Oblique Lumbar Interbody Fusion Research Articles

L5 Nerve Root Radiculopathy as a Rare Complication Following Oblique Lateral Interbody Fusion at L5/S1 Combined With Posterior Fixation via Percutaneous Pedicle Screws for Adult Spinal Deformity

L5 Nerve Root Radiculopathy as a Rare Complication Following Oblique Lateral Interbody Fusion at L5/S1 Combined With Posterior Fixation via Percutaneous Pedicle Screws for Adult Spinal Deformity

[Efficacy analysis of OLIF combined with posterior percutaneous internal fixation in patients with lumbar spinal stenosis with or without redundant nerve roots].

To investigate the clinical efficacy of oblique lumbar interbody fusion(OLIF) combined with posterior percutaneous internal fixation in patients with lumbar spinal stenosis with or without redundant nerve roots(RNRs). A retrospective analysis of 92 patients with lumbar spinal stenosis treated by oblique lateral lumbar interbody fusion combined with posterior percutaneous internal fixation from June 2019 to June 2022 was performed. There were 32 males and 60 females, aged from 44 to 82 years old with an average of (63.67±9.93) years old. All patients were divided into RNRs positive group and RNRs negative group according to redundancy or not before operation. There were 38 patients in RNRs positive group, including 15 males and 23 females. The age ranged from 45 to 82 years old with an average of (65.45±10.37) years old. The disease duration was 24.00(12.00, 72.00) months. There were 54 patients in RNRs negative group, including 17 males and 37 females. The age ranged from 44 to 77 years old with an average of (62.42±9.51) years old. The disease duration was 13.50(9.00, 36.00) months. The general data of patients were recorded, including operation time, intraoperative blood loss and complications. The imaging parameters before and after operation were observed, including the number of stenosis segments, intervertebral space height, lumbar lordosis angle and dural sac area. The visual analogue scale (VAS) was used to evaluate the back and lower extremity pain, and the Oswestry disability index (ODI) was used to evaluate the activities of daily living. All patients were followed up for 8 to 18 months with an average of (11.04±3.61) months, and no complications were found during the follow-up period.The number of stenosis segments in RNRs positive group (1.71±0.46) was more than that in RNRs negative group(1.17±0.38). In RNRs positive group, intervertebral space height, dural sac area, low back pain VAS, lower extremity pain VAS, ODI score were (1.11±0.19) cm, (0.46±0.17) cm2, (5.39±1.00) scores, (5.05±1.01) points, (55.74±4.05) points, respectively. RNRs negative groups respectively (0.97±0.23) cm, (0.69±0.26) cm2, (4.50±0.77) scores, (4.00±0.58) scores, (47.33±3.43) %. In RNRs positive group, intervertebral space height, dural sac area, low back pain VAS, leg pain VAS, ODI score were (1.60±0.19) cm, (0.74±0.36) cm2, (3.39±0.72) scores, (3.05±1.01) scores, (46.74±4.82) scores, respectively. RNRs negative groups respectively (1.48±0.25) cm, (1.12±0.35) cm2, (3.00±0.82) scores, (3.00±0.82) scores, (37.67±3.58) %. The postoperative intervertebral space height, dural sac area, low back pain VAS score, lower extremity pain VAS and ODI score of the patients in the RNRs positive group and the negative group were significantly improved compared with those before operation, and the differences were statistically significant (P<0.05). There were statistically significant differences in the number of stenosed segments, preoperative intervertebral space height, dural sac area, low back pain VAS, lower extremity pain VAS, and ODI between the two groups(P<0.05). There were significant differences in postoperative intervertebral space height and postoperative ODI between the two groups(P<0.05), but there was no significant difference in intervertebral space height before and after operation and ODI score before and after operation(P>0.05). There were significant differences in operation time, intraoperative blood loss, postoperative dural sac area, difference of dural sac area before and after operation, postoperative low back pain VAS, difference of low back pain VAS score before and after operation, difference of lower extremity pain VAS before and after operation between the two groups(P<0.05). OLIF combined with posterior percutaneous internal fixation has a good effect on patients with or without RNRs. Multi-segmental lumbar spinal stenosis and decreased dural sac area may lead to the occurrence of RNRs, and LSS patients with RNRs have more severe symptoms. LSS patients with RNRs have worse surgical outcomes than those without RNRs.

