Does approach matter? A comparative radiographic analysis of spinopelvic parameters in single-level lumbar fusion

Background Context

Lumbar fusion is a popular and effective surgical option to provide stability and restore anatomy. Particular attention has recently been focused on sagittal alignment and radiographic spinopelvic parameters that apply to lumbar fusion as well as spinal deformity cases. Current literature has demonstrated the effectiveness of various techniques of lumbar fusion; however, comparative data of these techniques are limited.

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.     

Single position lateral decubitus anterior lumbar interbody fusion (ALIF) and posterior fusion reduces complications and improves perioperative outcomes compared with traditional anterior-posterior lumbar fusion

BACKGROUND CONTEXTLateral decubitus single position anterior-posterior (AP) fusion utilizing anterior lumbar interbody fusion and percutaneous posterior fixation is a novel, minimally invasive surgical technique. Single position lumbar surgery (SPLS) with anterior lumbar interbody fusion (ALIF) or lateral lumbar interbody fusion (LLIF) has been shown to be a safe, effective technique. This study directly compares perioperative outcomes of SPLS with lateral ALIF vs. traditional supine ALIF with repositioning (FLIP) for degenerative pathologies.PURPOSETo determine if SPLS with lateral ALIF improves perioperative outcomes compared to FLIP with supine ALIF.STUDY DESIGN/SETTINGMulticenter retrospective cohort study.PATIENT SAMPLEPatients undergoing primary AP fusions with ALIF at 5 institutions from 2015 to 2020.OUTCOME MEASURESLevels fused, inclusion of L4-L5, L5-S1, radiation dosage, operative time, estimated blood loss (EBL), length of stay (LOS), perioperative complications. Radiographic analysis included lumbar lordosis (LL), pelvic incidence (PI), and PI-LL mismatch.METHODSRetrospective analysis of primary ALIFs with bilateral percutaneous pedicle screw fixation between L4-S1 over 5 years at 5 institutions. Patients were grouped as FLIP or SPLS. Demographic, procedural, perioperative, and radiographic outcome measures were compared using independent samples t-tests and chi-squared analyses with significance set at p <.05. Cohorts were propensity-matched for demographic or procedural differences.RESULTSA total of 321 patients were included; 124 SPS and 197 Flip patients. Propensity-matching yielded 248 patients: 124 SPLS and 124 FLIP. The SPLS cohort demonstrated significantly reduced operative time (132.95±77.45 vs. 261.79±91.65 min; p <0.001), EBL (120.44±217.08 vs. 224.29±243.99 mL; p <.001), LOS (2.07±1.26 vs. 3.47±1.40 days; p <.001), and rate of perioperative ileus (0.00% vs. 6.45%; p =.005). Radiation dose (39.79±31.66 vs. 37.54±35.85 mGy; p =.719) and perioperative complications including vascular injury (1.61% vs. 1.61%; p =.000), retrograde ejaculation (0.00% vs. 0.81%, p =.328), abdominal wall (0.81% vs. 2.42%; p =.338), neuropraxia (1.61% vs. 0.81%; p =.532), persistent motor deficit (0.00% vs. 1.61%; p =.166), wound complications (1.61% vs. 1.61%; p =.000), or VTE (0.81% vs. 0.81%; p =.972) were similar. No difference was seen in 90-day return to OR. Similar results were noted in sub-analyses of single-level L4-L5 or L5-S1 fusions. On radiographic analysis, the SPLS cohort had greater changes in LL (4.23±11.14 vs. 0.43±8.07 deg; p =.005) and PI-LL mismatch (-4.78±8.77 vs. -0.39±7.51 deg; p =.002).CONCLUSIONSSingle position lateral ALIF with percutaneous posterior fixation improves operative time, EBL, LOS, rate of ileus, and maintains safety compared to supine ALIF with prone percutaneous pedicle screws between L4-S1.     

