Functional and radiological outcome of anterior retroperitoneal versus posterior transforaminal interbody fusion in the management of single-level lumbar degenerative disease

Segmental Sagittal Alignment in Lumbar Spinal Fusion: A Review of Evidence-Based Evaluation of Preoperative Measurement, Surgical Planning, Intraoperative Execution, and Postoperative Evaluation

BACKGROUND AND OBJECTIVES

Maintaining and restoring global and regional sagittal alignment is a well-established priority that improves patient outcomes in patients with adult spinal deformity. However, the benefit of restoring segmental (level-by-level) alignment in lumbar fusion for degenerative conditions is not widely agreed on. The purpose of this review was to summarize intraoperative techniques to achieve segmental fixation and the impact of segmental lordosis on patient-reported and surgical outcomes.

METHODS

In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, PubMed, Embase, Cochrane, and Web of Science databases were queried for the literature reporting lumbar alignment for degenerative lumbar spinal pathology. Reports were assessed for data regarding the impact of intraoperative surgical factors on postoperative segmental sagittal alignment and patient-reported outcome measures. Included studies were further categorized into groups related to patient positioning, fusion and fixation, and interbody device (technique, material, angle, and augmentation).

RESULTS

A total of 885 studies were screened, of which 43 met inclusion criteria examining segmental rather than regional or global alignment. Of these, 3 examined patient positioning, 8 examined fusion and fixation, 3 examined case parameters, 26 examined or compared different interbody fusion techniques, 5 examined postoperative patient-reported outcomes, and 3 examined the occurrence of adjacent segment disease. The data support a link between segmental alignment and patient positioning, surgical technique, and adjacent segment disease but have insufficient evidence to support a relationship with patient-reported outcomes, cage subsidence, or pseudoarthrosis.

CONCLUSION

This review explores segmental correction's impact on short-segment lumbar fusion outcomes, finding the extent of correction to depend on patient positioning and choice of interbody cage. Notably, inadequate restoration of lumbar lordosis is associated with adjacent segment degeneration. Nevertheless, conclusive evidence linking segmental alignment to patient-reported outcomes, cage subsidence, or pseudoarthrosis remains limited, underscoring the need for future research.

Stand-Alone Percutaneous Pedicle Screw Lumbar Fixation to Indirectly Decompress the Neural Elements in Spinal Stenosis: A Radiographic Assessment Case Series

BACKGROUND

 The ideal surgical treatment of lumbar canal stenosis remains controversial. Although decompressive open surgery has been widely used with good clinical outcome, minimally invasive indirect decompression techniques have been developed to avoid the complications associated with open approaches. The purpose of this study was to evaluate the radiologic outcome and safety of the indirect decompression achieved with stand-alone percutaneous pedicle screw fixation in the surgical treatment of lumbar degenerative pathologies.

METHODS

 Twenty-eight patients presenting with spinal degenerative diseases including concomitant central and/or lateral stenosis were treated with stand-alone percutaneous pedicle screw fixation. Radiographic measurements were made on axial and sagittal magnetic resonance (MR) images, performed before surgery and after a mean follow-up period of 25.2 months. Measurements included spinal canal and foraminal areas, and anteroposterior canal diameter.

RESULTS

 Percutaneous screw fixation was performed in 35 spinal levels. Measurements on the follow-up MR images showed statistically significant increase in the cross-sectional area of the spinal canal and the neural foramen, from a mean of 88.22 and 61.05 mm2 preoperatively to 141.52 and 92.18 mm2 at final follow-up, respectively. The sagittal central canal diameter increased from a mean of 4.9 to 9.1 mm at final follow-up. Visual analog scale (VAS) pain score and Oswestry Disability Index (ODI) both improved significantly after surgery (p < 0.0001).

CONCLUSION

 Stand-alone percutaneous pedicle screw fixation is a safe and effective technique for indirect decompression of the spinal canal and neural foramina in lumbar degenerative diseases. This minimally invasive technique may provide the necessary decompression in cases of common degenerative lumbar disorders with ligamentous stenosis.

Stand-alone ALIF versus TLIF in patients with low back pain - A propensity-matched cohort study with two-year follow-up

Introduction

Instrumented lumbar fusion by either the anterior or transforaminal approach has different advantages and disadvantages. Few studies have compared PatientReported Outcomes Measures (PROMs) between stand-alone anterior lumbar interbody fusion (SA-ALIF) and transforaminal lumbar interbody fusion (TLIF).