Clinical efficacy and imaging analysis of oblique lateral lumbar interbody fusion in the treatment of different types of lumbar intervertebral foramen stenosis

PurposeTo analyze and study the clinical efficacy and imaging indexes of oblique lateral lumbar interbody fusion (OLIF) in the treatment of lumbar intervertebral foramen stenosis(LFS) caused by different causes.Method33 patients with LFS treated with OLIF from January 2018 to May 2022 were reviewed. Oswestry Dysfunction Index (ODI) and visual analogue scale (VAS) were calculated before and after operation. Segmental lordotic angle (SLA), lumbar lordotic angle (LLA) and segmental scoliosis angle (SSA), disc height (DH), posterior disc height (PDH), lateral disc height (LDH), foraminal height (FH), foramen width (FW) and foraminal cross-sectional area (FSCA) were measured before and after operation.ResultThe VAS and ODI after operation were significantly improved as compared with those before operation. Compared with pre-operation, the DH, PHD increased by 67.6%, 94.6%, LDH increased by 107.4% (left), 101.7% (right), and FH increased by 30.2% (left), 34.5% (right). The FSCA increased by 93.1% (left), 89.0% (right), and the FW increased by 137.0% (left), 149.6% (right). The postoperative SSA was corrected by 74.5%, the postoperative SLA, LLA were corrected by 70.2%, 38.1%, respectively. All the imaging indexes were significantly improved (p < 0.01).ConclusionThe clinical efficacy and imaging data of OLIF in the treatment of LFS caused by low and moderate lumbar spondylolisthesis, intervertebral disc bulge and reduced intervertebral space height, degenerative lumbar scoliosis, articular process hyperplasia or dislocation have been well improved. OLIF may be one of the better surgical treatments for LFS caused by the above conditions.

Comparing OLIF Combined with Lateral Screw Fixation Versus Minimally Invasive TLIF for Treating Single-Level Degenerative Lumbar Spondylolisthesis: A Retrospective Cohort Study.

The present study aimed to compare the clinical and radiological outcomes of oblique lumbar interbody fusion (OLIF) combined with lateral screw fixation and minimally invasive transforaminal lumbar interbody fusion (Mis-TLIF) for the treatment of single-level degenerative lumbar spondylolisthesis (DLS). Data regarding clinical and radiological outcomes for single-level DLS treated using OLIF combined with lateral screw fixation or Mis-TLIF between November 2017 and June 2020 were retrospectively analyzed. Seventy-five patients with single-level DLS (≥ 2 years' follow-up) were included and divided into 2 groups according to surgical method: OLIF (n=33); and Mis-TLIF (n=42). Operative time, intraoperative blood loss, and length of hospital stay were significantly lower in the OLIF group than that in the Mis-TLIF group. There were no significant differences in preoperative low back pain (LBP), leg pain (LP) visual analog scale (VAS) scores, and Oswestry Disability Index (ODI) between the two groups, although the OLIF group had significantly lower LBP VAS scores at 1, 3, and 6 months postoperatively. Additionally, the LP VAS score was significantly lower in the Mis-TLIF group than that in the OLIF group at 1 month postoperatively, and the ODI of the OLIF group at 3 months postoperatively was significantly lower than that of the Mis-TLIF group. There was no significant difference in the preoperative and postoperative lumbar lordosis angles between the two groups, whereas the postoperative surgical segmental lordosis angle and disc height (1, 6, 12, and 24 months) in the OLIF group were significantly higher than those in the Mis-TLIF group. Additionally, there was no significant difference in complication rates between the two groups (OLIF, 18.2% versus Mis-TLIF, 11.9%; p=0.520). Conclusion OLIF combined with lateral screw fixation yielded better clinical and radiological outcomes than Mis-TLIF in patients with single-level DLS.

