Lumbar Interbody Fusion Technique Research Articles

A Comparison of 2 Cage Sizes in Biportal Endoscopic Transforaminal Lumbar Interbody Fusion.

Retrospective study. This study compared the fusion and subsidence rate and clinical outcomes when using different-sized static PEEK cages in BE-TLIF. Biportal endoscopic techniques for transforaminal lumbar interbody fusion (BE-TLIF) have been shown to have similar clinical and fusion outcomes with faster clinical recovery in comparison to tubular surgery. Subsidence of the interbody, however, could be a complication. Patients who underwent 1 or 2 level BE-TLIF for degenerative and isthmic spondylolisthesis between January 2019 and January 2022 were included. A 32×10mm cage (group A) and a 40×15mm cage (group B) were compared. The visual analog scale (VAS) for back and leg symptoms, and Oswestry disability index (ODI) were collected. Plain radiographs and computed tomography assessed fusion and subsidence at a minimum of 12 months. Of the 69 enrolled patients, 39 group A patients (51 levels) and 30 group B patients (32 levels) were compared. The operation time per level was 123 ± 15.8 and 138 ± 10.5 minutes per fusion level in groups A and B, respectively (P < 0.05). ODI improved from 64.8 ± 6.2 to 15.7 ± 7.1 in group A and from 65.3 ± 5.6 to 15.1 ± 6.3 in group B at the final follow-up (P < 0.05). VAS leg and back score improvement between the groups did not differ; however, the 3-month postoperative VAS back improvement was significantly higher in group B. The final fusion rate at the final follow-up did not significantly differ; however, the fusion ratio at 1 year was higher in group B (P < 0.05). Subsidence occurred in 5 cases (9.8%) in group A and none in group B (P < 0.05). BE-TLIF using a larger cage can be performed safely with similar patient-reported outcome measures with a faster fusion rate with less subsidence risk. III.

Endoscopic MIS-TLIF with Destandau's system: leveraging endoscopy with conventional instruments.

This presentation showcases an endoscopic minimally invasive spine surgery (MISS) technique for lumbar interbody fusion. Significantly expanding the scope of Destandau's system within MISS, it serves as a pivotal link to unilateral biportal endoscopy (UBE) for endofusion. The method involves minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) using a 4-mm rigid endoscope through Destandau's system. With the widespread familiarity with Destandau's system and the absence of specialized instrument requirements, this approach is easily adoptable, particularly in resource-limited centers. The favorable clinical and radiological outcomes underscore the effectiveness of this technique, propelling the role of endoscopy in MISS, particularly in endofusion. The video can be found here: https://stream.cadmore.media/r10.3171/2024.1.FOCVID23216.

The Optimal Patient Position on the Surgical Table for Lateral Lumbar Interbody Fusion in Adult Spinal Deformity Using Three-Dimensional Computed Tomography: A Retrospective Study.

Lateral lumbar interbody fusion (LLIF) techniques have been extensively used in adult spinal deformity surgery. Preoperative knowledge of the optimal position of the patient on the surgical table is essential for a safe procedure. Therefore, this study aims to determine the optimal angle for positioning the patient on the surgical table during LLIF using three-dimensional computed tomography (3DCT). Data from 59 patients (2 males, 57 females, mean age 66.3±8.6 years) with adult spinal deformities treated by performing corrective spinal surgery were included in this observational retrospective study. Simulated fluoroscopic images were obtained using 3DCT images rotated from the reference position with the spinous process of S1 as the midline to the position with the spinous process in the center of the bilateral pedicle of T12-L5. The rotation angle of each vertebra was measured and defined as the optimal rotation angle (ORA). The angle that bisected the angle between the maximum and minimum ORA was defined as the optimal mean angle of the maximum and minimum ORA (OMA) and considered the optimal angle for the patient's position on the surgical table, as this position could minimize the rotation angle of the surgical table during surgery. A multiple regression analysis was performed to predict OMA. Multiple regression analysis revealed the following equation: OMA=1.959+(0.238×lumbar coronal Cobb angle)+(-0.208×sagittal vertical axis). When the patient is placed on the surgical table by rotating them at the OMA, the rotation of the surgical table can be reduced, ensuring a safe and efficient surgical procedure.