Research question

This is a register-based dual-center study on patients with severe disc degeneration (DD) and low back pain (LBP) undergoing single-level SA-ALIF or TLIF. Comparing PROMs, including disability, quality of life, back- and leg-pain and patient satisfaction two years after SA-ALIF or TLIF, respectively.

Material and methods

Data were collected preoperatively and at one and two-year follow-up. The primary outcome was Oswestry Disability Index (ODI). The secondary outcomes were patient satisfaction, walking ability, visual analog scale (VAS) scores for back and leg pain, and quality of life (QoL) measured by the European Quality of Life-5 Dimensions (EQ-5D) index score. To reduce baseline differences between groups, propensity-score matching was employed in a 1:1 fashion.

Results

92 patients were matched, 46 S A-ALIF and 46 TLIF. They were comparable preoperatively, with no significant difference in demographic data or PROMs (P > 0.10). Both groups obtained statistically significant improvement in the ODI, QoL and VAS-score (P < 0.01), but no significant difference was observed (P = 0.14). No statistically significant differences in EQ-5D index scores (P = 0.25), VAS score for leg pain (P = 0.88) and back pain (P = 0.37) at two years follow-up.

Conclusion

Significant improvements in ODI, VAS-scores for back and leg pain, and EQ-5D index score were registered after two-year follow-up with both SA-ALIF and TLIF. No significant differences in improvement.

Anterior Lumbar Interbody Fusion in Elderly Patients: Peri- and Postoperative Complications and Clinical Outcome

BACKGROUND

 Anterior lumbar interbody fusion (ALIF) is an effective surgical technique for treating various lumbar pathologies, but its use in elderly patients is controversial. Data concerning complications and effectiveness are sparse. We investigated peri- and postoperative complications, radiographic parameters, and clinical outcome in elderly patients.

METHODS

 Patients ≥65 years who underwent ALIF between January 2008 and August 2020 were included in the study. All surgeries were performed through a retroperitoneal approach. Clinical and surgical data as well as radiologic parameters were collected prospectively and analyzed retrospectively.

RESULTS

 A total of 39 patients were included; the mean age was 72.6 (±6.3) years (range: 65-90 years); and the mean American Society of Anesthesiologists (ASA) risk classification was 2.3 (±0.6). A laceration of the left common iliac vein was the only major complication recorded (2.6%). Minor complications occurred in 20.5% of patients. Fusion rate was 90.9%. Reoperation rate at the index level was 12.8 and 7.7% in adjacent segments. The multidimensional Core Outcome Measures Index (COMI) improved from 7.4 (±1.4) to 3.9 (±2.7) after 1 year and to 3.3 (±2.6) after 2 years. Oswestry disability index (ODI) improved from 41.2 (±13.7) to 20.9 (±14.9) after 1 year and to 21.5 (±18.8) after 2 years. Improvements of at least the minimal clinically important change score of 2.2 and 12.9 points in the ODI and COMI after 2 years were noted in 75 and 56.3% of the patients, respectively.

CONCLUSION

 With careful patient selection, ALIF is safe and effective in elderly patients.

Procedures employing interbody devices and multi-level fusion require target price adjustment to build a sustainable lumbar fusion bundled payment model

BACKGROUND CONTEXT

Bundled payment models require risk adjustment to ensure appropriate targets are set. While this may be standardized for many services, spine fusions demonstrate significant variability in approach, invasiveness, and use of implants, that may require further risk adjustment.

PURPOSE

To evaluate variability in costs of spinal fusion episodes in a private insurer bundle payment program and identify whether current procedural terminology (CPT) code modifications are necessary for sustainable implementation.

STUDY DESIGN/SETTING

Retrospective single-institution cohort study.

PATIENT SAMPLE

A total of 542 lumbar fusion episodes in a private insurer bundled payment program from October 2018 to December 2020.

OUTCOME MEASURES

A total of 120-day episode of care net surplus/deficit, 90-day readmissions, discharge disposition, and length of hospital stay.