284 CT-Based Assessment of Prone Versus Lateral Pedicle Screw Placement Accuracy: A Retrospective Single-surgeon Study

INTRODUCTION: Lateral lumbar interbody fusion (LLIF) including the anterior-to-psoas oblique lumbar interbody fusion (OLIF) has conventionally relied on pedicle screw placement (PSP) for construct stabilization. Single-position surgery with lumbar interbody fusion (LIF) in the lateral decubitus position with concomitant PSP has been associated with increased operative efficiency. What remains unclear is the accuracy of PSP with robotic guidance when compared to the more familiar prone patient positioning. METHODS: We identified all consecutive patients treated with interbody fusion and PSP in the prone or lateral position by a single surgeon between January 2019 and October 2022. All pedicle screws placed were analyzed using CT imaging to determine appropriate positioning according to the Gertzbein-Robbins Classification Grading System. Multivariate logistic regression models were constructed to identify risk factors for the occurrence of a radiographically significant breach. RESULTS: 89 consecutive patients were included (n = 690 screws), of whom 46 were treated in the prone position (n = 477 screws) and 43 in the lateral decubitus position (n = 213 screws). There were fewer breaches in the prone (n = 13; 2.7%) versus lateral decubitus group (n = 15; 7.0%; p = 0.012). Nine (1.9%) radiographically significant breaches occurred in the prone group compared to 10 (4.7%) in the lateral decubitus group (p = 0.019), for a prone vs. lateral decubitus pedicle screw accuracy rate of 98.1% vs. 95.3%. There were no significant differences in BMI between prone vs. lateral decubitus cohorts (30.1 vs. 29.6) or breached patients vs. non-breached patients (31.2 vs. 29.5). In multivariate models, prone position was the only significant protective factor for screw accuracy; we did not identify any other significant risk factors for screw breach. CONCLUSIONS: The present data suggest pedicle screws placed with robotic assistance have higher placement accuracy in the prone position.

Biportal endoscopic transforaminal lumbar interbody fusion using a large cage for degenerative spondylolisthesis with stenosis.

Recently, biportal endoscopic transforaminal lumbar interbody fusion (TLIF) has been used to treat lumbar degenerative diseases, such as lumbar instability and spondylolisthesis. Biportal endoscopic TLIF may have the advantages of endoscopic spine approaches and minimally invasive lumbar fusion surgeries. In this biportal endoscopic TLIF, large cages similar to oblique lumbar interbody fusion (OLIF) cages have been used. Biportal endoscopic TLIF using a large cage can be successfully performed in the lower lumbar area. The author presents the surgical technique of biportal endoscopic TLIF using a large cage. The video can be found here: https://stream.cadmore.media/r10.3171/2024.1.FOCVID23231.

Delayed Fungal Infection After Anterior Lateral Interbody Fusion Treated With Oblique Lateral Interbody Fusion: A Case Report and Literature Review

This report presents a rare case of a fungal infection following an anterior lateral interbody fusion (ALIF) procedure. A 73-year-old man with rheumatoid arthritis underwent ALIF for lumbar spondylolisthesis and spinal stenosis. After surgery, he experienced severe back pain. Radiological tests showed pseudoarthrosis, osteolysis, and signs of surgical site infection. Revision surgery using oblique lateral interbody fusion (OLIF) and an allo-bone graft was performed. This addressed the complications, removed the previous cage, and provided interbody support. The patient’s pain significantly decreased, and he recovered from an Aspergillus fumigatus infection after voriconazole treatment. Follow-up examinations confirmed the infection’s resolution and the maintenance of spinal stability. It is crucial to identify fungal infections in patients on immunosuppressive drugs. The case validates the efficacy of voriconazole efficacy in treating Aspergillus spondylitis and the safety and effectiveness of OLIF for ALIF revision surgery.

