Lumbar Interbody Fusion Technique Research Articles

Safety Profile, Surgical Technique, and Early Clinical Results for Simultaneous Lateral Lumbar Interbody Fusion and Anterior Lumbar Interbody Fusion in a Lateral Position.

Description of surgical technique and retrospective review. To describe a novel surgical technique for multilevel lumbar fusion and describe early clinical results. Patients with multilevel lumbar spinal stenosis and adult degenerative scoliosis often require multilevel interbody placement to achieve indirect decompression and lordosis. We describe a case series of patients treated with simultaneous lateral lumbar interbody fusion (LLIF) and anterior lumbar interbody fusion (ALIF) at L5-S1. We retrospectively reviewed a consecutive series of patients treated for multilevel lumbar spinal stenosis with simultaneous ALIF and LLIF with at least 3-month follow-up. All patients received supplemental percutaneous bilateral pedicle screw placement as well. We measured on preoperative radiographs their lumbar lordosis, pelvic incidence, and L5-S1 lordosis. Intraoperative factors such as operative time, estimated blood loss, fluids provided, number of levels fused, and whether a trainee was present during the procedure were all recorded. There were 15 patients included within our case series (69.5, 4 F). There were no reported intraoperative vascular or neurological complications in 15 cases. The operative time for the cases ranged from 2.7 to 8.4 hours (average=5.2±1.9 h). The average lordosis gained at L5-S1 was 8.6±3.0 degrees and the average lumbar lordosis gained was 14.7±6.4 degrees. The average PI-LL mismatch went from 22.4±13.3 degrees preoperative to 7.8±10.2 degrees postoperative. One patient had a postoperative complication of a sacral fracture requiring placement of a pelvic screw for a L2-pelvis fusion. There were 8 patients with 4+ levels of fusion. For this cohort of patients, the average lumbar lordosis gained was 16.0±7.5 degrees and the average PI-LL mismatch went from 24.7±16.3 degrees preoperative to 8.8±12.9 degrees postoperative. For the patients with 4+ levels of fusion, the average operative time was 5.9±1.8 hours. We have described our early positive results with simultaneous LLIF/ALIF surgery for treatment of lumbar degenerative conditions.

Development of a lumbosacral intervertebral cage prototype for dogs

ABSTRACT: Several surgical procedures aim to decompress and/or stabilize the lumbosacral (LS) joint of dogs; however, the lumbar interbody fusion technique, by using a cage combined with a bone graft, is the most indicated and used in human medicine. No specific implant is available for application to the canine lumbosacral joint. Thus, this study measured lumbosacral discs in large dogs, determined whether a human cage model could fit the dogs’ L7-S1 intervertebral space, and developed a LS cage prototype for dogs. Ten cadaveric lumbosacral spines from adult dog weighing 20-35kg were used. The dogs had died for reasons unrelated to this study. The vertebral body dimensions and the L7-S1 intervertebral space occupied by the intervertebral disc were measured by lateral and ventrodorsal radiographs and by computed tomography in the dorsal, sagittal, and transverse views. Measurements were also taken of the anatomical specimens in the sagittal and transverse planes. After measuring the intervertebral discs, the following mean measures were obtained for L7-S1 discs: height 12.23mm, dorsal thickness 3.3mm, central thickness 4mm, ventral thickness 5.5mm, and width 24.74mm. The human lumbar cage models from brands LDR, Baumer Orthopedics, Stryker, Synthes, and Vertebral Technologies, Inc. and cervical stabilization cages from the brands B-Braun and Stryker were evaluated and were found to be unsuitable for large dogs. Cervical human cages had measurements similar to those found in this study; however, due to their quadrangular shape, the possibility of being introduced surgically through the surgical accesses available for the articulation between L7-S1 in dogs without injuring the cauda equina or the L7 root is small. A cage model was then developed using 3D modelling software. It was designed for insertion via dorsal laminectomy in the lateral portions of the intervertebral space. To avoid cauda equina lesion, the implant model was developed to be placed laterally to the midline. The cage surface is serrated to prevent using the locking screw to fix it, thus avoiding further injury to nerve structures. The serrated surfaces are also designed to avoid cage migration and promote stability. The prototype allows graft placement in the surrounding intervertebral space, which is fundamental for fusion through integration between the cage and the endplates as well as for bone growth between and around the cage. It was also considered studies on humans showing that the lateral regions of the endplates support a more considerable load. Biomechanical and in vivo studies on the developed model are necessary to evaluate the actual degree of distraction, mobility and the long-term rate of fusion between L7 and S1 and its possible impact on the adjacent motor units, combined or not with dorsal fixation techniques.