Lateral-PLIF for spinal arthrodesis: concept, technique, results, complications, and outcomes.

Posterior lumbar interbody fusion (PLIF) surgery represents an effective option to treat degenerative conditions in the lumbar spine. To reduce the drawbacks of the classical technique, we developed a variant, so-called Lateral-PLIF, which we then evaluated through a prospective consecutive series of patients. All adult patients treated at our institute with single or double level Lateral-PLIF for lumbar degenerative disease from January to December 2017 were prospectively collected. Exclusion criteria were patients < 18years of age, traumatic patients, active infection, or malignancy, as well as unavailability of clinical and/or radiological follow-up data. The technique consists of insert the cages bilaterally through the transition zone between the central canal and the intervertebral foramen, just above the lateral recess. Pre- and postoperative (2years) questionnaires and phone interviews (4years) assessed pain and functional outcomes. Data related to the surgical procedure, postoperative complications, and radiological findings (1year) were collected. One hundred four patients were selected for the final analysis. The median age was 58years and primary symptoms were mechanical back pain (100, 96.1%) and/or radicular pain (73, 70.2%). We found a high fusion rate (95%). A statistically significant improvement in functional outcome was also noted (ODI p < 0.001, Roland-Morris score p < 0.001). Walking distance increased from 812m ± 543m to 3443m ± 712m (p < 0.001). Complications included dural tear (6.7%), infection/wound dehiscence (4.8%), and instrument failure (1.9%) but no neurological deterioration. Lateral-PLIF is a safe and effective technique for lumbar interbody fusion and may be considered for further comparative study validation with other techniques before extensive use to treat lumbar degenerative disease.

Comparing the osteogenesis outcomes of different lumbar interbody fusions (A/O/X/T/PLIF) by evaluating their mechano-driven fusion processes

BackgroundIn lumbar interbody fusion (LIF), achieving proper fusion status requires osteogenesis to occur in the disc space. Current LIF techniques, including anterior, oblique, lateral, transforaminal, and posterior LIF (A/O/X/T/PLIF), may result in varying osteogenesis outcomes due to differences in biomechanical characteristics. MethodsA mechano-regulation algorithm was developed to predict the fusion processes of A/O/X/T/PLIF based on finite element modeling and iterative evaluations of the mechanobiological activities of mesenchymal stem cells (MSCs) and their differentiated cells (osteoblasts, chondrocytes, and fibroblasts). Fusion occurred in the grafting region, and each differentiated cell type generated the corresponding tissue proportional to its concentration. The corresponding osteogenesis volume was calculated by multiplying the osteoblast concentration by the grafting volume. ResultsTLIF and ALIF achieved markedly greater osteogenesis volumes than did PLIF and O/XLIF (5.46, 5.12, 4.26, and 3.15 cm3, respectively). Grafting volume and cage size were the main factors influencing the osteogenesis outcome in patients treated with LIF. A large grafting volume allowed more osteoblasts (bone tissues) to be accommodated in the disc space. A small cage size reduced the cage/endplate ratio and therefore decreased the stiffness of the LIF. This led to a larger osteogenesis region to promote osteoblastic differentiation of MSCs and osteoblast proliferation (bone regeneration), which subsequently increased the bone fraction in the grafting space. ConclusionTLIF and ALIF produced more favorable biomechanical environments for osteogenesis than did PLIF and O/XLIF. A small cage and a large grafting volume improve osteogenesis by facilitating osteogenesis-related cell activities driven by mechanical forces.

The Evolution of Lateral Lumbar Interbody Fusion: A Journey from Past to Present.

