Comparison of Clinical and Radiologic Results of Mini-Open Transforaminal Lumbar Interbody Fusion and Extreme Lateral Interbody Fusion Indirect Decompression for Degenerative Lumbar Spondylolisthesis

Radiological and Clinical Outcomes comparing 2-level MIS Lateral and MIS Transforaminal Lumbar Interbody Fusion in Degenerative Lumbar Spinal Stenosis

STUDY DESIGN

Retrospective Cohort Study.

OBJECTIVES

To compare early postoperative radiological and clinical outcomes between 2-level minimally invasive (MIS) trans-psoas lateral lumbar interbody fusion (LLIF) and MIS transforaminal lumbar interbody fusion (TLIF) for degenerative lumbar spinal stenosis.

METHODS

Fifty three consecutive patients undergoing 2-level lumbar interbody fusion from L3-L5 for degenerative lumbar spinal stenosis were enrolled. Twenty four patients underwent LLIF and 29 underwent TLIF.

RESULTS

Operative time and length of stay were similar between LLIF and TLIF (272.8 ± 82.4 vs 256.1 ± 59.4 minutes; 5.5 ± 2.8 vs 4.7 ± 3.3 days, P > .05), whereas blood loss was lower for LLIF (229.0 ± 125.6 vs 302.4 ± 97.1mls, P = .026). Neurological deficits were more common in LLIF (9 vs 3, P = .025), whereas persistent deficits were rare for both (1 vs 1, P = 1). For both groups, all patient reported outcomes visual analogue scale (VAS back pain, VAS leg pain, ODI, SF-36 physical) improved from preoperative to 2-years postoperative (P < .05), with both groups showing no significant differences in extent of improvement for any outcome. Lateral lumbar interbody fusion demonstrated superior restoration of disc height (L3-L4: 4.1 ± 2.4 vs 1.2 ± 1.9 mm, P < .001; L4-L5: 4.6 ± 2.4 vs .8 ± 2.8 mm, P < .001), foraminal height (FH) (L3-L4: 3.5 ± 3.6 vs 1.0 ± 3.6 mm, P = .014; L4-L5: 3.0 ± 3.5 vs -.1 ± 4.4 mm, P = .0080), segmental lordosis (4.1 ± 6.4 vs -2.1 ± 8.1°, P = .005), lumbar lordosis (LL) (4.1 ± 7.0 vs -2.3 ± 12.6°, P = .026) and pelvic incidence-lumbar lordosis (PI-LL) mismatch (-4.1 ± 7.0 vs 2.3 ± 12.6°, P = .019) at 2-years follow-up.

CONCLUSION

The superior radiological outcomes demonstrated by 2-level trans-psoas LLIF did not translate into difference in clinical outcomes compared to 2-level TLIF at the 2-years follow-up, suggesting both approaches are reasonable for 2-level lumbar interbody fusion in degenerative lumbar spinal stenosis.

Effect of Lateral Surgery Compared with Posterior Surgery on Lumbar Degenerative Disease: A Meta-Analysis of 41 Cohort Studies

OBJECTIVE

The purpose of this study was to compare the efficacy of the lateral approach and posterior approach in the treatment of lumbar degenerative diseases.

METHODS

Through a systematic search of relevant articles published on or before July 20, 2023, in the Embase, PubMed, and Cochrane libraries, the 2 authors independently extracted data and used the Newcastle‒Ottawa scale to evaluate the quality of the included studies. Using Stata16 software, the continuous variables were presented as the standard mean deviation, and the bipartite variables were analyzed using the pooled odds ratio with 95% confidence interval.

RESULTS

A total of 13,892 articles were screened and 10,908 studies were identified after deleting duplicates, of which 41 met the criteria and were included in the meta-analysis. The meta-analysis showed that the lateral approach was superior to the posterior approach in reducing blood loss, operation time, and hospital stay. At the same time, compared with the posterior approach, the lateral approach has more advantages in the long-term Japanese Orthopaedic Association score and Oswestry Disability Index score, adjusting mid- and long-term LL and short- and long-term disc height.

CONCLUSIONS

Lateral and posterior surgery have similar clinical effects in the treatment of lumbar degenerative diseases and can significantly reduce pain and improve postoperative SL. At the same time, the lateral approach has more advantages in improving long-term quality of life, reducing the long-term disability index, adjusting mid- and long-term LL and short- and long-term disc height.

Different lumbar fusion techniques for lumbar spinal stenosis: a Bayesian network meta-analysis

OBJECTIVE

To comprehensively compare and assess the effects of different lumbar fusion techniques in patients with lumbar spinal stenosis (LSS).

METHODS

PubMed, Embase, Cochrane Library, and Web of Science databases were systematically searched up to December 24, 2022 in this network meta-analysis. Outcomes were pain (pain, low back pain, and leg pain), Japanese Orthopaedic Association (JOA), Oswestry Disability Index (ODI), complications, reoperation, and fusion. Network plots illustrated the direct and indirect comparisons of different fusion techniques for the outcomes. League tables showed the comparisons of any two fusion techniques, based on both direct and indirect evidence. The efficacy of each fusion technique for LSS was ranked by rank probabilities.

RESULTS

Totally 29 studies involving 2,379 patients were eligible. For pain, percutaneous endoscopic transforaminal lumbar interbody fusion (Endo-TLIF) was most likely to be the best technique, followed by minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF), extreme lateral interbody fusion (XLIF), and transforaminal lumbar interbody fusion (TLIF). Percutaneous endoscopic posterior lumbar interbody fusion (Endo-PLIF) had the greatest likelihood to be the optimal technique for low back pain, followed sequentially by MIS-TLIF, minimally invasive posterior lumbar interbody fusion (MIS-PLIF), XLIF, Endo-TLIF, TLIF, oblique lumbar interbody fusion (OLIF), posterior lumbar interbody fusion (PLIF), and posterolateral lumbar fusion (PLF). MIS-PLIF was ranked the most effective technique concerning leg pain, followed by Endo-TLIF, MIS-TLIF, TLIF, Endo-PLIF, PLIF, OLIF, PLF, and XLIF. As regards JOA scores, Endo-TLIF had the maximum probability to be the best technique, followed by MIS-TLIF and TLIF. Endo-PLIF had the greatest likelihood to be the optimum technique for complications, followed by TLIF, MIS-TLIF, Endo-TLIF, OLIF, and XLIF.

CONCLUSION

Minimally invasive fusion techniques may be effective in the treatment of LSS, compared with traditional techniques. Minimally invasive techniques were likely non-inferior with regards to postoperative complications.

Early Radiological Assessment of Static and Expandable Cages in Lateral Single Position for Indirect Decompression- Lateral Lumbar Interbody Fusion

OBJECTIVE

This study aimed to compare the postoperative alignment of static and expandable cages in lateral single-position (LSP) for indirect decompression in lateral lumbar interbody fusion (LLIF).

METHODS

We included sixty-seven patients who underwent LSP-LLIF for lumbar degenerative disease. We performed radiological assessments preoperatively and two weeks postoperatively using computed tomography and magnetic resonance imaging. We divided the patients into the expandable cage group (23 patients) and the static cage group (44 patients). We measured disc height (DH), segmental lordosis (SL), and foraminal area (FA) from computed tomography images and the area of the dural sac from magnetic resonance imaging. We recorded surgical outcomes and complications.