Biomechanical Comparison of Different Surgical Approaches for the Treatment of Adjacent Segment Diseases after Primary Transforaminal Lumbar Interbody Fusion: A Finite Element Analysis

Background and objective

Adjacent segment disease (ASD) is a well-known complication after interbody fusion. Revision surgery is necessary for symptomatic ASD to further decompress and fix the affected segment. However, no optimal construct is accepted as a standard in treating ASD. The purpose of this study was to compare the biomechanical effects of different surgical approaches for the treatment of ASD after primary transforaminal lumbar interbody fusion (TLIF).

Methods

A finite element model of the L1-S1 was conducted based on computed tomography scan images. The primary surgery model was developed with a single-level TLIF at L4-L5 segment. The revision surgical models were developed with anterior lumbar interbody fusion (ALIF), lateral lumbar interbody fusion (LLIF), or TLIF at L3-L4 segment. The range of motion (ROM), intradiscal pressure (IDP), and the stress in cages were compared to investigate the biomechanical influences of different surgical approaches.

Results

The results indicated that all the three surgical approaches can stabilize the spinal segment by reducing the ROM at revision level. The ROM and IDP at adjacent segments of revision model of TLIF was greater than those of other revision models. While revision surgery with ALIF and LLIF had similar effects on the ROM and IDP of adjacent segments. Compared among all the surgical models, cage stress in revision model of TLIF was the maximum in extension and axial rotation.

Conclusion

The IDP at adjacent segments and stress in cages of revision model of TLIF was greater than those of ALIF and LLIF. This may be that direct extension of the surgical segment in the same direction results in stress concentration.     

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.     

What is the fate of the adjacent segmental angles 6 months after single-level L3–4 or L4–5 lateral lumbar interbody fusion?

Background ContextLateral lumbar interbody fusion (LLIF) is an effective technique for fusion and sagittal alignment correction/maintenance. Studies have investigated the impact on the segmental angle and lumbar lordosis (and pelvic incidence-lumbar lordosis mismatch), however not much is documented regarding the immediate compensation of the adjacent angles.PurposeTo evaluate acute adjacent and segmental angle as well as lumbar lordosis changes in patients undergoing a L3–4 or L4–5 LLIF for degenerative pathology.Study Design/SettingRetrospective cohort study.Patient SamplePatients included in this study were analyzed pre- and post-LLIF performed by one of three fellowship-trained spine surgeons, 6 months following surgery.Outcome MeasuresPatient demographics (including body mass index, diabetes diagnosis, age, and sex) as well as VAS and ODI scores were measured. Lateral lumbar radiograph parameters: lumbar lordosis (LL), segmental lordosis (SL), infra and supra-adjacent segmental angle, and pelvic incidence (PI).MethodsMultiple regressions were applied for the main hypothesis tests. We examined any interactive effects at each operative level and used the 95% confidence intervals to determine significance: a confidence interval excluding zero indicates a significant effect.ResultsWe identified 84 patients who underwent a single level LLIF (61 at L4–5, 23 at L3–4). For both the overall sample and at each operative level, the operative segmental angle was significantly more lordotic postop compared to preop (all ps≤.01). Adjacent segmental angles were significantly less lordotic postop compared to pre-op overall (p=.001). For the overall sample, greater lordotic change at the operative segment led to more compensatory reduction of lordosis at the supra-adjacent segment. At L4–5, more lordotic change at the operative segment led to more compensatory lordosis reduction at the infra-adjacent segment.ConclusionThe present study demonstrated that LLIF resulted in significant increase in operative level lordosis and a compensatory decrease in supra- and infra-adjacent level lordosis, and subsequently no significant impact on spinopelvic mismatch.     

Which procedure is better for lumbar interbody fusion: anterior lumbar interbody fusion or transforaminal lumbar interbody fusion?

Introduction

Both anterior lumbar interbody fusion (ALIF) and transforaminal lumbar interbody fusion (TLIF) surgeries are performed to obtain a solid fusion to treat lumbar spondylosis. This systematic review investigated whether surgical complications, nonfusion rate, radiographic outcome, and clinical outcome of ALIF were significantly different from those of TLIF.

Method

A computerized search of the electronic databases MEDLINE was conducted. Only therapeutic studies with a prospective or retrospective comparative design were considered for inclusion in the present investigation. Two reviewers independently extracted relevant data from each included study. Statistical comparisons were made when appropriate.