Lumbar interbody fusion procedures have seen a significant evolution over the years, with various approaches being developed to address spinal pathologies and instability, including posterior lumbar interbody fusion (PLIF), transforaminal lumbar interbody fusion (TLIF), anterior lumbar interbody fusion (ALIF), and lateral lumbar interbody fusion (LLIF). LLIF, a pivotal technique in the field, initially emerged as extreme/direct lateral interbody fusion (XLIF/DLIF) before the development of oblique lumbar interbody fusion (OLIF). To ensure comprehensive circumferential stability, LLIF procedures are often combined with posterior stabilization (PS) using pedicle screws. However, achieving this required repositioning of the patient during the surgical procedure. The advent of single-position surgery (SPS) has revolutionized the procedure by eliminating the need for patient repositioning. With SPS, LLIF along with PS can be performed either in the lateral or prone position, resulting in significantly reduced operative time. Ongoing research endeavors are dedicated to further enhancing LLIF procedures making them even safer and easier. Notably, the integration of robotic technology into SPS has emerged as a game-changer, simplifying surgical processes and positioning itself as a vital asset for the future of spinal fusion surgery. This literature review aims to provide a succinct summary of the evolutionary trajectory of lumbar interbody fusion techniques, with a specific emphasis on its recent advancements.

Short-term and mid-term evaluation of three types of minimally invasive lumbar fusion surgery for treatment of L4/L5 degenerative spondylolisthesis

This was a single-centre retrospective study. Minimally invasive techniques for transforaminal lumbar interbody fusion (MIS-TLIF), oblique lumbar interbody fusion (OLIF), and percutaneous endoscopic transforaminal lumbar interbody fusion (Endo-TLIF) have been extensively used for lumbar degenerative diseases. The present study analyses the short-term and mid-term clinical effects of the above three minimally invasive techniques on L4/L5 degenerative spondylolisthesis. In this retrospective study, 98 patients with L4/L5 degenerative spondylolisthesis received MIS-TLIF, 107 received OLIF, and 114 received Endo-TLIF. All patients were followed up for at least one year. We compared patient data, including age, sex, body mass index (BMI), Oswestry disability index (ODI), visual analogue scale of low back pain (VAS-B), visual analogue scale of leg pain (VAS-L), surgical time, blood loss, drainage volume, hospital stay, complications, and neurological status. Moreover, we performed imaging evaluations, including lumbar lordosis angle (LLA), disc height (DH) and intervertebral fusion status. No significant differences were noted in age, sex, BMI, preoperative ODI, preoperative VAS-B, preoperative VAS-L, preoperative LLA, or preoperative DH. Patients who underwent OLIF had significantly decreased blood loss, a lower drainage volume, and a shorter hospital stay than those who underwent MIS-TLIF or Endo-TLIF (P < 0.05). The VAS-B in the OLIF group significantly decreased compared with in the MIS-TLIF and Endo-TLIF groups at 6 and 12 months postoperatively (P < 0.05). The VAS-L in the Endo-TLIF group significantly decreased compared with that in the MIS-TLIF and OLIF groups at 6 months postoperatively (P < 0.05). The ODI in the OLIF group was significantly better than that in the MIS-TLIF and Endo-TLIF groups at 6 months postoperatively (P < 0.05). No statistically significant differences in the incidence of complications and healthcare cost were found among the three groups. Follow-up LLA and DH changes were significantly lower in the OLIF group than in the other groups (P < 0.05). The intervertebral fusion rate was significantly higher in the OLIF group than in the other groups at 6 and 12 months postoperatively (P < 0.05). In conclusion, while MIS-TLIF, OLIF, and Endo-TLIF techniques can effectively treat patients with L4/5 degenerative spondylolisthesis, OLIF has more benefits, including less operative blood loss, a shorter hospital stay, a smaller drainage volume, efficacy for back pain, effective maintenance of lumbar lordosis angle and disc height, and a higher fusion rate. OLIF should be the preferred surgical treatment for patients with L4/5 degenerative spondylolisthesis.

Radiographic Robustness of Lumbar Interbody Fusion Techniques.