How I do it? Extraforaminal lumbar interbody fusion assisted with biportal endoscopic technique.

The biportal endoscope-assisted unilateral foraminal approach is an option for various foraminal pathologies. Lumbar interbody fusion is the standard treatment for foraminal stenosis because both direct and indirect neural decompressions can be obtained. We used the biportal endoscopic technique for extraforaminal lumbar interbody fusion (BE-EFLIF) and have described the steps, with discussion regarding the indications, advantages, possible complications, and ways to overcome complications. BE-EFLIF achieves direct neural decompression of lateral spinal canal under endoscopic visualization. It achieves indirect neural decompression using a large footprint lordotic interbody cage, while preserving the lumbar posterior arch as much as possible.

Comparison of Minimal Invasive Versus Biportal Endoscopic Transforaminal Lumbar Interbody Fusion for Single-level Lumbar Disease.

Study Design:Retrospective study.Objective:The authors aimed to compare the clinical outcomes of biportal endoscopic transforaminal lumbar interbody fusion (BE-TLIF) with those of minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) using a microscope.Summary of Background Data:Lumbar spinal fusion has been widely performed for various lumbar spinal pathologies. Minimally invasive transforaminal interbody fusion using a tubular retractor under a microscope is a method of achieving fusion while reducing soft tissue injury. Recently, several studies have reported minimally invasive techniques for lumbar discectomy, decompression, and interbody fusion using biportal endoscopic spinal surgery.Materials and Methods:This retrospective study included 87 patients who underwent single-level TLIF for degenerative or isthmic spondylolisthesis between 2015 and 2018. Thirty-two and 55 patients underwent BE-TLIF (group A) and MI-TLIF (group B), respectively. Visual Analogue Scale scores of the back and leg and Oswestry Disability Index were collected perioperatively.Further, data regarding perioperative complications, including length of hospital stay, time to ambulation, and fusion rate, were collected.Results:The Visual Analogue Scale score at 2 weeks and 2 months postoperatively was significantly lower in group A (P=0.001). All other clinical scores showed improvement with no significant difference between the 2 groups (P>0.05). The difference in the fusion rates between group A (93.7%) and group B (92.7%) were not significant (P=0.43).Conclusions:Because BE-TLIF yieldeds lesser early postoperative back pain than did MI-TLIF, it may allow early ambulation and a shorter hospitalization period. BE-TLIF may be a viable alternative to MI-TLIF in patients with degenerative or isthmic spondylolisthesis with superior clinical results in the early postoperative period.

Rooting, and growing with luxuriant branches and leaves-the story of oblique lateral interbody fusion in China

Oblique lateral interbody fusion (OLIF) is a popular minimally invasive lumbar fusion technique in the world, which has become an important technique for lumbar interbody fusion. In 2014, OLIF was firstly introduced into the mainland of China, however, due to some defects of OLIF technique, such as steep learning curve, high rates of early complications, and difficult surgical exposure approach, the initial development of OLIF in China was not smooth. In order to make OLIF simpler and safer, the domestic scholars designed special exposure retractors for OLIF, and put forward a new technique for OLIF, called anteroin-ferior psoas exposure technique under direct vision. Driven by the OLIF technique trainings, live operation demonstrations, and literature publications, et al., the OLIF technique begun to settle down and flourish in China. Up to now, the number of surgical cases of Medtronic OLIF25 has reached more than 6 000, and the domestic scholars have published more than 30 OLIF papers in the international journals. However, our domestic spine surgeons still need to pay attention to the standardized application of OLIF, appropriate OLIF devices according to the Chinese anatomical characteristics, and the multicenter randomized controlled study of large samples, et al.

Oblique Lumbar Interbody Fusion With Stereotactic Navigation: Technical Note.

Study Design:Surgical technical note.Objectives:Describe the preoperative evaluation, approach, and technical considerations for an oblique lumbar interbody fusion using neuronavigation.Methods:A thorough review of previous technical and anatomic descriptions for pre- and transpsoas interbody techniques was performed and incorporated into the technical considerations warranting discussion for a navigated oblique lateral interbody fusion.Results:The prepsoas technique, also known as an oblique lumbar interbody fusion (OLIF), is an alternative approach for lumbar interbody fusion that utilizes a retroperitoneal corridor between the aorta/inferior vena cava. This corridor is devoid of neurovascular structures and obviates the need for real time electromyography monitoring. This approach spares the psoas and provides direct visualization of key structures and minimizes risk of injury to the great vessels, ureter, and lumbar plexus.Conclusions:A navigated prepsoas retroperitoneal approach is an effective minimally invasive technique for lumbar interbody fusion that may help mitigate some of the vascular and neurologic complications present with anterior lumbar interbody fusion or lateral lumbar interbody fusion and minimize radiation exposure to the surgeon.

