XLIF Procedure Research Articles

A retrospective case-control study on the effectiveness of preoperative diffusion tensor imaging for mitigating nerve injury in extreme lateral interbody fusion surgery

Extreme Lateral Interbody Fusion (XLIF) has been established as an effective treatment for degenerative disorders of the lumbar spine. Nevertheless, there is a potential risk of lumbar plexus damage associated with XLIF, especially during surgeries at the L4-5 segment. Diffusion Tensor Imaging (DTI) evaluates the directional diffusion of water molecules in tissue, providing a more intricate depiction of internal tissue microstructure compared to conventional MRI techniques. The capability of DTI sequences to elucidate the 3-dimensional interplay between lumbar nerve pathways and adjacent musculoskeletal structures, potentially reducing the incidence of nerve injury complications related to XLIF, remains to be established. This study evaluates the effectiveness of preoperative Diffusion Tensor Imaging (DTI) in reducing neurological complications after Extreme Lateral Interbody Fusion (XLIF) surgeries at the L4-5 level, focusing on the interaction between lumbar nerves and the psoas major muscle. Retrospective case-control study. The study included 128 patients undergoing XLIF surgery for degenerative disorders at the L4-5 segment: 68 in the traditional group and 62 in the DTI group. The study assessed Visual Analogue Scale (VAS) and Oswestry Disability Index (ODI) scores, along with complication rates. It also documented psoas major muscle morphology and its correlation with nerve pathways. A retrospective analysis of 128 patients undergoing XLIF surgery for degenerative disorders at the L4-5 segment between February 2020 and August 2022 was conducted. The cohort was divided into a traditional group (68 patients) receiving presurgery MRI scans to identify surgical entry points at the intervertebral space midpoint (Zones II-III junction) and a DTI group (62 patients) who additionally underwent preoperative DTI to customize entry points. The study evaluated VAS and ODI scores, complication rates, psoas major muscle morphology, and its interaction with nerve pathways. The traditional group uniformly chose the Zone II-III junction for entry. In contrast, the DTI group's entry points varied. Postoperative follow-up revealed significant improvements in VAS and ODI scores in both groups. However, the DTI group experienced fewer immediate postoperative complications such as thigh pain, numbness, and motor disturbances. The study also noted a ventral shift in nerve positioning in patients with elevated psoas muscles. Preoperative DTI effectively maps the relationship between the psoas major muscle and lumbar nerves. Tailoring surgical entry points based on DTI results significantly reduces the risk of nerve damage in XLIF surgeries. The study underscores the importance of recognizing variability in lumbar nerve pathways due to differing psoas muscle morphologies, highlighting a higher risk of nerve injury in patients with elevated psoas muscles during XLIF procedures.

Extreme Lateral Interbody Fusion (XLIF) Including the Segment L5/S1 for Multi-level Lumbar Spondylodesis

Study Design: This is a single centre retrospective study of 24 cases of multilevel degeneration of the lumbar spine treated with the XLIF procedure including the level L5/S1. Objective: The purpose of this study is to report the feasibility of including the L5/S1 segment in treating the degenerative lumbar spine using the XLIF procedure and demonstrating the preoperative conditions necessary to do so. Summary of background data: In the last decades, more and more elderly patients suffer from pain and disability due to degenerative instability of the lumbar spine. Spinal fusion procedures, including XLIF, have proven good results despite significant complication and revision rates. Methods: 24 patients (mean age 66 years, range 32 – 89 years) who would be candidates for XLIF surgery at L5/S1 were included. Preoperative anatomical assessment of the iliac crest in relation to the L5/S1 disc space was performed. All patients were operated with the aid of neuromonitoring using a mini-invasive XLIF approach with direct visualisation of the psoas muscle. Complication rates, surgery time, and blood loss were calculated as well as clinical results using the VAS score preoperative, and at 6 weeks, 3 months and 1 year postoperative. Results: The mean postoperative VAS score improved from 7.8 preoperative to 3.1 at one-year followup. There was one case of pseudoarthrosis at the L5/S1 level. There were no new neurological deficits postoperatively. We report a total complication rate of 29%. Conclusion: The XLIF procedure for multilevel lumbar spine fusion is feasible at the L5/S1 level in patients with certain anatomical prerequisites, predominantly in females. The procedure should be done under direct visualization. The clinical outcome and revision rate is comparable to other multilevel fusion techniques

