腰椎三角固定装置的三维有限元分析

[目的]研究三角固定装置的生物力学特性,并与常规椎弓根螺钉固定方法比较.[方法]建立L3～5 TLIF三维有限元模型,分别用双侧椎弓根螺钉固定(BPSF)、单侧椎弓根螺钉固定(UPSF)、三角固定装置固定(TCF).L3表面施加500 N预载荷,再施加10N·m的力距模拟腰椎前屈、后伸、左右侧屈、轴向旋转等生理活动,测试不同工况下L4～L5节段角位移,椎弓根螺钉或经椎板关节突螺钉、融合器应力分布情况.[结果] BPSF与TCF L4～L5节段角位移小于UPSF; UPSF的螺钉应力峰值明显高于BPSF、TCF; UPSF椎间融合器的应力峰值在各种工况下高于BPSF、TCF,BPSF与TCF基本相似.[结论]TCF生物力学稳定性优于UPSF,与BPSF相似.     

几种微创椎间融合术内固定术式的生物力学比较

目的 探讨经椎间孔减压椎间融合术(transforaminal lumbar interbody fusion,TLIF)微创内固定方法的选择.方法 选取5具人新鲜尸体脊椎标本L4,5节段为受试节段,在生物力学实验机上分别测量每具标本施术前、双侧椎弓根钉棒固定、同侧椎弓根钉棒固定、对侧椎弓根钉棒固定、同侧椎弓根钉棒加对...     

经椎间孔入路和后路椎间融合术即刻稳定性的生物力学比较

目的 比较后路椎间融合术(PLIF)、经椎间孔入路椎间融合术(TLIF)及附加单侧和双侧椎弓根螺钉后即刻稳定性变化和差异.方法 选用15具新鲜小牛标本,随机分为PLIF组、TLIF组及正常对照组,附加单侧和双侧椎弓根螺钉后,在WE-10万能试验机上测试其生物力学特性.结果 行椎间融合术后,两者的各项稳定性指标比正常组下降,附加单侧内固定后,各稳定性指标有所增加,只有附加双侧椎弓根螺钉固定后,两者各稳定性指标都明显增加并超过了正常组.结论 TLIF的稳定性能优于PLIF;附加双侧椎弓根螺钉固定或TLIF附加单侧椎弓根螺钉固定可以有效地增加腰椎初始稳定性.     

单枚椎间融合器并对侧经皮椎弓根螺钉固定的生物力学研究

目的对单枚融合器联合单侧钉棒系统固定的生物力学性能进行评价。方法5具新鲜小牛腰椎标本，建立以下力学模型：A组：双侧开窗＋双枚融合器置入＋双侧椎弓根钉棒固定；B组：单侧小关节切除＋单枚融合器斜向置入＋同侧椎弓根钉棒固定；C组：单侧开窗＋单枚融合器置入＋同侧椎弓根钉棒固定；D组：单侧开窗＋单枚融合器置入＋对侧椎弓根钉棒固定。在生物力学平台上测试各试验组在不同工况下的ROM值。结果A组的固定最稳固，各工况下ROM值最低。B组的前后抗弯ROM值与A组差异无显著性，其左右侧弯和旋转方向的稳定性较A组有所降低。与B组比较，D组的前后弯曲性能与B组差异无显著性，其左右侧弯方向的ROM低与B组。两组的抗旋转ROM值差异无显著性。C组的左右抗弯及抗旋转性能均差于B、D组。结论单枚椎间融合器联合对侧椎弓根钉棒固定是一种力学性能较为优良组合，可以替代单侧斜向融合器并同侧椎弓根钉棒技术用于下腰椎微创手术。     