RESULTS

Both static and expandable cages demonstrated improvements in DH, SL, FA, and dural sac expansion. However, we found no statistically significant differences in the average change in DH (4.4 ± 2.1 mm vs. 4.2 ± 1.8 mm, P = 0.685), the average change in SL (1.0 ± 4.4° vs. 1.9 ± 3.6°, P = 0.310), or FA change (32.5 ± 31.7 mm2 vs. 34.9 ± 29.5 mm2, P = 0.966) between the expandable and static cage groups. We also found no statistically significant difference in dural sac enlargement between the two groups. We observed no significant differences in operation time, estimated blood loss, or length of hospital stay between the two groups. No severe adverse events or additional surgeries were reported.

CONCLUSIONS

In LSP-LLIF without facet joint resection or other posterior techniques, static and expandable cages showed comparable effectiveness in achieving increased DH, SL, FA, and indirect decompression.

Lateral versus posterior approaches to treat degenerative lumbar pathologies-systematic review and meta-analysis of recent literature

INTRODUCTION

The lateral lumbar interbody fusion arose as a revolutionary approach to treating several spinal pathologies because the techniques were able to promote indirect decompression and lordosis restoration through a minimally invasive approach allowing for reduced blood loss and early recovery for patients. However, it is still not clear how the technique compares to other established approaches for treating spinal degenerative diseases, such as TLIF, PLIF, and PLF.

MATERIAL AND METHODS

This is a systematic review and meta-analysis of articles published in the last 10 years comparing lateral approaches to posterior techniques. The authors included articles that compared the LLIF technique to one or more posterior approaches, treating only degenerative pathologies, and containing at least one of the key outcomes of the study. Exclusion articles that were not original and the ones that the authors could not obtain the full text; also articles without the possibility to calculate the standard deviation or mean were excluded. For count variables, the odds ratio was used, and for continuous variables, the standard means difference (SMD) was used, and the choice between random or fixed-effects model was made depending on the presence or not of significant (p < 0.05) heterogeneity in the sample.

RESULTS

Twenty-four articles were included in the quantitative review. As for the intra-/perioperative variables, the lateral approaches showed a significant reduction in blood loss (SMD-1.56, p < 0.001) and similar operative time (SMD =  - 0.33, p = 0.24). Moreover, the use of the lateral approaches showed a tendency to lead to reduced hospitalization days (SMD =  - 0.15, p = 0.09), with significantly reduced odds ratios of complications (0.53, p = 0.01). As for the clinical outcomes, both approaches showed similar improvement both at improvement as for the last follow-up value, either in ODI or in VAS-BP. Finally, when analyzing the changes in segmental lordosis and lumbar lordosis, the lateral technique promoted significantly higher correction in both outcomes (p < 0.05).

CONCLUSION

Lateral approaches can promote significant radiological correction and similar clinical improvement while reducing surgical blood loss and postoperative complications.

Is Indirect Decompression and Fusion More Effective than Direct Decompression and Fusion for Treating Degenerative Lumbar Spinal Stenosis With Instability? A Systematic Review and meta-Analysis

Study design: Systematic Review and Meta-analysis.Objective: Surgical alternatives to treat lumbar spinal stenosis and instability include indirect (ALIF, OLIF, and LLIF) and direct (TLIF or posterior lumbar interbody fusion) decompression and fusion interventions. Although both approaches have proven to be effective in reducing symptoms, it is unknown if there is any difference in effectiveness between them. In this systematic review and meta-analysis, we aimed to evaluate postoperative pain and disability in patients treated whit indirect vs direct decompression and fusion approaches.Methods: We conducted a systematic review of the literature consulting several databases and identified studies that enrolled patients diagnosed with degenerative lumbar spinal stenosis and instability treated with indirect or direct decompression and fusion techniques. Our primary endpoints were the visual analogue scale, Oswestry Disability Index, and the Japanese Orthopedics Association Back Pain Evaluation Questionnaire 1 year after the procedure. Secondary outcomes included complication rate, blood loss, and surgical time.Results: Nine retrospective and comparative studies were included enrolling a total of 1004 participants. Both surgical strategies had satisfactory clinical outcomes with no significant difference at 1 year. Although the complication rate was similar for both groups, the profile of the adverse events was different. In addition, patients treated with indirect decompression and fusion had significantly less blood loss and operative times.Conclusions: Indirect and direct decompression and fusion techniques are similarly effective in treating patients with lumbar spinal stenosis and instability. The ID group had significantly lower intraoperative blood loss and surgical time values.

The Prone Lateral Approach for Lumbar Fusion-A Review of the Literature and Case Series

Lateral lumbar interbody fusion is an evolving procedure in spine surgery allowing for the placement of large interbody devices to achieve indirect decompression of segmental stenosis, deformity correction and high fusion rates through a minimally invasive approach. Traditionally, this technique has been performed in the lateral decubitus position. Many surgeons have adopted simultaneous posterior instrumentation in the lateral position to avoid patient repositioning; however, this technique presents several challenges and limitations. Recently, lateral interbody fusion in the prone position has been gaining in popularity due to the surgeon's ability to perform simultaneous posterior instrumentation as well as decompression procedures and corrective osteotomies. Furthermore, the prone position allows improved correction of sagittal plane imbalance due to increased lumbar lordosis when prone on most operative tables used for spinal surgery. In this paper, we describe the evolution of the prone lateral approach for interbody fusion and present our experience with this technique. Case examples are included for illustration.

The impact of cage positioning on lumbar lordosis and disc space restoration following minimally invasive lateral lumbar interbody fusion

OBJECTIVE

The objective of this study was to evaluate patient and surgical factors that predict increased overall lumbar lordosis (LL) and segmental lordosis correction following a minimally invasive lateral lumbar interbody fusion (LLIF) procedure.

METHODS

A retrospective review was conducted of all patients who underwent one- or two-level LLIF. Preoperative, initial postoperative, and 6-month postoperative measurements of LL, segmental lordosis, anterior disc height, and posterior disc height were collected from standing lateral radiographs for each patient. Cage placement was measured utilizing the center point ratio (CPR) on immediate postoperative radiographs. Spearman correlations were used to assess associations between cage lordosis and radiographic parameters. Multivariate linear regression was performed to assess independent predictors of outcomes.

RESULTS

A total of 106 levels in 78 unique patients were included. Most procedures involved fusion of one level (n = 50, 64.1%), most commonly L3-4 (46.2%). Despite no differences in baseline segmental lordosis, patients with anteriorly or centrally placed cages experienced the greatest segmental lordosis correction immediately (mean anterior 4.81° and central 4.46° vs posterior 2.47°, p = 0.0315) and at 6 months postoperatively, and patients with anteriorly placed cages had greater overall lordosis correction postoperatively (mean 6.30°, p = 0.0338). At the 6-month follow-up, patients with anteriorly placed cages experienced the greatest increase in anterior disc height (mean anterior 6.24 mm vs posterior 3.69 mm, p = 0.0122). Cages placed more posteriorly increased the change in posterior disc height postoperatively (mean posterior 4.91 mm vs anterior 1.80 mm, p = 0.0001) and at 6 months (mean posterior 4.18 mm vs anterior 2.06 mm, p = 0.0255). There were no correlations between cage lordotic angle and outcomes. On multivariate regression, anterior cage placement predicted greater 6-month improvement in segmental lordosis, while posterior placement predicted greater 6-month improvement in posterior disc height. Percutaneous screw placement, cage lordotic angle, and cage height did not independently predict any radiographic outcomes.