Extreme Lateral Interbody Fusion: An Observational Study of Functional and Radiological Outcome

Introduction: Extreme lateral interbody fusion (XLIF) constitutes a minimally invasive procedure employed to address a spectrum of conditions including degenerative disc disorders, trauma, infections, and deformities. Despite its potential, there exists a scarcity of studies exploring perioperative functional and radiological outcomes. This prospective observational study seeks to address this gap by reporting these outcomes in patients treated at the King Faisal Specialist Hospital & Research Centre (KFSHRC) over a mean follow-up period of 5 years.
 Methods This case series amassed baseline patient data, encompassing gender, age, body mass index (BMI), American Society of Anesthesiology (ASA) classification, operated level, and posterior fixation type. Primary outcome measures encompassed the Oswestry Disability Index (ODI), Roland-Morris Disability Index (RMDI), Euro-Qol (EQ)-5D, visual analog scale (VAS), and EQ-5D index scores. Additionally, the study delved into secondary outcomes encompassing radiological parameters such as sagittal balance, lumbar lordosis, sacral slope, pelvic tilt, and pelvic incidence.
 Results: The study embraced 51 patients, comprising 9 females and 42 males, with a mean age of 58.6 years and a mean BMI of 29.3. The patients were followed for an average of 5.2 years. Stratification according to ASA classification revealed that 11.8% of patients were classified as ASA I, 52.9% as ASA II, and 35.3% as ASA III. The levels of operation included 60.8% at L4-L5, 33.3% at L3-L4, and 5.9% at L2-L3. The fixation techniques employed encompassed 58.8% bilateral and 41.2% unilateral approaches. The analysis of the primary clinical outcomes unveiled statistically significant enhancements in ODI, RMDI, EQ-5D VAS, and EQ-5D index scores. While lumbar lordosis registered a significant decrease, radiological parameters indicated non-significant shifts in pelvic incidence, pelvic tilt, and sacral slope.
 Conclusion The XLIF procedure emerges as an efficacious and minimally invasive avenue for managing degenerative disc disorders. The reported functional and radiological outcomes prove satisfactory. However, while demonstrably effective, the generation of clinical recommendations necessitates the compilation of results from randomized clinical trials.

Unique Characteristics of New Bone Formation Induced by Lateral Lumbar Interbody Fusion Procedure.

Despite the absence of bone grafting in the area outside the cage, lateral bridging callus outside cages (LBC) formation is often observed here following extreme lateral interbody fusion (XLIF) conversely to conventional methods of transforaminal lumbar interbody fusion and posterior lumbar interbody fusion. The LBC, which may increase stabilization and decrease nonunion rate in treated segments, has rarely been described. This study aimed to identify the incidence and associated factors of LBC following XLIF. We enrolled 136 consecutive patients [56 males, 80 females; mean age 69.6 (42-85) years] who underwent lumbar fusion surgery using XLIF, including L4/5 level with posterior fixation at a single institution between February 2013 and February 2018. One year postoperatively, the treated L4/5 segments were divided into the LBC formation and non-formation groups. Potential influential factors, such as age, sex, body mass index, bone density, height of cages, cage material (titanium or polyetheretherketone [PEEK]), presence or absence of diffuse idiopathic skeletal hyperostosis (DISH), and radiological parameters, were evaluated. Multivariate logistic regression analysis was performed for factors significantly different from the univariate analysis. The incidence of LBC formation was 58.8%. Multivariate logistic regression analysis showed that the length of osteophytes [+1 mm; odds ratio, 1.29; 95% confidence interval, 1.17-1.45; p<0.0001] was significant LBC formation predictive factors. Receiver operating characteristic curve analysis demonstrated that the cut-off value for osteophyte length was 14 mm, the sensitivity was 58.8%, the specificity was 84.4%, and the area under the ROC curve for this model was 0.79. The incidence of LBC formation was 58.8% in L4/5 levels one year after the XLIF procedure. We demonstrated that the length of the osteophyte was significantly associated with LBC formation.