枢椎棘突螺钉单侧应用联合对侧椎弓根螺钉固定的有限元分析

目的分析枢椎棘突螺钉单侧应用联合对侧椎弓根螺钉固定在寰枢和枕颈固定中的生物力学稳定性。方法构建正常枢椎解剖、椎板薄和椎动脉变异椎弓根细小3种不同解剖状态下的完整上部颈椎有限元模型作为完整模型组,然后分别模拟齿状突骨折进行寰枢固定和寰椎骨折进行枕颈固定。在寰枢固定中,比较单侧枢椎棘突螺钉+对侧椎弓根螺钉+双侧寰椎侧块螺钉固定组(棘突螺钉组)和枢椎双侧椎弓根螺钉+双侧寰椎侧块螺钉固定组(椎弓根螺钉组);在枕颈固定中,比较单侧枢椎棘突螺钉+对侧椎弓根螺钉+枕骨螺钉固定组(棘突螺钉组)和枢椎双侧椎弓根螺钉+枕骨螺钉固定组(椎弓根螺钉组)。枢椎棘突螺钉分别测试水平、斜向、垂直置钉3种不同的固定技术。模拟颈椎运动,测量枕颈的屈伸、侧屈、旋转的关节活动范围(ROM)。结果在寰枢和枕颈固定中,棘突螺钉组和椎弓根螺钉组的C1~C2屈伸、侧屈、旋转ROM均较完整模型组均明显下降。在寰枢固定中棘突螺钉组C0~C2屈伸、侧屈、旋转的ROM大于椎弓根螺钉组;在枕颈固定中,棘突螺钉组C1~C2侧屈的ROM大于椎弓根螺钉组,棘突螺钉组的C0~C2旋转的ROM大于椎弓根螺钉组。枢椎棘突螺钉分别测试水平、斜向、垂直固定间有差异,但不明显。结论在寰枢和枕颈固定中,枢椎双侧椎弓根螺钉固定和枢椎单侧棘突螺钉联合对侧椎弓根螺钉组合式固定方法均具有良好的稳定性。在寰枢固定中,相对于枢椎棘突螺钉组合式固定,枢椎双侧椎弓根螺钉固定具有更好的寰枢稳定性。在枕颈固定中,枢椎双侧椎弓根螺钉固定在侧屈和旋转活动上较枢椎棘突螺钉组合式固定稳定性更好。枢椎三种棘突螺钉置钉技术间的稳定性差异并不明显。     

异种骨椎间融合器椎弓根钉固定腰椎体间融合术的生物力学评价

[目的]评价异种骨椎间融合器行后路腰椎椎体间融合的即刻稳定效果及自身强度.[方法]取16具新鲜成年男性L1～5腰椎标本,分别对完整L1～5（正常组）;模拟后路间盘L3、4摘除置融合器（对照1组）;模拟后路间盘L3、4、L4、5摘除置融合器（对照2组）;模拟后路间盘L3、4摘除置融合器附加椎弓根钉固定（对照3组）;模拟后路间盘L3、4、L4、5摘除置融合器附加椎弓根钉固定（对照4组）进行前屈、后伸、扭转、轴向压缩和腰椎移位时融合器的最大拨出力及粘弹性实验研究.[结果]显示椎间融合器植入后腰椎压缩、前屈、后伸、位移和扭转角度较正常组有一定差异,但不显著（P＞0.05）;而椎间植入融合器附加椎弓根固定,压缩、前屈、后伸、位移、扭转角度较正常组差异显著（P＜0.05）.腰椎移位时拨出力实验结果表明,对照1、2融合器植入椎体移位时最大拨出力为1.83KN.对照1、2、3、4组7 200s三应力松驰量和蠕变量较正常组差异不显著（P＞0.05）,对照3、4组初始蠕变量明显低于正常组和（1、2组）.[结论]异种骨椎间融合器具有足够的支撑、抗滑、维持或增加椎间隙高度的功能,符合生物力学及临床要求.     

