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

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

BACKGROUND CONTEXT

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.

PURPOSE

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.

STUDY DESIGN

Retrospective case-control study.

PATIENT SAMPLE

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.

OUTCOME MEASURES

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Evaluation and Rehabilitation after Adult Lumbar Spine Surgery

Purpose: With an increase in the proportion of elderly patients, the global burden of spinal disease is on the rise. This is gradually expected to increase the number of surgical procedures all over the world in the near future. As we know, rehabilitation following spine surgery is critical for optimal recovery. However, the current literature lacks consensus regarding the appropriate post-operative rehabilitation protocol. The purpose of this review is to evaluate the optimal protocol for rehabilitation after lumbar spine surgery in adults. Materials and Methods: The goals of rehabilitation after lumbar spine surgery are to improve physical and psychosocial function and may include multiple modalities such as physical therapy, cognitive behavioral therapy, specialized instruments, and instructions to be followed during activities of daily living. In recent years, not only are a greater number of spine surgeries being performed, but various different techniques of lumbar spine surgery and spinal fusion have also emerged. (1) Our review summarizes post-operative rehabilitation under the following headings-1. Historical aspects, 2. Subjective functional outcomes, and (3) Actual rehabilitation measures, including balance. Results: Physical therapy programs need to be patient-specific and surgery-specific, such that they consider patient-reported outcome measures and take into consideration the technique of spinal fusion used and the muscle groups involved in these surgeries. By doing so, it is possible to assess the level of functional impairment and then specifically target the strengthening of those muscle groups affected by surgery whilst also improving impaired balance and allowing a return to daily activities. Conclusions: Rehabilitation is a multi-faceted journey to restore mobility, function, and quality of life. The current rehabilitation practice focuses on muscle strengthening, but the importance of spinal balance is less elaborated. We thus equally emphasize muscle strengthening and balance improvement post-lumbar spine surgery.

Towards a More Realistic Appraisal of Complications Following Staged Lateral Lumbar Interbody Fusion: A Single Institution Series

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

With steadily increasing implementation of far lateral approaches in spine surgery, surgeons can utilize the advantages of different approaches synergistically to ensure an optimal patient outcome. Our single institution study aimed to assess the complication rates of patients who underwent a lateral interbody fusion as the index procedure and additional anterior or posterior instrumentation as part of a planned staged surgical reconstruction effort.

METHODS

This study was approved by our institutional review board (STUDY2021000113). We included 576 patients who received a lateral lumbar interbody fusion (LLIF) as the index procedure followed by transforaminal lumbar interbody fusion (TLIF), posterior lumbar interbody fusion (PLIF) or anterior lumbar interbody fusion (ALIF) between 2016 and 2020. Primary outcomes were complications identified during the initial inpatient stay, which were categorized into approach-related and secondary complications. Secondary outcomes tracked up to 6 years post-surgery.

RESULTS

The overall complication rate was 19.2% (10.5% approach related, 8.7% secondary complications). Significant intraoperative hemorrhage (mean 659.3 mL vs 131.4 mL, P < .01) was the most common approach related complication with an incidence of 4%, followed by temporary hip flexor weakness in 2.6%. A permanent (femoral) nerve damage was verified in 1 patient. The most common secondary complication was impaired wound healing in 12 patients (2.1%). We identified a 7.1% (41 of 576 patients) rate of revision surgery, on average after 372 days (±34 days).

CONCLUSIONS

We recorded an overall complication rate of 19.2% for staged adult deformity corrective surgeries utilizing far lateral interbody fusions at several lumbar levels followed by a more comprehensive posterior surgical reconstruction.

Cortical Endplate Bone Density Measured by Novel Phantomless Quantitative Computed Tomography May Predict Cage Subsidence more Conveniently and Accurately

OBJECTIVE

Previous studies have shown that bone mineral density (BMD) is a predictor of cage subsidence. Phantom-less quantitative computed tomography (PL-QCT) can measure volumetric bone mineral density (vBMD) of lumbar trabecular and cortical bone. The study of endplate vBMD (EP-vBMD) is important in predicting cage settlement after extreme lateral interbody fusion (XLIF). This study aimed to determine the risk factors for postoperative cage subsidence after XLIF, particularly focusing on the relationship between vBMD measured by automatic PL-QCT and cage subsidence.

METHODS

Patients who underwent XLIF surgery from January 2018 to October 2020 with a minimum of 6 months of follow-up were retrospectively included. Cage subsidence was defined as >2 mm cage sinking on the adjacent endplate in follow-up imaging evaluation. Outcome measures were localized vBMDs included EP-vBMDs with different region of interest (ROI) heights measured by PL-QCT based on a customized muscle-fat algorithm. Shapiro-Wilk test, one-way ANOVA, Mann-Whitney test, Fisher exact test, univariable and multivariable logistic regression and receiver operating characteristic (ROC) curve analysis were executed in this study.

RESULTS

One hundred and thirteen levels of 78 patients were included in the analysis. The mean age was 65 ± 7.9 years for 11 males and 67 females. Cage subsidence occurred on 45 (39.8%) surgical levels. There was no significant difference in demographics, fused levels, or preoperative radiographic parameters. 1.25-mm EP-vBMD (0.991 [0.985,0.997], p = 0.004) and P-TB-vBMD (cage-positioned trabecular volumetric bone mineral density) (0.988 [0.977-0.999], p = 0.026) were cage-subsidence relevant according to univariate analysis. Low 1.25-mm EP-vBMD (0.992 [0.985, 0.999], p = 0.029) was an independent risk factor according to multifactorial analysis.

CONCLUSION

Preoperative low EP-vBMD was an independent risk factor for postoperative cage subsidence after XLIF. EP-vBMD measured by most cortex-occupied ROI may be the optimal vBMD parameter for cage subsidence prediction.