Retrospective chart review. Lumbar interbody fusion (LIF) can be achieved with various techniques. Evidence supporting the long-term clinical advantages of one technique over another are inconclusive. The purpose of this study was to (1) determine the changes in sagittal parameters in the preoperative, intraoperative, and post-operative phase, (2) evaluate the radiographic maintenance of these parameters over time, and (3) compare the demographics and patient reported outcomes of patients undergoing various LIF techniques. We performed a retrospective chart review of patients with degenerative spine disease undergoing single level anterior (ALIF), lateral (LLIF), posterior (PLIF), or transforaminal (TLIF) lumbar interbody fusion. Data collected included patient demographics and diagnosis at time of surgery. Upright lumbar radiographs taken pre-operatively, intra-operatively, and post-operatively were measured for lumbar lordosis (LL), segmental lordosis (SL), posterior disc height (PDH), and foraminal height (FH). 194 patients in a single center were included. PDH and FH increased intra-operatively following ALIF (P < .0001), PLIF (P < .0001), LLIF (P < .0001), and TLIF (P < .0001). SL also increased intra-operatively for ALIF (P = .002) and LLIF (P = .0007). Compared to intra-operative radiographs, PDH and FH decreased at latest post-operative phase for ALIF (P < .03), LLIF (P < .003), TLIF (P < .001), and PLIF (P < .005). SL decreased for ALIF (P = .0008), and TLIF (P = .02). LL did not change postoperatively across techniques. Patient reported outcomes improved post-surgically and disability index decreased, but neither differed between techniques. LIF, regardless of technique, was shown to provide significant radiographic changes in PDH and FH. Techniques utilizing larger intervertebral cage sizes (ALIF/LLIF) improved SL. Single level LIF did not affect overall LL. No single technique displayed superior radiographic robustness over time.

Comparative study of posterior lumbar interbody fusion by strut laminar autograft versus cage in degenerative lumbar spine diseases

Abstract Background Degenerative spondylolisthesis and lumbar disk degeneration are common degenerative diseases of the spine that may lead to lower back pain and radicular leg pain. The perfect surgical treatment remains a point of debate; interbody fusion has been recognized as having a ‘golden role’ in the treatment of lumbar degenerative diseases, but spinal interbody fusion with polyetheretherketone (PEEK) cage surgery often incurs numerous complications such as cage retropulsion, nonunion, and high cost. We hypothesize that the autologous strut laminar graft will show clinical and radiological results similar to those obtained using a PEEK cage. Objective To compare the primary outcome (clinical pain relief) and the secondary outcome (radiological signs of union and rate of fusion) when using strut laminar graft versus PEEK cage in posterior lumbar interbody fusion (PLIF) technique in the surgical management of degenerative lumbar diseases. Patients and methods Forty patients with single-level lumbar degenerative disk disease and/or degenerative spondylolisthesis grades 1 or 2 underwent PLIF surgery between November 2017 and December 2020. All patients were randomly divided into two groups according to the method of fusion (group A: laminar strut graft and group B: PEEK cage). Single-level PLIF was performed in all patients. Clinical, radiological, functional, and perioperative data were recorded and compared. Results The mean follow-up was 22 ± 6 months. Clinical improvement and radiological fusion were significantly documented in each group (P&gt;0.05). However, no significant difference existed between the two groups regarding demographic, radiological, and functional outcomes. Conclusions The results suggest that the laminar strut graft when used instead of the cage seems to be an equally safe and low-priced method of interbody fusion.

Innovative Developments in Lumbar Interbody Cage Materials and Design: A Comprehensive Narrative Review.

This narrative review comprehensively examines the evolution and current state of the interbody cage technology for lumbar interbody fusion (LIF). This review highlights the biomechanical and clinical implications of transition from traditional static cage designs to advanced expandable variants for spinal surgery. The review begins by exploring the early developments in cage materials, highlighting the roles of titanium and polyetheretherketone in advancing LIF techniques. It discusses the strengths and limitations of these materials, leading to innovations in surface modifications and the introduction of novel materials, such as tantalum, as an alternative material. Advancements in three-dimensional printing and surface modification technologies form a significant part of this review, emphasizing the role of these technologies in enhancing the biomechanical compatibility and osseointegration of interbody cages. This review also explores the rise of biodegradable and composite materials such as polylactic acid and polycaprolactone, addressing their potential to mitigate long-term implant-related complications. A critical evaluation of static and expandable cages is presented in this review, including their respective clinical and radiological outcomes. While static cages have been a mainstay of LIF, expandable cages are noted for their ability to adapt to the patient's anatomy, potentially reducing complications such as cage subsidence. However, this review highlights the ongoing debate and the lack of conclusive evidence regarding the superiority of either cage type in terms of clinical outcomes. Finally, this review proposes future directions for cage technology, focusing on the integration of bioactive substances and multifunctional coatings and development of patient-specific implants. These advancements aim to further enhance the efficacy, safety, and personalized approach of spinal fusion surgeries. This review offers a nuanced understanding of the evolving landscape of cage technology in LIF and provides insights into the current practices and future possibilities in spinal surgery.