内窥镜下后路腰椎椎体间融合附加单侧椎弓根螺钉固定的力学基础

[目的]通过生物力学试验评价内窥镜下后路腰椎椎体间融合(PLIF)附加单侧椎弓根螺钉固定的稳定性及力学合理性。[方法]建立PLIF术式相关的小牛腰椎模型,进行前屈、后伸、左右侧屈、扭转等的非破坏性测定,记录融合节段L4、5和邻近节段L3、4的应变、应力、腰椎的轴向刚度和扭转刚度等力学量并对比分析。[结果]PLIF附加单侧椎弓根螺钉固定组融合节段上的应变、应力在前屈、后伸、侧屈等工况下较正常组有所减少但差异无统计学意义(P>0.05),而与PLIF附加双侧椎弓根螺钉固定组间差异有非常显著性意义(P<0.01)。在500 N载荷作用下,PLIF附加单侧椎弓根螺钉固定组脊柱位移为(2.56±0.34)mm,轴向刚度较正常组增加了5%,但差异无统计学意义(P>0.05);而与PLIF附加双侧椎弓根螺钉固定组间差异有统计学意义(P<0.05)。PLIF附加单侧椎弓根螺钉固定后扭转刚度较正常组差异无显著性(P>0.05),但明显低于PLIF附加双侧椎弓根螺钉固定组(P<0.05)。同时,PLIF附加单侧椎弓根螺钉固定后,邻近节段L3、4小关节上的应变、应力及L3、4椎间盘上的应力在各种不同工况下与正常组间差异无统计学意义(P>0.05),而在前屈时与PLIF附加双侧椎弓根螺钉固定组间差异有统计学意义(P<0.05)。[结论]PLIF附加单侧椎弓根螺钉固定可以弥补由于后方骨性和韧带结构部分破坏所造成的医源性不稳,增强腰椎的初始稳定性;在重建脊柱稳定性的同时,并没有增加邻近节段退行性疾病发生的危险。     

椎弓根钉内固定联合椎体成形术治疗骨质疏松性胸腰椎爆裂骨折的三维有限元研究

目的采用有限元方法比较骨质疏松性胸腰椎爆裂骨折在椎弓根钉内固定联合椎体成形术与椎弓根钉结合伤椎置钉内固定术后的生物力学稳定性。方法建立骨质疏松性L_1椎体爆裂骨折有限元模型,模拟短节段椎弓根钉联合椎体成形术(A组)以及椎弓根钉结合伤椎置钉内固定术(B组),比较2组前屈、后伸、侧屈、旋转载荷下L_1椎体最大位移及内固定物最大应力值。结果在前屈、后伸、侧屈、旋转载荷下,L_1椎体最大位移见于前屈载荷,2组前屈、后伸、侧屈、旋转载荷下L_1椎体最大位移比较差异无统计学意义(P0.05)。在前屈、后伸及侧屈载荷时,内固定物应力最大值为下位螺钉尾部与钛棒联接处,A组前屈、后身、侧屈内固定应力较B组小,差异有统计学意义(P0.05);在旋转载荷时,A组内固定物应力最大部位仍为下位螺钉尾部与钛棒联接处,B组内固定物应力最大部位为伤椎螺钉尾部与钛棒联接处,A组旋转内固定物应力较B组小,差异有统计学意义(P0.05)。结论椎弓根钉内固定联合椎体成形术治疗骨质疏松性胸腰椎爆裂骨折生物力学稳定性强,可获得比椎弓根钉结合伤椎置钉内固定术更小的内固定物应力,能有效防止内固定物失效。     