Position of lumbar plexus nerves in the psoas major: Application to transpsoas approaches to the lumbar spine

Far lateral interbody fusion is a minimally invasive operating technique. However, the incidence of postoperative neurological complications is high, and some scholars question its safety. This study describes the neuroanatomical features and spatial orientation within the psoas major. Ten embalmed male cadavers were selected and the left psoas major was dissected. Subsequently, the area between the anterior and the posterior edges of the vertebral body was divided into three equal zones. The nerves' distribution, number, and spatial orientation of the L1/2 to L4/5 intervertebral discs were examined. A caliper was used to measure the diameter of the nerve. The safety zone of the L1/2 intervertebral disc level is located in zone I and II, the relative safe zones of the L2/3 and L4/5 intervertebral discs are located in zone II, and the safety zone of the L3/4 intervertebral disc level is located in the caudal side of zone II. The genitofemoral nerve exits the psoas major in a co-trunk or two-branch pattern, and its exit point was distributed between the L3 and L4 vertebral bodies, mainly at the L3/4 intervertebral disc level. The sympathetic ganglia in the psoas major appeared only in zone I at the L2/3 intervertebral disc level. This is a systematic anatomical study that describes the nerves of the psoas major. Spine surgeons can use this study-which consists of important clinical implications-for preoperative planning, and thus, reduce the risk of nerve injury during surgery.

Lumbar lateral interbody fusion: step-by-step surgical technique and clinical experience

Lateral lumbar interbody fusion (LLIF) is a minimally invasive surgical approach used to treat a variety of degenerative and deformity conditions of the lumbar spine such as advanced degenerative disease, degenerative scoliosis, foraminal and central stenosis. It has emerged as an alternative to the traditional posterior and anterior lumbar approaches with some potential benefits such as lower blood loss and shorter hospital stay. In this article, we provide our single institutional surgical experience including main indications and contraindications, a step-by-step surgical technique description, a detailed preoperative imaging assessment with a focus on magnetic resonance imaging (MRI) psoas anatomy, operative room (OR) setup and patient positioning. A descriptive surgical technical note of the following steps is provided: positioning and fluoroscopic confirmation, incision and intraoperative level confirmation, discectomy and endplate preparation, implant size selection and insertion and final fluoroscopic control, hemostasis check and wound closure along with an instructional surgical video with tips and pearls, postoperative patient care recommendations, common approach-related complications, along with our historical clinical institutional group experience. Finally, we summarize our research experience in this surgical approach with a focus on LLIF as a standalone procedure. Based on our experience, LLIF can be considered an effective surgical technique to treat degenerative lumbar spine conditions. Proper patient selection is mandatory to achieve good outcomes. Our institutional experience shows higher fusion rates with good clinical outcomes and a relatively low rate of complications.

Perspective; high frequency of intraoperative errors due to extreme, oblique, and lateral lumbar interbody fusions (XLIF, OLIF, LLIF): Are they "safe"?

Background

Extreme Lateral Lumbar Interbody Fusions (XLIF), Oblique Lateral Interbody Fusion (OLIF,) and Lateral Lumbar Interbody Fusion (LLIF) were largely developed to provide indirect lumbar decompressions for spinal stenosis, deformity, and/or instability.

Methods

Here, we have reviewed and updated the incidence of intraoperative errors attributed to XLIF, OLIF, and LLIF. Specifically, we focused on how often these procedures caused new neurological deficits, major vessel, visceral, and other injuries, including those warranting secondary surgery.

Results

Performing XLIF, OLIF, and LLIF can lead to significant intraoperative surgical errors that include varying rates of; new neurological injuries (i.e. iliopsoas motor deficits (4.3-19.7-33.6-40%), proximal hip/upper thigh sensory loss/dysesthesias (5.1% to 21.7% to 40%)), life-threatneing vascular injuries (i.e., XLIF (0% - 0.4%-1.8%), OLIF (3.2%), and LLIF (2%) involving the aorta, iliac artery, inferior vena cava, iliac vein, and segmental arteries), and bowel/viscarl injuries (0.03%-0.4%) leading to reoperations (i.e., XLIF (1.8%) vs. LLIF (3.8%) vs. XLIF/LLIF/OLIF 2.2%)).

Conclusion

Varying reports documented that XLIF, OLIF and LLIF caused up to a 40% incidence of new sensory/motor deficits, up to a 3.2% incidence of major vascular insults, a 0.4% frequency of visceral/bowel perforations, and a 3.8% need for reoperations. These high frequencies of intraoperative surgical errors attributed to XLIF, OLIF, and LLIF should prompt reconsideration of whether these procedures are "safe."

Percutaneous Endoscopic Transforaminal Lumbar Interbody Fusion (PETLIF): Current Techniques, Clinical Outcomes, and Narrative Review

Full endoscopic techniques are becoming more popular for degenerative lumbar pathologies. Percutaneous endoscopic lumbar interbody fusion (PETLIF) is a minimally invasive surgical technique for spondylolisthesis and lumbar spinal canal stenosis with instability. Nagahama first introduced PETLIF in 2019. This study investigated the clinical outcomes and complications of 24 patients who underwent PETLIF in our facility and compared them with previous studies. Literature searches were conducted on PubMed and Web of Science. The PETLIF surgical technique involves three steps to acquire disc height under general anesthesia. The procedure includes bone harvesting, spondylolisthesis reduction, endoscopic foraminoplasty, disc height expansion using an oval dilator, and intervertebral disc curettage. A cage filled with autologous bone is inserted into the disc space and secured with posterior fixation. Patients underwent PETLIF with an average operation time of 130.8 min and a blood loss of 24.0 mL. Postoperative hospital stays were 9.5 days. Improvement in VAS, disc height, spinal canal area, and % slip was observed, while lumbar lordosis remained unchanged. Complications included end plate injury, subsidence, and exiting nerve root injury. The differences between PETLIF and the extracted literature were found in patients' age, direct decompression, epidural or local anesthesia, approach, order of PPS, and cage insertion. In conclusion, PETLIF surgery is a practical, minimally invasive surgical technique for patients with lumbar degenerative diseases suffering from back and leg pain, demonstrating significant improvements in pain scores. However, it is essential to carefully consider the potential complications and continue to refine the surgical technique further to enhance the safety and efficacy of this procedure.