CONCLUSIONS

LLIF procedures reliably improve LL and increase intervertebral disc space. Anterior cage placement improves the lordosis angle greater than posterior placement, which better corrects sagittal alignment, but there is still a significant improvement in lordosis even with a posteriorly placed cage. Posterior cage placement provides greater restoration in posterior disc space height, maximizing indirect decompression, but even the anteriorly placed cages provided indirect decompression. Cage parameters including cage height, lordosis angle, and material do not impact radiographic improvement.

Comparison of Outcomes of Multi-Level Anterior, Oblique, Transforaminal Lumbar Interbody Fusion Surgery : Impact on Global Sagittal Alignment

OBJECTIVE

To compare the outcomes of anterior lumbar interbody fusion (ALIF), oblique lumbar interbody fusion (OLIF), and transforaminal lumbar interbody fusion (TLIF) in terms of global sagittal alignment.

METHODS

From January 2007 to December 2019, 141 adult patients who underwent multilevel interbody fusion for lumbar degenerative disorders were enrolled. Regarding the approach, patients were divided into the ALIF (n=23), OLIF (n=60), and TLIF (n=58) groups. Outcomes, including local radiographic parameters and global sagittal alignment, were then compared between the treatment groups.

RESULTS

Regarding local radiographic parameters, ALIF and OLIF were superior to TLIF in terms of the change in the anterior disc height (7.6±4.5 mm vs. 6.9±3.2 mm vs. 4.7±2.9 mm, p<0.001), disc angle (-10.0°±6.3° vs. -9.2°±5.2° vs. -5.1°±5.1°, p<0.001), and fused segment lordosis (-14.5°±11.3° vs. -13.8°±7.5° vs. -7.4°±9.1°, p<0.001). However, regarding global sagittal alignment, postoperative lumbar lordosis (-42.5°±9.6° vs. -44.4°±11.6° vs. -40.6°±12.3°, p=0.210), pelvic incidence-lumbar lordosis mismatch (7.9°±11.3° vs. 6.7°±11.6° vs. 11.5°±13.0°, p=0.089), and the sagittal vertical axis (24.3±28.5 mm vs. 24.5±34.0 mm vs. 25.2±36.6 mm, p=0.990) did not differ between the groups.

CONCLUSION

Although the anterior approaches were superior in terms of local radiographic parameters, TLIF achieved adequate global sagittal alignment, comparable to the anterior approaches.

Assessing the differences in operative and patient-reported outcomes between lateral approaches for lumbar fusion: a systematic review and indirect meta-analysis

OBJECTIVE

Anterior-to-psoas lumbar interbody fusion (ATP-LIF), more commonly referred to as oblique lateral interbody fusion, and lateral transpsoas lumbar interbody fusion (LTP-LIF), also known as extreme lateral interbody fusion, are the two commonly used lateral approaches for performing a lumbar fusion procedure. These approaches help overcome some of the technical challenges associated with traditional approaches for lumbar fusion. In this systematic review and indirect meta-analysis, the authors compared operative and patient-reported outcomes between these two select approaches using available studies.

METHODS

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) approach, the authors conducted an electronic search using the PubMed, EMBASE, and Scopus databases for studies published before May 1, 2019. Indirect meta-analysis was conducted on fusion rate, cage movement (subsidence plus migration), permanent deficits, and transient deficits; results were depicted as forest plots of proportions (effect size [ES]).

RESULTS

A total of 63 studies were included in this review after applying the exclusion criteria, of which 26 studies investigated the outcomes of ATP-LIF, while 37 studied the outcomes of LTP-LIF. The average fusion rate was found to be similar between the two groups (ES 0.97, 95% CI 0.84-1.00 vs ES 0.94, 95% CI 0.91-0.97; p = 0.561). The mean incidence of cage movement was significantly higher in the ATP-LIF group compared with the LTP-LIF group (stand-alone: ES 0.15, 95% CI 0.06-0.27 vs ES 0.09, 95% CI 0.04-0.16 [p = 0.317]; combined: ES 0.18, 95% CI 0.07-0.32 vs ES 0.02, 95% CI 0.00-0.05 [p = 0.002]). The mean incidence of reoperations was significantly higher in patients undergoing ATP-LIF than in those undergoing LTP-LIF (ES 0.02, 95% CI 0.01-0.03 vs ES 0.04, 95% CI 0.02-0.07; p = 0.012). The mean incidence of permanent deficits was similar between the two groups (stand-alone: ES 0.03, 95% CI 0.01-0.06 vs ES 0.05, 95% CI 0.01-0.12 [p = 0.204]; combined: ES 0.03, 95% CI 0.01-0.06 vs ES 0.03, 95% CI 0.00-0.08 [p = 0.595]). The postoperative changes in visual analog scale (VAS) and Oswestry Disability Index (ODI) scores were both found to be higher for ATP-LIF relative to LTP-LIF (VAS: weighted average 4.11 [SD 2.03] vs weighted average 3.75 [SD 1.94] [p = 0.004]; ODI: weighted average 28.3 [SD 5.33] vs weighted average 24.3 [SD 4.94] [p < 0.001]).

CONCLUSIONS

These analyses indicate that while both approaches are associated with similar fusion rates, ATP-LIF may be related to higher odds of cage movement and reoperations as compared with LTP-LIF. Furthermore, there is no difference in rates of permanent deficits between the two procedures.

Usefulness of Lateral Lumbar Interbody Fusion Combined with Indirect Decompression for Degenerative Lumbar Spondylolisthesis: A Systematic Review

Background and Objective: The aim of this review was to analyze the existing literature and investigate the outcomes or complications of lateral lumbar interbody fusion (LLIF) combined with indirect decompression for degenerative lumbar spondylolisthesis (DS). Materials and Methods: A database search algorithm was used to query MEDLINE, COCHRANE, and EMBASE to identify the literature reporting LLIF with indirect decompression for DS between January 2010 and December 2021. Improvements in outcome measures and complication rates were pooled and tested for significance. Results: A total of 412 publications were assessed, and 12 studies satisfied the inclusion criteria after full review. The pooled data available in the included studies showed that 438 patients with lumbar spondylolisthesis (mean age 65.2 years; mean body mass index (BMI) 38.1 kg/m²) underwent LLIF. A total of 546 disc spaces were operated on. The most frequently treated levels were L4–L5 and L3–L4. Clinically, the average improvement was 32.5% in ODI, 46.3 mm in low back pain, and 48.3 mm in leg pain estimated from the studies included. SF-36 PCS improved by 51.5% and MCS improved by 19.5%. For radiological outcomes, a reduction in slippage was seen in 6.3%. Disc height increased by 55%, foraminal height increased by 21.1%, the foraminal area on the approach side increased by 21.9%, and on the opposite side it increased by 26.1%. The cross-sectional spinal canal area increased by 20.6% after surgery. Post-operative complications occurred in 5–40% of patients with thigh symptoms, such as anterior thigh numbness, dysesthesia, discomfort, pain, and sensory deficits. Conclusions: Indirect decompression by LLIF for DS is an effective method for improving pain and dysfunction with less surgical invasion. In addition, it has the effect of significantly improving disc height, foraminal height and area, and segmental lordosis on radiological outcomes compared to the posterior approach.