Transforaminal lumbar interbody fusion with a tantalum cage: lumbar lordosis redistribution and sacral slope restoration with a modified posterior technique

BackgroundTransforaminal lumbar interbody fusion (TLIF), a commonly used procedure in spine surgery, has the advantage of a lower incidence of nerve lesions compared to the posterior lumbar interbody fusion (PLIF) technique. The intersomatic arthrodesis has always been carried out with a single tantalum cage normally used for PLIF. Tantalum is a metal that is particularly used in orthopedic surgery. It has a modulus of elasticity similar to marrow and leads to high primary stability of the implant.Materials and methodsOur study was a retrospective monocentric observational study evaluating clinical and radiological outcomes of tantalum cages in a modified TLIF technique with posterior instrumentation and autologous and/or homologous posterolateral bone grafting. The aim of the study was to evaluate clinical outcomes and the increase in or redistribution of lumbar lordosis. The intersomatic arthrodesis was always carried out with a single tantalum cage normally used for PLIF to reduce the neurological risk. We retrospectively studied 105 patients who were treated with a modified unilateral TLIF approach by two surgeons between 2013 and 2018. We evaluated the Oswestry Disability Index (ODI), Visual Analogue Scale (VAS) for back pain, global lumbar lordosis, lordosis of L4–sacrum, segmental lordosis of functional motion units that underwent arthrodesis, pelvic tilt, pelvic incidence, and the sacral slope in 77 patients. All patients were suffering from grade III or IV Pfirrmann, instability, or foraminal post-laminectomy stenosis and/or grade I–II degenerative spondylolisthesis or low-grade isthmic spondylolisthesis. They had no significant sagittal imbalance, with a sagittal vertical axis (SVA) of < 5 mm. The average follow-up duration was 30 months.ResultsWe achieved excellent clinical results, with only four cases of failure (5.2%). Moreover, we noticed a statistically significant redistribution of lumbar lordosis, with an average percentage increase in L4–S1 lordosis equal to 19.9% (P < 0.001), an average increase in the L4–S1/Lumbar lordosis (LL) ratio from 0.53 to 0.63 (P < 0.001), and a mean percentage increase in sacral slope equal to 7.6% (P < 0.001).Conclusion Thanks to the properties of tantalum, our modified single-portal TLIF technique is a valid surgical solution to obtain a solid arthrodesis and restore the correct lumbar lordosis distribution while reducing neurological complications and the number of failures.Level of evidence: 4Trial registration statement: retrospective observational study, no trial registration.

Transforaminal lumbar interbody fusion with placement of steerable banana cage: A single-center retrospective analysis of radiographic parameters of success

IntroductionThe transforaminal lumbar interbody fusion (TLIF) is among the most utilized methods for the surgical treatment of lumbar degenerative disc disease. The TLIF has advanced significantly with several iterative changes since its inception in the early 1980s, with the advent of several generations of interbody types, shapes, and materials. Steerable curvilinear interbodies are among the most recent innovations in this space and may offer biomechanical advantages, namely in preservation of lumbar and segmental lordosis. While radiographic parameters have been investigated for other cage shapes and lumbar interbody fusion techniques, no study has investigated postoperative radiographic outcomes specific to TLIFs done with curvilinear interbodies. MethodsThis study is a retrospective review of TLIFs performed with curvilinear interbodies between 2019 and 2022 at a single institution. Upright radiographs were obtained preoperatively and at several timepoints postoperatively. Radiographic variables including interspace height and segmental lordosis were collected. Results26 surgeries with 32 curvilinear interbodies were performed across 3 years. There was significant increase in segmental lordosis at the L4-L5 (p = 0.0183) and L5-S1 levels (p = 0.004) as well as interspace height postoperatively at levels L3-L4 (p = 0.011) and L4-L5 (p = 0.002). Pain as measured with the numeric rating scale significantly improved in the overall cohort postoperatively (p<0.001). ConclusionsTLIF with curvilinear interbody placement increases segmental lordosis and interspace height at the L4-L5 and L5-S1 levels, and increased interspace height at the L3-L4 and L4-L5 levels. Further investigation into additional radiographic parameters is warranted and expanded cohort size would benefit deeper analysis of other spinal levels. Implications for practiceAs an increasing number of cage designs and materials are brought to market, studies such as this allow for better understanding of cage specific outcomes allowing for better informed device selection.