METHODS

A review was conducted of all lumbar fusions in a single institution's payer database. Surgical characteristics (approach [posterior lumbar decompression and fusion (PLDF), transforaminal lumbar interbody fusion (TLIF), and circumferential fusion], levels fused, and primary vs revision) were collected from manual chart review. Episode of care cost data were collected as net surplus or deficit with respect to target prices. A multivariate linear regression model was constructed to measure the independent effects of primary versus revision, levels fused, and approach on the net cost savings.

RESULTS

Most procedures were PLDFs (N=312, 57.6%), single-level (N=416, 76.8%) and primary fusions (N=477, 88.0%). Overall, 197 (36.3%) resulted in a deficit, and were more likely to be three levels (7.11% vs 2.03%, p=.005), revisions (18.8% vs 8.12%, p<.001), and TLIF (47.7% vs 35.1%, p<.001) or circumferential fusions (p<.001). One-level PLDFs resulted in the greatest cost savings per episode ($6,883). Across both PLDFs and TLIFs, 3-level procedures resulted in significant deficit of -$23,040 and -$18,887, respectively. For circumferential fusions, 1-level fusions resulted in deficit of -$17,169 per case which rose to -$64,485 and -$49,222 for 2- and 3-level fusions. All 2- and 3-level circumferential spinal fusions resulted in a deficit. On multivariable regression, TLIF and circumferential fusions were independently associated with a deficit of -$7,378 (p=.004) and -$42,185 (p<.001), respectively. Three-level fusions were independently associated with an additional -$26,003 deficit compared to single-level fusions (p<.001).

CONCLUSIONS

Interbody fusions, especially circumferential fusions, and multi-level procedures are not adequately risk adjusted by current bundled payment models. Health systems may not be able to financially support these alternative payment models with improved procedure-specific risk adjustment.

A systematic review of anterior lumbar interbody fusion (ALIF) versus posterior lumbar interbody fusion (PLIF), transforaminal lumbar interbody fusion (TLIF), posterolateral lumbar fusion (PLF)

PURPOSE

The rate of elective lumbar fusion has continued to increase over the past two decades. However, there remains to be a consensus on the optimal fusion technique. This study aims to compare stand-alone anterior lumbar interbody fusion (ALIF) with posterior fusion techniques in patients with spondylolisthesis and degenerative disc disease through a systematic review and meta-analysis of the available literature.

METHODS

A systematic review was performed by searching the Cochrane Register of Trials, MEDLINE, and EMBASE from inception to 2022. In the two-stage screening process, three reviewers independently reviewed titles and abstracts. The full-text reports of the remaining studies were then inspected for eligibility. Conflicts were resolved through consensus discussion. Two reviewers then extracted study data, assessed it for quality, and analysed it.

RESULTS

After the initial search and removal of duplicate records, 16,435 studies were screened. Twenty-one eligible studies (3686 patients) were ultimately included, which compared stand-alone ALIF with posterior approaches such as posterior lumbar interbody fusion (PLIF), transforaminal lumbar interbody fusion (TLIF), and posterolateral lumbar fusion (PLF). A meta-analysis showed surgical time and blood loss was significantly lower in ALIF than in TLIF/PLIF, but not in those who underwent PLF (p = 0.08). The length of hospital stay was significantly shorter in ALIF than in TLIF, but not in PLIF or PLF. Fusion rates were similar between the ALIF and posterior approaches. The Visual Analogue Scale (VAS) scores for back and leg pain were not significantly different between the ALIF and PLIF/TLIF groups. However, VAS back pain favoured ALIF over PLF at one year (n = 21, MD - 1.00, CI - 1.47, - 0.53), and at two years (2 studies, n = 67, MD - 1.39, CI - 1.67, - 1.11). The VAS leg pain scores (n = 46, MD 0.50, CI 0.12 to 0.88) at two years significantly favoured PLF. The Oswestry Disability Index (ODI) scores at one year were not significantly different between ALIF and the posterior approaches. At two years, ODI scores were also similar between the ALIF and the TLIF/PLIF. However, the ODI scores at two years (2 studies, n = 67, MD - 7.59, CI - 13.33, - 1.85) significantly favoured ALIF over PLF (I2 = 70%). The Japanese Orthopaedic Association Score (JOAS) for low back pain at one year (n = 21, MD - 0.50, CI - 0.78) and two years (two studies, n = 67, MD - 0.36, CI - 0.65, - 0.07) significantly favoured ALIF over PLF. No significant differences were found in leg pain at the 2-year follow-up. Adverse events displayed no significant differences between the ALIF and posterior approaches.