Postoperative Low Back Pain after Posterior Lumbar Interbody Fusion Surgery Using Cortical Bone Trajectory Screws.

Study DesignRetrospective analysis of a case series of prospectively collected data. PurposeTo compare clinical and radiological outcomes between two posterior lumbar interbody fusion techniques: cortical bone trajectory (CBT) and traditional pedicle screw (PS).Overview of LiteratureBiomechanical studies have revealed the benefits of the CBT technique. However, clinical evidence obtained from the direct comparison of outcomes between CBT and PS is limited.MethodsWe retrospectively investigated 104 patients who had undergone posterior lumbar interbody fusion using CBT or PS. Clinical symptoms were evaluated and compared between CBT and PS using the Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ) and Visual Analog Scale (VAS) before and 1 year after surgery. Spinal fusion status was assessed by multiplanar reconstruction computed tomography at 1 year after surgery.ResultsThe CBT and PS techniques were performed on 36 and 68 patients, respectively. Both CBT- and PS-treated patients exhibited improvement in each subdomain of the JOABPEQ and in the VAS. With regard to postoperative improvement of low back pain, the treatment effect, as assessed by the JOABPEQ, was greater for PS than for CBT. The spinal fusion rate was slightly lower for CBT than for PS, although the difference between them was not significant. The effect of treatment on postoperative low back pain was smaller for CBT than for PS, regardless of whether rigid spinal fusion was achieved.Conclusions Clinical symptoms and spinal fusion efficiency were not significantly different between CBT and PS except for postoperative improvement in low back pain. The treatment effect on postoperative low back pain was smaller for CBT than for PS.

Minimally invasive unilateral lumbar interbody fusion (UNILIF) in over-80-year-olds. Continuous series of 42 patients at 1.4 years’ follow-up

IntroductionIn lumbar stenosis, surgery aims to improve quality of life in increasingly elderly patients. Minimally invasive techniques better suit the requirements of elderly patients with increasing functional demand. HypothesisThe UNILIF unilateral lumbar interbody fusion technique improves functional scores at 1 year in over-80 year-olds, with low morbidity. MethodPatients undergoing minimally invasive decompression with transforaminal lumbar interbody fusion (TLIF) associated to unilateral pedicle screwing for degenerative lumbar stenosis were analyzed at a minimum 1 year's follow-up. SF12, Oswestry Disability Index (ODI) and Quebec scores and sagittal spinopelvic radiographic parameters were assessed at follow-up. Surgical and general complications were also collated. ResultsIn all, 42 patients (64.3% female; mean age, 83.7±2.9 years) were treated by UNILIF at levels L2-L3 (3.8%), L3-L4 (15.4%), L4-L5 (71.2%) and L5-S1 (9.6%). Mean follow-up was 520±226 days (range, 340–1166 days). Mean preoperative SF12 score was 77.5±10.9, with significant improvement at last follow-up: 81.9±138 (p<0.05). Mean preoperative ODI was 44.4%±14.0, with significant improvement at last follow-up: 32.4%±13.3 (p<0.001). Mean preoperative Quebec score was 42.9±19.9, with significant improvement at last follow-up: 28.5±21.9 (p<0.001). Spinopelvic sagittal balance was not affected by the UNILIF procedure. There were no cases of infection or severe general complications during follow-up, although 2 cases of non-union required revision surgery. ConclusionLumbar stenosis surgery by UNILIF improved functional scores at 1 year, with low morbidity. It is a suitable strategy for degenerative lumbar stenosis in elderly patients. Level of evidenceIV, non-comparative cohort study.

Full Percutaneous Transforaminal Lumbar Interbody Fusion Using the Facet-sparing, Trans-Kambin Approach.

