Lumbar sagittal contour after posterior interbody fusion: threaded devices alone versus vertical cages plus posterior instrumentation

STUDY DESIGN: An observational radiographic study examining lumbar sagittal contour of patients undergoing posterior interbody arthrodesis. OBJECTIVES: To compare operative alterations of lumbar sagittal contour after posterior interbody fusion using threaded interbody devices alone versus vertical cages combined with posterior compression instrumentation. SUMMARY OF BACKGROUND DATA: Technique-related alterations of lumbar sagittal contour during interbody arthrodesis have received little attention in the spinal literature. METHODS: Standing lumbar radiographs were measured for preoperative and postoperative segmental lordosis at levels undergoing posterior interbody arthrodesis using either stand-alone side-by-side threaded devices or vertical cages combined with posterior transpedicular compression instrumentation. Sagittal plane segmental correction (or loss of correction) was calculated and statistically compared. RESULTS: The radiographs of 30 patients (34 spinal segments) undergoing lumbar or lumbosacral arthrodesis were compared. Seventeen patients (18 segments) had undergone interbody fusion using threaded cages,whereas 13 patients (16 segments) underwent fusion using vertically oriented mesh cages combined with posterior compression instrumentation. Preoperative segmental lordosis averaged 8 degrees for both groups. For patients undergoing fusion with threaded cages, there was a mean lordotic loss of 3 degrees/segment. For patients undergoing fusion with vertically oriented mesh cages combined with posterior compression instrumentation,there was a mean lordotic gain of 5 degrees/segment. This difference in segmental sagittal plane contour was highly significant (P = 0.00). CONCLUSION: Threaded fusion devices placed under interbody distraction with the endplates parallel fail to preserve or reestablish segmental lordosis. Vertical cages, however, when combined with posterior compression instrumentation, not only maintain segmental lordosis, but also can correct sagittal plane deformity.     

经椎间孔与经后外侧入路椎间融合术治疗退变性腰椎滑脱症的疗效比较

目的比较经椎间孔腰椎椎间融合术(TLIF)和后外侧腰椎椎间融合术(PLIF)治疗退变性腰椎滑脱症(DLS)的临床疗效和影像学变化。方法收集2008年3月—2014年3月在本院采用TLIF(n=64)和PLIF(n=52)治疗的退变性腰椎滑脱症患者的临床资料,包括疼痛视觉模拟量表(VAS)评分、Oswestry功能障碍指数(ODI)、融合率和医源性神经功能损伤(INRD)情况,以及手术节段滑脱程度、腰椎前凸角度、椎间隙后缘高度、椎间孔高度。结果两组的融合率和神经功能恢复情况差异无统计学意义(P0.05)。两种术式术后VAS评分、ODI改善率差异无统计学意义(P0.05)。术后PLIF组术侧神经功能损伤发生率高于TLIF组,差异有统计学意义(P0.05);对侧肢体的神经功能损伤发生率TLIF组高于PLIF组,差异有统计学意义(P0.05)。末次随访时,TLIF组在维持局部腰椎前凸角度方面优于PLIF组,差异有统计学意义(P0.05);PLIF组在恢复椎间隙后缘高度、椎间孔高度方面优于TLIF组,差异有统计学意义(P0.05)。结论 TLIF及PLIF在INRD发生率,恢复局部腰椎前凸角度、椎间孔高度及椎间隙高度方面各有优劣,医师可根据患者病情及自身情况选择合适入路进行手术。     