Risk factors for postoperative sympathetic chain dysfunction following oblique lateral lumbar interbody fusion: a multivariate analysis

PURPOSE

Postoperative sympathetic chain dysfunction (PSCD) was a relatively common complication after anterior lumbar interbody fusion due to the manipulation adjacent to the lumbar sympathetic chain (LSC). This study aimed to investigate the incidence of PSCD and identify its related independent risk factors after oblique lateral lumbar interbody fusion (OLIF) surgery.

METHODS

PSCD was defined as either of the following in the affected lower limb compared to the contralateral: (1) increase in skin temperature by 1 ºC or more, (2) reduced skin perspiration, (3) limb swelling or skin discoloration. Consecutive patients who underwent OLIF at L4/5 level from February 2018 and May 2022 at a single institution were retrospectively reviewed and divided into two groups: patients with PSCD and patients without PSCD. Binary logistic regression analyses were performed on patients' demographic, comorbidities, radiological datum and perioperative factors to identify independent risk factors for PSCD.

RESULTS

Twelve (5.7%) of 210 patients experienced PSCD following OLIF surgery. Multivariate logistic regression analysis identified the identification of lumbar dextroscoliosis (OR = 7.907, P = 0.012) and the presence of "tear-drop" psoas (OR = 7.216, P = 0.011) as independent risk factors for the PSCD following OLIF.

CONCLUSION

This study identified the lumbar dextroscoliosis and the "tear-drop" psoas as independent risk factors for the development of PSCD after OLIF. Spine alignment examination and the morphological identification of psoas major muscle should be highly noticed for the PSCD prevention following OLIF.

Extreme Lateral Interbody Fusion as a Feasible Treatment for Thoracolumbar Spondylodiscitis: A Multicenter Belgian Case-Series

BACKGROUND

Spondylodiscitis is, after tissue sampling, initially managed with intravenous antibiotics. In patients with treatment failure, surgical debridement and stabilization is considered. An anterior or posterior approach has already been reported as a successful surgical access, but is associated with a large exposure and a significant morbidity.

METHODS

We present a multicenter Belgian case-series on the use of a minimally invasive extreme lateral interbody fusion procedure with add-on percutaneous pedicle screw fixation for patients with a need for surgical debridement and tissue samples or intractable back pain due to spondylodiscitis. Patient characteristics, microbiology results, antibiotic treatment, pre- and postoperative Visual Analogue Pain Score (VAS) scores, time to bony consolidation, complications and duration of the hospital stay were collected.

RESULTS

Seven patients with one level spondylodiscitis were included. The mean age 64 years with a mean preoperative VAS score of 8.86 ( ± 0.90). Postoperative VAS score significantly decreased to 2.57 (-70.3%, P < 0.001). Mean antibiotic treatment duration was 8 weeks. Median duration of the hospital stay was 14 days. Patients were followed for 1 year. Complete bony consolidation was observed in 6 out of 7 patients after 1 year. One patient had a stable pseudarthrosis.

CONCLUSIONS

These results indicate that extreme lateral interbody fusion topped off with a percutaneous pedicle screw fixation might be a feasible, safe and valuable choice to surgically treat patients with spondylodiscitis with fast and important improvement in VAS. Further prospective research might strengthen the sparsely existing literature of minimally invasive surgery for spondylodiscitis to provide the best possible care.

Lateral Lumbar Interbody Fusion (Direct Lateral Interbody Fusion/Extreme Lateral Interbody Fusion) versus Posterior Lumbar Interbody Fusion Surgery in Spinal Degenerative Disease: A Systematic Review

BACKGROUND

Degenerative diseases of the lumbar spine are often treated with posterior interbody fusion surgery (posterior lumbar interbody fusion [PLIF]) for spinal instability or intractable back pain with neurologic impairment. Several lateral, less invasive procedures have recently been described (lateral lumbar interbody fusion [LLIF]/direct lateral interbody fusion/extreme lateral interbody fusion [XLIF]). The aim of this systematic review is to compare structural and functional outcomes of lateral surgical approaches to PLIF.

METHODS

We conducted a MEDLINE (PubMed), Web of Science, ScienceDirect, and Cochrane Library search for studies focusing on outcomes and complications comparing LLIF (direct lateral interbody fusion/XLIF) and PLIF. The systematic review was reported using the PRISMA criteria.

RESULTS

In total, 1000 research articles were identified, of which 5 studies were included comparing the outcomes and complications between the lateral and posterior approach. Three studies found significantly less perioperative blood loss with a lateral approach. Average hospital stay was shorter in populations who underwent the lateral approach compared with PLIF. Functional outcomes (visual analog scale score/Oswestry Disability Index) were similar or better with LLIF. In most of the included studies, complication rates did not differ between the posterior and lateral approach. Most of the neurologic deficits with XLIF/LLIF were temporary and healed completely within 1 year follow-up.

CONCLUSIONS

A lateral approach (XLIF/LLIF) is a good and safe alternative for PLIF in single-level degenerative lumbar diseases, with comparable functional outcomes, shorter hospital stays, and less blood loss. Future prospective studies are needed to establish the role of lateral minimally invasive approaches in spinal degenerative surgery.

Outcomes With a Mobile Digital Health Platform for Patients Undergoing Spine Surgery: Retrospective Analysis

BACKGROUND

Digital health solutions have been shown to enhance outcomes for individuals with chronic medical illnesses, but few have been validated for surgical patients. The digital health platform ManageMySurgery (MMS) has been validated for spine surgery as a feasible method for patients along their surgical journey through in-app education and completion of patient-reported outcomes surveys.

OBJECTIVE

The aim of this study is to determine the rates of 90-day emergency room (ER) visits, readmissions, and complications in patients undergoing spine surgery using MMS compared to patients using traditional perioperative care alone.

METHODS

Patients undergoing spine surgery at a US-based academic hospital were invited to use MMS perioperatively between December 2017 and September 2021. All patients received standard perioperative care and were classified as MMS users if they logged into the app. Demographic information and 90-day outcomes were acquired via electronic health record review. The odds ratios of having 90-day ER visits, readmissions, mild complications, and severe complications between the MMS and non-MMS groups were estimated using logistic regression models.