CONCLUSIONS

Stand-alone-ALIF demonstrated a shorter operative time and less blood loss than the PLIF/TLIF approach. Hospitalisation time is reduced with ALIF compared with TLIF. Patient-reported outcome measures were equivocal with PLIF or TLIF. VAS and JOAS, back pain, and ODI scores mainly favoured ALIF over PLF. Adverse events were equivocal between the ALIF and posterior fusion approaches.

A novel less invasive endoscopic-assisted procedure for complete reduction of low-and high-grade isthmic spondylolisthesis performed by anterior and posterior combined approach

PURPOSE

The optimal surgical management of low- and high-grade isthmic spondylolisthesis (LGS and HGS -IS) is debated as well as whether reduction is needed especially for high-grade spondylolisthesis. Both anterior and posterior techniques can be associated with mechanical disadvantages as hardware failure with loss of reduction and L5 injury. We purpose a novel endoscopic-assisted technique (Sled technique, ST) to achieve a complete reduction in two surgical steps: first anteriorly through a retroperitoneal approach to obtain the greatest part of correction and then posteriorly to complete reduction in the same operation.

METHODS

ST efficacy and complications rate were evaluated through a retrospective functional and radiological analysis.

RESULTS

Thirty-one patients, 12 male (38.7%) and 19 female (61.3%), average age: 45.4 years with single level IS underwent olisthesis reduction by ST. Twenty-three IS involved L5 (74.2%), 7 L4 (22.5%) and 1 L3 (3.3%). No intraoperative complications were recorded. One patient required repositioning of a pedicle screw. A significant improvement of functional and radiological parameters (L4-S1 and L5-S1 lordosis) outcomes was recorded (p < 0.001).

CONCLUSION

ST provides a complete reduction in the slippage in LGS and HGS. The huge anterior release as well as the partial reduction in the slippage by the endoscopic-assisted anterior procedure, because of the cage is acting as a "guide rail", facilitate the final posterior reduction, always complete in our series, minimizing mechanical stresses and neurological risks.

CLINICALTRIALS

gov Identifier: NCT03644407.

OLIF versus ALIF: Which is the better surgical approach for degenerative lumbar disease? A systematic review

PURPOSE

The aim of this study was to compare the clinical and radiographical outcomes between OLIF and ALIF in treating lumbar degenerative diseases.

METHODS

We searched PubMed, Embase, Web of Science, and Cochrane Library for relevant studies. Changes in disc height (DH), segmental lordosis angle (SLA), lumbar lordosis (LL), visual analogue scale (VAS) score, and Oswestry disability index (ODI) between baseline and final follow-up, along with other important surgical outcomes, were assessed and analysed. Data on the global fusion rate and main complications were collected and compared.

RESULTS

Approximately, 2041 patients from 36 studies were included, consisting of 1057 patients who underwent OLIF and 984 patients who underwent ALIF. The results reveal no significant difference in DH, SLA, VAS score, and ODI between the two groups (all P > 0.05). The operation time, estimated blood loss, and length of hospital stay were also comparable between the two groups. Over 90% of the fusion rate was achieved in both groups. The OLIF group showed a higher complication rate than the ALIF group (OLIF 18.83% vs ALIF 7.32%).

CONCLUSIONS

OLIF leads to a higher complication rate, with the most notable complication being cage subsidence. Both OLIF and ALIF are effective treatments for degenerative lumbar diseases and have similar therapeutic effects. ALIF was expected to be more expensive for patients because of the necessity of involving vascular surgeons.

Radiographic comparison of L5-S1 lateral anterior lumbar interbody fusion cage subsidence and displacement by fixation strategy: anterior plate versus integrated screws

OBJECTIVE

The aim of this study was to radiographically compare cage subsidence and displacement between L5-S1 lateral anterior lumbar interbody fusion (ALIF) cages secured with an anterior buttress plate and cages secured with integrated screws.