Femoral Neuropathy Following Extreme Lateral Interbody Fusion (XLIF) Procedure: A Case Report

Background The extreme lateral interbody fusion approach (XLIF) is a surgical technique introduced two decades ago for spinal fusions. However, little has been published on the particular complications associated with this surgical technique and the rehabilitation. The purpose of this report is to describe a case of post-operative complication of retroperitoneal hematoma following XLIF with subsequent femoral neuropathy and the physical therapy intervention approach applying the repetitions in reserve (RIR) concept. Case Presentation A 60-year-old female presented with severe right hip flexor and quadriceps weakness from a retroperitoneal hematoma following a right-sided XLIF procedure for severe right L4-5 radiculopathy. Post-surgical physical therapy treatment and 6-month outcomes are described. Outcome and Follow Up By post-operative week 12, the patient obtained a knee brace that eliminated her falls due to quadriceps weakness. At 6 months post-operatively, she demonstrated significantly improved quadriceps and hip flexor strength (from 1/5 and 2+/5, respectively, to 3+/5), and improved lower extremity functional scale score, from 30 to 58. She was also able to complete a 6-minute walk test and ambulated 128 m. Discussion Significant improvement in motor function and functional outcomes was noted by post-operative month six. The role of physical therapy was to focus on the timing of muscle reactivation using electrical stimulation and progressive resistance exercises using the RIR concept as nerve function returned. JOSPT Cases 2022;2(3):162–165. Epub: 21 June 2022. doi:10.2519/josptcases.2022.10895

Ceramic bone graft substitute vs autograft in XLIF: a prospective randomized single-center evaluation of radiographic and clinical outcomes.

Purpose of the StudyThe objective of this prospective, parallel, randomized, single-center study is to evaluate the clinical success of a commercial ceramic bone graft substitute (CBGS) for autograft in eXtreme Lateral Interbody Fusion (XLIF) procedures. Please confirm if the author names are presented accurately and in the correct sequence (given name, middle name/initial, family name). Author 1 Given name: [Cristiano Magalhães], Last name [Menezes]. Author 2 Given name: [Gabriel Carvalho], Last name [Lacerda]. Author 5 Given name: [Erica Godinho], Last name [Menezes]. Also, kindly confirm the details in the metadata are correct.yesMethodsForty-five adult subjects were consecutively enrolled and randomized into a single-level XLIF procedure using either CBGS or iliac crest bone graft autograft (30 and 15 subjects, respectively). The primary outcome was fusion rate at 12, 18, and 24 months. Secondary outcomes were pain and disability measured by HRQOL questionnaires. Kindly check and confirm whether the corresponding author and his corresponding affiliations is correctly identified.yesResultsThe fusion rates for both CBGS and autograft groups at the 24-month follow-up were 96.4% and 100%, respectively. For the CBGS group, mean ODI, mean back pain, and mean worst leg pain significantly improved at the 24-month follow-up by 76.7% (39.9–9.3), 77.6% (7.3–1.6), and 81.3% (5.1–1.0), respectively. For the autograft group, mean ODI, mean back pain, and mean worst leg pain significantly improved during the same time period by 77.1% (35.9–8.2), 75.6% (6.1–1.5), and 86.0% (6.6–0.9), respectively (all time points between groups, p < 0.05).ConclusionThe results of this prospective, randomized study support the use of CBGS as a standalone bone graft substitute for autograft in single-level XLIF surgery. The clinical performance and safety outcomes reported here are consistent with published evidence on CBGS. Improvements in patient-reported back pain, leg pain, and disability outcomes were comparable between the CBGS and autograft groups.

Perspective on the true incidence of bowel perforations occurring with extreme lateral lumbar interbody fusions. How should they be treated?

Background: What is the risk of bowel perforation (BP) with open or minimally invasive (MI) extreme lateral lumbar interbody fusion (XLIF)? What is the truth? Further, if peritoneal symptoms/signs arise following XLIF/MI XLIF, it is critical to obtain an emergent consultation with general surgery who can diagnose and treat a potential BP.Literature Review: In multiple series, the frequency of BP ranged markedly from 0.03% (i.e. 1 of 2998 patients), to 0.08% (11/13,004), to 0.5%, to 8.3% (1 in 12 patients), up to 12.5% (1 in 8 patients). BPs attributed to different causes carry high mortality rates varying from 11.1% to 23%. For the 11 (0.08%) BP occurring out of 13,004 patients undergoing XLIF in one series, there was one (9.09%) death due to uncontrolled sepsis. In another series, where 31 BP were identified for multiple lumbar surgical procedures identified through PubMed (1960–2016), including 10 (32.2%) for lateral lumbar surgery including XLIF, the overall mortality rate was 12.9% (4/31).Conclusion: The incidence of BPs occurring following XLIF/MI XLIF procedures ranged from 0.03% to 12.5% in various reports. What is the true incidence of these errors? Certainly, it is more critical that when spine surgeons’ patients develop acute peritoneal symptoms/signs following these procedures, they immediately consult general surgery to both diagnose, and treat potential BP in a timely fashion to avoid the high morbidity (87.1%) and mortality rates (12.9%) attributed to these perforations.