RESULTS

A total of 1015 patients were invited, with 679 using MMS. MMS users and nonusers had similar demographics: the average ages were 57.9 (SD 12.5) years and 61.5 (SD 12.7) years, 54.1% (367/679) and 47.3% (159/336) were male, and 90.1% (612/679) and 88.7% (298/336) had commercial or Medicare insurance, respectively. Cervical fusions (559/1015, 55.07%) and single-approach lumbar fusions (231/1015, 22.76%) were the most common procedures for all patients. MMS users had a lower 90-day readmission rate (55/679, 8.1%) than did nonusers (30/336, 8.9%). Mild complications (MMS: 56/679, 8.3%; non-MMS: 32/336, 9.5%) and severe complications (MMS: 66/679, 9.7%; non-MMS: 43/336, 12.8%) were also lower in MMS users. MMS users had a lower 90-day ER visit rate (MMS: 62/679, 9.1%; non-MMS: 45/336, 13.4%). After adjustments were made for age and sex, the odds of having 90-day ER visits for MMS users were 32% lower than those for nonusers, but this difference was not statistically significant (odds ratio 0.68, 95% CI 0.45-1.02; P=.06).

CONCLUSIONS

This is one of the first studies to show differences in acute outcomes for people undergoing spine surgery who use a digital health app. This study found a correlation between MMS use and fewer postsurgical ER visits in a large group of spine surgery patients. A planned randomized controlled trial will provide additional evidence of whether this digital health tool can be used as an intervention to improve patient outcomes.

Impact of cage position on biomechanical performance of stand-alone lateral lumbar interbody fusion: a finite element analysis

Background

This study aimed to compare the biomechanical performance of various cage positions in stand-alone lateral lumbar interbody fusion(SA LLIF).

Methods

An intact finite element model of the L3-L5 was reconstructed. The model was verified and analyzed. Through changing the position of the cage, SA LLIF was established in four directions: anterior placement(AP), middle placement(MP), posterior placement(PP), oblique placement(OP). A 400 N vertical axial pre-load was imposed on the superior surface of L3 and a 10 N/m moment was applied on the L3 superior surface along the radial direction to simulate movements of flexion, extension, lateral bending, and axial rotation. Various biomechanical parameters were evaluated for intact and implanted models in all loading conditions, including the range of motion (ROM) and maximum stress.

Results

In the SA LLIF models, the ROM of L4-5 was reduced by 84.21–89.03% in flexion, 72.64–82.26% in extension, 92.5-95.85% in right and left lateral bending, and 87.22–92.77% in right and left axial rotation, respectively. Meanwhile, ROM of L3-4 was mildly increased by an average of 9.6% in all motion directions. Almost all stress peaks were increased after SA LLIF, including adjacent disc, facet joints, and endplates. MP had lower stress peaks of cage and endplates in most motion modes. In terms of the stress on facet joints and disc of the cephalad segment, MP had the smallest increment.

Conclusion

In our study, SA LLIF risked accelerating the adjacent segment degeneration. The cage position had an influence on the distribution of endplate stress and the magnitude of facet joint stress. Compared with other positions, MP had the slightest effect on the stress in the adjacent facet joints. Meanwhile, MP seems to play an important role in reducing the risk of cage subsidence.

Complication rates following stand-alone lateral interbody fusion: a single institution series after 10 years of experience

PURPOSE

This retrospective single institution study's goal was to analyze and report the complications from stand-alone lateral lumbar interbody fusions (LLIF).

METHODS

This research was approved by the institutional review board (STUDY2021000113). We retrospectively reviewed the database of patients with adult degenerative spine deformity treated via LLIF at our institution between January 2016 and December 2020.

RESULTS

Stand-alone LLIF was performed in 158 patients (145 XLIF, 13 OLIF; mean age 65 y.; 88 f., 70 m.). Mean surgical time was 85 min (± 24 min). Mean follow-up was 14 months (± 5 m). Surgical blood loss averaged 120 mL (± 187 mL) and the mean number of fused levels was 1.2 (± 0.4 levels). Overall complication rate was 19.6% (31 total; 23 approach-related, 8 secondary complications).

CONCLUSION

Lateral interbody fusion appears to be a safe surgical intervention with relatively low complication- and revision rates.

Retroperitoneal Hematoma Due to Drainage Tube Insertion in Extreme Lateral Interbody Fusion: A Case Report

CASE

A 73-year-old woman presented with degenerative kyphoscoliosis. Radiographs revealed sagittal and coronal imbalance with lumbar spinal stenosis. Extreme lateral interbody fusion (XLIF) was performed in the first stage of 2-stage surgery, and a closed-suction drainage tube was placed in the retroperitoneal cavity. Postoperatively, there was massive bleeding through the tube. Contrast-enhanced computed tomography revealed lumbar artery injury, which required emergency arterial embolization.

CONCLUSION

Placing a drainage tube in the retroperitoneal cavity during XLIF surgery can help detect complications such as intestinal and ureteral injuries, the lumbar artery within the lumbar muscle can be injured during drain placement.

Radiographic analysis of neuroforaminal and central canal decompression following lateral lumbar interbody fusion

Background

Lateral lumbar interbody fusion (LLIF) is a minimally invasive surgical option for treating symptomatic degenerative lumbar spinal stenosis (DLSS) in select patients. However, the efficacy of LLIF for indirectly decompressing the lumbar spine in DLSS, as well as the best radiographic metrics for evaluating such changes, are incompletely understood.

Methods

A single-institutional cohort of patients who underwent LLIF for DLSS between 5/2015 – 12/2019 was retrospectively reviewed. Diameter, area, and stenosis grades were measured for the central canal (CC) and neural foramina (NF) at each LLIF level based on preoperative and postoperative T2-weighted MRI. Baseline facet joint (FJ) space, degree of FJ osteoarthritis, presence of spondylolisthesis, interbody graft position, and posterior disc height were analyzed as potential predictors of radiographic outcomes. Changes to all metrics after LLIF were analyzed and compared across lumbar levels. Preoperative and intraoperative predictors of decompression were then assessed using multivariate linear regression.