Lateral interbody release for fused vertebrae via transpsoas approach in adult spinal deformity surgery: a preliminary report of radiographic and clinical outcomes

BACKGROUND

Lateral interbody release (LIR) via a transpsoas lateral approach is a surgical strategy to address degenerative lumbar scoliosis (DLS) patients with anterior autofusion of vertebral segments. This study aimed to characterize the clinical and radiographic outcomes of this lumbar reconstruction strategy using LIR to achieve anterior column correction.

METHODS

Data for 21 fused vertebrae in 17 consecutive patients who underwent LIR between January 2014 and March 2020 were reviewed. Demographic and intraoperative data were recorded. Radiographic parameters were assessed preoperatively and at final follow-up, including segmental lordotic angle (SLA), segmental coronal angle (SCA), bone union rate, pelvic incidence (PI), lumbar lordosis (LL), pelvic tilt, sacral slope, PI-LL mismatch, sagittal vertical axis, Cobb angle, and deviation of the C7 plumb line from the central sacral vertical line. Clinical outcomes were evaluated using Oswestry Disability Index (ODI), visual analog scale (VAS) scores for low back and leg pain, and the short form 36 health survey questionnaire (SF-36) postoperatively and at final follow-up. Complications were also assessed.

RESULTS

Mean patient age was 70.3 ± 4.8 years and all patients were female. Average follow-up period was 28.4 ± 15.3 months. Average procedural time to perform LIR was 21.3 ± 9.7 min and was not significantly different from traditional lateral interbody fusion at other levels. Blood loss per single segment during LIR was 38.7 ± 53.2 mL. Fusion rate was 100.0% in this cohort. SLA improved significantly from - 7.6 ± 9.2 degrees preoperatively to 7.0 ± 8.8 degrees at final observation and SCA improved significantly from 19.1 ± 7.8 degrees preoperatively to 8.7 ± 5.9 degrees at final observation (P < 0.0001, and < 0.0001, respectively). All spinopelvic and coronal parameters, as well as ODI and VAS, improved significantly. Incidence of peri- and postoperative complications such as iliopsoas muscle weakness and leg numbness in patients who underwent LIR was as much as XLIF. Incidence of postoperative mechanical failure following LIR was also similar to XLIF. Reoperation rate was 11.8%. However, there were no reoperations associated with LIR segments.

CONCLUSIONS

The LIR technique for anterior column realignment of fused vertebrae in the context of severe ASD may be an option of a safe and effective surgical strategy.

Comparison of Outcomes Between Single-level Lateral Lumbar Interbody Fusion and Transforaminal Lumbar Interbody Fusion: A Meta-analysis and Systematic Review

STUDY DESIGN

This is a meta-analysis and systematic review of the available literature.

OBJECTIVE

This study aims to compare the clinical and radiologic outcomes of single-level lateral lumbar interbody fusion (LLIF) with single-level transforaminal lumbar interbody fusion (TLIF).

SUMMARY OF BACKGROUND DATA

In the treatment of adult spinal deformity, LLIF allows interbody fusion while avoiding complications associated with an anterior or transforaminal approach, although the clinical outcomes of LLIF compared with other approaches have not been well established.

METHODS

We searched PubMed, Embase, and Scopus for 385 unique studies. On the basis of our exclusion criteria, 8 studies remained for our systematic review. Data were analyzed using Review Manager 5.3 using Mantel-Haenszel statistics and random effect models. This study identified self-reported Visual Analog Scale (VAS), Oswestry Disability Index, length of stay, blood loss, complication rate, and radiologic parameters (disk height, lumbar lordosis, segmental lordosis).

RESULTS

Our meta-analysis showed that LLIF contributed to decreased blood loss [mean difference (MD)=-67.62 mL, 95% confidence interval (CI): -104 to -30.90, P<0.001], superior restoration of segmental lordosis (MD=1.91 degrees, 95% CI: 0.71-3.10, P=0.002), lumbar lordosis (MD=1.95 degrees, 95% CI: 0.15-3.74, P=0.03), and disk height (MD=2.18 mm, 95% CI: 1.18-3.17, P<0.001) when compared with TLIF. However, current data suggests no significant difference in clinical outcomes between LLIF and TLIF based on overall complication rates (P=0.22), length of hospital stay (P=0.65), postoperative Oswestry Disability Index (P=0.13), postoperative VAS Back Pain (P=0.47) and VAS Leg Pain (P=0.16).

CONCLUSIONS

LLIF is an increasingly popular option for single-level anterior column reconstruction. When compared with single-level TLIF, single-level LLIF is associated with greater changes in lumbar lordosis and disk height. The single-level LLIF is a viable alternative to TLIF, demonstrating comparable clinical outcomes and better restoration of spinopelvic parameters.

LEVEL OF EVIDENCE

Level III.

Analysis of Temporal Changes in Dural Sac Morphology After XLIF Indirect Decompression

STUDY DESIGN

Retrospective study.

OBJECTIVE

To investigate temporal changes in dural sac morphology after extreme lateral interbody fusion (XLIF) indirect decompression for central lumbar spinal stenosis and to study the factors influencing the changes.

METHODS

The morphology of the dural sac was categorized into 4 grades (A, minor; B, moderate; C, severe; and D, extreme) by partially modifying Schizas classification (m-Schizas). The study involved 38 patients and 47 intervertebral spaces treated with indirect decompression (grade C or D). We evaluated m-Schizas before surgery, immediately after surgery, and at final follow-up. We performed a statistical analysis on the risk factors of grade C or D stenosis (poor morphological improvement) at final follow-up. The factors evaluated were preoperative dural sac cross-section area (CSA), diagnosis, cage size, location of cage insertion, locked facets, bony lateral recess stenosis, end plate injury, and changes in the posterior disc height (PDH) and disc angle (DA).

RESULTS

On morphological evaluation, improvement to grade A or B was seen in 10 intervertebral spaces (21.2%) immediately after the surgery, and improvement was achieved in 38 intervertebral spaces (80.8%) at final follow-up. The risk factor of poor morphological improvement was found to be small preoperative dural sac CSA (odds ratio 1.32, P < .002).

CONCLUSIONS

After XLIF indirect decompression, the morphological improvement of the dural sac was remodeled with time and further expansion was seen in many patients. However, the study suggested that sufficient morphological improvement may not be achieved in spinal stenosis whose preoperative state is severe.

Three-dimensional computed tomographic evaluation of lateral lumbar interbody fusion: morphometric change of intervertebral structure

PURPOSE

Two-dimensional (2D) analyses of intervertebral disc (IVD) height and foramen measurements following lateral lumbar interbody fusion (LLIF) have been reported. However, three-dimensional (3D) morphometric analysis of intervertebral structure using 3D computed tomography (3D CT) provides increased precision for measuring morphological changes. The purpose of this study was to evaluate 3D changes of lumbar IVD height and foramen diameter in degenerative lumbar disease patients following LLIF.

METHODS

Subject-based 3D CT lumbar models were created for 26 patients before and following LLIF. IVD height (whole and five anatomical zones) and foramen diameter (minimum and maximum) were measured based on the model using custom software. The sagittal placement of cages (SPC) and cross-sectional area of the thecal sac (CSA) were measured. Changes in these parameters by LLIF were quantified and statistically analysed.