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。     

PLIF与PLF技术治疗腰椎滑脱症的疗效比较

目的 回顾性比较后路椎间融合术（PLIF）和椎体后外侧融合术（PLF）治疗腰椎滑脱症的临床疗效。方法 自2007-06-2013-02在后路减压复位、椎弓根系统内固定的基础上行融合术治疗腰椎滑脱症42例：PLIF组13例,PLF组29例。结果 术后所有滑脱椎体均获得不同程度的复位。PLIF组与PLF组术中平均出血量分别为（816.6±69.3）ml、（355.2±45.8）ml;2组术后椎间隙后高均较术前增加（P〈0.05）,而末次随访PLIF组椎间后高优于PLF组（P〈0.05）。PLIF组术后翻修1例,余均获得融合,融合率92.3%,术中硬脊膜撕裂2例,未遗留神经症状;PLF组术后26例获得融合,融合率为89.7%,3例融合失败,随访椎间隙高度丢失,出现腰臀部疼痛复发,该组未出现神经损伤。术后PLIF组与PLF组ODI评分均较术前明显改善（P〈0.05）。结论 PLIF与PLF技术均为治疗腰椎滑脱症有效的融合方式,前者具有良好的椎间撑开作用,适合术前椎间高度丢失较多的患者;而后者手术出血少、术中并发症少,较适合体弱、高龄、椎间高度丢失不显著的患者。     

经神经根孔入路腰椎融合加椎弓根固定治疗腰椎间盘源性下腰痛

目的研究经神经根孔入路腰椎融合(transforaminal lumbar interbody fusion,TLIF)加椎弓根固定治疗腰椎间盘源性下腰痛的手术疗效。方法26例腰椎间盘源性下腰痛,选择行后路TLIF手术加椎弓根固定治疗。分别于术前、术后对患者的腰痛情况进行VAS评分,同时评估术后腰椎融合率。结果术后随访时间8~24个月,平均16个月。25例术后腰腿痛症状基本消失,1例仍有轻度腰痛,融合率为100%。结论严格掌握手术适应证,后路腰椎椎体间融合术是治疗腰椎间盘源性下腰痛的有效方法。     

Fusion techniques for adult isthmic spondylolisthesis: a systematic review

Introduction

Various fusion techniques have been used to treat lumbar spine isthmic spondylolisthesis (IS) in adults, including anterior lumbar interbody fusion (ALIF), posterior lumbar interbody fusion (PLIF), transforaminal lumbar interbody fusion (TLIF), posterolateral fusion (PLF), and circumferential fusion. The objective of this study was to evaluate which fusion technique provides the best clinical and radiological outcome for adult lumbar IS.

Materials and methods

A systematic review was performed. MEDLINE databases and reference lists of selected articles were searched. Inclusion criteria stated that the studies had to be controlled and that they compared clinical and radiological outcomes of various fusion techniques for treating adult IS. Exclusion criteria were use of only one treatment and non-English language articles. Two reviewers independently extracted relevant data from each included study. Statistical comparisons were made when appropriate.

Results

Nine studies that compared two surgical approaches to IS were included in this systematic review. Three were prospective studies, and six were retrospective studies. Two studies compared ALIF with instrumented PLF and ALIF with percutaneous pedicle screw fixation, two studies compared ALIF and TLIF, and five studies compared PLIF and PLF. ALIF was superior to other techniques regarding restoration of disc height, segmental lordosis, and whole lumbar lordosis. TLIF had lower complication rates. ALIF combined with PLF showed lower nonfusion rates than other techniques. However, there were no significant differences in clinical outcomes between any two techniques.

Conclusion

Compared to other fusion techniques, TLIF shows fewer complications, ALIF shows better sagittal alignment, and circumferential fusion showed better fusion rates. It was difficult to make recommendations about the optimal approach because of the methodological variance in the publications.     

The impact of interbody approach and lumbar level on segmental,adjacent, and sagittal alignment in degenerative lumbar pathology: a radiographic analysis six months following surgery