Results

A total of 102 patients comprising 153 fused levels were analyzed. Pairwise linear regression of stenosis grade to diameter and area revealed significant correlations for both the CC and NF. All metrics except CC area were significantly improved after LLIF (p < 0.05, 2-tailed t-test). Worse FJ osteoarthritis ipsilateral to the surgical approach was predictive of greater post-operative CC and NF stenosis grade (p < 0.05, univariate and multivariate ordinary least squares linear regression). Lumbar levels L3-5 had significantly higher absolute postoperative CC stenosis grades while relative change in CC stenosis at the L2-3 was significantly greater than other lumbar levels (p < 0.05, one-way ANOVA). There were no baseline or postoperative differences in NF stenosis grade across lumbar levels.

Conclusions

Radiographically, LLIF is effective at indirect compression of the CC and NF at all lumbar levels, though worse FJ osteoarthritis predicted higher degrees of post-operative stenosis.

Lateral Lumbar Interbody Fusion: Single Surgeon Learning Curve

OBJECTIVE

To characterize lateral lumbar interbody fusion surgical learning curve and investigate changes in perioperative and postoperative clinical parameters associated with increased operative experience.

METHODS

In a case series, surgical learning curve was defined using 3-parameter asymptotic regression and piecewise linear regression, yielding learning phase (patients 1-53) and proficient phase (patients 54-179) cohorts. Using a 5-point grading scale, ipsilateral iliopsoas (hip-flexion) and quadriceps (knee-extension) muscle strength and thigh and groin sensory disturbances were compared for differences preoperatively versus postoperatively using χ² test. Patient-reported outcome measures were collected preoperatively and postoperatively and compared between cohorts with unpaired t test.

RESULTS

The proficient phase cohort demonstrated significantly reduced operative time, estimated blood loss, postoperative length of stay, and narcotic consumption on postoperative days 0 and 1. The proficient phase cohort displayed decreased disability at 6 weeks and 6 months and demonstrated significant improvement at all time points for disability, pain, and physical function except for 6 weeks and 2 years for physical function, whereas the learning phase cohort demonstrated improvement in disability beginning at 6 months, leg pain at all time points, and back pain through 6 months. Ipsilateral groin and thigh sensory disturbances and iliopsoas and quadriceps weakness improved with increasing operative experience.

CONCLUSIONS

The proficient phase cohort demonstrated significantly improved perioperative profile, reduced complication rate, and reduced rates of iliopsoas and quadriceps weakness. While the proficient phase cohort demonstrated earlier improvement in disability and physical function scores compared with the learning phase cohort, 2-year outcome measures did not differ. Long-term clinical outcomes suggest that patient safety and quality of life are not compromised during the learning phase, but patients may be particularly susceptible to femoral nerve injury early in a surgeon's practice.

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.

Comparison of Simultaneous Single-Position Oblique Lumbar Interbody Fusion and Percutaneous Pedicle Screw Fixation with Posterior Lumbar Interbody Fusion Using O-arm Navigated Technique for Lumbar Degenerative Diseases

Minimally invasive posterior or transforaminal lumbar interbody fusion (MI-PLIF/TLIF) are widely accepted procedures for lumbar instability due to degenerative or traumatic diseases. Oblique lateral interbody fusion (OLIF) is currently receiving considerable attention because of the reductions in damage to the back muscles and neural tissue. The aim of this study was to compare clinical and radiographic outcomes of simultaneous single-position OLIF and percutaneous pedicle screw (PPS) fixation with MI-PLIF/TLIF. This retrospective comparative study included 98 patients, comprising 63 patients with single-position OLIF (Group SO) and 35 patients with MI-PLIF/TLIF (Group P/T). Cases with more than 1 year of follow-up were included in this study. Mean follow-up was 32.9 ± 7.0 months for Group SO and 33.7 ± 7.5 months for Group P/T. Clinical and radiological evaluations were performed. Comparing Group SO to Group P/T, surgical time and blood loss were 118 versus 172 min (p < 0.01) and 139 versus 374 mL (p < 0.01), respectively. Cage height, change in disk height, and postoperative foraminal height were significantly higher in Group SO than in Group P/T. The fusion rate was 96.8% in Group SO, similar to the 94.2% in Group P/T (p = 0.985). The complication rate was 6.3% in Group SO and 14.1% in Group P/T (p = 0.191). Simultaneous single position O-arm-navigated OLIF reduces the surgical time, blood loss, and time to ambulation after surgery. Good indirect decompression can be achieved with this method.

Bowel Injury and Insidious Pneumoperitoneum after Lateral Lumbar Interbody Fusion

Study Design

Retrospective review of prospectively collected cases.

Purpose

To report bowel injury cases and determine the incidence and risk factors of insidious pneumoperitoneum after lateral lumbar interbody fusion (LLIF).

Overview of Literature

Minimally invasive LLIF is considered a safe surgical approach with a low risk of complications. Visceral injury after LLIF is rare and, to our knowledge, no studies on pneumoperitoneum after LLIF have been performed. Bowel injury is a catastrophic complication, but the clinical signs may not be apparent. After we encountered two cases of bowel injury after LLIF, we decided to perform computed tomography of the abdomen and pelvis (APCT) after surgery for all patients who underwent LLIF.

Methods

A total of 90 patients underwent APCT within 48 hours of surgery. Medical records were reviewed to determine each patient’s age, sex, body mass index, medical and surgical histories, characteristics of LLIF procedures, and subjective symptoms and abnormal findings in the physical examination related to acute abdomen after surgery. Various parameters were compared between patients with and without pneumoperitoneum.

Results

Bowel injuries were identified in the first two patients and five patients (5.5%) were diagnosed with pneumoperitoneum only on APCT. We found that the greater the number of fused segments, the higher the incidence of postoperative bowel injury and/or pneumoperitoneum. The incidence was significantly high when the L2–3 level was included in the LLIF surgery.

Conclusions

Pneumoperitoneum after LLIF indicates damage to the peritoneum and the presence of bowel injury that may lead to peritonitis. However, it is difficult to distinguish pneumoperitoneum and/or bowel injury from general abdominal pain after surgery because patients may present with a wide range of symptoms. We recommend that APCT be routinely performed after LLIF surgery in order to promptly identify pneumoperitoneum and bowel injury.