This was a prospective, multicenter, consecutive case series' study. The objective of this study was to evaluate a novel facet-sparing, percutaneous transforaminal lumbar interbody fusion (pTLIF) technique consisting of percutaneous insertion of an expandable interbody cage through an endoscopic cannula with the trans-Kambin approach and complemented with percutaneous transpedicular screws and rods. Lumbar interbody fusion by open or minimally invasive surgery is the usual treatment for degenerative disk disease but requires a relatively long recovery period. The transforaminal trans-Kambin approach is a standard in endoscopic spine surgery for safe intradiscal access without facet resection. Preoperative and postoperative Visual Analogue Scale (VAS) and Oswestry Disability Index scores were quantitatively assessed at 1, 3, 6, and 12 months after surgery and then every 12 months for patients treated with pTLIF between 2009 and 2018 in 2 health care centers. An immediate postoperative control computed tomography scan was performed, whereas conventional postoperative x-ray controls were performed at 1 month and 1 year. Statistical evaluation was performed with the Student t test. A total of 51 patients (mean age, 59.3 y) were evaluated. The overall mean VAS score for axial lumbar pain improved from 6.6 to 1.8 (P<0.01), mean VAS score for leg pain from 5.5 to 1.2 (P<0.01), and mean Oswestry Disability Index scores from 30.3 to 11.8 (P<0.01) postoperatively with a mean follow-up of 27.9 months (range, 1-77.8 mo). Median estimated blood loss was 103.6 mL. Postoperative complications included 12 (22%) cases with transitory ipsilateral dysesthesia, 2 (4%) cases with transitory ipsilateral muscle weakness, and 3 (6%) clinically asymptomatic cases with radiologic cage subsidence. Median hospital stay was 1.4 days (range, 1-3.2 d). Postoperative scores for pTLIF significantly improved with minimal blood loss and no long-term complications. On the basis of this experience, the facet-sparing pTLIF is a reliable and safe technique with early hospital discharge, opening the way to outpatient instrumented spine surgery. Level III.

The 25 most cited articles on lateral lumbar interbody fusion: short review.

The lateral lumbar interbody fusion technique for lumbar arthrodesis is gaining popularity and being added as an option to traditional posterior and anterior approaches. In light of this, we analyzed the literature to identify the 25 most cited articles regarding lateral lumbar interbody fusion. The Thomson Reuters Web of Science was systematically searched to identify papers pertaining to lateral lumbar interbody fusion. The results were sorted in order to identify the top cited 25 articles. Statistical analysis was applied to determine metrics of interest, and observational studies were further classified. A search of all databases in the Thomson Reuters Web of Science identified 379 articles pertaining to lateral lumbar interbody fusion, with a total of 3800 citations. Of the 25 most cited articles, all were case series, reporting on a total of 2981 patients. These 25 articles were cited 2232 times in the literature and total citations per article ranged from 29 to 433. The oldest article was published in 2006, whereas the most recent article was published in 2015. The most cited article, by Ozgar et al., was cited 433 times, and the journal Spine published 7 of the 25 most cited articles. Herein, we report and analyze the 25 most cited articles on lateral lumbar interbody fusion, which include 25 cases series reporting a variety of data on a total of 2513 patients. Such data might assist in the design and interpretation of future studies pertaining to this topic.

Unilateral Versus Bilateral Facetectomy and its Effect on Segmental Lordosis and Disc Height in MIS TLIF

Background: Minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) techniques have allowed for improved recovery and other metrics compared to its open counterpart. Our expanding literature has increasingly demonstrated the importance of spinopelvic parameters. One of the concerns with MIS TLIF is that the limited exposure and existing technology make it difficult to restore lumbar lordosis at the degenerative level requiring surgery. We hypothesize that bilateral facetectomy with MIS techniques will allow for increased ability to restore segmental lumbar lordosis versus traditional unilateral facetectomy. Methods: This is a retrospective chart review of all patients who underwent single level MIS TLIF between 2017 and 2018. We collected baseline characteristics and reviewed operative records to determine whether unilateral or bilateral facetectomies were performed. We used intraoperative CT (O-Arm) sagittal reformatted images to measure segmental lordosis as well as anterior, middle, and posterior disc heights. Results: Forty patients were identified. Eighteen underwent bilateral facetectomy, and 22 had unilateral facetectomy. We found a significantly increased middle disc height in the bilateral facetectomy group of 3.6 mm vs 2.8 mm in the unilateral group (p=0.04). We also found increased lordosis (4.4 vs. 3.7, respectively) as well as anterior (4.5 vs 3.5) disc height in the bilateral facetectomy group but neither reached statistical significance. Conclusion: Bilateral facetectomy is a tool that can help achieve maximal lordosis and disc height restoration in MIS TLIF surgery. Benefits besides lordosis and disc height restoration include increased autograft for fusion. Across various papers there seems to be a trend toward greater lordosis and disc height restoration, however most papers including ours have been underpowered to find significance.