Robotic-assisted single-position lateral for multilevel circumferential lumbar interbody fusion: how I do it.

Lateral lumbar interbody fusion supplemented with insertion of pedicle screws is a surgical procedure that has gained popularity in the last years, becoming an important tool in the armamentarium of spine surgeons. In recent years, there is a trend to complete both procedures in a single position, thus avoiding flipping the patient prone to insert the pedicle screws. We describe a step-by-step workflow of the robotic-assisted technique for multilevel lateral lumbar interbody fusion supplemented with posterior instrumentation. The surgical procedure is performed in a single lateral position. For access to L4-5 or L5-S1, an oblique abdominal incision is performed in the same position, and the desired disc space is approached through an oblique or anterior corridor in the retroperitoneal space. Robotic-assisted single-position lateral for multilevel circumferential lumbar interbody fusion is a safe and effective procedure in patients where lumbar stabilization is required. This technique provides patients with a faster recovery and low risk of complications.

Surgical video demonstrating minimally invasive lateral lumbar interbody fusion technique to the L3-L4 disc space.

Surgical video demonstrating minimally invasive lateral lumbar interbody fusion technique to the L3-L4 disc space.

Clinical and Radiologic Outcomes of Biportal Endoscopic Lumbar Interbody Fusion With a Long Polyetheretherketone Cage

Objective: With the latest advances and innovations in field of spine surgery, the new generation of spine surgeons has been increasingly preferring the endoscopic lumbar interbody fusion technique to treat the pathology of lumbar degenerative disease. The aim of this study was to elucidate the clinical and radiologic outcomes of biportal endoscopic lumbar interbody fusion with a long polyetheretherketone (PEEK) cage.Methods: This study included 40 patients treated by biportal endoscopic lumbar interbody fusion with a long PEEK cage between January 2020 and December 2021. The clinical evaluation was conducted using improvements in visual analogue scale (VAS) and Oswestry Disability Index (ODI) scores. Radiological outcomes were evaluated by changes in disc height and segmental and lumbar lordosis. Fusion was assessed based on computed tomography scans using the Bridewell criteria. Surgical parameters (e.g., operative duration, blood loss and complications) were noted.Results: Of the 40 patients in this study, 13 were male and 27 were female. Most patients had significant clinical improvement as indicated by improvements in VAS and ODI scores (p &lt; 0.05). Disc height, segmental lordosis, and lumbar lordosis showed significant improvements (p &lt; 0.05). The mean surgical duration was 180 minutes, and the mean blood loss was 80 mL. All patients had grade 1 or 2 fusion.Conclusion: Biportal endoscopic fusion using a long PEEK cage is an excellent option for achieving good interbody fusion when indicated. A long-term follow-up study would be needed to fully clarify the effectiveness of this procedure.

The novel Kambin Torpedo full-endoscopic lumbar interbody fusion technique: a case series.

Full-endoscopic lumbar interbody fusion (FELIF) is a new-generation treatment for spondylolisthesis. However, owing to their unique characteristics, the two main endoscopic fusion trajectories, the trans-Kambin and posterolateral approaches, have important limitations. Herein, we aimed to introduce a new technique called Kambin Torpedo FELIF (KT-FELIF). The KT-FELIF technique is based on the trans-Kambin approach. It additionally completes ipsilateral total facetectomy and contralateral direct decompression. Thus, this novel technique combines the advantages of the trans-Kambin and posterolateral approaches. We reported on the indications and technical steps of KT-FELIF and provided intraoperative and animated videos to clarify the procedure. Short-term follow-up based on 3-month postoperative computed tomography and plain films images taken at least 3months after surgery showed adequate bony decompression, a large bone graft contact area, and good intervertebral trabecular bone growth without radiolucent lines between the graft, cage, and end plate. The clinical results, such as ipsilateral and contralateral visual analog scale and Oswestry disability index values, gradually improved at 1 and 3months postoperatively. No complications were observed. KT-FELIF is a promising FELIF technique for achieving bilateral direct decompression through a unilateral approach while accomplishing thorough discectomy and endplate preparation.