METHODS

Consecutive patients who underwent L5-S1 lateral ALIF with supplemental posterior fixation by a single surgeon from June 2016 to January 2021 were reviewed. Radiographs were analyzed and compared between the two groups based on the type of fixation used to secure the L5-S1 lateral ALIF cage: 1) anterior buttress plate or 2) integrated screws. The following measurements at L5-S1 were analyzed on radiographs obtained preoperatively, before discharge, and at latest follow-up: 1) anterior disc height, 2) posterior disc height, and 3) segmental lordosis. Cage subsidence and anterior cage displacement were determined radiographically.

RESULTS

One hundred thirty-nine patients (mean age 60.0 ± 14.3 years) were included for analysis. Sixty-eight patients were treated with an anterior buttress plate (mean follow-up 12 ± 5 months), and 71 were treated with integrated screws (mean follow-up 9 ± 3 months). Mean age, sex distribution, preoperative L5-S1 lordosis, preoperative L5-S1 anterior disc height, and preoperative L5-S1 posterior disc height were statistically similar between the two groups. After surgery, the segmental L5-S1 lordosis and L5-S1 anterior disc heights significantly improved for both groups, and each respective measurement was similar between the groups at final follow-up. Posterior disc heights significantly increased after surgery with integrated screws but not with the anterior buttress plate. As such, posterior disc heights were significantly greater at final follow-up for integrated screws. Compared with patients who received integrated screws, significantly more patients who received the anterior buttress plate had cage subsidence cranially through the L5 endplate (20.6% vs 2.8%, p < 0.01), cage subsidence caudally through the S1 endplate (27.9% vs 0%, p < 0.01), and anterior cage displacement (22.1% vs 0%, p < 0.01).

CONCLUSIONS

In this radiographic analysis of 139 patients who underwent lateral L5-S1 ALIF supplemented by posterior fixation, L5-S1 cages secured with an anterior buttress plate demonstrated significantly higher rates of cage subsidence and anterior cage displacement compared with cages secured with integrated screws. While the more durable stability afforded by cages secured with integrated screws suggests that they may be a more viable fixation strategy for L5-S1 lateral ALIFs, there are multiple factors that can contribute to cage subsidence, and, thus, definitive presumption cannot be made that the findings of this study are directly related to the buttress plate.

Single-Position Oblique Lumbar Interbody Fusion and Percutaneous Pedicle Screw Fixation under O-Arm Navigation: A Retrospective Comparative Study

The insertion of pedicle screws in the lateral position without a position change has been reported. We completed a retrospective comparison of the radiologic and clinical outcomes of 36 patients who underwent either single-position oblique lateral lumbar interbody fusion (SP-OLIF) using the O-arm (36 cases) or conventional OLIF (C-OLIF) using the C-arm (20 cases) for L2-5 single-level lumbar degenerative diseases. Radiological parameters were analyzed, including screw accuracy (Gertzbein-Robbins classification system; GRS), segmental instability, and fusion status. Screw misplacement was defined as a discrepancy of ≥2 mm. Clinical outcomes, including visual analog scale, Oswestry Disability Index (ODI), 36-Item Short Form Health Survey (SF-36), and postoperative complications, were assessed. The spinal fusion rate was not different between the SP-OLIF and C-OLIF groups one year after surgery (p = 0.536). The ODI score was lower (p = 0.015) in the SP-OLIF than the C-OLIF group. Physical (p = 0.000) and mental component summaries (p = 0.000) of the SF-36 were significantly higher in the SP-OLIF group. Overall complication rates, including revision, surgical site infection, ipsilateral weakness, and radicular pain/numbness, were not significantly different. SP-OLIF using the O-arm procedure is feasible, with acceptable accuracy, fusion rate, and complication rate. This may be an alternative to conventional two-stage operations.

Lumbar Interbody Fusion and Osteobiologics for Lumbar Fusion

Lumbar interbody fusion (LIF) is an excellent treatment option for a number of lumbar diseases. LIF can be performed through posterior, transforaminal, anterior, and lateral or oblique approaches. Each technique has its own pearls and pitfalls. Through LIF, segmental stabilization, neural decompression, and deformity correction can be achieved. Minimally invasive surgery has recently gained popularity and each LIF procedure can be performed using minimally invasive techniques to reduce surgery-related complications and improve early postoperative recovery. Despite advances in surgical technology, surgery-related complications after LIF, such as pseudoarthrosis, have not yet been overcome. Although autogenous iliac crest bone graft is the gold standard for spinal fusion, other bone substitutes are available to enhance fusion rate and reduce complications associated with bone harvest. This article reviews the surgical procedures and characteristics of each LIF and the osteobiologics utilized in LIF based on the available evidence.