Minimally Invasive Surgery Combining Cortical Bone Trajectory Screws and Pedicle Screws to Treat Spondylodiskitis: Technical Notes and Preliminary Results

Various surgical techniques for treating spondylodiskitis have been proposed, but the most appropriate surgical treatment remains controversial. In this study, we propose a new hybrid approach combining the use of cortical bone trajectory screws and pedicle screws with the technique of transforaminal lumbar interbody debridement and fusion. With this method, we can shorten the length of the segment that needs to be fixed, minimize the extent of surgical dissection, and reduce the risk of adjacent level degeneration. Patients with clinical and radiographic evidences of single-level lumbar spondylodiskitis seen between January and December of 2017 were included in the study. Demographic data, including age and sex, were recorded. The intraoperative details, results of culture, functional outcome, radiologic outcome, and length of hospital stay were recorded. The mean age of 15 patients was 62.8 years. The mean operative time was 135 minutes, and the mean blood loss was 260 mL. The culture rate was 80%. The mean Numeric Rating Scale score and Oswestry Disability Index score significantly improved from 6.60 to 2.47 and from 21.20 to 10.20, respectively. No major perioperative complications occurred. With the proposed hybrid approach using cortical bone trajectory and pedicle screws with the transforaminal lumbar interbody debridement and fusion technique, the damaged anterior column can be debrided and reconstructed, and spinal stabilization can also be achieved.

Impact of lumbar interbody fusion surgery on postoperative outcomes in patients with recurrent lumbar disc herniation: Analysis of the US national inpatient sample

Little information is available on associations between different lumbar interbody fusion (LIF) surgeries and postoperative outcomes. The present study aims to comprehensively investigate whether different LIF techniques are associated with postoperative outcomes such as complications and length of hospital stay. The United States Nationwide Inpatient Sample (NIS) was searched for patients diagnosed with recurrent lumbar disc herniation who underwent lumbar interbody fusion (LIF) surgeries between 2005 and 2014. Patients were categorized based on LIF approaches: anterior lumbar interbody fusion (ALIF); lateral lumbar interbody fusion (LLIF); or posterior lumbar interbody fusion/transforaminal lumbar interbody fusion (PLIF/TLIF). A total of 2625 patients were included in this study. After adjusting for age, severity of illness, and comorbidities, patients who received LLIF and PLIF/TLIF approaches had significantly shorter hospital stays than those receiving ALIF (LLIF vs. ALIF, β = −0.64; PLIF/TLIF vs. ALIF, β = −0.40). In addition, patients who received LLIF and PLIF/TLIF approaches had significantly lower risk of digestive system complications compared to those receiving ALIF (LLIF vs. ALIF, aOR = 0.25; PLIF/TLIF vs. ALIF, aOR = 0.18). In conclusion, in patients with recurrent lumbar disc herniation, LLIF and PLIF/TLIF approaches are associated with shorter hospital stays and lower risk of digestive system complications than ALIF. However, LIF approaches do not correlate significantly with the risk of postoperative bleeding or nervous system complications.

295. Comparison of the biomechanical performances among PLF, TLIF, OLIF and XLIF: a finite element analysis

BACKGROUND CONTEXT Posterolateral fusion (PLF) and lumbar interbody fusion (LIF) are the commonly used techniques for the treatment of lumbar degenerative diseases. Although the superiority of PLF or LIF remains controversial, LIF technique provides the potential advantages of anterior column supports and 360° arthrodesis. The most commonly used LIF technique is transforaminal LIF (TLIF). Lateral approaches including extreme LIF (XLIF) and the subsequent oblique LIF (OLIF), have been accepted by an increasing number of spine surgeons due to their unique advantages. Previous studies revealed that radiological outcomes significantly varied among PLF, TLIF, XLIF and OLIF, suggesting their different biomechanical properties. PURPOSE To compare the biomechanical differences among PLF, TLIF, XLIF and OLIF construct and determine which surgical construct was most beneficialto the segmental stability and cage subsidence resistance. STUDY DESIGN/SETTING a finite element (FE) analysis. OUTCOME MEASURES The ranges of motion (ROMs) and stress peaks in the cortical endplate, cancellous bone and posterior instrumentations were compared among the five constructs. METHODS An intact FE model of the L3-L5 lumbar spine was constructed. After validation, the PLF, TLIF with a banana-shaped cage, TLIF with a straight cage, XLIF and OLIF procedures were simulated at the L4/5 level. A bilateral pedicle screw fixation was added in each construct. The TLIF banana-shaped cage was placed on the anterior one-third portion of the endplate. The TLIF straight cage was placed around the midpoint of the endplate and was diagonally positioned at an angle of 45° . The XLIF cage was placed at the mid-endplate and the OLIF cage was placed more anteriorly. An axial preload of 400 N was imposed on the superior surface of L3 to simulate the corresponding physiologic compression. Another 8 Nm was applied on L3 to simulate flexion, extension, bending and axial rotation. RESULTS The PLF construct has much higher ROMs than the LIF constructs (0.44° to -1.05° vs 0.29° to -0.72°). TLIF with a straight cage induces the highest stress peak in the endplate and cancellous bone (23.2-63.7 MPa and 0.69-2.03 MPa, respectively), followedby TLIF with a banana-shaped cage (23.7-44.8 MPa and 0.6-1.36 MPa, respectively). OLIF (16.76-32.41 MPa and 0.54-1.07 MPa, respectively) and XLIF (17.01-35.34 MPa and 0.56-1.12 MPa, respectively) constructs induces much lower stress peaks in the endplate and cancellous bone. In the PLF construct, the stress peaks in the posterior instrument range from 244.6 MPa to 377.4 MPa, which are significantly higher than those in the LIF constructs (123.9-237.4 MPa). CONCLUSIONS The PLF construct had\s less stability than the LIF construct due to the higher ROMs and stress peaks in the posterior instrument. TLIF with a banana-shaped cage outperforms TLIF with a straight cage in decreasing the stress peaks in the endplate and cancellous bone, as the banana-shaped cage is ideally located more anteriorly and placed on the strong cortical rim of the endplate. Compared with TLIF constructs, the much larger cages used in the OLIF and XLIF constructs induce significantly fewer stress peaks and increase homogeneous stress distributions in the endplate cancellous bone, which was beneficial to the subsidence resistance and maintenance of disc height and segmental angle. FDA DEVICE/DRUG STATUS XLIF (Approved for this indication), OLIF (Approved for this indication)