Results

Nine studies were determined to be appropriate for the systematic review, and all studies were retrospective comparative studies. Blood loss and operative time in ALIF was greater than in TLIF. There was no significant difference in the complication rate between ALIF and TLIF. The restoration of disc height, segmental lordosis, and whole lumbar lordosis in ALIF was superior to TLIF. However, clinical outcomes in ALIF were similar with TLIF, and there was no significant difference in nonfusion rate between the two techniques. Costs of ALIF were greater than those of TLIF.

Conclusion

Clinical outcomes and nonfusion rate in ALIF were similar to TLIF. However, the restoration of disc height, segmental lordosis, and whole lumbar lordosis in ALIF were superior to those in TLIF, while blood loss, operative time, and costs in ALIF were greater than in TLIF.     

Effect of intraoperative position used in posterior lumbar interbody fusion on the maintenance of lumbar lordosis

OBJECT: The objective in this study was to compare retrospectively the use of different operating tables with different positions for posterior lumbar interbody fusion (PLIF) and the effect on intraoperative and postoperative lumbar lordosis and segmental lordosis. METHODS: One hundred seventy-two patients with degenerative disease of the lumbar spine who underwent posterior decompression and PLIF in which a 0 degrees polyetheretherketone cage and pedicle screw fixation were used were evaluated. Ninety-one patients underwent surgery on a Wilson table (Group I) and 81 patients were treated on an OSI Jackson spinal table (Group II). Preoperative standing, intraoperative prone, and postoperative standing lateral radiographs were obtained in each patient. The total lumbar and segmental lordosis were compared and analyzed according to the position in which the patients were placed for their operation. RESULTS: The intraoperative total lumbar lordosis was significantly decreased compared with the preoperative value. The postoperative total lumbar lordosis was similar, however, to the preoperative values in both groups. In Group I, the intraoperative segmental lordosis of L2-3 and L3-4 was significantly decreased compared with the pre-operative segmental lordosis. In Group II, the intraoperative segmental lordosis of L3-4, L4-5, L5-S1, and L4-S1 was significantly decreased compared with the preoperative segmental lordosis. The postoperative segmental lordosis of L4-5 was significantly decreased and L2-3 was significantly increased compared with the preoperative lordosis in both groups. CONCLUSIONS: Intraoperative position does not affect postoperative total lumbar lordosis and segmental lordosis in short-segment PLIF of the lumbar spine in a retrospective analysis of the surgical procedure to maintain lordosis.     

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。     

Comparison of Lumbosacral Fusion Grade in Patients after Transforaminal and Anterior Lumbar Interbody Fusion with Minimum 2-Year Follow-Up

Objective

Generally, anterior lumbar interbody fusion (ALIF) was believed superior to transforaminal lumbar interbody fusion (TLIF) in induction of fusion. However, many studies have reported comparable results in lumbosacral fusion rate between the two approaches. This study aimed to evaluate the realistic lumbosacral arthrodesis rates following ALIF and TLIF in patients with degenerative spondylolisthesis as measured by CT and radiology.

Methods

Ninety-six patients who underwent single-level L5-S1 fusion through ALIF (n = 48) or TLIF (n = 48) for degenerative spondylolisthesis at the Spine Center, University of California San Francisco, between October 2014 and December 2017 were retrospectively evaluated. Fusion was independently evaluated and categorized as solid fusion, indeterminate fusion, or pseudarthroses by two radiologists using the modified Brantigan–Steffee–Fraser (mBSF) grade. Clinical data on sex, age, body mass index, Meyerding grade, smoking status, follow-up times, complications, and radiological parameters including disc height, disc angle, segmental lordosis, and overall lumbar lordosis were collected. The fusion results and clinical and radiographic data were statistically compared between the ALIF and TLIF groups by using t-test or chi-square test.

