究

目的从生物力学角度研究单纯腰椎小关节分级切除对脊柱稳定性的影响,以期探讨腰椎小关节的生物力学特性和明确椎间孔外型腰椎间盘突出手术减压的安全界限.方法选用5具新鲜成人尸体脊柱L4/5功能单位(FSU),通过分级切除L4/5节段的左侧小关节,共造成5种实验验模型(正常脊柱结构、小关节切除外侧1/4、小关节切除外侧1/2、小关节切除外侧3/4、左侧小关节全切除),运用脊柱三维运动实验机测试各模型的稳定性.结果小关节外侧切除大于1/2,脊柱功能单位的左右侧屈及左、右轴向旋转稳定性与正常结构之间存在明显差异,表明腰椎稳定性受到显著性破坏.结论腰椎小关节对脊柱的稳定性有重要作用.椎管减压时,应尽量保留腰椎小关节的相对完整性.     

全椎板减压与双侧开窗的腰椎生物力学分析

目的评估全椎板切除与双侧椎板开窗术后腰椎的运动范围与稳定性的区别。方法采用脊柱运动模拟器对6具新鲜冰冻腰椎的L1～L5进行试验。采用生理跟踪器对腰椎屈伸、侧弯与轴向旋转进行监测：（1）内部结构未进行手术;（2）L2～L5进行了椎板开窗术;（3）L2～L5行全椎板减压术。采用Vicom运动系统对腰椎的运动进行测量。记录所有脊柱的运动范围与脊柱的强度,采用SPSS13．0统计软件进行统计分析。结果双侧椎板开窗术屈伸的范围增加了14．3％,全椎板减压术增加了32％（P〈0．05）,统计每节段表明：在每一节段全椎板减压术与双侧椎板开窗术相比运动范围是其大致2倍（P〈0．05）。在3节段椎板开窗术中其强度平均减少了11.8％,在3节段全椎板减压术中强度平均减少了27．2％（P〈0．05）。结论这些数据表明双侧椎板开窗术与全椎板减压术相比明显减少了运动范围及强度变形。保留中后侧的骨与韧带复合结构可能对减压后的脊柱滑脱有稳定的作用。     

单侧小关节分级切除对腰椎稳定性影响的三维运动研究

本实验采用８具新鲜尸体腰椎功能单位，通过脊柱三椎运动实验机施加量大载荷为１０，ＯＮ，ｍ的６种力偶，使脊柱产生前屈／后伸、左／右侧弯和左／右轴向旋转运动。     

同种异体骨钉在椎管扩大成形术中的应用

早在1900年sachs和Frankel首次报告全椎板切除椎管减压术治疗椎管狭窄或椎间盘突出症，取得较好的临床效果。到了20世纪40年代后该术式在全世界范围内得到普遍应用，手术切开皮肤、皮下、筋膜、剥离两侧椎旁肌至小关节突，显露切除狭窄节段的棘上韧带、棘间韧带、黄韧带、棘突及椎板，甚至两侧的部分关节突，直视下获得充分暴露椎管，彻底解除马尾及神经压迫，术后近期效果理想。但是随着手术数量增多和时间延长，经长期随访发现术后一些患者腰腿痛容易复发，甚至出现严重的新腰腿痛症状。究其原因，一方面全椎板切除术，破坏了腰椎后部结构，会导致腰椎不稳，甚至滑脱。另一方面椎管内硬脊膜失去遮蔽保护作用，     

下腰椎的三维有限元分析

目的为研究下腰椎活动提供三维有限元力学模型。方法选取成年男性的下腰椎典型CT影像,建立几何模型后利用有限元划分和分析软件建立有限元模型,设定边界条件并加载负荷,记录下腰椎在前屈、后伸、侧屈和轴向旋转等不同工况下的运动范围和应力分布。结果建立的下腰椎三维有限元模型中4面体单元总数为114953。模型在各工况下的运动范围与体外生物力学试验所测定的结果比较,差异无统计学意义(P>0.05)。结论建立的下腰椎三维有限元模型能够模拟下腰椎的生理活动,可用于进一步的研究。     

The rotational stability of lumbar spine following unilateral multilevel resection of spinal posterior structure: a biomechanical study

Lumharspinalstenosisisacommonspinaldisease.MulhplestenosisaccountSfor22%ofallthe...,[IJ.Thesurgicaltreatmentformultilevellulnbarspinalstenosisisdecompressionofthemultiplestenoticareas.Dependingontheextentofthestenosis,thespinalposteriorstructureisremovedforvariousextentS,fromunilateralldrinectomytototallahanectomy,usuallycombinedwithpartialortotalfacetectodries,torestorethespaceofthelulnbarspinalcanal.Theexperiment,abiomechanicalstudy,wasdesignedtoevaluatetheinfluenceoftinilateralresectionof…     