BACKGROUND CONTEXTInterbody fusion, including: transforaminal (TLIF), posterior (PLIF), anterior (ALIF), and lateral (LLIF); effectively treat lumbar degenerative pathology and provide spinopelvic balance. Although the decision on surgical approach and technique are multifactorial and patient specific, the impact of the interbody approach on segmental and adjacent level lordosis could be an important factor to consider during pre-operative planning to achieve pre-specified alignment goals.PURPOSEThe purpose of this study is to compare the 6-month postoperative radiographic outcomes in the lumbar spine following 1 to 2 level transforaminal (TLIF), posterior (PLIF), anterior (ALIF), and lateral (LLIF) interbody fusions at the L3-4, L4-5, and L5-S1 levels. As our primary outcome, we evaluated the change in segmental lordosis at the level of fusion in ALIF/LLIF approaches compared to TLIF/PLIF. Secondarily, we evaluated the pelvic incidence to lumbar lordosis (PI-LL) mismatch and examined the compensatory lordotic changes at the adjacent levels 6 months following surgery.STUDY DESIGNRetrospective cohort.PATIENT SAMPLEThis retrospective study included 18 centers of various practice settings across the United States. Patients were included in the study if they underwent a one- or two-level primary lumbar fusion for degenerative pathology.OUTCOMES MEASURESMeasurements of the pre-operative and 6-month post-operative lumbar AP and lateral lumbar plain radiographs included: pelvic incidence (PI), pelvic tilt, lumbar lordosis from L1-S1 (LL), as well as segmental lordosis (SL) of each segment between L1-S1.METHODSDue to there being 2 evaluated time points, patients were then grouped based on alignment into categories of preserved, restored, not corrected, and worsened.RESULTS474 patients underwent 608 levels of fusion. ALIF/LLIF resulted in significantly more segmental lordosis compared to TLIF/PLIF procedures at both L4-5 and L5-S1 (p<.001). Overall, ALIF/LLIF resulted in significantly more global lumbar lordotic alignment change compared to TLIF/PLIF (p=.01). Whether patients’ alignment was preserved versus worsened was not significantly predicted by type of procedure. Similarly, whether patients’ alignment was restored versus not corrected was not significantly predicted by type of procedure. Finally, anterior approaches resulted in decreased lordosis at adjacent levels, thus resulting in a more neutral position.CONCLUSIONIn this large multicenter retrospective study of 1 to 2 level interbody fusion surgeries, we identified that A/LLIF procedures at L4-L5 and L5-S1 resulted in greater segmental lordosis restoration and PI-LL mismatch improvement compared to T/PLIF procedures. A/LLIF may also significantly reduce lordosis (compared to T/PLIF) at the adjacent levels in a fashion that serves to reduce the lumbar lordosis that may have been increased at the fused level.     

两种椎间植骨融合术治疗退行性腰椎滑脱症的疗效比较

目的 比较腰椎经椎间孔椎间植骨融合术(TLIF)与腰椎后路椎间植骨融合术(PLIF)治疗退行性腰椎滑脱症的效果.方法 对120例腰椎滑脱症患者分别采用TLIF(60例)与PLIF(60例).回顾两组患者的临床资料,比较两种植骨方式术后植骨融合率及临床症状改善情况.结果 随访16～35个月(平均23个月).所有手术均获得成功.所有患者所有节段均获骨性融合,未见融合器后移及沉陷.无并发感染.JOA评分:TLIF组优良率83.3%,PLIF组优良率81.7%,两组差异无统计学意义(P＞0.05).手术总优良率为82.5%.滑脱率、复位率术后与术前比较都有明显改善(P＜0.01);两组复位率丢失程度相似(P＞0.05).椎间隙高度及椎间孔高度:术前、术后相比差异有统计学意义(P＜0.01),两组之间相比差异无统计学意义(P＞0.05),两组丢失率相近(P＞0.05).结论 TLIF与PLIF治疗腰椎滑脱症的疗效相近,TLIF单侧植入椎间融合器,较PLIF简便安全.     

椎弓根器械复位固定后两种融合方法治疗腰椎滑脱症的疗效比较

目的 观察比较椎弓根器械复位固定后两种不同融合法PLF（后外侧融合）与PLIF（后路椎体间融合）对腰椎滑脱症的疗效。方法 Ⅱ度以内腰椎峡部不连型滑脱共47例，一组22例，椎弓根器械复位固定后行PLF（PLF组）；另一组25例，椎弓根器械复位固定后行PLIF（PLIF组）。对两组的临床疗效（ODI评分）、X线影像学结果（滑脱矫正、滑脱节段椎间隙高度改变、滑脱节段前突角改变及骨融合）及并发症进行对比观察。结果 术后即刻X线影像学结果（滑脱矫正、滑脱节段椎间盘高度、滑脱节段前突角），两组间无显著差异（P〉0．05）；术后2年随访时，滑脱矫正及滑脱节段椎间隙高度的维持上PLIF组优于PLF组（P〈0．05），骨融合率及滑脱节段前突角两组间无显著差异（P〉0．05），但两组间临床疗效（ODI评分）及并发症发生率无显著差异（P〉0．05），内固定失败率PLF组高于PLIF组。结论 椎弓根器械复位固定并PLF与PLIF都是治疗Ⅱ度以内峡部裂型滑脱的有效方法，PLIF在对滑脱矫形的维持及结构的稳定上具有优越的力学性能，PLF后期易出现矫正丢失及内固定失败，但临床疗效不受明显影响。     