RESULTS

Following LLIF, disc height increased by an average of 2.9 mm (P < 0.01). Post-operative measurements of both minimum and maximum diameters of the foramen were significantly increased by 1.0 mm and 1.9 mm, respectively (P < 0.01). Change in maximum foramen diameter was significantly correlated with change in disc height (P < 0.05). The SPC was significantly correlated with the changes in disc height and foraminal diameters (P < 0.05, respectively). No significant change between the change in disc height and CSA was found.

CONCLUSION

This preliminary study quantifies disc height and foramen diameter changes in 3D following LLIF. The presented data provide baseline intervertebral changes for future comparisons with follow-up studies and clinical outcomes.

LEVEL OF EVIDENCE I

Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding.

Lateral lumbar interbody fusion after reduction using the percutaneous pedicle screw system in the lateral position for Meyerding grade II spondylolisthesis: a preliminary report of a new lumbar reconstruction strategy

BACKGROUND

Utilization of a cage with a large footprint in lateral lumbar interbody fusion (LLIF) for the treatment of spondylolisthesis leads to a high fusion rate and neurological improvement owing to the indirect decompression effect and excellent alignment correction. However, if an interbody space is too narrow for insertion of an LLIF cage for cases of spondylolisthesis of Meyerding grade II or higher, LLIF cannot be used. Therefore, we developed a novel strategy, LLIF after reduction by the percutaneous pedicle screw (PPS) insertion system in the lateral position (LIFARL), for surgeons to perform accurate and safe LLIF with PPS in patients with such pathology. This study aimed to introduce the new surgical strategy and to present preliminary clinical and radiological results of patients with spondylolisthesis of Meyerding grade II.

METHODS

Six consecutive patients (four men and two women; mean age, 72.7 years-old; mean follow-up period, 15.3 months) with L4 spondylolisthesis of Meyerding grade II were included. Regarding the surgical procedure, first, PPSs were inserted into the L4 and L5 vertebrae fluoroscopically, and both rods were placed in the lateral position. The L5 set screws were fixed tightly, and the L4 side of the rod was floated. Second, the L4 vertebra was reduced by fastening the L4 set screws so that they expanded the anteroposterior width of the interbody space. At that time, the L4 set screws were not fully tightened to the rods to prevent the endplate injury. Finally, the LLIF procedure was started. After inserting the cage, a compression force was added to the PPSs, and the L4 set screws were completely fastened.

RESULTS

The mean operative time was 183 min, and the mean blood loss was 90.8 mL. All cages were positioned properly. Visual analog scale score and Oswestry disability index improved postoperatively. Bone union was observed using computed tomography 12 months after surgery.

CONCLUSION

For cases with difficulty in LLIF cage insertion for Meyerding grade II spondylolisthesis due to the narrow anteroposterior width of interbody space, LIFARL is an option to achieve LLIF combined with posterior PPS accurately and safely.

TRIAL REGISTRATION

UMIN-Clinical Trials Registry, UMIN000040268, Registered 29 April 2020, https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000045938.

Short-term comparison of preoperative and postoperative pain after indirect decompression surgery and direct decompression surgery in patients with degenerative spondylolisthesis

The purpose of this study was to compare the short-term clinical outcomes between extreme lateral interbody fusion (XLIF) and minimally invasive surgery (MIS)–transforaminal interbody fusion (TLIF) in patients with degenerative spondylolisthesis with stenosis. One hundred-six patients were enrolled; 44 were treated with MIS–TLIF (direct decompression group; DP), and 62 were treated with XLIF (indirect decompression group; IDP). Perioperative indexes included operation time and intraoperative bleeding. Perioperative indexes preoperative and postoperative numeric rating scale (NRS) scores for low back pain (NRS-BP), leg pain (NRS-LP), and leg numbness (NRS-LN), and the preoperative score on the Japanese version of the painDETECT questionnaire (PDQ-J) were also assessed. The average follow-up period for the collection of NRS scores was 12.6 months. The operation time was significantly shorter in the IDP than in the DP group (109.9 ± 35.4 vs. 153.3 ± 50.9 min; p < 0.001). Intraoperative blood loss was also significantly less in the IDP group than in the DP group (85.4 ± 125.4 vs. 258.3 ± 220.4 mL; p < 0.001). The PDQ-J score and preoperative NRS scores (NRS-BP, NRS-LP, and NRS-LN) did not differ significantly between groups. Less improvement in the NRS-BP (ΔNRS-BP) was observed in the DP group than in the IDP group (p < 0.05). Although pain improved after surgery in both groups, IDP surgery was advantageous in minimizing bleeding and preserving posterior support elements such as the facet joints, lamina, and paraspinal muscles. These findings suggest that this may have contributed to the higher rate of improvement in low back pain compared with DP surgery.

The feasibility for a novel minimally invasive surgery-percutaneous endoscopic transforaminal lumbar interbody fusion (PE-TLIF) for the treatment of lumbar degenerative diseases: a cadaveric experiment

Background

The objective of the study was to evaluate our innovative percutaneous endoscopic transforaminal lumbar interbody fusion (PE-TLIF) for the treatment of lumbar degenerative diseases.

Methods

Two fresh-frozen human cadavers with soft tissues were donated for the experiment. Both cadavers had no history of previous spine surgery. The PE-TLIF surgery was performed on 3 levels (L4-5 of the first one, and L3-4, L4-5 of the second one) in October 2015. The PE-TLIF technique mainly included the following aspects: primary guide pins and a specially designed superior articular process (SAP) guide insertion, working channel setup, endoscopic decompression and fusion, and pedicle screw implantation and fixation. Under the surveillance of C-arm fluoroscope, four primary guide pins were inserted. The inferior primary guide in the hypothetically symptomatic side was confirmed as the first guide pin. At the end of the first guide pin, the specially designed SAP guide was installed. The secondary guide pin was inserted in the SAP via self-designed SAP guide. Under the protection cannula, part of the superior articular process was removed by oriented SAP resection device, so the working channel was smoothly put through the Kambin’s triangle. The endoscope was inserted close to the exiting nerve root. Rotation of the working channel kept the nerve root out of it.

Results

Three levels of PE-TLIF were successfully performed in two cadavers. Self-designed SAP guide made the secondary guide pin inserting the SAP accurately. Decompression was adequate and the traversing nerve root was relieved. Three aimed intervertebral levels are implanted with two 7-mm-high PEEK cages and one expandable cage. The expandable cage could be adjusted from 8 mm to 13 mm. Surgical incisions included four 15 mm incisions for percutaneous screw fixation and one 12 mm incision for working channel. There was no nerve injury during the operations.

Conclusions

Our present results showed that the novel minimally invasive surgery PE-TLIF was feasible for the treatment of lumbar degenerative diseases.

Comparison of extreme lateral approach with posterior approach in the treatment of lumbar degenerative diseases: A meta-analysis of clinical and imaging findings

OBJECTIVE

To compare clinical and imaging findings between extreme lateral lumbar interbody fusion (XLIF) and posterior fusion (PF) via meta-analysis for the treatment of lumbar degenerative diseases.

METHODS

English papers reporting clinical and imaging findings for the treatment of lumbar degenerative diseases with XLIF and PF published electronically in the PubMed, Embase, Cochrane Library, and Web of Science databases from January 2006 to August 2019 were retrieved. Two authors independently extracted data and evaluated the quality of the included literature. Meta-analysis of outcome measures was performed using Stata 14 and RevMan 5.3 software.