Utilization of lateral anterior lumbar interbody fusion for revision of failed prior TLIF: illustrative case

BACKGROUND

The use of the lateral decubitus approach for L5–S1 anterior lumbar interbody fusion (LALIF) is a recent advancement capable of facilitating single-position surgery, revision operations, and anterior column reconstruction. To the authors’ knowledge, this is the first description of the use of LALIF at L5–S1 for failed prior transforaminal lumbar interbody fusion (TLIF) and anterior column reconstruction. Using an illustrative case, the authors discuss their experience using LALIF at L5–S1 for the revision of pseudoarthrosis and TLIF failure.

OBSERVATIONS

The patient had prior attempted L2 to S1 fusion with TLIF but suffered from hardware failure and pseudoarthrosis at the L5–S1 level. LALIF was used to facilitate same-position revision at L5–S1 in addition to further anterior column revision and reconstruction by lateral lumbar interbody fusion at the L1–2 level. Robotic posterior T10–S2 fusion was then added to provide stability to the construct and address the patient’s scoliotic deformity. No complications were noted, and the patient was followed until 1 year after the operation with a favorable clinical and radiological result.

LESSONS

Revision of a prior failed L5–S1 TLIF with an LALIF approach has technical challenges but may be advantageous for single position anterior column reconstruction under certain conditions.

Successful salvage strategy using anterior retroperitoneal approach in failed posterior lumbar interbody fusion. A retrospective analisys on lumbar lordosis and clinical outcome

OBJECTIVE

Posterior and transforaminal lumbar interbody fusion (PLIF, TLIF) are among the most popular surgical options for lumbar interbody fusion. If non-union occurs with consequent pain and reduced quality of life, revision surgery should correct any previous technical errors, avoiding further complications. The aim of this study was to analyze technical advantages, radiological and clinical outcomes of anterior approaches (ALIF) in case of failed PLIF or TLIF.

METHODS

Retrospective analysis of consecutive patients with persistent low back pain after failed PLIF/TLIF where salvage ALIF through an anterior retroperitoneal miniopen video-assisted technique was performed. Surgical, clinical and radiological data were analysed. Uni and multivariate statistical analysis were applied.

RESULTS

Thirty-six patients (average age: 47.1 years) were included. Mean follow-up was 34.4 months. In 30 patients (83.3%) a posterior surgical step was necessary. Non-union (86.1%), cage migration (5.5%), infection (8.3%) were the causes of revision surgery. In 22 patients (61.1%) the involved level was L5-S1, in 12 patients (33.4%) L4-L5, in 1 patient (2.7%) L3-L4. One patient (2.7%) had two levels (L4-L5 and L5-S1) involved. No major intraoperative complications were recorded. Significant correlation between clinical and radiological outcomes (L4-S1 and L5-S1 lordosis improvement) were observed (postoperative VAS and L5-S1, p = 0.038).

CONCLUSIONS

Salvage ALIF is a safe option that can significantly ameliorate residual pain achieving primary interbody stability with an ideal segmental lordosis according to pelvic parameters. The advantages of a naive anterior approach fulfils the main objectives of a revision surgery in order to significantly increase the chances of definitive fusion.

Postoperative spinal alignment comparison of lateral versus supine patient position L5-S1 anterior lumbar interbody fusion

PURPOSE

Over the past decade, alternative patient positions for the treatment of the anterior lumbar spine have been explored in an effort to maximize the benefits of direct anterior column access while minimizing the inefficiencies of single or multiple intraoperative patient repositionings. The lateral technique allows for access from L1 to L5 through a retroperitoneal, muscle-splitting, transpsoas approach with placement of a large intervertebral spacer than can reliably improve segmental lordosis, though its inability to be used at L5-S1 limits its overall adoption, as L5-S1 is one of the most common levels treated and where high levels of lordosis are optimal. Recent developments in instrumentation and techniques for lateral-position treatment of the L5-S1 level with a modified anterior lumbar interbody fusion (ALIF) approach have expanded the lateral position to L5-S1, though the positional effect on L5-S1 lordosis is heretofore unreported. The purpose of this study was to compare local and regional alignment differences between ALIFs performed with the patient in the lateral (L-ALIF) versus supine position (S-ALIF).