Neuropathic inguinal pain due to nerve injury after a laparoscopic appendectomy: first pediatric case described in the literature

OBJECTIVE

To describe the first pediatric case in the literature of neuropathic inguinal pain secondary to iatrogenic nerve injury that occurred during a laparoscopic appendectomy, detailing clinical and morphological findings before and after surgery. The literature on adult patients is reviewed and pathophysiological, therapeutic, and prognostic factors are discussed.

CLINICAL PRESENTATION

A 14-year-old female patient presented with a history of a laparoscopic appendectomy 3 years previously. Three months post-operatively, she developed progressively worsening neuropathic inguinal pain refractory to neuromodulators and several nerve blocks. Given her deterioration, poor response to conservative therapy, and clearly meeting the criteria for chronic post-operative inguinal pain (CPIP), surgical management was undertaken.

RESULTS

Open surgery was performed through the previous incision, during which injury to a branch of the iliohypogastric nerve (IH) was confirmed. Neurolysis of the affected branch was performed, after which the patient experienced significant pain relief, resolution of allodynia, and reversal of skin hyperpigmentation. After discharge, analgesic therapy was gradually withdrawn and, ultimately, discontinued altogether.

CONCLUSIONS

Understanding the neuroanatomy of the inguinal region is an indispensable requirement for all surgeons operating in this region, to avoid complications including CPIP and optimize patient outcomes. Surgical management of CPIP can be effective for controlling severe pain in patients in whom conservative management has failed. Studies are needed in the pediatric population to identify specific characteristics of this entity in youth.

Cellular allograft for multilevel stand-alone anterior cervical discectomy and fusion

OBJECTIVE

Anterior cervical discectomy and fusion (ACDF) is the most common treatment for degenerative disease of the cervical spine. Given the high rate of pseudarthrosis in multilevel stand-alone ACDF, there is a need to explore the utility of novel grafting materials. In this study, the authors present a single-institution retrospective study of patients with multilevel degenerative spine disease who underwent multilevel stand-alone ACDF surgery with or without cellular allograft supplementation.

METHODS

In a prospectively collected database, 28 patients who underwent multilevel ACDF supplemented with cellular allograft (ViviGen) and 25 patients who underwent multilevel ACDF with decellularized allograft between 2014 and 2020 were identified. The primary outcome was radiographic fusion determined by a 1-year follow-up CT scan. Secondary outcomes included change in Neck Disability Index (NDI) scores and change in visual analog scale scores for neck and arm pain.

RESULTS

The study included 53 patients with a mean age of 53 ± 0.7 years who underwent multilevel stand-alone ACDF encompassing 2.6 ± 0.7 levels on average. Patient demographics were similar between the two cohorts. In the cellular allograft cohort, 2 patients experienced postoperative dysphagia that resolved by the 3-month follow-up. One patient developed cervical radiculopathy due to graft subsidence and required a posterior foraminotomy. At the 1-year CT, successful fusion was achieved in 92.9% (26/28) of patients who underwent ACDF supplemented with cellular allograft, compared with 84.0% (21/25) of patients who underwent ACDF without cellular allograft. The cellular allograft cohort experienced a significantly greater improvement in the mean postoperative NDI score (p < 0.05) compared with the other cohort.

CONCLUSIONS

Cellular allograft is a low-morbidity bone allograft option for ACDF. In this study, the authors determined favorable arthrodesis rates and functional outcomes in a complex patient cohort following multilevel stand-alone ACDF supplemented with cellular allograft.

Cadaveric Evidence of Complete Transection of the Lumbar Sympathetic Trunk After Extreme Lateral Transpsoas Approach to the Lumbar Spine: A Word of Caution

Lateral transpsoas approaches to the lumbar spine are believed to entail less risk of injury to the lumbar sympathetic trunk and plexus than anterior approaches. However, even the lateral approach can occasionally injure the sympathetic trunk. We report a literature review and cadaveric case of complete resection of the left sympathetic trunk at L3 following lateral transpsoas approach performed by a well-trained spine surgeon. A left lateral approach to the lumbar spine for a two-level total discectomy at L3-L4 and L4-L5 was undertaken on a fresh-frozen cadaver by an experienced spinal surgeon. The procedure followed standard spinal technique under fluoroscopy guidance. The cadaver was placed in a right lateral position and an operative corridor to the lateral aspect of the psoas major muscle was developed. Blunt dissection was carried through the muscle and standard total discectomy was completed at the target levels. Following the procedure, the lumbar spine and adjacent structures were anatomically dissected. It was found that the sympathetic trunk had been completely transected at the L3 level during the surgical procedure. Other major structures such as the femoral nerve, obturator nerve, and roots of the lumbar spinal nerves had not been injured. The above case highlights the proximity of the sympathetic trunk to lateral transpsoas approaches and the possibility of injury to it. We review the literature on postoperative cases of lumbar sympathetic dysfunction (SD) following such procedures and posit that some of these are due to direct iatrogenic injury.

Simultaneous Combined Major Arterial and Lumbar Plexus Injury During Primary Extra Lateral Interbody Fusion: Case Report and Review of the Literature

Extra lateral interbody fusion (XLIF) has been established in recent years as an effective approach to address degenerative lumbar disc disease (DLDD). Although neurological and vascular complications during XLIF have been reported, to our knowledge, a combination of simultaneous vascular and neurovascular complication during XLIF has not been reported to date. A 72-year-old female patient was admitted to our orthopaedic department because of back pain associated with severe neuropathic radicular pain to her both lower extremities, incomplete paraplegia and low back fistula with serous secretion for several weeks. She had been wheel-chair bound since nine years before her admission in our department when she had her initial XLIF operation in another institution. Intraoperatively, an aorta lesion occurred, which was emergently addressed, along with lumbar plexus injury. Since then, she had an extensive history of subsequent operations that ended with a T10-S1 posterior lumbar fusion, with no improvement of her neurological condition, complicated by hardware-induced infection. She underwent her last operation in our department; removal of the posterior lumbar construct and extensive debridement of the posterior lumbar spine. We present this rare case and we perform an extensive literature review. Although XLIF has been established in recent years, the report of major vascular injuries, although rare, has questioned its safety profile. Spine surgeons should be aware of catastrophic major neurovascular complications associated with this procedure and be prepared to address them.