Results

The mean follow-up period was 37.5 (ranging from 24 to 51) months. Clear, solid radiographic fusions were higher in the ALIF group compared with the TLIF group at the last follow-up (75% vs 47.9%, p = 0.006). Indeterminate fusion occurred in 20.8% (10/48) of ALIF cases and in 43.8% (21/48) of TLIF cases (p = 0.028). Radiographic pseudarthrosis was not significantly different between the TLIF and ALIF groups (16.7% vs 8.3%; p = 0.677). In subgroup analysis of the patients without bone morphogenetic protein (BMP), the solid radiographic fusion rate was significantly higher in the ALIF group than that in the TLIF group (78.6% vs 45.5%; p = 0.037). There were no differences in sex, age, body mass index, Meyerding grade, smoking status, or follow-up time between the two groups (p > 0.05). The ALIF group had more improvement in disc height (7.8 mm vs 4.7 mm), disc angle (5.2° vs 1.5°), segmental lordosis (7.0° vs 2.5°), and overall lumbar lordosis (4.7° vs 0.7°) compared with the TLIF group (p < 0.05). Overall complication rates were similar between the TLIF and ALIF groups (10.4% vs 8.33%; p > 0.999).

Conclusions

With a minimum 2-year radiographic analysis of arthrodesis at lumbosacral level by radiologists, the rate of solid radiographic fusions was higher in the ALIF group compared with the TLIF group, whereas the TLIF group had a higher rate of indeterminate fusion. Radiographic pseudarthrosis did not differ significantly between the TLIF and ALIF groups.     

Failure of a polyether-ether-ketone expandable interbody cage following transforaminal lumbar interbody fusion

Purpose

Expandable cages are a more recent option for maintaining or restoring disc height and segmental lordosis with transforaminal lumbar interbody fusion (TLIF). Complications associated with expandable cages have not yet been widely reported. We report a case of postoperative failure of a polyether-ether-ketone (PEEK) expandable interbody device used during TLIF.

Methods

A 50-year-old man presented with severe back and right leg pain after undergoing L4-5 and L5-S1 TLIFs with expandable cages and L3-S1 posterior instrumented fusion. Imaging showed retropulsion of a portion of the interbody cage into the spinal canal causing nerve compression. Displacement occurred in a delayed manner. In addition, pseudoarthrosis was present.

Results

The patient underwent re-exploration with removal of the retropulsed wafer and redo fusion.

Conclusions

Expandable cages are a recent innovation; as such, efficacy and complication data are limited. As with any new device, there exists potential for mechanical failure, as occurred in the case presented.

     

Comparison of complications,costs, and length of stay of three different lumbar interbody fusion techniques: an analysis of the Nationwide Inpatient Sample database

Background contextLumbar interbody fusion (LIF) techniques have been used for years to treat a number of pathologies of the lower back. These procedures may use an anterior, posterior, or combined surgical approach. Each approach is associated with a unique set of complications, but the exact prevalence of complications associated with each approach remains unclear.PurposeTo investigate the rates of perioperative complications of anterior lumbar interbody fusion (ALIF), posterior/transforaminal lumbar interbody fusion (P/TLIF), and LIF with a combined anterior-posterior interbody fusion (APF).Study design/settingRetrospective review of national data from a large administrative database.Patient samplePatients undergoing ALIF, P/TLIF, or APF.Outcome measuresPerioperative complications, length of stay (LOS), total costs, and mortality.MethodsThe Nationwide Inpatient Sample database was queried for patients undergoing ALIF, P/TLIF, or APF between 2001 and 2010 as identified via International Classification of Diseases, ninth revision codes. Univariate analyses were carried out comparing the three cohorts in terms of the outcomes of interest. Multivariate analysis for primary outcomes was carried out adjusting for overall comorbidity burden, race, gender, age, and length of fusion. National estimates of annual total number of procedures were calculated based on the provided discharge weights. Geographic distribution of the three cohorts was also investigated.ResultsAn estimated total of 923,038 LIFs were performed between 2001 and 2010 in the United States. Posterior/transforaminal lumbar interbody fusions accounted for 79% to 86% of total LIFs between 2001 and 2010, ALIFs for 10% to 15%, and APF decreased from 10% in 2002 to less than 1% in 2010. On average, P/TLIF patients were oldest (54.55 years), followed by combined approach (47.23 years) and ALIF (46.94 years) patients (p<.0001). Anterior lumbar interbody fusion, P/TLIF, and combined surgical costs were $75,872, $65,894, and $92,249, respectively (p<.0001). Patients in the P/TLIF cohort had the greatest number of comorbidities, having the highest prevalence for 10 of 17 comorbidities investigated. Anterior-posterior interbody fusion group was associated with the greatest number of complications, having the highest incidence of 12 of the 16 complications investigated.ConclusionsThese data help to define the perioperative risks for several LIF approaches. Comparison of outcomes showed that a combined approach is more expensive and associated with greater LOS, whereas ALIF is associated with the highest postoperative mortality. These trends should be taken into consideration during surgical planning to improve clinical outcomes.     