P20. Titanium expandable interbody spacers placed via bilateral-TLIF provides stability similar to ALIF: an in-vitro range of motion analysis

BACKGROUND CONTEXT The transforaminal lumbar interbody fusion (TLIF) approach was developed to avoid the risks of the anterior lumbar interbody fusion (ALIF) and posterior lumbar interbody fusion (PLIF) approaches, and their potential for damage to the major vessels and the neurological elements, respectively. Construct stability of these various lumbar interbody fusion techniques is paramount to promote arthrodesis. Placement of two titanium expandable interbody spacers intradiscally following a bilateral facetectomy has the theoretical advantage of increased stability. PURPOSE This biomechanical study aims to compare the stability of bilateral-TLIF with titanium expandable interbody spacers compared to various standard constructs in an in-vitro range of motion kinematic analysis in cadaveric models. STUDY DESIGN/SETTING In vitro biomechanics study. OUTCOME MEASURES Range of motion in flexion-extension (FE), lateral bending (LB), and axial rotation (AR) was captured for each specimen. METHODS Twenty-four fresh frozen cadaveric spines (L3–L4/L5–S1) were divided into four groups with equivalent bone mineral density average scores (n=6). Specimens were instrumented with either (1) one static ALIF spacer; (2) one static oblique TLIF spacer (Ob); (3) two static bilateral-TLIF spacers (BiSt); or (4) two expandable bilateral-TLIF spacers (BiEx). Constructs were tested according to a load control protocol (±6.0Nm) before and after posterior fixation in FE, LB, and AR. Motion was captured for the (1) intact condition, (2) interbody spacer with posterior pedicle screw and rod fixation (Spacer+PI), and (3) spacer-alone (Spacer). Motion was normalized to intact, change in stability from intact to Spacer+PI and Spacer constructs was calculated, and statistical analyses were performed (p RESULTS All groups with PI reduced motion from intact in all modes. BiST resulted in comparable stability to ALIF in FE and AR. BiEX Spacer increased stability in all modes and was the only group to gain stability in FE (31% vs. -74%[ALIF], -46%[Ob], and -20%[BiST]). BiEX Spacer added significantly more stability than Ob Spacer in LB (49% vs. -7% [p=0.014]). CONCLUSIONS The proposed bilateral-TLIF technique resulted in comparable stability to an ALIF spacer. Adding posterior fixation to the construct notably increased stability in all modes, emphasizing the need for supplemental fixation. When examining the sole effect of the spacer, only the expandable bilateral-TLIF spacer group gained stability from intact in all modes of motion, illustrating the biomechanical benefits of expandable technology. FDA DEVICE/DRUG STATUS Interbody spacers are indicated for this application (Approved for this indication)

Changes in Sagittal Alignment Following Short-Level Lumbar Interbody Fusion: Comparison between Posterior and Lateral Lumbar Interbody Fusions.