A Review of Minimally Invasive Techniques in Thoracolumbar Trauma

The development of endoscopy, microscopy, and image guidance system provided the impetus for the adoption of minimally invasive surgery (MIS) techniques in the management of spinal trauma patients. The underlying drive has been an attempt to achieve the functional and biomechanical goals inherent to trauma care but through MIS techniques. Broadly the MIS techniques for spinal trauma can be divided into two categories—fusion and nonfusion methods. Fusion methods include mini-open or keyhole approaches that allow for discectomy and/or corpectomy and cage reconstruction via an anterior/lateral/posterior operative corridor. The nonfusion methods primarily include percutaneous pedicle screw fixation, kyphoplasty, and vertebroplasty, all without placement of bone graft or other attempts at inducing arthrodesis. In this review article, we have stratified the MIS techniques based on the operative corridor used and briefly described the decision-making process, technical nuances, pros, and cons of each technique.

Is stand-alone lateral lumbar interbody fusion superior to instrumented lateral lumbar interbody fusion for the treatment of single-level, low-grade, lumbar spondylolisthesis?

BACKGROUND

The aim of this study was to compare surgical trauma and radiographic and clinical outcomes of stand-alone and instrumented lateral lumbar interbody fusion (LLIF) in the treatment of single-level low-grade lumbar spondylolisthesis.

METHODS

Ninety-five patients with single-level low-grade lumbar spondylolisthesis, who underwent stand-alone LLIF (stand-alone group, [n = 54]) or LLIF plus percutaneous posterior fixation (instrumented group, [n = 41]) were enrolled in this study. Operative time, intraoperative blood loss, serum C-reactive protein (CRP) and creatine kinase (CK) levels, the length of postoperative bed rest time, and hospital stay were compared between the 2 groups. Disc height, the percent of slip, segment lordosis, lumbar lordosis, the visual analog scale score, the Oswestry Disability Index and complications were also compared.

RESULTS

Operative and bed rest time were shorter, intraoperative blood loss was less, and postoperative CRP and CK levels were lower in the stand-alone group. During follow-up, 6 patients in stand-alone group underwent posterior fixation due to cage subsidence. Although satisfactory radiographic results were achieved in both groups, the maintenance of increased disc heights and segment lordosis was inferior in the stand-alone group at the final follow-up. Greater improvement in postoperative VAS scores and ODI were observed in the stand-alone group, although the rates of cage subsidence and revision were higher.

CONCLUSION

Stand-alone LLIF was superior to instrumented LLIF in terms of tissue trauma for the treatment of single-level low-grade lumbar spondylolisthesis. However, stand-alone LLIF was inferior in the maintenance of disc height and segment lordosis, and the occurrence of cage subsidence and revision.

Incisional hernia after extreme lateral interbody fusion on the lumbar spine: A case report

INTRODUCTION

Extreme lateral interbody fusion is a minimally invasive lateral transpsoas approach for spine surgery. We herein report a case of an incisional hernia after an extreme lateral interbody fusion on the lumbar spine that was successfully treated by laparoscopic surgery with intraperitoneal onlay mesh repair.

PRESENTATION OF CASE

A 78-year-old woman was referred to our hospital with a complaint of left abdominal bulge and pain. She had undergone an extreme lateral interbody fusion for a lumbar spinal canal stenosis from L1 to L4 a year prior. Abdominal computerized tomography showed a left lumbar incisional hernia, and laparoscopic surgery was performed. The hernia orifice was sutured closed and covered with mesh. The patient was discharged five days after the operation with no complications.

DISCUSSION

When performing XLIF for a spinal disorder, the muscles should be separated bluntly along their fibers to prevent muscle atrophy, and the incised fascia should be securely sutured closed. Abdominal wall incisional hernias can occur after spinal surgeries such as extreme lateral interbody fusion.

CONCLUSION

Laparoscopic repair for abdominal wall incisional hernia after spine surgery is safe and feasible.

The History of Anterior and Lateral Approaches to the Lumbar Spine

Anterior and lateral approaches to the lumbar spine are commonly used today for a variety of indications. These approaches can ultimately be traced back to early attempts to treat Pott's disease. Evidence of Mycobacterium tuberculosis infection of the spine dates as far back as 2400 BCE, with ancient Egyptian mummies exhibiting lesions consistent with Pott's disease. For many centuries, Pott's disease was treated conservatively, and surgery came to be used when conservative therapy was ineffective, as medical therapy had yet to become available. In 1779, Percivall Pott recommended that peripheral paraspinal tuberculous abscesses be drained after noticing that patients' lower limb function improved after the formation of spontaneous draining sinuses. Building on Pott's ideas, Ménard described the first lateral approach to the spine via a costotransversectomy approximately 1 century after Pott's theory. Most importantly, the surge in understanding anatomy with respect to developing safe corridors to the deeper structures of the human body brought together advances in technology, instrumentation, and visualization. Surgeons were thus emboldened to explore more complex anterior approaches to the spine. In 1906, Müller reported the first successful anterior approach to the spine in a patient with Pott's disease. Over the next several decades, the efforts of surgeons such as Ito, Capener, Burns, and Mercer would lead to the development of the anterior lumbar interbody fusion. The costotransversectomy later evolved into the lateral rhachotomy and lateral extracavitary approach, which along with advances in the anterior lumbar interbody fusion paved the way for the oblique lumbar interbody fusion and lateral lumbar interbody fusion.

