退变性腰椎滑脱后路融合术后的远期疗效分析

[目的]探讨后路减压复位融合内固定术治疗退变性腰椎滑脱的远期疗效.[方法]2001年1月～2005年7月行后路减压、植骨融合、椎弓根螺钉复位内固定术,资料完整并获得未次随访的退变性腰椎滑脱患者62例,随访5～9年(平均6.4年).融合方式有后外侧融合(PLF)、自体髂骨椎问融合(PLIF)、椎间Cage植入融合(PLJF+Cage).评价JOA评分改善率、优良率、满意度、融合及临近节段退变情况等,对术前、术后及末次随访时滑脱率、椎问高度、椎间盘角、节段侧凸角等影像学指标进行比较和分析.[结果]JOA评分改善率(67.7±19.4)%,优良率85.5%,满意度87.1%,融合率95.2%,临近节段退变或原有退变加重26例(41.9%),各融合方式间均无显著性差异(P>0.05).术后滑脱率、椎间高度、椎间盘角及节段侧凸角较术前均显著改善(P<0.05),末次随访时滑脱复位、椎间高度、椎间盘角有所丢失,椎间Cage植入融合丢失最少.[结论]后路减压、植骨融合、椎弓根螺钉复位内固定术治疗退变性腰椎滑脱远期疗效满意,椎间Cage植入融合的放射学表现更佳.     

Lumbar interbody fusion using the Brantigan I/F cage for posterior lumbar interbody fusion and the variable pedicle screw placement system: two-year results from a Food and Drug Administration investigational device exemption clinical trial

STUDY DESIGN: A carbon fiber-reinforced polymer cage implant filled with autologous bone was designed to separate the mechanical and biologic functions of posterior lumbar interbody fusion. OBJECTIVES: To test the safety and efficacy of the carbon cage with pedicle screw fixation in a 2-year prospective study performed at six centers under a protocol approved by the Food and Drug Administration, and to present the data supporting the Food and Drug Administration approved indications. SUMMARY OF BACKGROUND DATA: The success of posterior lumbar interbody fusion has been limited by mechanical and biologic deficiencies of the donor bone. Some failures of pedicle screw fixation may be attributable to the absence of adequate load sharing through the anterior column. Combining an interbody fusion device with pedicle screw fixation may address some limitations of posterior lumbar interbody fusion or pedicle screw fixation in cases that are more complex mechanically. METHODS: This clinical study of posterior lumbar interbody fusion with pedicle screw fixation involved a prospective group of 221 patients. RESULTS: Fusion success was achieved in 176 (98.9%) of 178 patients. In the management of degenerative disc disease in patients with prior failed discectomy surgery, clinical success was achieved in 79 (86%) of 92 patients, and radiographic bony arthrodesis in 91 (100%) of 91 patients. Disc space height, averaging 7.9 mm before surgery, was increased to 12.3 mm at surgery and maintained at 11.7 mm at 2 years. Fusion success was notdiminished over multiple fusion levels. These results were significantly better than those reported in prior literature. Although significant surgical complications occurred, those attributable to the implant devices occurred less frequently and generally were minor. CONCLUSIONS: The Brantigan I/F Cage for posterior lumbar interbody fusion and the Variable Screw Placement System are safe and effective for the management of degenerative disc disease.     

Posterior lumbar interbody fusion using one diagonal fusion cage with transpedicular screw/rod fixation