RESULTS

This meta-analysis included 744 patients from nine studies, two of which were prospective studies, while the others were retrospective studies. The quality of each study was determined to be high. The meta-analysis showed no significant differences in the operative time, length of hospital stay, clinical effectiveness, and improvement in postoperative global sagittal alignment between two approaches (P > 0.05). However, XLIF was significantly better than PF in reducing intraoperative blood loss and recovery of local sagittal alignment (P < 0.05). Moreover, the high incidence of postoperative complications were detected in XLIF group (P < 0.05).

CONCLUSIONS

Both surgical approaches have equally promising clinical effectiveness for the treatment of lumbar degenerative diseases. Although XLIF can reduce intraoperative blood loss and obtain better postoperative local sagittal alignment than PF, the high incidence of postoperative complications should prompt us to consider why XLIF procedure is still being offered to our patients and how we can reduce these complications. In addition, any conclusions should be taken with caution because of the mix of prospective and retrospective studies, and the high heterogeneity and bias.

Comparison of Outcomes of Oblique Lateral Interbody Fusion with Percutaneous Posterior Fixation in Lateral Position and Minimally Invasive Transforaminal Lumbar Interbody Fusion for Degenerative Spondylolisthesis

Study Design

Single-center retrospective study.

Purpose

To compare the physical function and quality of life (QOL) parameters of two minimally invasive surgical (MIS) procedures: oblique lateral interbody fusion with percutaneous posterior fixation in lateral position (OLIF-LPF) and minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) for single-level degenerative spondylolisthesis (DS).

Overview of Literature

To date, many options for the surgical treatment of lumbar DS and reports have described the effectiveness of minimally invasive lateral access surgery and MIS-TLIF. However, there is still a paucity of comparative data regarding the physical function and QOL outcomes of OLIF and MIS-TLIF.

Methods

Eighty-six patients were enrolled in this study (group O: OLIF-LPF, n=38; group T: MIS-TLIF, n=48). We evaluated the operation time, estimated blood loss (EBL), postoperative laboratory data, preoperative and postoperative radiographic parameters, overall functional outcome with the Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ) effectiveness rate, and Visual Analog Scale (VAS) score for low back pain, leg pain, and leg numbness.

Results

No statistical differences in operation time, EBL, and C-reactive protein level, 5 days postoperatively, between groups O and T. With respect to radiological outcome, preoperative and postoperative disc height change was significantly greater in group O than in group T (3.8 vs. 1.8 mm, p<0.05). Both groups showed postoperative improvements in the clinical outcome scores of all JOABPEQ domains, but the effectiveness rate increase in the psychological domain was significantly higher in group O than in group T (47.1% vs. 14.6%, p<0.05). No differences in the preoperative and postoperative VAS score change were noted between the two groups in any of the items.

Conclusions

The changes in physical function and QOL parameters after OLIF-LPF and MIS-TLIF were almost equivalent; however, OLIF-LPF had significant superiority in the psychological domain.

Novel Implementation of Extreme Lateral Interbody Fusion to Avoid Intraoperative Lumbar Plexus Injury: Technical Note and Preliminary Results

BACKGROUND

This study modified the traditional extreme lateral lumbar interbody fusion (XLIF) surgery and was intended to reduce the approach related to lumbar plexus injury.

METHODS

The patients receiving a new modified XLIF for treatment of lumbar degenerative diseases since September 2017 in our hospital were retrospectively collected. Postoperative additional symptoms of leg numbness, pain, or weakness were recorded as lumbar plexus nerve injury. Intraoperative electromyographic monitoring was recorded during surgery to evaluate the safety of the modified entry point. The visual analog scale and Oswestry Disability Index were adopted to evaluate the postoperative clinical efficacy. Modified MacNab criteria were introduced to evaluate the patients' satisfaction 12 months after surgery. The preoperative and postoperative intervertebral height, foraminal height, and lumbar lordotic angle were measured. Repeated measurement variance analysis was used for comparison of clinical and imaging indexes in various periods. P < 0.05 indicated statistical difference.

RESULTS

Fifty-nine patients were finally included in the retrospective study. The intraoperative average blood loss and operation time were 70 mL (40-130 mL) and 77.90 ± 13.65 minutes. The average follow-up time was 18 months. Postoperative visual analog scale and Oswestry Disability Index were significantly decreased compared with those before the operation. The intervertebral height and foraminal height were dramatically higher than those before surgery. No lumbar plexus injury occurred.

CONCLUSIONS

The initial result was optimistic in reducing lumbar plexus injury and obtaining good clinical efficacy. We need to further expand the sample size and carry out a comparative study to observe the advantages and disadvantages of modified XLIF.

Regional variations in acceptance, and utilization of minimally invasive spinal surgery techniques among spine surgeons: results of a global survey

Background

Regional differences in acceptance and utilization of MISST by spine surgeons may have an impact on clinical decision-making and the surgical treatment of common degenerative conditions of the lumbar spine. The purpose of this study was to analyze the acceptance and utilization of various minimally invasive spinal surgery techniques (MISST) by spinal surgeons the world over.

Methods

The authors solicited responses to an online survey sent to spine surgeons by email, and chat groups in social media networks including Facebook, WeChat, WhatsApp, and Linkedin. Surgeons were asked the following questions: (I) Do you think minimally invasive spinal surgery is considered mainstream in your area and practice setting? (II) Do you perform minimally invasive spinal surgery? (III) What type of MIS spinal surgery do you perform? (IV) If you are performing endoscopic spinal decompression surgeries, which approach do you prefer? The responses were cross-tabulated by surgeons' demographic data, and their practice area using the following five global regions: Africa & Middle East, Asia, Europe, North America, and South America. Pearson Chi-Square measures, Kappa statistics, and linear regression analysis of agreement or disagreement were performed by analyzing the distribution of variances using statistical package SPSS Version 25.0.

Results

A total of 586 surgeons accessed the survey. Analyzing the responses of 292 submitted surveys regional differences in opinion amongst spine surgeons showed that the highest percentage of surgeons in Asia (72.8%) and South America (70.2%) thought that MISST was accepted into mainstream spinal surgery in their practice area (P=0.04) versus North America (62.8%), Europe (52.8%), and Africa & Middle East region (50%). The percentage of spine surgeons employing MISST was much higher per region than the rate of surgeons who thought it was mainstream: Asia (96.7%), Europe (88.9%), South America (88.9%), and Africa & Middle East (87.5%). Surgeons in North America reported the lowest rate of MISST implementation globally (P<0.000). Spinal endoscopy (59.9%) is currently the most commonly employed MISST globally followed by mini-open approaches (55.1%), and tubular retractor systems (41.8%). The most preferred endoscopic approach to the spine is the transforaminal technique (56.2%) followed by interlaminar (41.8%), full endoscopic (35.3%), and over the top MISST (13.7%).

Conclusions

The rate of implementation of MISST into day-to-day clinical practice reported by spine surgeons was universally higher than the perceived acceptance rates of MISST into the mainstream by their peers in their practice area. The survey suggests that endoscopic spinal surgery is now the most commonly performed MISST.

Is Asia truly a hotspot of contemporary minimally invasive and endoscopic spinal surgery?

Background

The purpose of this study was to analyze the training in relation to practice patterns of surgeons in Asia who perform lumbar endoscopic spinal surgery in comparison to surgeons the world over. The authors solicited responses to an online survey sent to spine surgeons.