Complications in Extreme Lateral Interbody Fusion (XLIF®): A Retrospective Study in Siriraj Hospital

Background: Extreme Lateral Interbody Fusion (XLIF®) is a well-known transpsoas approach technique that confers advantages including excellent visualization, easy access to the lumbar disc, accommodation for a large anterior graft, restoration of disk height and lumbar alignment, and indirect decompression. However, no study in Thailand has investigated early postoperative complications after spinal fusion with XLIF surgery. Objective: To determine the early postoperative complication rates among Thai patients that underwent spinal fusion with XLIF procedure. Materials and Methods: The present study was a retrospective chart review to evaluate perioperative and early postoperative complications in patients that underwent spinal interbody fusion with XLIF procedure and were followed-up for a minimum of three months at the Department of Orthopedic Surgery, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand between 2015 and 2019. Results: One hundred eighteen patients, including 82 females and 36 males, with a mean age of 64.2 years and 165 levels, that were operated upon, were included. Eighty patients (67.8%) underwent one-level fusion, 29 (24.6%) had two-level fusion, and 9 (7.6%) underwent three-level fusion. Immediate postoperative complications occurred in 66 patients (55.9%), consisting of eight (6.7%) with medical complications, 57 (48.3%) with surgical complications, and one (0.8%) with combined medical and surgical complications. Postoperative complications were resolved within three months after surgery in 48 patients. Forty-one patients (34.7%) had postoperative proximal lower limb neuropathy. Only 10 patients (24.4%) still had neuropathy at the 3-month follow-up, but it did not affect their function. Conclusion: Postoperative proximal limb neuropathy, including thigh numbness, pain, or hip flexor weakness, had a high prevalence in the present study despite intraoperative neurophysiologic monitoring; however, most cases resolved by the 3-month follow-up. Patient education about potential nerve irritation complication is recommended, and meticulous preoperative radiographic assessment and careful step-by-step intraoperative surgical approach may reduce the rates of these postoperative complications. Keywords: Extreme lateral interbody fusion; Complications; Neuropathy; Postoperative

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

ObjectiveTo compare clinical and imaging findings between extreme lateral lumbar interbody fusion (XLIF) and posterior fusion (PF) via meta-analysis for the treatment of lumbar degenerative diseases. MethodsEnglish papers reporting clinical and imaging findings for the treatment of lumbar degenerative diseases with XLIF and PF published electronically in the PubMed, Embase, Cochrane Library, and Web of Science databases from January 2006 to August 2019 were retrieved. Two authors independently extracted data and evaluated the quality of the included literature. Meta-analysis of outcome measures was performed using Stata 14 and RevMan 5.3 software. ResultsThis meta-analysis included 744 patients from nine studies, two of which were prospective studies, while the others were retrospective studies. The quality of each study was determined to be high. The meta-analysis showed no significant differences in the operative time, length of hospital stay, clinical effectiveness, and improvement in postoperative global sagittal alignment between two approaches (P > 0.05). However, XLIF was significantly better than PF in reducing intraoperative blood loss and recovery of local sagittal alignment (P < 0.05). Moreover, the high incidence of postoperative complications were detected in XLIF group (P < 0.05). ConclusionsBoth surgical approaches have equally promising clinical effectiveness for the treatment of lumbar degenerative diseases. Although XLIF can reduce intraoperative blood loss and obtain better postoperative local sagittal alignment than PF, the high incidence of postoperative complications should prompt us to consider why XLIF procedure is still being offered to our patients and how we can reduce these complications. In addition, any conclusions should be taken with caution because of the mix of prospective and retrospective studies, and the high heterogeneity and bias.