Posterior lumbar interbody fusion (PLIF) using threaded cages has gained wide popularity for lumbosacral spinal disease. Our biomechanical tests showed that PLIF using a single diagonal cage with unilateral facetectomy does add a little to spinal stability and provides equal or even higher postoperative stability than PLIF using two posterior cages with bilateral facetectomy. Studies also demonstrated that cages placed using a posterior approach did not cause the same increase in spinal stiffness seen with pedicle screw instrumentation, and we concluded that cages should not be used posteriorly without other forms of fixation. On the other hand, placement of two cages using a posterior approach does have the disadvantage of risk to the bilateral nerve roots. We therefore performed a prospective study to determine whether PLIF can be accomplished by utilizing a single diagonal fusion cage with the application of supplemental transpedicular screw/rod instrumentation. Twenty-seven patients underwent a PLIF using one single fusion cage (BAK, Sulzer Spine-Tech, Minneapolis, MN, USA) inserted posterolaterally and oriented anteromedially on the symptomatic side with unilateral facetectomy and at the same level supplemental fixation with a transpedicular screw/rod system. The internal fixation systems included 12 SOCON spinal systems (Aesculap AG, Germany) and 15 TSRH spinal systems (Medtronic Sofamor Danek, USA). The inclusion criteria were grade 1 to 2 lumbar isthmic spondylolisthesis, lumbar degenerative spondylolisthesis, and recurrent lumbar disc herniations with instability. Patients had at least 1 year of low back pain and/or unilateral sciatica and a severely restricted functional ability in individuals aged 28-55 years. Patients with more than grade 2 spondylolisthesis or adjacent-level degeneration were excluded from the study. Patients were clinically assessed prior to surgery by an independent assessor; they were then reassessed at 1, 3, 6, 12, 18, and 24 months postoperatively by the same assessor and put into four categories: excellent, good, fair, and poor. Operative time, blood loss, hospital expense, and complications were also recorded. All patients achieved successful radiographic fusion at 2 years, and this was achieved at 1 year in 25 out of 27 patients. At 2 years, clinical results were excellent in 15 patients, good in 10, fair in 1, and poor in 1. Regarding complications, one patient had a postoperative motor and sensory deficit of the nerve root. Reoperation was required in one patient due to migration of pedicle screws. No implant fractures or deformities occurred in any of the patients. PLIF using diagonal insertion of a single threaded cage with supplemental transpedicular screw/rod instrumentation enables sufficient decompression and solid interbody fusion to be achieved with minimal invasion of the posterior spinal elements. It is a clinically safer, easier, and more economical means of accomplishing PLIF.     

Is one cage enough in posterior lumbar interbody fusion: a comparison of unilateral single cage interbody fusion to bilateral cages

Posterior lumbar interbody fusion (PLIF), as recommended with bilateral lumbar interbody cages and pedicle screw fixation, has increased the successful fusion rate to nearly 100%. Presently, a unilateral approach to the disc space with a variant of PLIF, the trans-foraminal interbody fusion is often used. There are few clinical studies of unilateral interbody fusion. The clinical and fusion results of unilateral interbody fusion are important as the usage of trans-foraminal interbody fusion procedure increases. This retrospective study of 26 consecutive patients treated with a unilateral cage asks whether fusion healing and clinical outcome is comparable with that obtained with bilateral cages. In this study, there were no pseudarthroses, instrumentation failures, or significant subsidence at any of the single cage levels. Disc space height and foraminal height were restored by the surgery and maintained at last follow-up. Using Prolo scores, 23/26 patients had clinical success (88%), and 3 were unsuccessful. Fusion was successful at all single cage fusion levels and overall in 23/26 (88%) reviewing all levels of fusion. In conclusion, fusion and clinical success rates were not diminished by the use of a unilateral interbody cage rather than the recommended 2 cages. This retrospective comparative study is a Level III-2 Therapeutic Study investigating the results of unilateral PLIF with a single interbody cage compared with historical series with interbody cages.     

The in vitro stabilising effect of polyetheretherketone cages versus a titanium cage of similar design for anterior lumbar interbody fusion

This biomechanical study was performed to test the primary segmental in vitro stabilising effect of a standard and large footprint radiolucent poly-ether-ether-ketone (PEEK) box cage versus a titanium box cage for anterior lumbar interbody fusion. Eighteen L2-L3 and sixteen L4-L5 cadaveric motion segments were divided into three groups and received a titanium cage or a radiolucent PEEK cage with standard or large footprint. All specimens were tested in three testing conditions: intact, stand-alone anterior cage and finally with supplemental translaminar screw fixation. Full range of motion and neutral zone measurements were determined and anterior cage pull out force was tested. The titanium design was significantly more effective in reducing the range of motion only in axial rotation. The larger footprint radiolucent cage did not increase stability as compared to the standard footprint. The titanium cage pull out force was significantly (P=0.0002) higher compared to both radiolucent cage constructs. Clinical relevance: Supplemental posterior fixation is strongly recommended to increase initial stability of any anterior interbody fusion cage construct. Although the biomechanical stability necessary to achieve spinal fusion is not defined, the radiolucent designs tested in this study, with a standard footprint as well as with a larger footprint, may be insufficiently stabilised with translaminar screws as compared to the titanium implant. Supplemental pedicle screw fixation may be required to obtain adequate stabilisation in the clinical setting.     