腰椎微创极外侧经椎间孔椎体间融合术的生物力学评价

目的 通过生物力学测试比较腰椎微创极外侧经椎间孔椎体间融合术(E-TLIF)与传统术式的生物力学稳定性.方法 采用正常猪脊柱运动节段标本24副,随机进行不同处理后分为正常对照组(CG组)、单纯椎弓根螺钉内固定组(SG组)、经椎间孔腰椎体间融合术(TLIF)组、E-TLIF组;分别测试不同载荷时各组在轴向压缩、前屈、后伸、左侧屈时的应变、位移变化及左侧扭转稳定性等生物力学指标,并进行统计学比较.结果 E-TLIF组的载荷-应变和位移、最大载荷下轴向稳定性、扭转稳定性等生物力学指标与TLIF组比较差异无统计学意义(P＞0.05).在左侧屈活动中,E-TLIF组[线性位移(3.40 ±0.09)mm,角位移2.57°±0.12°]稳定性优于TLIF组[线性位移(3.98 ±0.22)mm,角位移3.03°±0.18°](t=2.61,P＜0.05),E-TLIF组和TLIF组在轴向(前屈、后伸)、侧屈、旋转方向上的力学稳定性均高于SG组(t=4.17 ～4.53,P＜0.01).结论 E-TLIF手术是一种安全、有效的腰椎椎体间融合术式.     

脊柱骨折经伤椎椎弓根置钉附加横连短节段固定的稳定性测试

目的:探讨脊柱骨折经伤椎椎弓根置钉附加横连短节段钉棒固定的稳定性.方法:5具新鲜冰冻小牛腰椎标本(L1～L5)制备成L3椎体爆裂骨折模型,依次进行单纯经伤椎和上下相邻椎体椎弓根置钉短节段6钉固定(单纯经伤椎6钉固定组)和附加横连经伤椎和上下相邻椎体椎弓根置钉短节段6钉固定(附加横连经伤椎6钉固定组),测试L2～L4损伤前(对照组)、损伤后(骨折组)及单纯经伤椎6钉固定组和附加横连经伤椎6钉固定组的三维6个方向的运动范围(ROM),比较各组间的差异.结果:L3椎体爆裂骨折后L2～L4各方向的ROM明显增加,与损伤前比较均有显著性差异(P<0.05);单纯经伤椎6钉固定组与附加横连接经伤椎6钉固定组各方向的ROM均明显减小,与骨折组相比均有显著性差异(P<0.05),在前屈、后伸、侧弯运动方向的ROM小于对照组,差异有显著性(P<0.05),旋转方向上大于对照组(P<0.05).两种固定方式在前屈、后伸、侧弯方向上的ROM无显著性差异(P>0.05),附加横连经伤椎6钉固定组较单纯经伤椎6钉固定组在旋转方向上的ROM小,差异有显著性(P<0.05).结论:经伤椎椎弓根置钉短节段钉棒固定可提高骨折模型各个运动方向上的生物力学稳定性,附加横连经伤椎6钉固定技术较单纯经伤椎6钉固定技术在轴向旋转运动方向上可提供更强的力学稳定性.     

单侧椎弓根螺钉固定椎体间融合治疗腰椎退行性疾病

目的 探讨单侧椎弓根螺钉固定经椎间孔椎体间融合(transforaminal lumbar interbody fusion,TLIF)联合后外侧融合(posterolateral fusion,PLF)技术治疗腰椎退行性疾病的可行性及有效性.方法 分析2006年12月至2008年8月收治的因患腰椎退行性疾病行腰椎后路融合术并获得随访的患者78例.采用单侧椎弓根螺钉固定TLIF联合PLF技术治疗48例(单侧组),男25例,女23例;年龄31～64岁,平均47.6岁.采用双侧椎弓根螺钉固定TLIF联合PLF技术治疗30例(双侧组),男21例,女9例;年龄26～66岁,平均50.5岁.使用Oswestry功能障碍指数,疼痛视觉模拟评分(visual analogue score,VAS)评估两组患者术后疗效,并比较两组患者手术时间、出血量、融合率和椎间隙塌陷率等指标.结果 两组患者的Oswestry功能障碍指数、腰痛VAS评分、腿痛VAS评分在术前与术后3个月以及术后3个月与术后1年之间比较差异均有统计学意义,在术前与术后1年的评分改善方面差值比较无统计学意义.两组患者手术时间、出血量及住院费用比较差异均有统计学意义,单侧组少于双侧组.两组患者术后住院时间比较差异无统计学意义.单、双侧组融合率分别为91.7%(44/48)和93.3%(28/30).结论 椎间植骨联合单侧椎弓根螺钉固定能提供较好的脊柱即刻稳定性.单侧椎弓根固定TLIF联合PLF技术作为一种治疗腰椎退行性疾病的方法,疗效满意.     