Comparison of the Medium-term Outcomes of Anterior Lumbar Discectomy and Fusion with Minimally Invasive Transforaminal Lumbar Interbody Fusion: A Retrospective Cohort Study.

Lumbar degenerative diseases (LDDs) with huge herniation in the left lateral recess or central canal present challenges for oblique lateral lumbar interbody fusion (OLIF) or endoscope-assisted OLIF procedures. Currently, minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) is the primary approach for this issue. This study aims to provide a standardized technical description of the anterior lumbar discectomy and fusion (ALDF) and evaluate the medium-term clinical effectiveness of both ALDF and MIS-TLIF techniques. A retrospective review was performed on LDDs who underwent ALDF and MIS-TLIF surgery from January 2018 to January 2020. The evaluation encompassed various clinical outcomes, such as the visual analogue scale (VAS) scores for back pain and leg pain (VAS-back, VAS-leg), the Oswestry disability index (ODI), the 36-item short-form health survey mental component summary (SF-36 MCS), and the physical component summary (SF-36 PCS). Additionally, radiological parameters, including disc height (DH), segmental disk angle (SDA), lumbar lordosis (LL), and cross-sectional area (CSA), were assessed. Data including radiculopathy, estimated blood loss, operation time, time of getting out of bed, fusion rate, and complications were recorded. Student's independent samples t test and Pearson's chi-square test were used to compare the differences between groups. In total, 47 patients were treated by ALDF and 48 patients were treated by MIS-TLIF. The ALDF group exhibited statistically significant lower estimated blood loss and earlier time of getting out of bed compared to the MIS-TLIF group (p < 0.05). The ALDF group demonstrated lower VAS-back scores and a higher remission rate of low back pain 3 years after the surgery (p < 0.05). During the entire follow-up period, the ALDF group exhibited higher increases in DH and SDA compared to the MIS-TLIF group (p < 0.05). At 6 months, the fusion rate in the ALDF group was significantly higher than in the MIS-TLIF group (p < 0.05). The comparison revealed no statistically significant differences in complication rates between the two groups (p > 0.05). The ALDF could be considered as a viable surgical alternative for the treatment of LDDs that necessitate ventral neural direct decompression. ALDF exhibited favorable medium-term outcomes in patients with LDDs, displaying advantages in facilitating expedited recovery, enhancing radiographic outcomes, and elevating the remission rate of low back pain. Although ALDF presents slightly higher complication rates compared to MIS-TLIF, it does not adversely affect clinical outcomes.

[Comparative study of percutaneous transfacet screw and pedicle screw in oblique lumbar interbody fusion for the treatment of single-level lumbar spinal stenosis].

Objective: To conduct a comparative study of radiological and clinical outcomes between percutaneous transfacet screw (TFS) and pedicle screw (BPS) in oblique lateral lumbar interbody fusion (OLIF) for single-level lumbar spinal stenosis. Methods: A retrospective cohort study. Patients who underwent OLIF with TFS or BPS for the treatment of single-level lumbar spinal stenosis at Beijing Jishuitan Hospital from January 2019 to June 2022 were retrospectively analyzed. Radiological parameters and clinical indicators were compared between the two groups. Radiological parameters included preoperative, immediate postoperative (within 5 days), and 1-year postoperative measurements of disc height and segmental lordosis angle, as well as interbody fusion status at 1 year postoperatively. Clinical indicators included operative time, blood loss, length of hospital stay, complications, and Oswestry Disability Index (ODI), visual analogue scale (VAS) scores for back pain, and leg pain before and 1 year after surgery. Results: Four male and 10 female patients with an average age of (61.0±11.2) years underwent OLIF with TFS, while 9 male and 12 female patients underwent OLIF with BPS, with a mean age of (60.9±6.7) years. There was no statistically significant difference in preoperative disc height between the TFS and BPS groups (P>0.05). The immediate postoperative disc height was (12.9±2.1) mm and it was (10.4±1.7) mm at 1-year follow-up in the TFS group; in the BPS group, it was (12.9±2.1) mm immediately postoperatively and (11.9±2.1) mm at 1-year follow-up; there was statistically significant difference between the two groups at 1-year follow-up (P=0.037). The segmental lordosis angle showed no significant differences within each group or between the two groups at preoperative, immediate postoperative, or 1-year postoperative follow-up (all P>0.05). At 1-year postoperative follow-up, the fusion rates was 92.9%(13/14) in the TFS group and 95.2%(20/21) in the BPS group, with no statistically significant difference between the two groups (P>0.05). The TFS group had a significantly shorter operative time and less blood loss compared to the BPS group [(164.3±33.9) minutes vs (191.7±31.8) minutes and (74.3±46.9) ml vs (124.8±54.0) ml, respectively] (both P<0.05). Both groups showed significant improvement in ODI and VAS scores at 1 year postoperatively compared to those preoperatively, but with no statistically significant difference was found between the groups (both P>0.05). Conclusions: OLIF with TFS fixation can effectively restore disc height and alleviate back and leg pain in patients with single-level lumbar spinal stenosis. Compared to the OLIF with BPS procedure, OLIF with TFS has shorter operative time and less blood loss.