Methods

Pearson Chi-Square measures, Kappa statistics, and linear regression analysis of agreement or disagreement were performed by analyzing the distribution of variances of responses in relation to surgeons' training using statistical package SPSS Version 25.0.

Results

A total of 430 surgeons accessed the survey. The completion rate was 67.4%. Analyzing the responses of 292 surveys submitted by 97 neurosurgeons (33.2%), 161 orthopaedic surgeons (55.1%), and 34 surgeons of other postgraduate training (11.6%) showed that only 14.0% (41/292) of surgeons had completed a fellowship. Ninety-one of the 292 respondents were from Asian countries/regions. A statistically significantly higher percentage of Asian surgeons (96.7%) compared to non-Asian surgeons (81.6%) indicated that they perform modern minimally invasive (MIS) and endoscopic spinal (ES) surgery (P=0.001). Spinal endoscopy was employed by 70.3% of Asian versus 55.2% of non-Asian surgeons (P=0.015). Endoscopic decompression techniques requiring advanced training was employed nearly twice as high by the Asian surgeons than by non-Asian.

Conclusions

Training requirements for MIS and ES surgery and implementation of privileges vary in different parts of the world. While industry-sponsored weekend cadaver workshops have remained the mainstay of training aspiring endoscopic spinal surgeons in North America and Europe leaving many of them to become autodidacts.

Surgeon training and clinical implementation of spinal endoscopy in routine practice: results of a global survey

Background

Training of spine surgeons may impact the availability of contemporary minimally invasive spinal surgery (MIS) to patients and drive spine surgeons' clinical decision-making when applying minimally invasive spinal surgery techniques (MISST) to the treatment of common degenerative conditions of the lumbar spine. Training requirements and implementation of privileges vary in different parts of the world. The purpose of this study was to analyze the training in relation to practice patterns of surgeons who perform lumbar endoscopic spinal surgery the world over.

Methods

The authors solicited responses to an online survey sent to spine surgeons by email, and chat groups in social media networks including Facebook, WeChat, WhatsApp, and Linkedin. Surgeons were asked the following questions: (I) please indicate your training? (II) What type of MISST spinal surgery do you perform? (III) How would you rate your experience in MIS lumbar spinal surgery and what percentage of your practice is MISST? And (IV) which avenue did you use to train for the MISST you currently employ in your clinical practice today? Descriptive statistics were applied to count responses and cross-tabulated them to the surgeon's training. Pearson Chi-square measures, kappa statistics, and linear regression analysis of agreement or disagreement were performed by analyzing the distribution of variances using statistical package SPSS version 25.0.

Results

A total of 430 surgeons accessed the survey. The completion rate was 67.4%. Analyzing the responses of 292 surveys submitted by 97 neurosurgeons (33.2%), 161 orthopaedic surgeons (55.1%), and 34 surgeons of other postgraduate training (11.6%) showed that only 14% (41/292) of surgeons had completed a fellowship. Surgeons rated their skill level 33.5% of the time as master and experienced surgeon, and 35.6% of the time as novice or surgeon with some experience. There were more master (64.6% versus 29.2%) and experienced (52% versus 40%) surgeons amongst orthopaedic surgeons than amongst neurosurgeons at a statistically significant level (P=0.11). There were near twice as many orthopaedic surgeons (54.3%) using endoscopic procedures in the lumbar spine as their favorite MISST than neurosurgeons (35.4%; P=0.096). Endoscopic spine surgeons' main sources of knowledge acquisition were (I) learning in small meetings (57.3%), (II) attending workshops (63.1%), and (III) national and international conferences (59.8%).

Conclusions

The majority of spine surgeons reported more than half of their cases employing MISST at a high skill level. Very few MISST surgeons are fellowship trained but attend workshops and various meetings suggesting that many of them are self-thought. Orthopaedic surgeons were more likely to implement endoscopic spinal surgery into the routine clinical practice. As endoscopic spine surgery gains more traction and patient demand, minimal adequate training will be part of the ongoing debate.

Comparison of radiological changes after single- position versus dual- position for lateral interbody fusion and pedicle screw fixation

Background

There have been few comparisons between dual positions, which require a position change, and a single position, which does not require position change, and it is not clear whether there is a difference in indirect decompression achieved by the two procedures. Therefore, the purpose of this study was to compare perioperative and radiographic outcomes following lateral lumbar interbody fusion (LLIF) in two cohorts of patients who underwent surgery in a single position or dual position.

Methods

This study involved 45 patients who underwent indirect decompression at 68 levels, with LLIF and percutaneous pedicle screw (PPS) fixation for lumbar degenerative spondylolisthesis with spinal canal stenosis. Patient demographics and perioperative data were compared between two groups: patients who remained in the lateral decubitus position for pedicle screw fixation (SP group) and those turned to the prone position (DP group).

Results

A total of 26 DP and 19 SP patients were analyzed. The operation time was approximately 31 min longer for the DP group (129.7 ± 36.0 min) than for the SP group (98.4 ± 41.3 min, P < 0.01). We also evaluated the pre- and postoperative image measurements, there was no significant difference for lumbar lordosis, segmental disc angle, slipping length, and disc height between the groups. The CSA of the dural sac (DP group, from 55.3 to 78.4 mm²; SP group, from 54.7 to 77.2 mm²) and central canal diameter (DP group, from 5.9 to 7.9 mm; SP group, from 5.6 to 7.7 mm) was significantly larger after surgery in both groups. However, there were no statistically significant differences between the two groups (P = 0.684).

Conclusions

SP surgery could reduce the average surgery time by about 31 min. We found that the effect of indirect decompression by SP-PPS fixation following LLIF was considered to be a useful technique with no difference in dural sac enlargement or disc angle obtained compared with DP-PPS fixation.

Review of Risks and Complications of Extreme Lateral Interbody Fusion (XLIF)

Background

Extreme lateral interbody fusions (XLIF) and Minimally Invasive (MIS) XLIF were developed to limit the vascular injuries associated with anterior lumbar interbody fusion (ALIF), and minimize the muscular/ soft tissue trauma attributed to transforaminal lumbar interbody fusion (TLIF), posterior lumbar interbody fusion (PLIF), and posterolateral lumbar fusion (PLF).

Methods

Nevertheless, XLIF/MIS XLIF pose significant additional risks and complications that include; multiple nerve injuries (e.g. lumbar plexus, ilioinguinal, iliohypogastric, genitofemoral, lateral femoral cutaneous, and subcostals (to the anterior abdominal muscles: abdominal oblique), and sympathectomy), major vascular injuries, bowel perforations/postoperative ileus, seromas, pseudarthrosis, subsidence, and reoperations.

Results

The risks of neural injury with XLIF/MIS XLIF (up to 30-40%) are substantially higher than for TLIF, PLIF, PLF, and ALIF. These neural injuries included: lumbar plexus injuries (13.28%); new sensory deficits (0-75% (21.7%-40%); permanent 62.5%); motor deficits (0.7-33.6%-40%); iliopsoas weakness (9%-31%: permanent 5%), anterior thigh/groin pain (12.5-34%), and sympathectomy (4%-12%). Additional non-neurological complications included; subsidence (10.3%-13.8%), major vascular injuries (0.4%), bowel perforations, recurrent seroma, malpositioning of the XLIF cages, a 45% risk of cage-overhang, pseudarthrosis (7.5%), and failure to adequately decompress stenosis. In one study, reviewing 20 publications and involving 1080 XLIF patients, the authors observed "Most (XLIF) studies are limited by study design, sample size, and potential conflicts of interest."