Indirect decompression via oblique lateral interbody fusion for severe degenerative lumbar spinal stenosis: a comparative study with direct decompression transforaminal/posterior lumbar interbody fusion

Background contextPrevious studies have shown that oblique lateral interbody fusion (OLIF) can improve neurological symptoms via “indirect decompression.” However, data are lacking in terms of its benefits when compared with conventional transforaminal lumbar interbody fusion (TLIF) and/or posterior lumbar interbody fusion (PLIF) approach, especially in patients with severe central canal stenosis.PurposeTo investigate the clinical outcome of OLIF without posterior decompression versus conventional TLIF and/or PLIF in severe lumbar stenosis diagnosed on preoperative magnetic resonance imaging.Study designRetrospective comparative study.Patient sampleFifty-one patients who underwent OLIF and 41 patients who underwent conventional TLIF and/or PLIF.Outcome measuresClinical outcome score by Japanese Orthopedic Association (JOA) score and radiographic outcomes (disc height and fusion rate on computed tomography scan).Materials/methodsWe retrospectively reviewed 51 patients who underwent OLIF with supplemental percutaneous pedicle screws (55 levels; OLIF group) and 41 patients who underwent conventional TLIF and/or PLIF (47 levels; TPLIF group). The cross-sectional area of the thecal sac was measured preoperatively in OLIF and TPLIF groups, but postoperatively only in the OLIF group. All patients were diagnosed with severe stenosis based on Schizas classification (Grade C or D) on magnetic resonance imaging. We compared radiographic and clinical outcome scores (JOA score) between the 2 groups at 1 year of follow-up. The radiographic evaluation included the fusion status and disc height on computed tomography scan. Surgical data and perioperative complications were also investigated.ResultsThe baseline demographic data of the 2 groups were equivalent in preoperative diagnosis, JOA score, and disc height and/or angle. The cross-sectional area significantly increased postoperatively, which confirmed indirect decompressive effect in the OLIF group. The JOA score improved in both groups at the 1-year follow up (76.6% vs. 73.5% improvement rate in the OLIF and TPLIF groups, respectively). The fusion rate at the 1-year follow-up was higher in the OLIF group than in the TPLIF group (87.2% vs. 57.4%). The disc height restoration was also better in the OLIF group. The operative data demonstrated less estimated blood loss and operative time in the OLIF group.ConclusionsOLIF and conventional TLIF and/or PLIF demonstrated comparable short-term clinical outcomes in the treatment of severe degenerative lumbar stenosis. However, the surgical and radiographic outcomes were better in the OLIF group. Surgeons should choose an appropriate approach on a case by case basis, recognizing the perioperative complications specific to each fusion procedure.     

Circumferential arthrodesis using PEEK cages at the lumbar spine

Usual interbody cages at the lumbar spine are made of titanium or carbon fiber-polyetheretherketone (PEEK). Pure PEEK cages have more recently been proposed for its lower elasticity modulus. The goal of our study was to investigate a series of patients with circumferential fixation using anterior PEEK cages for degenerative lumbar spine disorders with a specific interest in the local lordosis. Fifty-seven consecutive patients aged 54.6 years (29 to 75) were reviewed. The level of arthrodesis varied from L2L3 to L5S1. The clinical status and the radiologic variations in local lordosis at the level of arthrodesis were measured. Decrease in lordosis at follow-up was tested in a multivariate analysis regarding age, obesity, spinal level, bone graft amount, type of posterior instrumentation, postoperative lordosis increase, and cage height. The average follow-up was 5.7 years (4 to 8). Clinical outcomes were excellent or good in 49 cases. Fusion was definite in 56 cases. Although 47 patients had no change in lordosis after surgery, 10 cases showed lordosis increase (8.2 degrees; 5 to 12). At follow-up, local lordosis decreased in 13 cases (5.6 degrees; 4 to 8). The linear model was significant (P<0.001; R=0.590) showing that loss in lordosis was related with postoperative lordosis increase (P=0.01), cage height (P<0.001), posterior instrumentation rigidity (P=0.026), age (P=0.047), and low level (P=0.013). Lumbar circumferential arthrodesis using PEEK cages provided good clinical results and fusion rate. However, lordosis correction was not maintained at follow-up, especially at lower levels, using high cages, in older patients, and when associated with a rigid primary posterior instrumentation. Regarding the last point, this is likely that the order of the instrumentation (posterior first, then anterior) played a role in the loss of lordosis in case of rigid posterior fixation.     