经后路PLIF加BIOFLEX治疗腰椎失稳症

目的 探讨经后路植入椎体间可撑开螺文融合器PLIF及弹性椎弓根内固定系统BIOFLEX对腰椎失稳定症治疗的临床效果.方法 对132例腰椎失稳症患者采用后路椎管及神经根管减压,BIOFLEX椎弓根系统固定并椎间植入PLIF手术治疗.结果 132例术后随访8～23个月,平均15个月,未发现椎间植骨不融合情总,术后优良率97.7%.结论 经后路植入椎体间传统椎间融合术的许多不足,大大减少了术后并发症,提高了腰椎失稳症的治疗效果.     

Achievement of normal sagittal plane alignment using a wedged carbon fiber reinforced polymer fusion cage in treatment of spondylolisthesis.

BACKGROUND CONTEXT: Previous clinical studies of interbody fusion cages have generally failed to report sagittal plane alignment. In some cases, parallel-sided cages have contributed to loss of lumbar lordosis. A wedged-shaped carbon-fiber-reinforced polymer (CFRP) cage implant filled with autologous bone was designed to allow surgeons to more easily achieve normal sagittal plane alignment in posterior lumbar interbody fusion (PLIF). PURPOSE: This study was conducted to test the safety and efficacy of the wedged CFRP cage and the ability of surgeons to achieve normal anatomic alignment using an implant of this shape. STUDY DESIGN/SETTING: The wedged CFRP cage with pedicle screw fixation was evaluated in the treatment of patients with spondylolisthesis in a 2-year prospective study performed at 12 centers under a Food and Drug Administration (FDA)-approved protocol PATIENT SAMPLE: Inclusion criteria included patients with isthmic or degenerative spondylolisthesis at a single level below L4 with a translational malalignment of 3 mm or greater. Exclusion criteria included patients with more than 90% translation, previous surgery or abnormalities at more than two levels. OUTCOME MEASURES: Traditional outcome measures have included clinical success (improvement in pain and function) and fusion success (proof of living bone bridging the fusion area). This study adds a more complete analysis of anatomic success (restoration or maintenance of normal disc space height and sagittal plane alignment). METHODS: A clinical study of PLIF with pedicle screw fixation included a prospective group of 46 patients treated for spondylolisthesis. This article presents the data from the FDA-approval protocol. RESULTS: Fusion success was achieved in 35 of 36 patients (97.2%) reaching the 2-year follow-up interval. Clinical success was achieved in 35 of 37 (94.6%), and overall success was achieved in 33 of 36 (91.2%). Disc space height averaged 8.3 mm preoperatively, was increased to 10.2 mm at surgery and was maintained at 9.8 mm at 2 years. L4-S1 sagittal plane alignment was maintained within normal range, averaging 30.6 degrees after surgery. Clinical and fusion success rates trended higher than previous results with the rectangular cage but were not statistically different. Fusion success was significantly better than prior literature for treatment of spondylolisthesis (p=.0160). Complications of the surgery trended lower but were not statistically different from the study of the rectangular cage. CONCLUSIONS: The wedged CFRP cage with pedicle screw fixation allows surgeons to maintain normal sagittal plane alignment. These devices are safe and effective for treatment of spondylolisthesis and are FDA approved in the United States.     

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.     

Complications and strategies for salvage of intervertebral fixation devices

The recent evolution of interbody fixation devices, known as threaded interbody fusion cages, is a significant new form of segmental fixation for application to the lumbar and lumbosacral spine. This article discusses the construction, biomechanics, and use of these devices, which serve as carriers for autogenous graft material while restoring segmental stability to the involved motion segment. The biomechanics of these devices greatly surpasses those of the interbody spacers used historically. Interbody spacers have traditionally been utilized as a component of an overall construct that also employed segmental posterior instrumentation. Threaded interbody cages, on the other hand, are able to confer a degree of stability to the diseased motion segment as stand-alone constructs.     