腰椎单侧小关节突分级切除的生物力学影响及微创外科的修复与重建

目的通过生物力学实验以研究腰椎单侧小关节突分级切除后对稳定性的影响,并通过临床研究以评价内窥镜下单侧小关节突切除、腰椎间植骨融合、单侧椎弓根螺钉内固术的初期临床结果。方法选用5具新鲜成人尸体脊柱制成5个L4～L5椎功能单位,以研究小关节突分级切除后对腰椎前屈、后伸、侧屈及轴向旋转运动范围的影响。并对23例手术患者的初期临床结果进行评价。其中男16例,女7例;年龄32～74岁,平均47．7岁。手术在内窥镜下单侧小关节突切除、椎间盘摘除、神经根松解和减压、自体松质骨椎间植骨、单枚椎间融合器斜向椎间植入,单侧椎弓根螺钉内同定。结果腰椎单侧小关节突分级切除对早期腰椎的前屈和后伸活动无明显的影响。当单侧小关节突切除范围超过1／2时,对腰椎侧弯和轴向旋转活动有明显的影响（均P〈0．05）。本组23例患者,疗效评定按照VAS疼痛目测评分法、ODI功能障碍指数和Nakai分级评定。根据Nakai分级,优15例（65．2％）,良6例（26．1％）,可2例（8．7％）。优良率91．3％。植骨融合率为95．6％。结论腰椎单侧小关节突切除范围超过1／2时,显著影响腰椎的稳定性。内窥镜下经单侧神经管减压、椎间植骨融合、单侧椎弓根螺钉内固定是一种可供临床选择的微创外科术式。     

Biomechanange ical chof lumbar unilateral graded facetectomy and strategies of its microsurgical reconstruction: report of 23 cases

Objective: To evaluate the lumbar stability and the primary clinical results of unilateral facetectomy, transforaminal lumbar interbody fusion (TLIF) and unilateral pedicle screw fixation by X-Tube system. Methods: Five human lumbar cadaveric functional spine units(FSU) were obtained and graded facetectomy by 0, 1/4, 1/2, 3/4 and 4/4 were performed respectively on the left articular process of them. The stability of these 5 models was evaluated at flexion, extension, lateral bending and axial rotation. After a serial of biomechanical researches, 23 patients from June 2004 to March 2006 in our department underwent unilateral facetectomy, transforaminal lumbar interbody fusion (posterior lumbar interbody fusion) and unilateral pedicle screw instrumentation by X-Tube system. After general anaesthesia, with the guide of fluoroscopy and using X-Tube system, procedures of unilateral endoscopic faceteetomy, spinal nerve root decompression, autologus spongy bone transplantation, one cage oblique insertion and unilateral pedicle screw instrumentation were performed. Results: There was no significant difference in flexion, extension, lateral bending and axial rotation of lumbar motion range after unilateral graded facetectomy. The stability of left/right axial direction was greatly affected when the range of graded facetectomy exceed 1/2. According to the Nakai criteria, for the 23 patients, the clinical result was excellent in 15 (65.2%), good in 6 (26.1%) and fair in 2 (8.7%). The fusion rate was 95.6% in excellent and good cases. Although partial absorption of bone grafts was observed in 1 case which might indicate a unsuccessful fusion, there was no loosing and replacement of instrument and no clinical symptoms occurred. Conclusion: The lumbar stability will be affected significantly when the range of graded facetectomy exceeds 1/2. Procedures of unilateral facetectomy, transforaminal lumbar interbody fusion and unilateral pedicle screw fixation is an optional strategy for microsurgical reconstruction, though the indications of the procedure should be carefully restricted.     