Less invasive posterior fixation method following transforaminal lumbar interbody fusion: a biomechanical analysis.

BACKGROUND CONTEXT: Current surgical trends increasingly emphasize the minimization of surgical exposure and tissue morbidity. Previous research questioned the ability of unilateral pedicle screw instrumentation to adequately stabilize posterior fusion constructs. No study to date has addressed the effects of reduced posterior instrumentation mass on interbody construct techniques. Unilateral surgical exposure for transforaminal lumbar interbody fusion (TLIF) allows ipsilateral pedicle screw placement. Theoretically, percutanous contralateral facet screw placement could provide supplemental construct support without additional surgical exposure. PURPOSE: Identify the biomechanical effects of reduced spinal fusion instrumentation mass on interbody construct stability. STUDY DESIGN: An in vitro biomechanical study using human lumbar spines comparing stability of TLIF constructs augmented by: (1) bilateral pedicle screw fixation, (2) unilateral pedicle screw fixation, or (3) a novel unilateral pedicle screw fixation supplemented with contralateral facet screw construct. METHODS: Seven fresh frozen human cadaveric specimens were tested in random construct order in flexion/extension, lateral bending, and axial rotation using +/-5.0 Nm torques and 50 N axial compressive loads. Analysis of torque rotation curves determined construct stability. Using paired statistical methods, comparison of construct stiffness and total range of motion within each specimen were performed using the Wilcoxon signed ranks test with a Holm-Sidák multiple comparison procedure (alpha=0.05). RESULTS: In flexion/extension, lateral bending, and axial rotation, there were no measurable differences in either stiffness or range of motion between the standard bilateral pedicle screw and the novel construct after TLIF. After TLIF, the unilateral pedicle screw construct provided only half of the improvement in stiffness compared with bilateral or novel constructs and allows for significant off-axis rotational motions, which could be detrimental to stability and the promotion for fusion. CONCLUSIONS: All tested TLIF constructs with posterior instrumentation decreased segmental range of motion and increased segmental stiffness. While placing unilateral posterior instrumentation decreases overall implant bulk and dissection, it allows for significantly increased segmental range of motion, less stiffness, and produces off-axis movement. The technique of contralateral facet screw placement provides the surgical advantages of unilateral pedicle screw placement with stability comparable to TLIF with bilateral pedicle screws.     

Unilateral versus bilateral pedicle screw fixation with transforaminal lumbar interbody fusion for treatment of lumbar foraminal stenosis

BACKGROUND CONTEXTTransforaminal lumbar interbody fusion (TLIF) with bilateral pedicle screw fixation (BPSF) is an effective treatment for lumbar foraminal stenosis (LFS). However, the effects of TLIF with unilateral pedicle screw fixation (UPSF) on LFS treatment have not been clearly elucidated.PURPOSEWe conducted this study to compare clinical outcomes and radiographic results of TLIF with UPSF and BPSF 2 years after the surgical treatment.DESIGNProspective randomized study.PATIENT SAMPLEThis study included 23 patients undergoing TLIF with UPSF and 25 patients undergoing TLIF with BPSF.OUTCOME MEASURESClinical outcomes were evaluated by visual analog scale (VAS) for low back pain and leg pain and Oswestry Disability Index (ODI) score. Radiographic outcomes included foraminal height, disc space height, segmental lordosis, and final fusion rates.METHODSThe clinical and radiographic outcomes were compared between the UPSF and BPSF group. The postoperative improvements were evaluated in either group. Intraoperative data such as duration of operation and estimated blood loss were collected. This study was registered at clinicaltrials.gov.RESULTSAnalysis of the VAS and ODI scores showed significant improvements in clinical outcomes within each group. No significant differences between the 2 groups were noted in the improvements of the VAS and ODI scores. The mean operative duration and blood loss were significantly greater in the BPSF group than in the UPSF group. There were significant improvements in the height of the foramen and intervertebral space and segmental lordosis in both groups, while there was no significant difference between the groups in amount of the improvements. No significant difference was found in the final fusion rates.CONCLUSIONSTLIF is an appropriate procedure for LFS treatment. With balanced intervertebral support using a cage, UPSF could achieve similar and satisfactory effects on lumbar segmental stability and fusion compared to BPSF. The unilateral approach appears to be associated with slightly shorter operative time and less blood loss.     