Prospective clinical outcomes of revision fusion surgery in patients with pseudarthrosis after posterior lumbar interbody fusions using stand-alone metallic cages.

BACKGROUND CONTEXT: Posterior lumbar interbody fusion (PLIF) is a popular method of arthrodesis for surgical treatment of instabilities and degenerative conditions of the spine. With the introduction of threaded titanium cage devices, surgeons began performing PLIF procedures using these cages as stand-alone devices. Complications have been reported, however, including pseudarthrosis with persistent pain. Outcomes after revision surgical treatment for these patients with failed PLIF are not known. PURPOSE: To prospectively evaluate clinical outcomes of revision fusion surgery in patients who previously underwent posterior lumbar interbody fusion with stand-alone metallic cages resulting in pseudarthrosis. STUDY DESIGN/SETTING: Prospective case series. METHODS: Nineteen patients referred to the senior author were evaluated and diagnosed with pseudoarthrosis having previously undergone a PLIF procedure with stand-alone metallic cages. History, physical exam, and imaging studies were performed preoperatively and postoperatively. All underwent revision posterolateral fusion with iliac crest graft and pedicle screw instrumentation. Patient demographics, SF-36, and Oswestry Disability Index (ODI) data were collected prior to surgery and two years postoperatively. RESULTS: Patients undergoing revision fusion surgery were found to have had extensive facetectomies and pseudarthrosis intraoperatively. Outcomes data was collected on eighteen of nineteen patients (95%). Mean clinical follow up was 3.2 years (range 2.5-3.5 years). Seventeen patients (94%) achieved a solid fusion. Improvement was noted in seven of eight SF-36 sub-categories, but was significant only in two (Physical Function and Role Emotional). There was no significant difference in ODI scores. CONCLUSIONS: Pseudarthrosis should be considered in the differential diagnosis if severe symptoms persist in patients who undergo PLIF with stand-alone metallic cages. Successful revision fusion did not always correlate with improved clinical outcomes in these challenging patients undergoing further surgery. Performing PLIF using stand-alone metallic cages, especially after total resection of the facet joints, is not advocated unless supplemental instrumentation is utilized.     

腰椎经椎弓根螺钉系统内固定治疗腰椎间盘突出症

目的分析使用椎弓根螺钉系统内固定治疗腰椎间盘突出症的适应证与近期临床效果。方法对222例腰椎间盘突出症患者行后路减压,经椎弓根植入椎弓根螺钉,用钉-棒联结结构固定棒杆,应用椎间融合器植骨(Cage)融合,或行横突间植骨。结果随访时间2~37个月,根据Macnab手术评价标准,优良率为98·20%。结论椎弓根螺钉系统内固定治疗腰椎间盘突出症是一种使用安全,近期随访疗效满意的方法。     

腰椎滑脱手术复位问题的探讨

目的探讨腰椎滑脱手术的复位问题。方法66例腰椎滑脱患者,其中36例(治疗组)采用椎弓根螺钉内固定加椎体间、后外侧植骨及Cage应用治疗,30例(对照组)采用后外侧原位植骨融合手术治疗。对两组术前、术后和最终随访时的X线片测量结果、融合率、断钉率、JOA评分等进行综合评价。结果①治疗组能明显增加椎间隙高度、相对椎间隙高度,提高复位率,降低滑脱率;②治疗组能明显提高术后1年、2年骨性融合率,降低断钉率;③治疗组能明显提高术后JOA评分。结论①腰椎滑脱症手术时滑脱椎体应尽可能复位;②不能过分强调解剖复位,主张部分复位比较安全;③滑脱复位后,术后常出现复位的丢失,如何减少复位的丢失,是需值得重视的问题;④在此基础上彻底的减压是基础,坚强的骨性融合是关键。     