后路腰椎间融合与经椎间孔腰椎间融合治疗单纯腰椎不稳的对比研究

[目的]对后路腰椎间融合(Posterior Lumbar Interbody Fusion,PLIF)及经椎间孔腰椎间融合(Transforami-nal Lumbar Interbody Fusion,TLIF)治疗单纯腰椎不稳的手术创伤、并发症及术后疗效进行比较。[方法]将2006年2月～2009年7月收治的单纯腰椎不稳患者采用随机数字表法将患者分为PLIF组(110例)、TLIF组(108例)。术前评估两组患者一般资料差异无统计学意义,具有可比性。分别对两组患者的手术创伤、术中并发症及功能恢复情况进行比较。[结果]术后随访时间14～36个月,平均21个月。手术时间:PLIF组为(125.6±45)min,TLIF组为(124.9±44)min(P>0.05);失血量:PLIF组为(1 000±450)ml,TLIF组为(995±405)ml(P>0.05);术中并发症:PLIF组为3例,TLIF组为0例(P<0.05);术后优良率:PLIF组为93.6%,TLIF组为94.4%(P>0.05);术后融合率:PLIF组为96.4%,TLIF组为98.1%(P>0.05);JOA评分:PLIF组为14.5...     

Lumbar lordosis restoration following single-level instrumented fusion comparing 4 commonly used techniques

A major sequelae of lumbar fusion is acceleration of adjacent-level degeneration due to decreased lumbar lordosis. We evaluated the effectiveness of 4 common fusion techniques in restoring lordosis: instrumented posterolateral fusion, translumbar interbody fusion, anteroposterior fusion with posterior instrumentation, and anterior interbody fusion with lordotic threaded (LT) cages (Medtronic Sofamor Danek, Memphis, Tennessee). Radiographs were measured preoperatively, immediately postoperatively, and a minimum of 6 months postoperatively. Parameters measured included anterior and posterior disk space height, lumbar lordosis from L3 to S1, and surgical level lordosis.No significant difference in demographics existed among the 4 groups. All preoperative parameters were similar among the 4 groups. Lumbar lordosis at final follow-up showed no difference between the anteroposterior fusion with posterior instrumentation, translumbar interbody fusion, and LT cage groups, although the posterolateral fusion group showed a significant loss of lordosis (-10°) (P<.001). Immediately postoperatively and at follow-up, the LT cage group had a significantly greater amount of lordosis and showed maintenance of anterior and posterior disk space height postoperatively compared with the other groups. Instrumented posterolateral fusion produces a greater loss of lordosis compared with anteroposterior fusion with posterior instrumentation, translumbar interbody fusion, and LT cages. Maintenance of lordosis and anterior and posterior disk space height is significantly better with anterior interbody fusion with LT cages.     

Radiographic Results of Single Level Transforaminal Lumbar Interbody Fusion in Degenerative Lumbar Spine Disease: Focusing on Changes of Segmental Lordosis in Fusion Segment

Background

To assess the radiographic results in patients who underwent transforaminal lumbar interbody fusion (TLIF), particularly the changes in segmental lordosis in the fusion segment, whole lumbar lordosis and disc height.

Methods

Twenty six cases of single-level TLIF in degenerative lumbar diseases were analyzed. The changes in segmental lordosis, whole lumbar lordosis, and disc height were evaluated before surgery, after surgery and at the final follow-up.