下腰椎不同固定方式的生物力学对比研究

目的 观察下腰椎不同固定方式对腰椎稳定性的影响.方法 新鲜成人尸体下腰椎标本6具,测定L4/5节段屈伸、左右侧屈、左右旋转6个方向ROM和刚度值的变化,按5组顺序依次测试:A组(正常下腰椎标本组);B组(单侧椎板关节突螺钉固定+椎间单枚Cage);C组(单侧椎弓根螺钉固定+椎间单枚Cage);D组(单侧椎弓根螺钉联合对侧椎板关节突螺钉固定+椎间单枚Cage);E组(双侧椎弓根螺钉固定+椎间单枚Cage).结果 与A组比较,B组各运动状态ROM有减少,而刚度明显增加,差异有统计学意义(P＜0.05);与B组比较,C组各运动方向ROM与刚度,差异无统计学意义(P＞0.05);与C组比较,D组各运动状态ROM有减少,而刚度增加,差异有统计学意义(P＜0.05);与E组比较,D组各运动方向ROM与刚度,差异无统计学意义(P＞0.05);与E组比较,C组各运动状态ROM有增加,而刚度减少,差异有统计学意义(P＜0.05).结论 单侧椎板关节突螺钉固定并椎间融合器植骨方法提供了一定的稳定性,而单侧椎弓根螺钉联合对侧椎板关节突螺钉固定并椎间融合器植骨具有与双侧椎弓根螺钉固定相同的稳定性,临床上可根据病例的具体情况,如身高体质量指数、病变类型及病变节段稳定程度选择性地应用上述两种固定融合方法.     

椎弓根固定结合经椎间孔椎间融合治疗复发性腰椎间盘突出症伴腰椎不稳

目的：探讨经肌间隙入路椎弓根固定结合经椎间孔椎间融合（transforaminal lumbar interbody fusion,TLIF）治疗复发性腰椎间盘突出症伴腰椎不稳的临床疗效。方法：2008年3月至2010年5月收治35例复发性腰椎间盘突出症,其中15例行经肌间隙入路单边椎弓根固定结合TLIF术式（单边固定组）,20例行后正中入路双边椎弓根固定结合后路椎间植骨融合（posterior lumbar interbody fusion,PLIF）术式（双边固定组）.观察手术时间、术中出血量,并比较手术前后两组患者JOA评分、腰痛及腿痛VAS评分及融合情况。结果：所有患者获得随访,时间6～30个月,平均16.8个月。两组患者腰腿痛等临床症状较术前明显缓解,X线片显示植骨融合良好（双边固定组中1例未融合）,无融合器移位、下沉及内固定器械松动或断裂。两组患者手术时间、术中出血量比较差异有统计学意义（P<0.05）.术后JOA评分均较术前降低（P<0.05）.术后1周,两组患者腰痛VAS评分比较差异有统计学意义（P<0.05）,腿痛VAS评分比较差异无统计学意义（P>0.05）;末次随访,腰痛及腿痛VAS评分两组比较差异无统计学意义（P>0.05）.结论：两种术式在治疗复发性腰椎间盘突出症伴腰椎不稳均可达到满意的疗效,经肌间隙入路单边椎弓根固定结合TLIF术式切口较小,手术时间较短,术中出血量较少,术后腰痛缓解较快。     