Major complications in extreme lateral interbody fusion access: multicentric study by Italian S.O.L.A.S. group

The eXtreme Lateral Interbody Fusion (XLIF) approach has gained increasing importance in the last decade. This multicentric retrospective cohort study aims to assess the incidence of major complications in XLIF procedures performed by experienced surgeons and any relationship between the years of experience in XLIF procedures and the surgeon's rate of severe complications. Nine Italian members of the Society of Lateral Access Surgery (SOLAS) have taken part in this study. Each surgeon has declared how many major complications have been observed during his surgical experience and how they were managed. A major complication was defined as an injury that required reoperation, or as a complication, whose sequelae caused functional limitations to the patient after one year postoperatively. Each surgeon was finally asked about his years of experience in spine surgery and XLIF approach. Pearson correlation test was used to evaluate the association between the surgeon's years of experience in XLIF and the rate of major complications; a p-value of last than 0.05 was considered significant. We observed 14 major complications in 1813 XLIF procedures, performed in 1526 patients. The major complications rate was 0.7722%. Ten complications out of fourteen needed a second surgery. Neither cardiac nor respiratory nor renal complications were observed. No significant correlation was found between the surgeon's years of experience in the XLIF procedure and the number of major complications observed. XLIF revealed a safe and reliable surgical procedure, with a very low rate of major complications, when performed by an expert spine surgeon.

Custom-made trabecular titanium implants for the treatment of lumbar degenerative discopathy via ALIF/XLIF techniques: rationale for use and preliminary results.

Related to the development and diffusion of ALIF and XLIF, it is possible to correct sagittal malalignment in selected cases of lumbar degenerative discopathy with a relatively low invasiveness. Still, the malposition or the inappropriate size of the implanted cages may lead to the subsidence of the vertebral endplates with loss of correction as well as a decrease in the potential to restore spinal biomechanics in the long run. The aim of this study is to evaluate safety, feasibility, and preliminary clinical and radiological results when using custom-made, trabecular titanium cages in ALIF and XLIF procedures. We prospectively evaluated 18 consecutive patients who underwent either an ALIF or an XLIF procedure with the implant of a custom-made, trabecular titanium cage for lumbar degenerative disease with sagittal imbalance, with a minimum of 1-year clinical and radiological follow-up. After a mean follow-up of 14months, the Oswestry score dropped to a mean of 13 from a preoperative value of 48 (p < 0.0001). Lumbar lordosis was significantly improved, especially in the lower lumbar segment L4-S1 (+ 11 ± 7°; p < 0.0001). No cases of subsidence were noted. Custom-made, trabecular titanium cages allowed a segmental, steady, durable sagittal correction via ALIF and XLIF approaches. The absence of cage subsidence at 1 year encourages further studies on a larger cohort with longer follow-up. These slides can be retrieved under Electronic Supplementary Material.

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)

Comparison of Biomechanical Performance Among Posterolateral Fusion and Transforaminal, Extreme, and Oblique Lumbar Interbody Fusion: A Finite Element Analysis

We compared the biomechanical differences among posterolateral fusion (PLF) and transforaminal, extreme, and oblique lumbar interbody fusion (TLIF, XLIF, and OLIF, respectively) procedures. An intact finite element (FE) model of the L3-L5 lumbar spine was constructed. The PLF, TLIF with a banana-shaped cage, TLIF with a straight cage, XLIF, and OLIF procedures were simulated at the L4-L5 level. The range of motion (ROM) and stress peaks in the cortical endplate, cancellous bone, and posterior instrument were compared among the 5 constructs. The PLF construct had much greater ROM than did the other constructs (0.44°-1.05° vs. 0.28°-0.72°). The TLIFwith a straight cage induced the greatest stress peaks in the endplate and cancellous bone (24.94-60.03 MPa and 0.72-1.96 MPa, respectively), followed by the TLIF with a banana-shaped cage (23.73-44.8 MPa and 0.6-1.36 MPa, respectively). The OLIF construct (16.76-32.41 MPa and 0.54-1.07 MPa, respectively) and XLIF construct (17.01-35.34 MPa and 0.56-1.12 MPa, respectively) induced much lower stress peaks in the endplate and cancellous bone. In the PLF construct, the stress peaks in the posterior instrument ranged from 244.6 to 377.4 MPa, significantly greater than those in the other constructs (123.9-237.4 MPa). The PLF had less stability than the other 3 fusion procedures owing to the greater ROM and stress peaks in the posterior instrument. The OLIF and XLIF induced fewer stress peaks in the cortical endplate and cancellous bone than did the TLIF procedure, which was beneficial for subsidence resistance and disc height and segmental angle maintenance.