Hidden Blood Loss and Its Risk Factors for Oblique Lumbar Interbody Fusion.

(1) Background: The amount of blood loss during oblique lumber interbody fusion (OLIF) surgery is often underestimated and may contribute to adverse postoperative outcomes. This study aims to evaluate hidden blood loss (HBL) in patients who underwent OLIF for degenerative lumbar spine disease and to analyze its risk factors. (2) Methods: The medical records of 179 patients who underwent OLIF surgery from 2015 to 2022 were reviewed. The HBL and total blood loss (TBL) were estimated using the Gross formula. Pearson correlation, Spearman correlation, and multivariate linear regression analyses were used to investigate risk factors for HBL. (3) Results: The mean HBL was 675.2 mL, and the mean hemoglobin loss was 1.7 g/dL during OLIF surgery. In the multivariate linear regression analysis, TBL (p < 0.001), estimated blood loss (p < 0.001), and pedicle screw fixation type (p = 0.039) were identified as independent risk factors of HBL. (4) Conclusions: The OLIF is associated with substantial perioperative HBL, for which we identified risk factors of TBL, EBL, and pedicle screw fixation type. Notably, OLIF with percutaneous pedicle screw fixation resulted in greater HBL than stand-alone OLIF or OLIF with open pedicle screw fixation.

Single position, prone oblique lateral interbody fusion (OLIF)-case illustration and technical considerations.

Oblique lateral interbody fusion (OLIF) is a powerful method to treat various spinal conditions and is frequently combined with posterior instrumentation. This is traditionally performed in dual positions, with the patient first in lateral then turned prone. Single position lateral surgery (SPS-L) has been studied in a bid to improve surgical efficiency and reduce operative costs, but various limitations have been identified. More recently, the single position prone surgery (SPS-P) has been described as an alternative to address some of these limitations. This case illustrates a patient who underwent SPS-P using an OLIF corridor with subsequent posterior decompression and instrumentation. The benefits and limitations of this procedure compared to the conventional techniques are highlighted in this case. We present the case of a 75-year-old female presenting with thoracic myelopathy over T11/12 and concurrent L2-4 spinal stenosis. She underwent OLIF of L2/3 and L3/4, posterior decompression of T11/12 and L2/3, and posterior instrumented fusion from T10-L4 via a single prone position. We aim to describe the advantages of this approach and the challenges encountered through our experience. SPS-P offers numerous benefits compared to the already powerful SPS-L. In the upper levels of the lumbar spine, a pre-psoas approach may also be feasible. However, the prone lateral technique does not replace all patients suited for a lateral interbody fusion but should be seen as a viable option for selected cases such as those with previous fusion at the L5/S1 with adjacent degeneration requiring extension and posterior fixation.