Single position circumferential fusion improves operative efficiency,reduces complications and length of stay compared with traditional circumferential fusion

BACKGROUND CONTEXTAnterior lumbar interbody fusion (ALIF) and lateral lumbar interbody fusion (LLIF) with percutaneous posterior screw fixation are two techniques used to address degenerative lumbar pathologies. Traditionally, these anterior-posterior (AP) surgeries involve repositioning the patient from the supine or lateral decubitus position to prone for posterior fixation. To reduce operative time (OpTime) and subsequent complications of prolonged anesthesia, single-position lumbar surgery (SPLS) is a novel, minimally invasive alternative performed entirely from the lateral decubitus position.PURPOSEAssess the perioperative safety and efficacy of single position AP lumbar fusion surgery (SPLS).STUDY DESIGNMulticenter retrospective cohort study.PATIENT SAMPLEThree hundred and ninety patients undergoing AP surgery were included, of which 237 underwent SPLS and 153 were in the Flip group.OUTCOME MEASURESOutcome measures included levels fused, percentage of cases including L5-S1 fusion, fluoroscopy radiation dosage, OpTime, estimated blood loss (EBL), length of stay (LOS), and perioperative complications. Radiographic analysis included lumbar lordosis (LL), pelvic incidence, pelvic tilt, and segmental LL.METHODSPatients undergoing primary ALIF and/or LLIF surgery with bilateral percutaneous pedicle screw fixation between L2-S1 were included over a 4-year period. Patients were classified as either traditional repositioned “Flip” surgery or SPLS. Outcome measures included levels fused, percentage of cases including L5-S1 fusion, fluoroscopy radiation dosage, OpTime, EBL, LOS, perioperative complications. Radiographic analysis included LL, pelvic incidence, pelvic tilt, and segmental LL. All measures were compared using independent samples t-tests and chi-squared analyses as appropriate with significance set at p < .05. Propensity matching was completed where demographic differences were found.RESULTSThree hundred and ninety patients undergoing AP surgery were included, of which 237 underwent SPLS and 153 were in the Flip group. Age, gender, BMI, and CCI were similar between groups. Levels fused (1.47 SPLS vs 1.52 Flip, p = .468) and percent cases including L5-S1 (31% SPLS, 35% Flip, p = .405) were similar between cohorts. SPLS significantly reduced OpTime (103 min vs 306 min, p < .001), EBL (97 vs 313 mL, p < .001), LOS (1.71 vs 4.12 days, p < .001), and fluoroscopy radiation dosage (32 vs 88 mGy, p < .001) compared to Flip. Perioperative complications were similar between cohorts with the exception of postoperative ileus, which was significantly lower in the SPLS group (0% vs 5%, p < .001). There was no significant difference in wound, vascular injury, neurological complications, or Venous Thrombotic Event. There was no significant difference found in 90-day return to operating room (OR).CONCLUSIONSSPLS improves operative efficiency in addition to reducing blood loss, LOS and ileus in this large cohort study, while maintaining safety.     

Anterior lumbar interbody fusion

Anterior lumbar interbody fusion (ALIF) is a common technique for treating a variety of lumbar spine disorders. Although used predominantly to obtain fusion, it is also excellent for restoring lumbar lordosis and can be used for indirect decompression, especially in the setting of foraminal stenosis.⁴ The technique is used predominantly at L4-5 and L5-S1, but can be used at L3-4 and even L2-3. ALIF provides an excellent biomechanical environment for arthrodesis. The anterior longitudinal ligament resection allows for excellent restoration of lordosis. ALIF can be performed as an isolated procedure or combined with posterior approaches. Although there are major risks associated with the required abdominal approach, ALIF has reached popularity for its reliability and versatility. With good knowledge of anatomical hazards, the properly indicated patient has much to gain with an ALIF surgery.     