PMD36 REDUCTION IN PEDICLE SCREW PLACEMENT TIME WITH A NOVEL GUIDEWIRELESS PEDICLE SCREW SYSTEM FOR MINIMALLY INVASIVE SPINE SURGERY: INITIAL FINDINGS

Current minimally invasive spine procedures are technically challenging and may result in protracted operative time compared to open approach procedures. The guide wireless pedicle screw system (GPSS), was developed to eliminate lengthy steps and potential risks associated with Jamshidi needles and K-wire insertion. The primary objective of this study was to compare screw insertion time in the GPSS with the current standard of care. This case study was conducted between July 2016 through May 2017. 29 patients with degenerative spinal pathologies underwent MIS TLIF or XLIF procedures with GPSS(n=15) vs. a standard MIS system (n=14). The primary outcome measure was the time taken for the screw to be inserted into the pedicle (preparation/tap/screw; PTS). Student’s t-tests were used to compare mean outcome measures between control and GPSS cases. Patient age ranged from 30-70+ years old. Overall, results demonstrated a 47% decrease (p<0.001) in mean time for PTS in the GPSS arm when compared to the control. No significant differences were seen between the two arms when analyzing mean total fluoroscopy time and total procedural time (p>0.05). In the TLIF subgroup analysis, mean total procedure time, PTS and fluoroscopy time decreased for the GPSS arm compared to control (1%, 46% and 10% respectively), however none were statistically significant. In the XLIF subgroup analysis, total mean procedure and PTS time decreased for the GPSS arm compared to control by 14% (p=0.34) and 48% (p=0.006) respectively. A 33% (p=0.46) increase in total fluoroscopy time was also noted in this subgroup. These initial findings demonstrate that GPSS has the potential to significantly decrease time for PTS when compared to compared to a standard MIS system. Additionally, while not statistically significant, GPSS demonstrated the potential to reduce total fluoroscopy time using a TLIF approach.

Fusion of the L5-S1 Segment in Degenerative Lumbar Spine Disease Using the Extreme Lateral Interbody Fusion Technique: A Case Report Study

Study design: This study is a single center case report study with 3 cases of degenerative lumbar spine disease treated with the XLIF procedure at the level L5-S1. Objective: The purpose of this case report study is to demonstrate the possibility of treating degenerative lumbar spine disease at the level L5-S1 using the XLIF procedure. Summary and Background of Data: There are several standard surgical techniques for the treatment of degenerative lumbar spine diseases that have failed conservative treatment. Interbody fusion can restore the proper alignment of the spine hereby leading to indirect decompression of the nerve roots. The XLIF procedure is a relatively recent retroperitoneal and transpsoas major muscle approach allowing the insertion of interbody implants. This approach has shown good results but for anatomical reasons it is limited at the lumbar spine to the segments L1-L5. Methods: A single center case report study with 3 cases of degenerative lumbar spine disease treated with the XLIF procedure at the level L5-S1. Results: All 3 patient were successfully operated at the level L5-S1 with an XLIF procedure. Conclusion: This case series suggests that the XLIF procedure is a safe, feasible and timesaving procedure to treat the segment L5-S1 in selected patients with severe degenerative lumbar spine disease and failed conservative treatment. Preoperative anatomical evaluation of the correlation of the iliac crest to L5 is necessary. The procedure should be performed with the aid of neuromonitoring and direct visualization during dissection of the psoas muscle should be achieved.