Biomechanical comparison of unilateral and bilateral pedicle screws fixation for transforaminal lumbar interbody fusion after decompressive surgery -- a finite element analysis

ABSTRACT: BACKGROUND: Little is known about the biomechanical effectiveness of transforaminal lumbar interbody fusion (TLIF) cages in different positioning and various posterior implants used after decompressive surgery. The use of the various implants will induce the kinematic and mechanical changes in range of motion (ROM) and stresses at the surgical and adjacent segments. Unilateral pedicle screw with or without supplementary facet screw fixation in the minimally invasive TLIF procedure has not been ascertained to provide adequate stability without the need to expose on the contralateral side. This study used finite element (FE) models to investigate biomechanical differences in ROM and stress on the neighboring structures after TLIF cages insertion in conjunction with posterior fixation. METHODS: A validated finite-element (FE) model of L1-S1 was established to implant three types of cages (TLIF with a single moon-shaped cage in the anterior or middle portion of vertebral bodies, and TLIF with a left diagonally placed ogival-shaped cage) from the left L4-5 level after unilateral decompressive surgery. Further, the effects of unilateral versus bilateral pedicle screw fixation (UPSF vs. BPSF) in each TLIF cage model was compared to analyze parameters, including stresses and ROM on the neighboring annulus, cage-vertebral interface and pedicle screws. RESULTS: All the TLIF cages positioned with BPSF showed similar ROM (<5 %) at surgical and adjacent levels, except TLIF with an anterior cage in flexion (61 % lower) and TLIF with a left diagonal cage in left lateral bending (33 % lower) at surgical level. On the other hand, the TLIF cage models with left UPSF showed varying changes of ROM and annulus stress in extension, right lateral bending and right axial rotation at surgical level. In particular, the TLIF model with a diagonal cage, UPSF, and contralateral facet screw fixation stabilize segmental motion of the surgical level mostly in extension and contralaterally axial rotation. Prominent stress shielded to the contralateral annulus, cage-vertebral interface, and pedicle screw at surgical level. A supplementary facet screw fixation shared stresses around the neighboring tissues and revealed similar ROM and stress patterns to those models with BPSF. CONCLUSIONS: TLIF surgery is not favored for asymmetrical positioning of a diagonal cage and UPSF used in contralateral axial rotation or lateral bending. Supplementation of a contralateral facet screw is recommended for the TLIF construct.     

腰椎间融合单、双侧内固定术的生物力学分析

目的通过4种力学模型,比较不同状态下腰椎的稳定性,探讨单侧椎弓根内固定椎间自体骨融合术的稳定性。方法选用20具猪的脊柱标本,标本依序进行不同处理并分组：a）正常组（A组）;b）左侧L4下关节突切除加椎间盘摘除组（B组）;c）腰椎左侧椎间植骨融合附加同侧椎弓根螺钉固定组（C组）;d）腰椎左侧椎间植骨融合双侧椎弓根螺钉固定组（D组）。将标本固定于特制的夹具上,用生物力学测试仪进行轴向压缩、前屈、后伸和左右侧屈,获得载荷-位移曲线,对所得数据进行分析。结果轴向压缩测试D组强度最高,C组强度次之,均高于A组。B组强度最小,A、C、D组之间没有统计学意义,A、C、D组与B组均有统计学意义（P〈0.01）。前屈测试D组获得最高强度,C组与A组没有差别,明显小于D组,B组强度最小。A组与C组没有统计学意义,A、C组与D组、B组均有统计学意义。后伸测试与前屈测试相似,D组获得最高强度,C组低于D组。他们强度都高于A组,B组明显低于其他组。A组与C组没有统计学意义,A、C组与D组、B组有统计学意义。左侧屈测试D组和C组是两个强度最高组,明显高于完整A组,B组是强度最低。D组与C组没有统计学意义,D、C组与B组、A组有统计学意义。右侧屈测试D组强度最高,C组强度次之,高于完整A组,B组强度最低。D组与C组没有统计学意义,D、C组与B组、D组与A组、C组与A组均有统计学意义。结论单侧椎弓根内固定椎间自体骨融合术生物力学测试,其强度高于或等同于完整组,符合人体生物力学要求,在治疗腰椎间盘突出症伴腰椎不稳时,可以成为取代双侧椎弓根内固定椎间自体骨融合术的一种新术式,对临床工作有一定指导意义。     