The anterior-to-psoas approach for interbody fusion at the L5-S1 segment: clinical and radiological outcomes

OBJECTIVE

Over the last few decades, many surgical techniques for lumbar interbody fusion have been reported. The anterior-to-psoas (ATP) approach is theoretically supposed to benefit from the advantages of both anterior and lateral approaches with similar complication rates, even in L5-S1. At this segment, the anterior lumbar interbody fusion (ALIF) requires retroperitoneal dissection and retraction of major vessels, whereas the iliac crest does not allow the lateral transpsoas approach. This study aimed to investigate clinical-radiological outcomes and complications of the ATP approach at the L5-S1 segment in a single cohort of patients.

METHODS

This is a prospective single-center study, conducted from 2016 to 2019. Consecutive patients who underwent ATP at the L5-S1 segment for degenerative disc disease or revision surgery after previous posterior procedures were considered for eligibility. Complete clinical-radiological documentation and a minimum follow-up of 12 months were set as inclusion criteria. Clinical patient-reported outcomes, such as the visual analog scale for low-back pain, Oswestry Disability Index, and 36-Item Short Form Health Survey (SF-36) scores, as well as spinopelvic parameters, were collected preoperatively, 6 weeks after surgery, and at the last follow-up visit. Intraoperative and perioperative complications were recorded. The fusion rate was evaluated on CT scans obtained at 12 months postoperatively.

RESULTS

Thirty-two patients met the inclusion criteria. The mean age at the time of surgery was 57.6 years (range 44-75 years). The mean follow-up was 33.1 months (range 13-48 months). The mean pre- and postoperative visual analog scale (7.9 ± 1.3 vs 2.4 ± 0.8, p < 0.05), Oswestry Disability Index (52.8 ± 14.4 vs 22.9 ± 6.0, p < 0.05), and SF-36 (37.3 ± 5.8 vs 69.8 ± 6.1, p < 0.05) scores significantly improved. The mean lumbar lordosis and L5-S1 segmental lordosis significantly increased after surgery. The mean pelvic incidence-lumbar lordosis mismatch and pelvic tilt significantly decreased. No intraoperative complications and a postoperative complication rate of 9.4% were recorded. The fusion rate was 96.9%. One patient needed a second posterior revision surgery for residual foraminal stenosis.

CONCLUSIONS

In the present case series, ATP fusion for the L5-S1 segment has resulted in valuable clinical-radiological outcomes and a relatively low complication rate. Properly designed clinical and comparative trials are needed to further investigate the role of ATP for different L5-S1 conditions.

Incidence of Major Vascular Injuries with Extreme Lateral Interbody Fusion (XLIF)

Background:

Extreme lateral interbody fusions (XLIF) and minimally invasive (MI) XLIF theoretically offer wide access to the lumbar disc space. The theoretical advantages of XLIF include; minimally disturbing surrounding structures (e.g. neural, vascular, soft-tissue), while offering stability. In addition to the well-known increased frequency of neurological deficits attributed to XLIF, here we explored how often major vascular injures occur with XLIF/MI XLIF procedures.

Methods:

In 13 XLIF/MI XLIF studies, we evaluated the frequency of major vascular injuries.

Results:

The studies citing the different frequencies of vascular injuries associated with XLIF/MI XLIF were broken down into three categories. Of the 5 small and larger case series, involving a total of 6,732 patients (e.g. range of 12 to 4,607 patients/study), the incidence of vascular injuries ranged from 0% (3 studies) up to 0.4%. Three case reports presented major vascular injuries attributed to XLIF/MI XLIF. Two involved the L4-L5 level. The three complications included: one fatal injury, one, a retroperitoneal hematoma with hemorrhagic shock, and one major vascular injury. For the 5 review articles, major vascular complications were just discussed in 2, one study cited 3 specific major vascular injuries (e.g. 1 fatal, 1 life threating, and 1 lumbar artery pseudoaneurysm requiring embolization), while 2 other studies stated the frequency of these injuries was 0.4% for XLIF, and 1.7 % for OLIF (Oblique Lumbar Interbody Fusion).

Conclusions:

According to 5 small and larger case series, 3 case reports, and 5 review articles, the incidence of major vascular injuries occurring during XLIF/MI XLIF ranges from 0 to 0.03% to 0.4%.

Anatomical Study of the Lumbar Segmental Arteries in Relation to the Oblique Lateral Interbody Fusion Approach

OBJECTIVE

To use computed tomography angiography to evaluate the regional anatomy of the lumbar segmental arteries (LAs) associated with the surgical field in oblique lateral interbody fusion (OLIF).

METHODS

Computed tomography angiography images from 50 patients were reviewed. In the sagittal plane, distances from the LA to the upper and inferior edges of the vertebral body were measured in the anterior quarter of the anterior and median lines of the intervertebral disc (IVD). LAs were classified as types I-IV based on the zone in which they passed through the vertebral body.

RESULTS

The LA branch angles were acute (<90°) at L1-L3 and blunt (>90°) at L4-L5. The average distances from the LA to the upper and inferior edges of the vertebral body in the anterior quarter position revealed that La1.2 > Lb1.2 and Lb3.4.5 > La3.4.5. For the IVD of L1-L2, Lb1 < La2; IVD of L2-L3, Lb2 < La3; IVD of L3-L4, Lb3 > La4; IVD of L4-L5, Lb4 > La5. In zone I, the most frequent LA type was type IV at L1 (n = 41; 85.4%) and L2 (n = 42; 84.0%), type III at L3 (n = 20; 40.0%), and type II at L4 (n = 36; 80.0%) and L5 (n = 5; 83.3%). In zone II, the most frequent LA type was type III at L1 (n = 38; 79.2%), L2 (n = 39; 78.0%), L3 (n = 43; 86.0%), and L4 (n = 28; 62.2%), whereas type II was the most frequent LA type at L5 (n = 5; 83.3%). In zone III, type III was the most frequent LA type at L1-L4. In zone IV, type IV was the most frequent LA type at L3 (n = 44; 88.0%), L4 (n = 42; 93.3%), and L5 (n = 6; 100%).

CONCLUSIONS

The risk of LA injury during OLIF is the least when the cage is placed in zones II and III. Care is required during OLIF in zone IV of L3-L5. The fixation pin should be fixed on the upper edge of the lower vertebral body at L1-L2 and L2-L3, and on the lower edge of the upper vertebral body at L3-L4 and L4-L5.