Results

The segmental lordosis increased significantly after surgery but decreased at the final follow-up. Compared to the preoperative values, the segmental lordosis did not change significantly at the final follow-up. Whole lumbar lordosis at the final follow-up was significantly higher than the preoperative values. The disc height was significantly higher in after surgery than before surgery (p = 0.000) and the disc height alter surgery and at the final follow-up was similar.

Conclusions

When performing TLIF, careful surgical techniques and attention are needed to restore and maintain the segmental lordosis at the fusion level.     

腰椎后路微创TLIF和开放PLIF两种术式临床短期效果报告

目的评价微创经椎间孔椎间融合术（transforaminal lumbar interbody fusion,TLIF）与开放后路椎间融合术（posterior lumbar interbody fusion,PLIF）行后路椎间融合及椎弓根钉内固定的短期临床疗效。方法2009年1-3月对30例腰椎退变性疾病患者分别采用微创TLIF（METRXQuadrant）和开放PLIF术式进行对照研究。结果术后1周微创TLIF组腰痛VAS评分的降低更为明显（P〈0．05）;术后1周及4个月2组腿痛VAS评分比较差异无统计学意义（P〉0．05）;术后1周微创TLIF组JOA评分同开放PLIF组比较差异具有统计学意义（P〈0．05）。结论METRX Quadrant系统下行微创TLIF后路腰椎管减压、椎间融合和椎弓根螺钉固定术,可促进患者早期康复,减少住院时间,是一种安全、可靠的方法。     

两种椎间融合手术治疗腰椎退变性疾病术后神经功能恢复的临床对照研究

目的评估腰椎后路椎体间融合术（posterior lumbar interbody fusion,PLIF）及椎间孔入路腰椎融合术（transforaminal lumbar interbody fusion,TLIF）治疗腰椎退变性疾病术后神经功能恢复情况。方法回顾性分析2003年6月～2011年1月行PLIF及TLIF的249例腰椎退变性疾病患者,记录医源神经根性损伤发生率、日本骨科学会（Jap-anese Orthopedics Association,JOA）评分改善率、中华骨科学会脊柱学组腰背痛手术评分,比较2种术式在神经功能恢复方面的异同。结果医源神经根性损伤发生率PLIF高于TLIF,两者差异有统计学意义（P〈0.05）。2组间手术优良率以及术后3个月、末次随访时JOA评分改善率差异无统计学意义（P〉0.05）。结论 TLIF术中医源性神经损伤发生率明显低于PLIF,长期神经功能改善情况,二者并无差异。     

Anterior lumbar interbody fusion in comparison with transforaminal lumbar interbody fusion: implications for the restoration of foraminal height, local disc angle, lumbar lordosis, and sagittal balance

OBJECT: A primary consideration of all spinal fusion procedures is restoration of normal anatomy, including disc height, lumbar lordosis, foraminal decompression, and sagittal balance. To the authors' knowledge, there has been no direct comparison of anterior lumbar interbody fusion (ALIF) with transforaminal lumbar interbody fusion (TLIF) concerning their capacity to alter those parameters. The authors conducted a retrospective radiographic analysis directly comparing ALIF with TLIF in their capacity to alter foraminal height, local disc angle, and lumbar lordosis. METHODS: The medical records and radiographs of 32 patients undergoing ALIF and 25 patients undergoing TLIF from between 2000 and 2004 were retrospectively reviewed. Clinical data and radiographic measurements, including preoperative and postoperative foraminal height, local disc angle, and lumbar lordosis, were obtained. Statistical analyses included mean values, 95% confidence intervals, and intraobserver/interobserver reliability for the measurements that were performed. RESULTS: Our results indicate that ALIF is superior to TLIF in its capacity to restore foraminal height, local disc angle, and lumbar lordosis. The ALIF procedure increased foraminal height by 18.5%, whereas TLIF decreased it by 0.4%. In addition, ALIF increased the local disc angle by 8.3 degrees and lumbar lordosis by 6.2 degrees, whereas TLIF decreased the local disc angle by 0.1 degree and lumbar lordosis by 2.1 degrees. CONCLUSIONS: The ALIF procedure is superior to TLIF in its capacity to restore foraminal height, local disc angle, and lumbar lordosis. The improved radiographic outcomes may be an indication of improved sagittal balance correction, which may lead to better long-term outcomes as shown by other studies. Our data, however, demonstrated no difference in clinical outcome between the two groups at the 2-year follow-up.     