Comparison of sagittal contour and posterior disc height following interbody fusion: threaded cylindrical cages versus structural allograft versus vertical cages

OBJECTIVE: Segmental restoration of sagittal contour is recognized as critical for improved long-term success following instrumented lumbar fusions. As such, the use of wedged implants has become more popular. Few studies exist to assess the postoperative lordotic and disc height changes following these varied techniques in spinal fusion. An observational radiographic study examining lumbar sagittal contour and posterior intervertebral disc space height following posterior lumbar interbody fusion (PLIF) or transforaminal lumbar interbody fusion (TLIF) was conducted using vertical cages (VCs), wedged structural allograft (WSA), and threaded cylindrical cages (TCCs). METHODS: Forty-nine consecutive patients (59 spinal segments) were evaluated following single- or two-level interbody fusion with either stand-alone TCCs (n = 18 levels), WSA with posterior transpedicular compression instrumentation (n = 25 levels), or VCs with posterior transpedicular compression instrumentation (n = 16 levels). Standing lumbar radiographs were measured by two independent observers preoperatively, immediately postoperatively (within 1 week), at 6-week follow-up (range 4-8 weeks), and postoperatively (at 1-year follow-up) for segmental lordosis at each level undergoing posterior interbody arthrodesis and posterior intervertebral disc space height to assess indirect nerve root decompression. RESULTS: At the 1-year follow-up, postoperative lordosis was improved in the VC group (+5.3 degrees ; P < 0.005), whereas it decreased in the WSA group (-0.9 degrees ; P = 0.407) and TCC group (-3.5 degrees ; P < 0.005). The posterior disc space height decreased in the VC group (-0.5 mm; P = 0.109), whereas it increased for both the WSA group (+1.2 mm; P = 0.05) and the TCC group (+0.8 mm; P = 0.219). CONCLUSIONS: PLIF with stand-alone TCC and PLIF (or TLIF) with WSA and posterior transpedicular instrumentation results in an increased posterior disc height and thus improved indirect nerve root decompression. PLIF (or TLIF) with VC and posterior transpedicular instrumentation results in an overall decrease in posterior disc height. However, TCC and WSA resulted in a loss of lumbar lordosis, whereas VC resulted in an increase in lumbar lordosis.     

实时三维导航辅助微创经椎间孔腰椎椎间融合术后腰骶部矢状位平衡参数变化分析

目的:探讨实时三维导航辅助微创经椎间孔腰椎椎体间融合术(minimally invasive transforaminal lumbar interbody fusion,MIS-TLIF)与传统开放TLIF术治疗腰椎退行性疾病后腰骶部矢状位参数的动态变化.方法:回顾性分析2017年9月至2019年9月行单节段手术治疗...     

选择性经椎间孔椎间融合结合后路融合术治疗退行性腰椎侧凸

目的 探讨后路融合结合选择性节段经椎间孔腰椎体间融合术(transforaminal lumbar in-terbody fusion,TLIF)治疗退行性腰椎侧凸的有效性.方法 2002年11月至2005年11月,共46例患者,男14例,女32例;年龄41～78岁,平均66.4岁.节段行TLIF的标准:运动节段存在僵硬的后凸畸形,椎体在任一个方向存在明显移位、节段不稳定,冠状位L3或L4椎体明显倾斜;3个节段行TLIF 3例,2个节段21例,1个节段22例.随访2～5年,平均3.6年.影像学评价包括腰椎侧凸Cobb角、腰椎前凸角和节段前凸角;临床疗效评价包括腰部和下肢症状的JOA评分.结果Cobb角术前平均31.7°3±14.4°,末次随访平均10.2°±6.5°,与术前比较差异有统计学意义(t=15.26,P<0.05),术后改善率67.8%.腰椎前凸角术前平均27.5°±12.6°,末次随访平均39.3°±9.7°,与术前比较差异有统计学意义(t=12.17,P<0.05),术后改善率44.4%.TLIF节段前凸角术前平均6.5°±5.1°,末次随访平均11.6°±5.9°;TLIF节段的脊柱其他畸形和椎体移位均得到明显矫正.术前JOA评分平均(14.1±4.2)分,末次随访平均(22.2±4.8)分,与术前比较差异有统计学意义(t=11.45,P<0.05),根据JOA评分恢复率,优良率84.8%;术后JOA评分增加与术后腰椎前凸角增加呈正相关(r=0.61.P=0.02).结论 选择性TLIF的应用有利于进一步恢复腰椎前凸、矫正节段畸形和移位,从而提高脊柱后路融合术治疗退行性腰椎侧凸的临床疗效.     