PLIF和ALIF对相邻节段生物力学影响的比较

目的比较PLIF和ALIF及附加椎弓根螺钉后相邻节段的力学性能。方法采用10具小牛腰椎标本,随机选5具为对照组,将10具标本分为L4/L5PLIF和ALIF单纯融合组及附加内固定组,比较L3/L4节段的应变、强度和位移。结果两种融合方法在附加内固定前后比对照组,应变和位移都增加,强度降低(P<0.01),两组间以ALIF组变化最大,PLIF最小(P<0.05);在内固定前后配对比较,附加内固定后应变、位移增加,强度降低(P<0.05)。结论PLIF和ALIF单纯融合及附加内固定有增加上位节段退变的趋势,以ALIF较为明显。附加内固定后比单纯融合有增加退变的趋势。     

PEEK椎间融合器在腰椎滑脱中的应用

目的探讨PEEK椎间融合器加椎弓根内固定技术治疗腰椎滑脱症的临床疗效。方法41例腰椎滑脱患者采用全椎板减压、椎弓根器械复位固定、椎体间放入PEEK融合器植骨融合。结果全部获得随访,时间12～54个月,40例植骨获得椎体间融合,融合时间6～24个月,融合率97．6％。临床疗效按Macnab标准评定：优17例,良21例,可2例,差1例,优良率达92．7％。结论PEEK椎间融合器植骨融合是一种较为实用的融合方式,避免了取自体髂骨带来的问题,在生物力学上保持腰椎生理前凸、提高腰椎生物力学功能,对恢复脊柱稳定性具有积极作用。     

Are 2 cages needed with instrumented PLIF? A comparison of 1 versus 2 interbody cages in a military population

Bovine biomechanical data have demonstrated adequate stability of a single threaded interbody cage when combined with a unilateral facet screw during posterior lumbar disc excision and interbody fusion (PLIF). Instrumented PLIF surgery using 1 versus 2 interbody cages was studied in 35 military men with disc disease and chronic low back pain. All patients underwent instrumented PLIF with bilateral diskectomy and partial facetectomy, pedicle screws, autogenous iliac crest bone graft, 1 or 2 interbody cages, and posterior lateral fusion. After an average of 15 months' follow-up, the 2-cage group had a higher rate of dural tear, but rates of other complications, hospital stay, fusion rates, pain levels, functional outcomes, and patient satisfaction were good and did not differ between groups. Costs were higher for the 2-cage group by 1728 dollars per patient.     

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。     

应用Cage与Cage联合椎弓根螺钉系统行后路腰椎体间融合术

目的:比较单独应用Cage和Cage联合后路推弓根螺钉内固定行后路腰椎体间融合术(PLIF)的治疗效果;探讨降低术后并发症以及提高术后疗效与融合率的方法。方法:5年内随访到202例共243个节段(L_2～S_1)PLIF手术患者,单个节段手术单独用Cage 110例,联合使用椎弓根螺钉固定50例;双节段单独使用Cage 18例,联合使用椎弓根螺钉23例;3节段1例,使用Cage联合椎弓根螺钉内固定。均采用后侧入路斜向置入单枚长Cage,其中圆柱形螺纹Cage 100枚,接触式Cage 90枚,楔形53枚。术后平均随访2.8年(6月～4.5年),并行影像学评估和临床效果评价,包括X线片和薄层CT扫描;用ODI作术前/后的临床评价。结果:融合率术后6月90.1％(219)、12月93.0％(226)、24月95.1％(231);临床症状缓解率术后3月91.6％(185例),6月以上95.0％(192例);术后并发症:一过性足下垂和伸踇乏力30例;Cage后滑出3例(1.2％);术后脑脊液漏5例(2.4％);术后下腰痛持续3月者10例,持续6月者3例,1年以上者1例;术后内植物下沉、假关节形成者1例。结论:应用PLIF腰椎体间置入Cage行融合术是满意而可靠的方法,2节段以上单独应用Cage可发生内植物滑出、椎体塌陷等并发症,Cage联用椎弓根螺钉可以有效防止融合器的松动和后滑出,尤其是多节段的后路减压融合术时。良好的手术技巧以     