PLIF与TLIF治疗腰椎不稳症的疗效比较

目的对比研究后路腰椎椎体间植骨融合术(posteriorlumbarinterbodyfusion,PLIF)与经腰椎间孔入路腰椎椎间植骨融合术(transforaminallumbarinterbodyfusion,TLIF)治疗腰椎不稳症的疗效。方法1999年2月~2006年3月,217例重度退变性腰椎不稳症患者接受腰椎后路椎间植骨融合,辅以相应节段椎弓根钉内固定术,其中76例经腰椎间孔椎体间植骨融合(TLIF组),另外141例经腰椎管内(硬脊膜外)椎体间植骨融合(PLIF组),比较两组手术方式的临床疗效、植骨融合率及手术并发症。结果217例患者手术切口均一期愈合,无椎间隙感染、下肢深静脉栓塞等并发症。PLIF组128例患者经6~82个月随访,平均64个月,发生硬脊膜撕裂4例,脑脊液漏1例,马尾神经及神经根一过性牵拉损伤3例。TLIF组67例经4~56个月随访,平均36个月,未发生神经损伤等并发症。两组平均手术时间、术中平均出血量、平均住院时间均无明显差异。TLIF组与PLIF组的临床优良率分别为89.86%和86.72%,两者无显著性差异(P>0.05),植骨融合率分别为92.75%和93.75%,两者无显著性差异(P>0.05)。结论经腰椎间孔入路椎间植骨融合术治疗腰椎不稳症,不但技术操作可行,而且能明显降低因侵入椎管而带来的各种并发症,是治疗重度退变性腰椎不稳症的有效手术方式。     

单侧椎弓根螺钉固定在腰椎退行性疾病的研究进展

〓【摘要】〓保守失败的腰椎退行性疾病常需要手术治疗,传统的双侧椎弓根螺钉腰椎融合术可能增加邻近节段退变的发生率。近年研究表明,单侧椎弓根螺钉结合椎体间融合术治疗腰椎退行性疾病可获得与传统双侧椎弓根螺钉固定相似的稳定性与融合率,并可预防固定融合节段的邻近节段退变,但应用单侧椎弓根螺钉固定需要严格掌握手术适应证。     

经椎间孔入路椎间融合术并单侧椎弓根螺钉固定治疗退变性腰椎不稳

目的研究经椎间孔入路椎间融合术并单侧椎弓根螺钉固定治疗腰椎退变伴不稳症的临床疗效。方法29例腰椎不稳症的患者行椎间孔入路椎间融合术并单侧椎弓根螺钉固定术,共融合29个椎间隙。记录其手术时间、出血量、术后并发症等。观察其临床疗效满意率和植骨融合率等。结果平均手术时间100 min,出血量约450 mL。所有患者伤口均Ⅰ期愈合。术中未出现硬膜囊撕裂、马尾神经损伤。患者均随访16～30个月。1年后所有病例均达到椎间隙骨性融合。3例术后0.5年仍遗留轻度腰背部疼痛,经非手术治疗后疼痛缓解失,临床疗效优良率为93.1%。结论经椎间孔入路椎间融合术并单侧的椎弓根螺钉固定创伤小、并发症少、临床疗效满意,是治疗退变性腰椎不稳症的安全、有效方法。