单节段后路椎间融合内固定术对腰椎前凸角度变化的影响

目的探讨L4/L5单节段后路椎间融合器置入椎弓根内固定术对患者腰椎前凸角度变化的影响。方法回顾性随访分析43例L4/L5单节段后路椎间融合器置入配合使用椎弓根内固定术的患者,对患者术前、术后总腰椎前凸角度、L4/L5节段前凸角、骶骨倾斜角进行比较。结果 L4/L5单节段后路椎间融合术后患者总腰椎前凸角度与术前对比平均增加8.4°（P〈0.01）;L4/L5节段前凸角与术前对比平均增加3.5°（P〈0.05）;骶骨倾斜角与术前对比平均增加4.2°（P〈0.05）。结论 L4/L5单节段后路椎间融合器置入椎弓根内固定术可以明显改善患者腰椎前凸角度,对于改善腰椎序列和缓解患者术后腰痛症状以及延缓邻近节段退变均有积极意义。     

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。     

Biomechanical comparison of anterior lumbar interbody fusion and transforaminal lumbar interbody fusion

STUDY DESIGN: An in vitro biomechanical comparison of 2 fusion techniques, anterior lumbar interbody fusion (ALIF) and transforaminal lumbar interbody fusion (TLIF), on cadaveric human spines. OBJECTIVE: To compare the immediate construct stability, in terms of range of motion (ROM) and neutral zone, of ALIF, including 2 separate approaches, and TLIF procedures with posterior titanium rod fixation. SUMMARY OF BACKGROUND DATA: Both ALIF and TLIF have been used to treat chronic low back pain and instability. In many cases, the choice between these 2 techniques is based only on personal preference. No biomechanical performance comparison between these 2 fusion techniques is available to assist surgical decision. METHODS: Twelve cadaveric lumbar motion segments were loaded sinusoidally at 0.05 Hz and 5 Nm in unconstrained axial rotation, lateral bending and flexion extension. Specimens were randomly divided into 2 groups with 6 in each group. One group was assigned for TLIF whereas the other group for ALIF. In the ALIF group, there were 3 steps. First, the lateral ALIF procedure with the anterior longitudinal ligament (ALL) intact was performed. Afterwards, the ALL was cut without removing the ALIF cage. Finally, another appropriately sized ALIF cage was inserted anteriorly. Biomechanical tests were conducted after each step. RESULTS: In the ALIF group, the lateral ALIF and subsequent anterior ALIF reduced segmental motion significantly (P=0.03) under all loading conditions. Removing the ALL increased ROM by 59% and 142% in axial rotation and flexion extension, respectively (P=0.03). The anterior ALIF approach was able to achieve similar biomechanical stability of the lateral approach in lateral bending and flexion extension (P>0.05) under all loading conditions. The TLIF procedure significantly reduced the range of motion compared with the intact state (P=0.03). However, no statistical difference was detected between the TLIF group and the ALIF group (P>0.05). CONCLUSIONS: Both ALIF and TLIF procedures combined with posterior instrumentation significantly improved construct stability of intact spinal motion segments. However, there was no statistical difference between these 2 fusion techniques. The 2 ALIF approaches (lateral and anterior) also had similar construct stability even though anterior longitudinal ligament severing significantly reduced stability.