Study DesignRetrospective case-control study.PurposeWe aimed to compare radiologic outcomes between posterior (PLIF) and lateral lumbar interbody fusion (LLIF) in short-level spinal fusion surgeries.Overview of LiteratureAlthough LLIF enables surgeons to insert large lordotic cages, it is unknown whether LLIF more effectively corrects local and global sagittal alignments compared with PLIF in short-level spinal fusion surgeries.MethodsRadiographic data acquired from patients with lumbar interbody fusion (≤3 levels) using PLIF or LLIF for degenerative lumbar diseases were analyzed. The following radiographic parameters were evaluated preoperatively and at 2 years postoperatively: segmental lordotic angle, disk height, lumbar lordosis (LL), pelvic tilt (PT), C7 sagittal vertical axis, and thoracic kyphosis (TK).ResultsIn total, 144 patients with PLIF (193 fused levels) and 101 with LLIF (159 fused levels) were included. Patients’ backgrounds and preoperative radiographic parameters for any level of fusion did not differ significantly between PLIF and LLIF procedures. The LLIF group exhibited significantly greater changes at 1-level fusion compared to the PLIF group in the parameters of segmental lordotic angle (5.1°±5.8° vs. 2.1°±5.0°, p<0.001), disk height (4.2±2.3 mm vs. 2.2±2.0 mm, p<0.001), LL (7.8°±7.6° vs. 3.9°±8.6°, p=0.004), and PI–LL (−6.9°±6.8° vs. −3.6°±10.1°, p=0.03). While, a similar trend was observed regarding 2-level fusion, significantly greater changes were only observed in LL (12.1°±11.1° vs. 4.2°±9.1°, p=0.047) and PI–LL (−11.2°±11.3° vs. −3.0°±9.3°, p=0.043), PT (−6.4°±4.9° vs. −2.5°±5.3°, p=0.049) and TK (7.8°±11.8° vs. −0.3°±9.7°, p=0.047) in the LLIF group at 3-level fusion.ConclusionsLLIF provides significantly better local sagittal alignment than PLIF in 1- or 2-level fusion cases and improves spinopelvic alignment and local alignment for 3-level fusion cases. Thus, LLIF was demonstrated to be a useful lumbar interbody fusion technique, constituting a powerful tool for achieving sagittal realignment with minimal surgical invasiveness.

Lateral and Oblique Lumbar Interbody Fusion-Current Concepts and a Review of Recent Literature.

To review the relevant recent literature regarding minimally invasive, lateral, and oblique approaches to the anterior lumbar spine, with a particular focus on the operative and postoperative complications. A literature search was performed on Pubmed and Web of Science using combinations of the following keywords and their acronyms: lateral lumbar interbody fusion (LLIF), oblique lateral interbody fusion (OLIF), anterior-to-psoas approach (ATP), direct lateral interbody fusion (DLIF), extreme lateral interbody fusion (XLIF), and minimally invasive surgery (MIS). All results from January 2016 through January 2019 were evaluated and all studies evaluating complications and/or outcomes were included in the review. Transient neurological deficit, particularly sensorimotor symptoms of the ipsilateral thigh, remains the most common complication seen in LLIF. Best available current literature demonstrates that approximately 30-40% of patients have postoperative deficits, primarily of the proximal leg. Permanent symptoms are less common, affecting 4-5% of cases. Newer techniques to reduce this rate include different retractors, direct visualization of the nerves, and intraoperative neuromonitoring. OLIF may have lower deficit rates, but the available literature is limited. Subsidence rates in both LLIF and OLIF are comparable to ALIF (anterior lumbar interbody fusion), but further study is required. Supplemental posterior fixation is an active area of investigation that shows favorable biomechanical results, but additional clinical studies are needed. Minimally invasive lumbar interbody fusion techniques continue to advance rapidly. As these techniques continue to mature, evidence-based risk-stratification systems are required to better guide both the patient and clinician in the joint decision-making process for the optimal surgical approach.

The influence of age on the peri- and postoperative clinical course in patients undergoing minimally invasive transforaminal lumbar interbody fusion techniques of the lumbar spine

ObjectiveAs a result of continuously increasing life expectancy, the number of requests for surgery to treat degenerative diseases of the spine in the elderly population will increase. Since older age is associated with the occurrence of medical comorbidities, the demand for less extensive surgical approaches is growing. The aim of this study is to establish whether minimally invasive fusion techniques are a safe and adequate tool for use in elderly patients. Patients and methodsWe analyzed 187 patients who underwent minimally invasive surgery (MIS) in the form of one- to four-level fusion procedures. In 146 patients, additional widening of the spinal canal was performed. The subjects were grouped into four age categories of approximately equal size (33–56, 56–66, 66–74 and 74–85). The effect of age on the incidence of peri- and postoperative complications was investigated and compared between the age groups. ResultsOlder age was not associated with the occurrence of perioperative complications, which include wound healing disorders, hematomas, wound traction-blisters and cerebrospinal fluid leakage. Fourteen patients (7.49%) encountered distinct surgical technique related complications, making surgical revision necessary in eight patients (4.28%). Furthermore, increasing age didn’t elevate the risk of postoperative adverse events, i.e. pulmonary embolism, ischemic heart attack or pneumonia, among others. However, older patients were found to stay in hospital longer than younger patients, especially when more than one level was fused. ConclusionsMinimally invasive surgery techniques are safe in elderly patients. The small-scale surgical approach guarantees a low incidence of infections and wound healing disorders. However, a longer hospital stay must be expected in older patients.