Posterior lumbar interbody fusion

Posterior lumbar interbody fusion (PLIF) and transforaminal lumbar interbody fusion (TLIF) create intervertebral fusion by means of a posterior approach. Both techniques are useful in managing degenerative disk disease, severe instability, spondylolisthesis, deformity, and pseudarthrosis. Successful results have been reported with allograft, various cages (for interbody support), autograft, and recombinant human bone morphogenetic protein-2. Interbody fusion techniques may facilitate reduction and enhance fusion. The rationale for PLIF and TLIF is biomechanically sound. However, clinical outcomes of different anterior and posterior spinal fusion techniques tend to be similar. PLIF has a high complication rate (dural tear, 5.4% to 10%; neurologic injury, 9% to 16%). These findings, coupled with the versatility of TLIF throughout the entire lumbar spine, may make TLIF the ideal choice for an all-posterior interbody fusion.     

椎弓根器械复位固定后两种不同融合方法对腰椎峡部裂型滑脱的疗效比较

目的观察比较椎弓根器械复位固定后两种不同融合法PLF与PLIF对峡部裂型滑脱的疗效。方法Ⅱ度以内腰椎峡部裂型滑脱共47例,一组22例,椎弓根器械复位固定后行PLF(PLF组);另一组25例,椎弓根器械复位固定后行PLIF(PLIF组)。对两组的临床疗效(ODI评分)、X线影像学结果(包括:滑脱矫正、滑脱节段椎间隙高度改变、滑脱节段前突角改变及骨融合)及并发症进行对比观察。结果术后即刻X线影像学结果,包括:滑脱矫正、滑脱节段椎间盘高度、滑脱节段前突角,两组间无显著差异(P>0.05);术后2年随访时,滑脱矫正及滑脱节段椎间隙高度的维持上PLIF组优于PLF组(P<0.05),骨融合率及滑脱节段前突角两组间无显著差异(P>0.05),但两组间临床疗效(ODI评分)及并发症发生率无显著差异(P>0.05),内固定失败率PLF组高于PLIF组。结论椎弓根器械复位固定并PLF与PLIF都是治疗Ⅱ度以内腰椎峡部裂型滑脱的有效方法,PLIF在对滑脱矫形的维持及结构的稳定上具有优越的力学性能,PLF后期易出现矫正丢失及内固定失败,但临床疗效不受明显影响。     

Posterolateral versus posterior interbody fusion in isthmic spondylolisthesis

Spondylolisthesis is a heterogeneous disorder characterized by subluxation of a vertebral body over another in the sagittal plane. Its most common form is isthmic spondylolisthesis (IS). This study aims to compare clinical outcomes of posterolateral fusion (PLF) with posterior lumbar interbody fusion (PLIF) with posterior instrumentation in the treatment of IS. We performed a randomized prospective study in which 80 patients out of a total of 85 patients with IS were randomly allocated to one of two groups: PLF with posterior instrumentation (group I) or PLIF with posterior instrumentation (group II). Posterior decompression was performed in the patients. The Oswestry low back pain disability (OLBP) scale and Visual Analogue Scale (VAS) were used to evaluate the quality of life (QoL) and pain, respectively. Fisher's exact test was used to evaluate fusion rate and the Mann-Whitney U test was used to compare categorical data. Fusion in group II was significantly better than in group I (p=0.012). Improvement in low back pain was statistically more significant in group I (p=0.001). The incidence of neurogenic claudication was significantly lower in group I than in group II (p=0.004). In group I, there was no significant correlation between slip Meyerding grade and disc space height, radicular pain, and low back pain. There was no significant difference in post-operative complications at 1-year follow-up. Our data showed that PLF with posterior instrumentation provides better clinical outcomes and more improvement in low back pain compared to PLIF with posterior instrumentation despite the low fusion rate.