METHODS

Retrospective, multi-center data and radiographs were collected from 476 consecutive patients who underwent L5-S1 L-ALIF (n = 316) or S-ALIF (n = 160) for degenerative lumbar conditions. Patients treated at L4-5 and above with other single-position interbody fusion and posterior fixation techniques were included in the analysis. Baseline patient characteristics were similar between the groups, though L-ALIF patients were slightly older (58 vs. 54 years), with a greater preoperative mean L5-S1 disk height (7.8 vs. 5.8 mm), and with less preoperative slip (6.6 vs. 8.5 mm), respectively. 262 patients were treated with only L-ALIF or S-ALIF at L5-S1 while the remaining 214 patients were treated with either L-ALIF or S-ALIF at L5-S1 along with fusions at other thoracolumbar levels. Lumbar lordosis (LL), L5-S1 segmental lordosis, L5-S1 disk space height, and slip reduction in L5-S1 spondylolisthesis were measured on preoperative and postoperative lateral X-ray images. LL was only compared between single-level ALIFs, given the variability of other procedures performed at the levels above L5-S1.

RESULTS

Mean pre- to postoperative L5-S1 segmental lordosis improved 39% (6.6°) and 31% (4.9°) in the L-ALIF and S-ALIF groups, respectively (p = 0.063). Mean L5-S1 disk height increased by 6.5 mm (89%) in the L-ALIF and 6.4 mm (110%) in the S-ALIF cohorts, (p = 0.650). Spondylolisthesis, in those patients with a preoperative slip, average reduction in the L-ALIF group was 1.5 mm and 2.2 mm in the S-ALIF group (p = 0.175). In patients treated only at L5-S1 with ALIF, mean segmental alignment improved significantly more in the L-ALIF compared to the S-ALIF cohort (7.8 vs. 5.4°, p = 0.035), while lumbar lordosis increased 4.1° and 3.6° in the respective groups (p = 0.648).

CONCLUSION

Use of the lateral patient position for L5-S1 ALIF, compared to traditional supine L5-S1 ALIF, resulted in at least equivalent alignment and radiographic outcomes, with significantly greater improvement in segmental lordosis in patients treated only at L5-S1. These data, from the largest lateral ALIF dataset reported to date, suggest that-radiographically-the lateral patient position can be considered as an alternative to traditional ALIF positional techniques.

Single position lumbar fusion: a systematic review and meta-analysis

BACKGROUND CONTEXT

Recently, a single position lumbar fusion has been described in which both the anterior or lateral interbody fusion as well as posterior percutaneous pedicle screw fixation are performed in a single position.

PURPOSE

The purpose of this study was to present and analyze the current evidence for single position lumbar fusion.

STUDY DESIGN/SETTING

This is a systematic review and meta-analysis.

PATIENT SAMPLE

Prospective or retrospective studies published in English that assessed outcomes of single position lumbar fusion surgery for patients with lumbar degenerative disease, spondylolisthesis, or radiculopathy were included.

OUTCOME MEASURES

Outcome measures included operative time, estimated blood loss, hospital length of stay, X-Ray exposure time, and postoperative outcomes including leg numbness or pain, leg weakness, lumbar lordosis, and segmental lordosis.

METHODS

This systematic review was performed in accordance with PRISMA guidelines. Two separate meta-analyses were performed. The first compared single position (SP) surgery, both lateral and prone, to dual position or flipped (F) surgery. The second meta-analysis compared lateral single position (LSP) surgery to prone single position (PSP) surgery. Variables were included if (1) they were a mean with a reported standard deviation or (2) if they were a categorical variable. For calculating standard error of the mean, we used sample size, mean, and standard deviation. A random effects model was used. The heterogeneity among studies was assessed with a significance level of <0.05.