Midline lumbar interbody fusion: a review of the surgical technique and outcomes.

Midline lumbar interbody fusion (MidLIF) is a mini-open posterior interbody fusion technique defined by a cortical screw trajectory wherein screws are placed from a more medial to lateral trajectory compared with traditional pedicle screws. This enables the surgeon to perform a smaller muscle dissection with the benefits of improved blood loss, less muscle retraction, decreased operative time, shorter length of stay, and improved back pain outcomes compared with the traditional posterior lumbar interbody fusion techniques utilizing pedicle screw fixation. Importantly, MidLIF offers comparable clinical outcomes and radiographic outcomes to other posterior lumbar interbody fusion techniques. In the current review, the authors aimed to educate readers about the MidLIF surgical technique, as well as surgical, clinical, radiographic, cost effectiveness, and biomechanical outcomes, when compared with both open and minimally invasive posterior lumbar interbody fusion techniques with pedicle screw fixation. Readers will be able to utilize this information to determine how the MidLIF procedure compares as an alternative to traditional techniques.

Anterolateral versus posterior minimally invasive lumbar interbody fusion surgery for spondylolisthesis: comparison of outcomes from a global, multicenter study at 12-months follow-up

BACKGROUND CONTEXTSeveral minimally invasive lumbar interbody fusion techniques may be used as a treatment for spondylolisthesis to alleviate back and leg pain, improve function and provide stability to the spine. Surgeons may choose an anterolateral or posterior approach for the surgery however, there remains a lack of real-world evidence from comparative, prospective studies on effectiveness and safety with relatively large, geographically diverse samples and involving multiple surgical approaches. PURPOSETo test the hypothesis that anterolateral and posterior minimally invasive approaches are equally effective in treating patients with spondylolisthesis affecting one or two segments at 3-months follow-up and to report and compare patient reported outcomes and safety profiles between patients at 12-months post-surgery. DESIGNProspective, multicenter, international, observational cohort study. PATIENT SAMPLEPatients with degenerative or isthmic spondylolisthesis who underwent 1- or 2-level minimally invasive lumbar interbody fusion. OUTCOME MEASURESPatient reported outcomes assessing disability (ODI), back pain (VAS), leg pain (VAS) and quality of life (EuroQol 5D-3L) at 4-weeks, 3-months and 12-months follow-up; adverse events up to 12-months; and fusion status at 12-months post-surgery using X-ray and/or CT-scan. The primary study outcome is improvement in ODI score at 3-months. METHODSEligible patients from 26 sites across Europe, Latin America and Asia were consecutively enrolled. Surgeons with experience in minimally invasive lumbar interbody fusion procedures used, according to clinical judgement, either an anterolateral (ie, ALIF, DLIF, OLIF) or posterior (MIDLF, PLIF, TLIF) approach. Mean improvement in disability (ODI) was compared between groups using ANCOVA with baseline ODI score used as a covariate. Paired t-tests were used to examine change from baseline in PRO for both surgical approaches at each timepoint after surgery. A secondary ANCOVA using a propensity score as a covariate was used to test the robustness of conclusions drawn from the between group comparison. RESULTSParticipants receiving an anterolateral approach (n=114) compared to those receiving a posterior approach (n=112) were younger (56.9 vs 62.0 years, p <.001), more likely to be employed (49.1% vs 25.0%, p<.001), have isthmic spondylolisthesis (38.6% vs 16.1%, p<.001) and less likely to only have central or lateral recess stenosis (44.9% vs 68.4%, p=.004). There were no statistically significant differences between the groups for gender, BMI, tobacco use, duration of conservative care, grade of spondylolisthesis, or the presence of stenosis. At 3-months follow-up there was no difference in the amount of improvement in ODI between the anterolateral and posterior groups (23.2 ± 21.3 vs 25.8 ± 19.5, p=.521). There were no clinically meaningful differences between the groups on mean improvement for back- and leg-pain, disability, or quality of life until the 12-months follow-up. Fusion rates of those assessed (n=158; 70% of the sample), were equivalent between groups (anterolateral, 72/88 [81.8%] fused vs posterior, 61/70 [87.1%] fused; p=.390). CONCLUSIONSPatients with degenerative lumbar disease and spondylolisthesis who underwent minimally invasive lumbar interbody fusion presented statistically significant and clinically meaningful improvements from baseline up to 12-months follow-up. There were no clinically relevant differences between patients operated on using an anterolateral or posterior approach.