Coflex内固定术与PLIF术治疗腰椎管狭窄症的疗效对比

[目的]探讨采用Coflex棘突间动态内同定植入术与传统PLIF术治疗单节段腰椎管狭窄症的疗效并进行对比研究.[方法]术前准确定位手术减压节段后分别采用腰后路减压Coflex棘突间动态内固定植入术(Coflex组)及腰后路减压植骨融合内固定术(PLIF组)治疗单节段腰椎管狭窄症72例,观察两组手术时间、出血量及并发症的差异;术前、术后随访时分别采用VAS评分和ODI进行相关功能评价;通过影像学观察手术节段及上邻节段术前、术后屈伸活动度变化.[结果]两组患者术后VAS、ODI评分均较术前明显下降(P<0.01),术后功能恢复无明显差异(P>0.05),而Coflex组手术时间、出血量均较传统PLIF组减少(P<0.01);术后1年Coflex组手术节段活动度与术前相比减少(P<0.05),PLIF组上邻椎间运动幅度组较术前增加(P<0.05),而Coflex组稍减少,与术前相比无明显差异(P>0.05).[结论]Coflex棘突间内固定技术治疗单节段腰椎管狭窄症疗效好,并且具有手术时间短,出血量小,能保留手术节段一定的活动度,对上邻节段活动度影响小等优点.     

使用椎弓根钉固定的PLF和PLIF的生物力学比较

目的比较在失稳腰椎使用椎弓根钉固定的侧后方融合和经后路椎体间融合的生物力学效果。方法10具L3—S1人新鲜尸体腰椎标本用于实验。完整脊柱测试后,于L4,5后方行连续性破坏,并用椎弓根钉固定(PS)和椎体间cage行以下各脊柱重建组：①完整脊柱及PS组。②两侧关节突关节内侧切除及PS组。③两侧关节突关节完全切除及PS组。④椎间盘部分切除及PS组。⑤椎间盘部分切除及PS／cage组。各组分别行载荷量6Nm的前后屈曲实验,记录并比较固定椎间L4,5的刚度值、L4椎弓根钉的折曲应变量、及上位相邻关节L3,4的运动范围(ROM)。结果固定椎间L4,5的刚度值：椎间盘部分切除及PS以外的所有重建组的脊柱刚度均显著大于完整脊柱组,椎间盘部分切除及PS／cage组的脊柱刚度显著大于其他固定组。L4螺钉的折曲应变量：椎间盘部分切除及PS组L4螺钉折曲应变量显著大于其他固定组,而椎间盘部分切除及PS／cage的螺钉应变量在所有重建组中最小。L3,4的ROM：与完整脊柱相比,所有重建组都显著增大了L3,4的ROM。更重要的是椎间盘部分切除及PS／cage组的ROM明显大于单纯PS组。结论若脊柱前方承载能力尚存,使用PS的侧后方融合可获得足够的力学稳定性。在此情况下,椎体间融合会进一步加大相邻关节的活动范围,故不应使用。当脊柱前方丧失其承载能力,单纯PS的脊柱刚度低,椎弓根钉的应力显著增大。对此种病例,cage的使用可增加重建脊柱的初期稳定性,有利于降低后方固定器械的应力。     

单枚融合器附加椎弓根螺钉系统在腰椎滑脱治疗中的应用

目的探索以单枚椎间融合器后斜向植入附加椎弓根螺钉系统内固定的后路腰椎椎体间融合术治疗腰椎滑脱症.方法1997年7月～2000年8月,我们收治了各类腰椎滑脱症65例患者(男32例,女33例.年龄28～58岁,平均43岁).其中,峡部型滑脱症(Ⅰ～Ⅱ°)26例,退行性滑脱症25例,腰椎后路减压术后滑脱症7例,发育不良性腰椎滑脱症5例,外伤性滑脱症2例.均有一年以上的下腰痛和/或下肢根性症状且保守治疗无效.所有患者均在减压的基础上行病变节段的单枚螺纹式椎间融合器(BAK)的后斜向植入并附加用椎弓根螺钉系统内固定.结果65例中有59例平均随访达18月,皆达到临床融合.临床效果评价优42例,良14例,无改善3例,差0例.患者主观评定满意41例,基本满意15例,可3例所有患者均无融合器的移位及椎弓根螺钉松动,患者主观满意率93%.结论经侧后方斜向植入单枚螺纹状椎间融合器并附加椎弓根螺钉内固定的后路腰椎椎体间融合术式能充分完成后路减压,并能保证可靠的融合,适用于滑脱程度严重、滑脱倾向大的患者,不失为一种比较理想的治疗各种腰椎滑脱症的术式.