Short-Term Clinical and Radiographic Evaluation of Patients Treated With Expandable and Static Interbody Spacers Following Lumbar Lateral Interbody Fusion

ObjectiveThe goal of this study was to evaluate, using computed tomography (CT) and magnetic resonance imaging (MRI), patients who underwent oblique lateral interbody fusion (OLIF) using either expandable or static interbody spacers. MethodsThirty-five patients with degenerative disc disease were surgically treated with one-level OLIF and were followed up for more than six months. The Static group consisted of 22 patients, and 13 patients were in the Expandable group. Intraoperative findings included operative time (min), blood loss (ml), and cage size.Low back pain, leg pain, and leg numbness were measured using the Japanese Orthopedic Association score, visual analogue score, and the Roland–Morris Disability Questionnaire. Radiological evaluation using CT and MRI allowed measurement of cage subsidence, cross-sectional area (CSA) of the dural sac, disc height, segmental lordosis, foraminal height, and foraminal CSA preoperatively and six months postoperatively. ResultsThe Expandable group had significantly larger cage height and lordosis than the Static group (p < 0.05). The Expandable group also had greater dural sac area expansion and enlargement of the intervertebral foramen, as well as better correction of vertebral body slip (p < 0.05). Cage subsidence was significantly lower in the Expandable group (p < 0.05). JOA score and VAS for leg numbness were significantly better in the Expandable group (p < 0.05). ConclusionsCompared with static spacers, expandable spacers significantly enlarged the dural sac area, corrected vertebral body slippage, expanded the intervertebral foramen, and achieved good indirect decompression while reducing cage subsidence, resulting in improvement in clinical symptoms.

Predicting adequate segmental lordosis correction in lumbar spinal stenosis patients undergoing oblique lumbar interbody fusion: a focus on the discontinuous segment.

To identify the factors associated with a correction of the segmental angle (SA) with a total change greater than 10° in each level following minimally invasive oblique lumbar interbody fusion (MIS-OLIF). Patients with lumbar spinal stenosis who underwent single- or two-level MIS-OLIF were reviewed. Segments with adequate correction of the SA >10° after MIS-OLIF in immediate postoperative radiograph were categorized as discontinuous segments (D segments), whereas those without such improvement were assigned as continuous segments (C segments). Clinical and radiological parameters were compared, and multivariate logistic regression analysis was performed to identify factors associated with SA correction >10° after MIS-OLIF. Of 211 segments included, 38 segments (18.0%) were classified as D segments. Compared with C segments, D segments demonstrated a significantly smaller preoperative SA (mean ± standard deviation [SD], - 1.1° ± 6.7° vs. 6.6° ± 6.3°, p < 0.001), larger change of SA (mean ± SD, 13.5° ± 3.4° vs. 3.1° ± 3.9°, p < 0.001), and a higher rate of presence of facet effusion (76.3% vs. 48.6%, p = 0.002). Logistic regression revealed preoperative SA (odds ratio (OR) [95% confidence interval (CI)]:0.733 [0.639-0.840], p < 0.001) and facet effusion (OR [95% CI]:14.054 [1.758-112.377], p = 0.027) as significant predictors for >10° SA correction after MIS-OLIF. Preoperative kyphotic SA and facet effusion can predict SA correction >10° following MIS-OLIF. For patients with lordotic SA and no preoperative facet effusion, supplemental procedures, such as anterior column release or posterior osteotomy, should be prepared for additional lumbar lordosis correction required for remnant global sagittal imbalance after MIS-OLIF.

Oblique lateral interbody fusion at L5-S1: feasibility, surgical approach window, incision line, and influencing factors.