Does Lumbar Interbody Fusion Modality Affect the Occurrence of Complications in an Osteoporotic Spine Under Whole-Body Vibration? A Finite Element Study

To evaluate the effects of 3 lumbar interbody fusion techniques on the occurrence of complications in an osteoporotic spine under whole-body vibration. A previously developed and validated nonlinear finite element model of L1-S1was modified to develop anterior lumbar interbody fusion (ALIF), posterior lumbar interbody fusion (PLIF), and transforaminal lumbar interbody fusion (TLIF) models with osteoporosis. In each model, the lower surface of the sacrum was absolutely fixed, a follower load of 400N was applied through the axis of the lumbar spine, and an axial sinusoidal vertical load of ±40N (5 Hz) was imposed on the superior surface of L1, to perform a transient dynamic analysis. The maximal values of intradiscal pressure, shear stress on annulus substance, disc bulge, facet joint stress, and screw and rod stress, along with their dynamic response curves, were collected. Among these 3 models, the TLIF model generated the greatest screw and rod stress, and the PLIF model generated the greatest cage-bone interface stress. At the L3-L4 level, compared with the other 2 models, the maximal values and dynamic response curves of intradiscal pressure, shear stress of annulus ground substance, and disc bulge were all lower in the ALIF model. However, the facet contact stress at the adjacent segment in the ALIF model was higher than that in the other 2 models. In an osteoporotic spine under whole-body vibration, TLIF has the highest risk of screw and rod breakage, PLIF has the highest risk of cage subsidence, and ALIF has the lowest risk of upper adjacent disc degeneration, but the highest risk of adjacent facet joint degeneration.

Single-Position Prone Lateral Lumbar Interbody Fusion Increases Operative Efficiency and Maintains Safety in Revision Lumbar Spinal Fusion.

Multi-centre retrospective cohort study. To evaluate the feasibility and safety of the single-position prone lateral lumbar interbody fusion (LLIF) technique for revision lumbar fusion surgery. Prone LLIF (P-LLIF) is a novel technique allowing for placement of a lateral interbody in the prone position and allowing posterior decompression and revision of posterior instrumentation without patient repositioning. This study examines perioperative outcomes and complications of single position P-LLIF against traditional Lateral LLIF (L-LLIF) technique with patient repositioning. A multi-centre retrospective cohort study involving patients undergoing 1 to 4 level LLIF surgery was performed at 4 institutions in the US and Australia. Patients were included if their surgery was performed via either: P-LLIF with revision posterior fusion; or L-LLIF with repositioning to prone. Demographics, perioperative outcomes, complications, and radiological outcomes were compared using independent samples t-tests and chi-squared analyses as appropriate with significance set at P <0.05. 101 patients undergoing revision LLIF surgery were included, of which 43 had P-LLIF and 58 had L-LLIF. Age, BMI and CCI were similar between groups. The number of posterior levels fused (2.21 P-LLIF vs. 2.66 L-LLIF, P =0.469) and number of LLIF levels (1.35 vs. 1.39, P =0.668) was similar between groups.Operative time was significantly less in the P-LLIF group (151 vs. 206 min, P =0.004). EBL was similar between groups (150mL P-LLIF vs. 182mL L-LLIF, P =0.31) and there was a trend toward reduced length of stay in the P-LLIF group (2.7 vs. 3.3d, P =0.09). No significant difference was demonstrated in complications between groups. Radiographic analysis demonstrated no significant differences in preoperative or postoperative sagittal alignment measurements. P-LLIF significantly improves operative efficiency when compared to L-LLIF for revision lumbar fusion. No increase in complications was demonstrated by P-LLIF or trade-offs in sagittal alignment restoration. Level 4.