Clinical evaluation of microendoscopy-assisted extreme lateral interbody fusion

Extreme lateral interbody fusion (XLIF) has rapidly become a popular operative procedure for lumbar canal stenosis and scoliosis. This approach provides direct access to the lateral aspect of the disc with minimal disruption of spinal structures, including ligaments and muscles. However, it involves risk of injuries to the lumbar nerve plexus, segmental artery and intestinal tract because of the limited surgical field. This study aimed to clarify the benefit of using a microendoscope to prevent these injuries. A total of 96 consecutive patients treated by a single surgeon were retrospectively analyzed. The basic approach via the psoas muscle was performed in accordance with the conventional XLIF procedure. Operative manipulations, such as insertion of the shim, discectomy, endplate preparation and intervertebral spacer placement, were performed with the assistance of a microendoscope. Preoperative and postoperative neurological status were evaluated using the Japanese Orthopedic Association (JOA) scores and the Oswestry Disability Index (ODI). Eighty-four patients underwent surgery for a single vertebral level, nine patients underwent surgery for 2 levels and three patients underwent surgery for 3 levels (average, 1.2 levels). The average age of patients was 61 years (range, 22-83 years); the mean follow-up period was 18 months (range, 3-36 months). Average preoperative and postoperative JOA scores were 11.9 and 15.6, with a mean recovery rate of 33%. Average preoperative and postoperative ODI scores were 38.6 and 19.1. There were 3 (3.1%) complications: 2 end-plate fractures and 1 deep surgical site infection. There were no bowel perforations or vascular injuries. Microendoscopy assistance is one solution for severe visceral and vascular injuries related to XLIF.

Endoscope-Assisted Extreme-Lateral Interbody Fusion: Preliminary Experience and Technical Note.

The extreme lateral lumbar interbody fusion (XLIF) technique is safe and effective; however, the deep and tight surgical corridor makes visual identification of important landmark structures, as well as sufficient endplate and contralateral preparation, challenging. In the present study, we analyzed the safety and feasibility of endoscope-assisted (EA) XLIF procedures. This was a retrospective single-center study on consecutive patients undergoing XLIF procedures between February 2014 and July 2016. EA-XLIF and conventional XLIF (c-XLIF) procedures were compared in terms of the duration of surgery, estimated blood loss (EBL), perioperative and postoperative complications, and postoperative outcomes. A total of 41 patients (mean age, 66.7 years ± 10.0 years; 22 males [53.7%]) underwent a XLIF procedure, including 6 (14.6%) who underwent EA-XLIF. EA-XLIF did not increase the duration of surgery or EBL. No perioperative or postoperative complications were observed in any of the EA-XLIF procedures. Clinical and radiologic outcomes at 6 weeks postsurgery and at the last follow-up (mean, 8.0 ± 5.8 months postsurgery) were similar for patients in the EA-XLIF and c-XLIF groups. The EA-XLIF technique was considered particularly helpful for checking the lumbar plexus anatomy on the psoas surface, identifying the relationship between the peritoneum andthe psoas muscle, positioning the shim into the disc space, removing the disk, and checking the quality of contralateral release and endplate preparation. The EA-XLIF technique is safe and may be considered as an adjunct procedure, offering improved visualization to guide the surgeon in key steps of the XLIFprocedure.

Preoperative assessment of the ureter with dual-phase contrast-enhanced computed tomography for lateral lumbar interbody fusion procedures.

Performing the minimally invasive lateral lumbar interbody fusion (LIF), such as the extreme lateral interbody fusion (XLIF) and oblique lateral interbody fusion (OLIF), through a retroperitoneal approach has become increasingly popular. Although urological injury is a major complication of LIF, the anatomical location of the ureter and its risk of injury have not been assessed. The purpose of this study was to evaluate the efficacy of dual-phase contrast-enhanced computed tomography for assessing the location of the ureter and risk of its injury in consecutive LIF cases. 27 cases (12 men and 15 women) were enrolled in the study. Dual-phase contrast-enhanced CT was performed preoperatively, and the risk of ureteral injury was assessed. The location of the ureter was classified using the psoas muscle and vertebral body as reference structures for OLIF and XLIF procedures, respectively. During the OLIF procedures, the location of the ureter was additionally assessed with direct vision and manual palpation in all cases. Simultaneously, potential vascular anomalies were assessed with both 3D and axial images of CT. A total of 125 among 162 ureters, excluding 13 with insufficient enhancement and 24 (44.4%) within the kidney at the L2-L3 level, were assessed preoperatively; 113 ureters (90.4%) were classified as anatomically close to the surgical corridor for OLIF, and 20 ureters (16.0%) as having a potential risk of injury during XLIF. In one case, OLIF was converted to a conventional posterior procedure because of a vascular anomaly. Intraoperative findings showed that ureters moved anteriorly with the peritoneum in all cases, as assessed by manual palpation under direct vision. Dual-phase contrast-enhanced CT is useful in assessing the location of the ureter, kidney, and vascular structures simultaneously. Both OLIF and XLIF have a potential risk of urological injury.

Effect of mono- or bisegmental lordosizing fusion on short-term global and index sagittal balance: a radiographic study.