RESULTS

Twenty-one articles were included for analysis. Three studies were prospective nonrandomized studies, while 18 were retrospective. Seven articles studied lateral single position only, 10 articles compared lateral single position to traditional repositioning surgery, three articles studied prone single position surgery, and one article compared prone single position surgery to traditional repositioning surgery. A detailed review is provided for all 21 articles. Seventeen studies were included for meta-analysis comparing the SP versus F groups, for a total of 942 patients in the SP group and 254 in the F group. Mean operative time was significantly less for the SP group compared with the F group (SP: 127.5±7.9, F: 188.7±15.5, p<.001). Average hospital length of stay was 2.87±0.3 days in the SP group and 6.63±0.6 days in the F group (p<.001). Complication rates did not significantly differ between groups. Pedicle screws placed in the lateral position had a higher rate of complication as compared with those placed in a prone position (L: 10.2±2%, P: 1.6±1%, p=.015). Seventeen studies were included in the LSP versus PSP analysis, including 13 in the LSP group and four in the PSP group, with a total of 785 patients in the LSP group and 85 patients in the PSP group. Operative time and X-Ray exposure was significantly less in the LSP compared with the PSP group (117.1±5.5 minutes vs. 166.9±21.9 minutes, p<.001; 43.7±15.5 minutes vs. 171.0±25.8 minutes, p<.001). Postoperative segmental lordosis was greater in the prone single position group (p<.001).

CONCLUSIONS

Single position surgery decreases operative times and hospital length of stay, while maintaining similar complication rates and radiographic outcomes. PSP surgery was found to be longer in duration and have increased radiation exposure time compared with LSP, while increasing postoperative segmental lordosis.

Can Indirect Decompression Reduce Adjacent Segment Degeneration and the Associated Reoperation Rate After Lumbar Interbody Fusion? A Systemic Review and Meta-analysis

OBJECTIVE

We sought to assess and compare the rate of adjacent segment degeneration (ASDeg), adjacent segment disease, and related reoperations between patients who underwent lumbar interbody fusion surgery using indirect or direct decompression.

METHODS

On the basis of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic review and meta-analysis was performed to identify and analyze studies that compared the rate of ASDeg, adjacent segment disease, and related reoperations between indirect and direct decompression techniques. Indirect decompression included anterior lumbar interbody fusion, lateral lumbar interbody fusion, and oblique lateral interbody fusion, whereas direct decompression included posterior or transforaminal lumbar interbody fusion.

RESULTS

Seven studies including a total of 576 patients (indirect: 314; direct: 262) were identified. The pooled rates of ASDeg were 19.4% (45/232) and 34.9% (66/189) for indirect and direct decompression, respectively. A fixed-effects model showed 0.34 times lower odds of developing ASDeg in the indirect decompression group (odds ratio = 0.34, 95% confidence interval [CI] = 0.20, 0.57). The pooled incidence of reoperation was 2.5% (8/314) and 6.1% (16/262) for indirect and direct decompression, respectively. A fixed-effects model showed 0.40 times lower odds of reoperation from ASDeg in the indirect decompression group (odds ratio = 0.40, 95% CI = 0.18, 0.89). The pooled mean difference for the segmental lordosis angle was 1.80 degrees (95% CI = 0.74, 2.86) and 7.11 degrees (95% CI = 4.47, 9.74) for total lumbar lordosis angle, favoring indirect decompression.

CONCLUSIONS

Indirect decompression showed lower odds of developing ASDeg and undergoing reoperation for ASDeg after lumbar interbody fusion surgery in this meta-analysis. However, the limited number and quality of the included studies should be considered when interpreting the results.

Lumbar Interbody Fusion: Techniques, Pearls and Pitfalls

Lumbar interbody fusion (LIF) is an effective and popular surgical procedure for the management of various spinal pathologies, especially degenerative diseases. Currently, LIF can be performed with posterior, transforaminal, anterior, and lateral approaches by open surgery or minimally invasive surgery (MIS). Each technique has its own advantages and disadvantages. In general, posterior LIF is a well-established procedure with good fusion rates and low complication rates but is limited by the possibility of iatrogenic injury to the neural structures and paraspinal muscles. Transforaminal LIF is frequently performed using an MIS technique and has an advantage of reducing these iatrogenic injuries. Anterior LIF (ALIF) can restore the disk height and sagittal alignment but has inherent approach-related challenges such as visceral and vascular complications. Lateral LIF and oblique LIF are performed using an MIS technique and have shown postoperative outcomes similar to ALIF; however, these approaches carry a risk of injury to psoas, lumbar plexus, and vascular structures. Herein, we provide a detailed description of the surgical procedures of each LIF technique. We shall then consider the pearls and pitfalls, as well as propose surgical indications and contraindications based on the available evidence in the literatures.