Endoscopic transforaminal lumbar interbody fusion without general anesthesia: operative and clinical outcomes in 100 consecutive patients with a minimum 1-year follow-up.

OBJECTIVEOpen spinal fusion surgery is often associated with significant blood loss, postoperative pain, and prolonged recovery times. Seeking to minimize surgical and perioperative morbidity, the authors adopted an endoscopic minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) technique performed without general anesthesia. In this report, they present data on the first 100 patients treated with this procedure.METHODSThe authors conducted a retrospective review of the first 100 patients who underwent awake endoscopic MIS-TLIF at a single institution between 2014 and 2017. Surgery was performed while the patient was sedated but without intubation or the use of general anesthetic or narcotic agents. Long-lasting (liposomal) bupivacaine was used for local analgesia. The discectomy and placement of an expandable interbody graft were performed endoscopically, followed by percutaneous pedicle screw implantation. Inclusion criteria for the procedure consisted of diagnosis of degenerative disc disease with grade I or II spondylolisthesis and evidence of spinal stenosis or nerve impingement with intractable symptomatology.RESULTSOf the first 100 patients, 56 were female and 44 were male. Single-level fusion was performed in 84 patients and two-level fusion in 16 patients. The most commonly fused level was L4-5, representing 77% of all fused levels. The mean (± standard deviation) operative time was 84.5 ± 21.7 minutes for one-level fusions and 128.1 ± 48.6 minutes for two-level procedures. The mean intraoperative blood loss was 65.4 ± 76.6 ml for one-level fusions and 74.7 ± 33.6 ml for two-level fusions. The mean length of hospital stay was 1.4 ± 1.0 days. Four deaths occurred in the 100 patients; all four of those patients died from complications unrelated to surgery. In 82% of the surviving patients, 1-year follow-up Oswestry Disability Index (ODI) data were available. The mean preoperative ODI score was 29.6 ± 15.3 and the mean postoperative ODI score was 17.2 ± 16.9, which represents a significant mean reduction in the ODI score of -12.3 using a two-tailed paired t-test (p = 0.000001). In four cases, the surgical plan was revised to include general endotracheal anesthesia intraoperatively and was successfully completed. Other complications included two cases of cage migration, one case of osteomyelitis, and one case of endplate fracture; three of these complications occurred in the first 50 cases.CONCLUSIONSThis series of the first 100 patients to undergo awake endoscopic MIS-TLIF demonstrates outcomes comparable to those reported in our earlier papers. This procedure can provide a safe and efficacious option for lumbar fusion with less morbidity than open surgery. Further refinements in surgical technique and technologies will allow for improved success.

Clinical outcomes of posterior thoracic cage interbody fusion (PTCIF) to treat trauma and degenerative disease of the thoracic and thoracolumbar junctional spine

Laminectomy followed by posterolateral fusion (PLF) is a standard procedure for thoracic and thoracolumbar (TL) compressive lesions. However, it is challenging to apply sufficient bone chips as the spinal cord is exposed after the laminectomy. Therefore, we performed posterior thoracic cage interbody fusion (PTCIF) as an alternative technique. A total of 25 patients operated with PTCIF technique between 2012 and 2017 were analyzed in our study. These patients required a posterior decompression and fusion in thoracic and TL spine for traumatic injury or degenerative disease. To evaluate the outcome of bone fusion, computed tomography (CT) was performed at least 3–4 months after PTCIF. The surgery was performed through insertion of screws and cages packed with autologous bone chips in a similar fashion to the posterior lumbar interbody fusion technique. Among 25 patients who underwent PTCIF, 22 patients were involved in our study. The mean age and follow-up interval were 58.6 (28–78) years and 27.1 (6–60) months, respectively. Traumatic spinal injury was diagnosed in 6 patients and degenerative disease in 16 patients. One level PTCIF was performed in 12 patients and 2 levels in 8 patients. After the operation, patients with degenerative disease showed neurological improvement, and trauma cases showed no neurological aggravation. Successful bone fusion was confirmed on CT for all patients. PTCIF is an effective treatment thereby we suggest this approach to be considered as an alternative procedure to decompression and fusion surgery in the thoracic and TL spine.