Sagittal balance is widely recognized as an important outcome factor in reconstructive spinal surgery for lumbar degenerative conditions. However, its role in short segmental fixation is unknown. The aim of this study was to evaluate the preoperative and short-term postoperative spino-pelvic balance after short (1 or 2 levels) lordosizing lumbar fusion for degenerative disc disease (DDD). Twenty-six consecutive patients (13 males and 13 females) undergoing mono- or bisegmental lordosizing lumbar fusion (XLIF/TLIF) for lumbar DDD were included in the study. Clinical parameters were retrospectively collected from charts. Preoperative and early postoperative (6 weeks and 3 months) full-spine EOS X-rays were evaluated. Spinal parameters evaluating sagittal curvatures, pelvic orientation, global sagittal and coronal alignment, spino-pelvic balance, index level segmental lordosis and disc height were measured and statistically analyzed. A total of 16 TLIF and 10 XLIF procedures were performed. Eighteen were mono- and 8 were bisegmental fixations for a total of 34 fused segments. Seven patients (26.9%) showed a preoperative sagittal imbalance (defined as SVA>50 mm); 7 patients presented preoperative severe pelvic retroversion (defined as PT>20°) and 1 patient presented both. Disc height, intervertebral angle and segmental lordosis at the operated level significantly increased after surgery (P<0.01). No postoperative significant change in global sagittal alignment (SVA, TPA, T1SPi, T9SPi), pelvic orientation (SS, PT), coronal alignment, lumbar and L4-S1 lordosis and thoracic kyphosis have been observed. Mono- and bisegmental lordosizing fusion techniques, as XLIF and TLIF, are able to restore disc height and improve segmental lordosis. However they do not allow restoration of sagittal balance or improvement of compensatory mechanisms. A limited spinal reconstructive surgery on symptomatic levels can be reasonably proposed to patients with hidden or evident sagittal imbalance with any short-term radiographic impact.

Extreme lateral interbody fusion (XLIF): A single-center clinical and radiological follow-up study of 20 patients

Extreme lateral interbody fusion (XLIF) is an alternative to standard posterior approaches for achieving fusion in the lumbar spine. It allows exposure of the lateral aspect of the lumbar disc through a lateral approach with the possibility to insert a wide footprint interbody cage as a stand-alone procedure or associated with a uni- or bilateral percutaneous fixation.This is a retrospective series of 20 consecutive patients operated with a XLIF procedure from 2014 to 2015. N=10 women and N=10 men with a mean age of 67.5years (range 37.9–81.2) were included in the study. N=18 patients have been operated at one level, while N=2 patients underwent a double-level XLIF. The index levels were: L2-L3 in 2, L3-L4 in 7, L4-L5 in 9 and L3-L5 in 2 patients, respectively. The mean clinico-radiological follow-up was 9.8months (range 2.5–16.6). The clinical outcome was assessed with the Oswestry Disability Index (ODI), Euro-Qol (EQ)-5D, visual analogue scale (VAS) and EQ-5D index scores. Preoperative, postoperative and follow-up sagittal balance was assessed by EOS full spine X-ray. Furthermore, presence or absence of fusion was assessed by thin cuts CT scan at the end of the follow-up.The analysis highlighted a clear clinical improvement for the study collective. The mean ODI improved from 41.6 preoperatively to 23.5 at the last follow-up (p<0.0036). EQ-5D VAS and EQ-5D index improved from 45.5 to 71.8 (p<0.0001) and from 0.454 to 0.693 (p<0.0002), respectively. Analysis of the sagittal balance revealed an increase of the total lumbar lordosis, however not in a statistically significant manner (p=0.164). Furthermore, an increase of 55.7% in mean disc height (from 7.0mm to 10.9mm) has been observed (p<0.0001). Surprisingly, the right foramen height was increased in a statistically significant manner compared to the left one, but both of them increased in absolute values. However, foraminal area on both sides did not significantly increase. The mean canal area was 115.7mm2 preoperatively and 136.5mm2 at follow-up (p=0.1325). Radiological fusion was observed in every case at the end of the follow-up period.The XLIF procedure accomplishes a secure and effective interbody fusion. This approach allows for an indirect decompression of neural structures by restoring foramen dimensions and disc space height, leading to an improvement of symptoms. Furthermore, XLIF seems to improve segmental sagittal balance.