Biomechanical change of lumbar unilateral graded facetectomy and strategies of its microsurgical reconstruction report of 23 cases

Objective： To evaluate the lumbar stability and the primary clinical results of unilateral facetectomy, transforaminal lumbar interbody fusion （TLIF） and unilateral pedicle screw fixation by X-Tube system. Methods： Five human lumbar cadaveric functional spine units（FSU） were obtained and graded facetectomy by 0, 1/4, 1/2, 3/4 and 4/4 were performed respectively on the left articular process of them. The stability of these 5 models was evaluated at flexion, extension, lateral bending and axial rotation. After a serial of biomechanical researches, 23 patients from June 2004 to March 2006 in our department underwent unilateral facetectomy, transforaminal lumbar interbody fusion （posterior lumbar interbody fusion） and unilateral pedicle screw instrumentation by X-Tube system. After general anaesthesia, with the guide of fluoroscopy and using X-Tube system, procedures of unilateral endoscopic facetectomy, spinal nerve root decompression, autologus spongy bone transplantation, one cage oblique insertion and unilateral pedicle screw instrumentation were performed. Results： There was no significant difference in flexion, extension, lateral bending and axial rotation of lumbar motion range after unilateral graded facetectomy. The stability of left/right axial direction was greatly affected when the range of graded facetectomy exceed 1/2. According to the Nakai criteria, for the 23 patients, the clinical result was excellent in 15 （65.2%）, good in 6 （26.1%） and fair in 2 （8.7%）. The fusion rate was 95.6% in excellent and good cases. Although partial absorption of bone grafts was observed in 1 case which might indicate a unsuccessful fusion, there was no loosing and replacement of instrument and no clinical symptoms occurred. Conclusion： The lumbar stability will be affected significantly when the range of graded facetectomy exceeds 1/2. Procedures of unilateral facetectomy, transforaminal lumbar interbody fusion and unilateral pedicle screw fixation is an optional strategy for microsurgi     

Effect of partial discectomy on the stability of the lumbar spine. A study of kinematics.

The effect on the stability of the lumbar motion segment, as affected by partial discectomy, was investigated using three-dimensional motion measurement technique. Eight functional spinal units from fresh cadaver lumbar spines were potted and clinically relevant loads applied through a special loading frame attached rigidly to the top vertebra of the specimen. Partial discectomy was performed on the right side of the specimen. The three-dimensional motions of each lumbar motion segment, before and after partial discectomy, were recorded. The results showed that partial discectomy significantly affects the stability of lumbar spinal motion segments. The clinical relevance of this finding is discussed.

     

腰椎经椎间孔椎体间融合不对称内固定的生物力学稳定性实验研究

目的 比较腰椎完整标本和3种L3-4节段的经椎间孔椎体间融合(TLIF)内固定的生物力学稳定性.方法 采用成人新鲜腰椎标本7例,分别于L3-4节段完整状态、左侧TLID同侧椎弓根螺钉(PS)固定、左侧TLIF同侧PS+对侧经关节突椎弓根螺钉(TFPS)固定、左侧TLIF双侧PS固定下,测定10Nm扭矩时前屈/后伸、左/右侧弯及左/右轴向旋转等6种运动下运动范围(ROM)并进行比较.结果 在前屈、后伸及左、右侧弯等4种运动状态下,L<3-4>节段标本完整组ROM明显大于其他3种融合内固定组,均有显著性差异(P<0.05).左、右轴向旋转时,标本完整状态与TLIF同侧PS固定组角位移无显著性差异,明显大于另外2个内固定组,有显著差异(P<0.05).前屈、左侧弯和左旋时,TLIF同侧PS固定与PS+对侧TFPS固定组角位移有显著性差异(P<0.05);6种运动状态下TLIF同侧PS固定的ROM明显大于双侧PS同定组,均有显著性差异(p<0.05).而PS+对侧TFPS固定、双侧PS同定组间ROM均无明显差异.结论 TLIF同侧PS+对侧TFPS周定的稳定性与TLIF双侧PS固定相似,该种腰椎融合不对称内同定方式可作为微创手术治疗的优先备选方案.     

CoflexTM和椎弓根钉棒系统联合应用对腰椎三维运动的影响

目的 探讨采用棘突间稳定装置Coflex TM和椎弓根钉棒内同定系统联合固定后对固定及邻近节段活动度的影响.方法 选取6具新鲜成人尸体脊柱标本(L1～S1段),在三维运动测试仪上进行前屈、后伸、左右侧弯和旋转6个运动方向的稳定性测试,计算L2/3,L3/4和L4/5 3个节段的三维运动范围(ROM)和中性区(NZ),分别比较完整标本(a)、L4/5节段坚强固定(b)、b+L3/4节段棘突间Coflex TM固定(c)3种状态下标本3个节段活动度.结果 L4/5节段6个方向上ROMb、ROMc0.05).结论 采用椎弓根钉坚强同定后其上一节段活动度明显增大,而采用棘突间稳定装置Coflex TM固定邻近节段后此节段活动度明显减少,仅仅造成更上的节段后伸时活动度增大.