The primary aim of this study was to describe the feasibility, surgical approach window (SAW), and incision line (IL) for oblique lateral interbody fusion at L5-S1 (OLIF51) using computed tomography (CT). A secondary aim was to identify associations among approach characteristics and demographic and anthropometric factors. We performed a radiographic study of 50 male and 50 female subjects who received abdominal CT imaging. SAW was measured as the distance from the midline to the medial border of the iliac vessel. IL was measured at the skin surface corresponding to the distance between the center of the disc space and SAW lateral margin. OLIF51 feasibility was defined as the existence of at least a 1-cm SAW without retraction of soft tissues. For the left side, the OLIF51 SAW and IL were 12.1 ± 4.6 and 175.1 ± 55.3mm. For the right side, these measures were 10.0 ± 4.3 and 185.0 ± 52.5mm. Correlations of r = 0.648 (p < 0.001) and r = 0.656 (p < 0.001) were observed between weight and IL on the left and right sides, respectively. OLIF51 was not feasible 23% of the time. To our knowledge, this is the largest CT study to determine the feasibility of performing an OLIF51. Without the use of retraction, OLIF51 is not feasible 23% of the time. Left-sided OLIF51 allows for a larger surgical approach window and smaller incision compared to the right side. Larger incisions are required for adequate surgical exposure in patients with higher weight.

Face, content, and construct validity of a novel VR/AR surgical simulator of a minimally invasive spine operation.

Mixed-reality surgical simulators are seen more objective than conventional training. The simulators' utility in training must be established through validation studies. Establish face-, content-, and construct-validity of a novel mixed-reality surgical simulator developed by McGill University, CAE-Healthcare, and DePuy Synthes. This study, approved by a Research Ethics Board, examined a simulated L4-L5 oblique lateral lumbar interbody fusion (OLLIF) scenario. A 5-point Likert scale questionnaire was used. Chi-square test verified validity consensus. Construct validity investigated 276 surgical performance metrics across three groups, using ANOVA, Welch-ANOVA, or Kruskal-Wallis tests. A post-hoc Dunn's test with a Bonferroni correction was used for further analysis on significant metrics. Musculoskeletal Biomechanics Research Lab, McGill University, Montreal, Canada. DePuy Synthes, Johnson & Johnson Family of Companies, research lab. Thirty-four participants were recruited: spine surgeons, fellows, neurosurgical, and orthopedic residents. Only seven surgeons out of the 34 were recruited in a side-by-side cadaver trial, where participants completed an OLLIF surgery first on a cadaver and then immediately on the simulator. Participants were separated a priori into three groups: post-, senior-, and junior-residents. Post-residents rated validity, median > 3, for 13/20 face-validity and 9/25 content-validity statements. Seven face-validity and 12 content-validity statements were rated neutral. Chi-square test indicated agreeability between group responses. Construct validity found eight metrics with significant differences (p < 0.05) between the three groups. Validity was established. Most face-validity statements were positively rated, with few neutrally rated pertaining to the simulation's graphics. Although fewer content-validity statements were validated, most were rated neutral (only four were negatively rated). The findings underscored the importance of using realistic physics-based forces in surgical simulations. Construct validity demonstrated the simulator's capacity to differentiate surgical expertise.

The analysis of segmental lordosis restored by oblique lumbar interbody fusion and related factors: building up preoperative predicting model

BackgroundOblique lumbar interbody fusion (OLIF) procedures have the potential to increase the segmental lordosis by inserting lordotic cages, however, the amount of segmental lordosis (SL) changes can vary and is likely influenced by several factors, such as patient characteristics, radiographic parameters, and surgical techniques. The objective of this study was to analyze the impact of related factors on the amount of SL changes in OLIF procedures and to build up predictive model for SL changes.MethodsThis is a retrospective study involving prospectively enrolled patients. A total of 119 patients with 174 segments undergoing OLIF procedure were included and analyzed. The lordotic cages used in all cases had 6-degree angle. Radiographic parameters including preoperative and postoperative segmental disc angle (SDA, preSDA and postSDA), SDA changes on flexion-extension views (ΔSDA-FE), CageLocation and CageInclination were measured by two observers. Interobserver reliability of measurements were ensured by analysis of interclass correlation coefficient (ICC > 0.75). Pearson correlation coefficient analysis and multivariate linear regression were employed to identify factors related to SDA changes and to build up predictive model for SDA changes.ResultsThe average change of segmental disc angle (ΔSDA, postSDA-preSDA) was 3.9° ± 4.8° (95% confidence interval [CI]: 3.1°-4.6°) with preSDA 5.3° ± 5.0°. ΔSDA was 10.8° ± 3.2° with negative preSDA (kyphotic), 5.0° ± 3.7° with preSDA ranging from 0° to 6°, and 1.0° ± 4.1° with preSDA> 6°. Correlation analysis revealed a significant negative correlation between ΔSDA and preSDA (r = − 0.713, P < 0.001), CageLocation (r = − 0.183, P = 0.016) and ΔSDA-FE (r = − 0.153, P = 0.044). In the multivariate linear regression, preSDA and CageLocation were included in the predictive model, resulting in minimal adjusted R2 change (0.017) by including CageLocation. Therefore, the recommended predictive model was ΔSDA = 7.9–0.8 × preSDA with acceptable fit. (adjusted R2 = 0.508, n = 174, P < 0.001).ConclusionsThe restoration of segmental lordosis through OLIF largely depends on the preoperative segmental lordosis. The predictive model, which utilized preoperative segmental lordosis, facilitates preoperative planning for corrective surgery using the OLIF procedure.