Conclusion

Many new neurological deficits and other adverse events/complications are attributed to MIS XLIF/ XLIF. Shouldn't these significant risk factors be carefully taken into consideration before choosing to perform MIS XLIF/XLIF?

Differences in radiographic and clinical outcomes of oblique lateral interbody fusion and lateral lumbar interbody fusion for degenerative lumbar disease: a meta-analysis

Background

In the current surgical therapeutic regimen for the degenerative lumbar disease, both oblique lateral interbody fusion (OLIF) and lateral lumbar interbody fusion (LLIF) are gradually accepted. Thus, the objective of this study is to compare the radiographic and clinical outcomes of OLIF and LLIF for the degenerative lumbar disease.

Methods

We conducted an exhaustive literature search of MEDLINE, EMBASE, and the Cochrane Library to find the relevant studies about OLIF and LLIF for the degenerative lumbar disease. Random-effects model was performed to pool the outcomes about disc height (DH), fusion, operative blood loss, operative time, length of hospital stays, complications, visual analog scale (VAS), and Oswestry disability index (ODI).

Results

56 studies were included in this study. The two groups of patients had similar changes in terms of DH, operative blood loss, operative time, hospital stay and the fusion rate (over 90%). The OLIF group showed slightly better VAS and ODI scores improvement. The incidence of perioperative complications of OLIF and LLIF was 26.7 and 27.8% respectively. Higher rates of nerve injury and psoas weakness (21.2%) were reported for LLIF, while higher rates of cage subsidence (5.1%), endplate damage (5.2%) and vascular injury (1.7%) were reported for OLIF.

Conclusions

The two groups are similar in terms of radiographic outcomes, operative blood loss, operative time and the length of hospital stay. The OLIF group shows advantages in VAS and ODI scores improvement. Though the incidence of perioperative complications of OLIF and LLIF is similar, the incidence of main complications is significantly different.

Summary of Guidelines for the Treatment of Lumbar Spondylolisthesis

Degenerative lumbar spondylolisthesis is a common cause of low back pain, affecting about 11.5% of the United States population. Patients with symptomatic lumbar spondylolisthesis may first be treated with conservative management strategies including, but not limited to, non-narcotic and narcotic pain medications, epidural steroid injections, transforaminal injections, and physical therapy. For well-selected patients who fail conservative management strategies, surgical management is appropriate. This article summarizes the guidelines for the treatment of lumbar spondylolisthesis.

Interbody options in lumbar fusion

Interbody devices have revolutionized lumbar fusion surgery by enhancing mechanical stability, optimizing sagittal parameters, and maximizing fusion potential. There are several lumbar interbody fusion approaches available for varying pathologic etiologies, surgical index levels, or due to surgeon preference. With the advancement of spinal instrumentation and interbody devices, a variety of cage materials and dimensions have been engineered to accommodate various lumbar fusion approaches. The efficacy of a fusion is dependent on the shape, size, and material makeup of that interbody device. Since there are numerous cages available in today's market, it is important to find the optimal cage to best accommodate specific lumbar fusion cases. This review will explain the properties and future advancements of various interbody devices available for lumbar fusions.

Comparison of Anterior Approach and Posterior Approach to Instrumented Interbody Fusion for Spondylolisthesis: A Meta-analysis

OBJECTIVE

To compare outcomes of instrumented interbody fusion by the anterior approach (anterior lumbar interbody fusion [ALIF] with posterior pedicle screw fixation [PPF] or lateral lumbar interbody fusion [XLIF] with PPF) or the posterior approach (transforaminal lumbar interbody fusion [TLIF] or posterior lumbar interbody fusion [PLIF]) for spondylolisthesis through meta-analysis.

METHODS

The MEDLINE via PubMed, Cochrane, Scopus, and Embase databases were searched for studies published between January 2010 and January 2019 evaluating outcomes including lumbar lordosis (LL), segmental lordosis (SL), slip rate, disc height (DH), back visual analogue scale (VAS), leg VAS, and Oswestry disability index (ODI) of ALIF with PPF or XLIF with PPF and TLIF or PLIF for spondylolisthesis. Two authors performed the data extraction independently. Any discrepancies were resolved by a consensus.

RESULTS

Eight comparative studies were identified. There was no significant difference between the anterior approach and the posterior approach for preoperative LL, SL, and DH. In addition, postoperative back and leg VAS, and ODI between the 2 groups were not different. However, the anterior approach was more effective for restoration of postoperative LL, SL, and DH than the posterior approach.

CONCLUSIONS

A literature review identified 8 comparative studies reporting outcomes of the anterior approach and the posterior approach in instrumented interbody fusion for spondylolisthesis. Despite heterogeneity, a limited meta-analysis showed that the postoperative restoration of LL, SL, and DH was better in the anterior approach group. Further large multicenter studies would be necessary to substantiate our results.

Neural decompression in challenging cases: advantages and disadvantages

The peculiarity of extreme lateral interbody fusion (LLIF) is the achievement of indirect neural decompression of the spinal canal while distracting the intervertebral disc space using an interbody cage. In this manuscript we will review the potentials and limitations of this technique when treating degenerative disc disease of the lumbar spine. A literature search of the PubMed-National Library of Medicine was performed. Only articles in English were included. The current available literature demonstrates that LLIF is an effective method to decompress foraminal and central canal stenosis. Based on the current available literature LLIF effects on lateral recess stenosis are less consistent. The aim of this review is to provide with a thorough overview of the latest literature available and provide the audience with targeted-oriented published results that will eventually improve the decision-making process when using the LLIF technique.

Transforaminal lumbar interbody fusion with expandable cages: Radiological and clinical results of banana-shaped and straight implants

Purpose

Expandable titanium transforaminal lumbar interbody fusion (TLIF) devices are a relatively new group of implants allowing restoration of lumbar lordosis (LL) and thus improvement of sagittal alignment. The purpose of our study is to compare clinical and radiological results of two different expandable TLIF devices.

Materials and Methods

In a retrospective study, patients who underwent TLIF surgery with a banana-shaped or straight TLIF cage in our spine center were analyzed. Primary outcome was change of disc height (DH), segmental lordosis angle (SLA), and lumbar lordotic angle (LLA). Moreover, basic patients parameters and cage subsidence were evaluated.

Results

Sixty-one patients were studied (33 banana-shaped and 28 straight cages). DH changed in the banana group from 4.8 mm (standard deviation SD 2.5) to 10.4 (SD 2.4) and in the straight cage group from 6.2 mm (SD 2.5) to 9.6 mm (SD 1.7). The difference was statistically significant (P = 0.03). In addition, SLA correction was higher in the banana group with 5.8° (SD 5.0)-3.7° (SD 3.6), but not significant. LLA improved in the straight group with 5.2 (SD 6.4) compared to 3.7° (SD 5.8) in the banana group. We found subsidence in four patients (6.6%) in the banana-shaped group and nine cases (14.8%) in the other group.

Conclusions

Expandable titanium implants show similar improvements in restoring segmental and global lordosis. Banana-shaped expandable cages offer higher potency restoring the intervertebral DH and show less rates of subsidence compared to straight expandable cages.