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

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

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

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

A Comprehensive Analysis of Potential Complications after OLIF : A Review of Postoperative Magnetic Resonance Scans in Over 400 Cases.

This study focuses on identifying potential complications following oblique lumbar interbody fusion (OLIF) through routine magnetic resonance (MR) scans. From 650 patients who underwent OLIF from April 2018 to April 2022, this study included those with MR scans taken one-week post-operatively, and only for indirect decompression patients. The analysis evaluated postoperative MR images for hematoma, cage insertion angles, and indirect decompression efficiency. Patient demographics, post-operatively symptoms, and complications were also evaluated. Out of 401 patients enrolled, most underwent 1- or 2-level OLIF. Common findings included approach site hematoma (65.3%) and contralateral psoas hematoma (19%). The caudal level OLIF was related with less orthogonality and deep insertion of cage. Incomplete indirect decompression occurred in 4.66% of cases but did not require additional surgery. Rare but symptomatic complications included remnant disc rupture (4 cases, 1%) and synovial cyst rupture (4 cases, 1%). This study has identified potential complications associated with OLIF, including approach site hematoma, contralateral psoas hematoma, cage malposition risk at caudal levels, and radiologically insufficient indirect decompression. Additionally, it highlights rare, yet symptomatic complications such as remnant disc rupture and synovial cyst rupture. These findings contribute insights into the relatively under-explored area of OLIF complications.

Minimally Invasive L4-5 Oblique Lumbar Interbody Fusion With Robot-Assisted Single-Position Posterior Fixation: 2-Dimensional Operative Video.

We present here a 58-year-old female patient with L4-5 spondylolisthesis, who underwent a minimally invasive L4-5 oblique lumbar interbody fusion (OLIF) with robot-assisted bilateral posterior instrumented fixation in a single lateral position (Mazor X Stealth Edition, Medtronic). There has been interest in detailed video-based descriptions of single-position surgery with lateral approach interbody fusions, either in the prone or lateral decubitus position.1-6 Particularly, the addition of robotics has been shown to help increase overall operating efficiency in the lateral position with reduced case times even with the increased up-front robot setup time.7,8 The OLIF, also known as an anterior-to-psoas approach, allows for single-position posterior fixation and can be very effective at L4-5 where the anatomy of the iliac crest or lumbar plexus does not preclude this surgical corridor the way it could in the transpsoas lateral lumbar interbody fusion. Clinical outcomes between these 2 lateral approaches have been shown to be very good,9 and OLIF has reduced blood loss while still restoring alignment parameters compared with anterior lumbar interbody fusion, with better fusion and reduced subsidence compared with transforaminal lumbar interbody fusion.10,11 To our knowledge, this is the first video demonstrating a view of the OLIF approach through a high-definition retractor-based camera (MaxView Camera, Viseon Inc). There is no identifying patient information in this video. The participants and any identifiable individuals consented to publication of his/her image, and the patient consented to the procedure.