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Background: This study aimed to evaluate the impact of iliac crest height on clinical and radiological outcomes following oblique lateral interbody fusion (OLIF) at the L4–5 level. Methods: Data of patients who underwent single-level OLIF at the L4–5 level for degenerative spinal stenosis were retrospectively analyzed. The patients were categorized into three groups based on their iliac crest height measured relative to the L4 and L5 pedicles. Categorical and quantitative analyses, including univariate and multivariate logistic regressions, were performed to identify subsidence predictors. Clinical outcomes, including visual analog scale scores for back and leg pain, were assessed over a minimum 2-year follow-up. Results: No significant differences in cage obliquity were observed across the iliac crest height groups (axial angles, p = 0.39; coronal angles, p = 0.79). However, subsidence was significantly more common in patients with higher iliac crest heights, particularly at crest level III, where the subsidence rate reached 43% (p = 0.01). Subsidence was predominantly associated with damage to the L5 endplate, which occurred in 83% of subsidence cases at crest level III. A cutoff value of 12 mm for iliac crest height, above which the risk of subsidence significantly increased, was identified (AUC = 0.688, p = 0.042). Conclusions: Iliac crest height is a critical factor for predicting subsidence following OLIF at the L4–5 level. Surgeons should consider alternative strategies and meticulous preoperative planning in patients with an iliac crest height ≥ 12 mm to reduce the risk of adverse outcomes. Further studies are needed to validate these findings and to explore their long-term implications. [ABSTRACT FROM AUTHOR]

Abstract Lumbar disc herniation (LDH) often necessitates surgical intervention when conservative treatments fail. Oblique Lateral Interbody Fusion (OLIF) and Transforaminal Lumbar Interbody Fusion (TLIF) are two commonly used techniques for treating LDH, each offering distinct surgical approaches. This study aimed to compare the efficacy of OLIF versus TLIF in terms of pain relief, functional outcomes, spinal alignment correction, fusion success, and postoperative recovery. A retrospective study was conducted on 133 patients who underwent either OLIF (n = 68) or TLIF (n = 65) between January 2020 and December 2022. Data on patient demographics, pain and functional outcomes (measured by Visual Analogue Scale [VAS] and Oswestry Disability Index [ODI]), radiological outcomes (sagittal and coronal Cobb angles, apical vertebra deviation), fusion and collapse rates, and postoperative recovery (ambulation time and hospitalization duration) were collected. Statistical analysis was performed using t-tests and chi-square tests, with significance set at P

BACKGROUND: Stand-alone oblique lateral interbody fusion has a high rate of complications of fusion segment sink. Oblique lateral interbody fusion with posterior fixation can provide stable support, but intraoperative position changes and double incisions weaken the advantages of this technique. Oblique lateral interbody fusion combined with lateral plate fixation can achieve one-stage decompression in the same incision, while the lateral internal fixation provides stable support. OBJECTIVE: To analyze the short-term efficacy of oblique lateral interbody fusion combined with lateral plate fixation in the treatment of single-level lumbar degenerative disease. METHODS: The clinical data of 34 patients with single-level lumbar degenerative disease treated with oblique lateral interbody fusion combined with lateral plate fixation were collected from May 2020 to October 2022. Among them, 14 were males and 20 were females aged from 41 to 72 years at the mean age of (58.6 ±9.9) years. There were 11 cases of lumbar spondylolisthesis (I°), 7 cases of lumbar disc herniation with segmental instability, and 16 cases of lumbar spinal stenosis. Operation time, blood loss, and complications were recorded. Visual analog scale scores of lumbago, radiative pain of both lower limbs, and Oswestry disability index scores were evaluated before surgery, 3 months after surgery, and the last follow-up. Dural sac cross-sectional area, intervertebral height, and intervertebral fusion were measured and observed. RESULTS AND CONCLUSION: (1) The 34 patients were followed up for 14-36 months, with an average of (21.3±5.2) months. (2) The operation time ranged from 50 to 92 minutes, with an average of (68.5±11.1) minutes. Intraoperative blood loss was 50-170 mL, with an average of (71.6±25.3) mL. (3) Compared with the preoperative results, the visual analog scale scores and Oswestry disability index scores were significantly decreased at 3 months after surgery and at the last follow-up (P < 0.001), and the maximum Oswestry disability index scores were improved by nearly 50%. (4) Bone fusion was achieved in all patients during half-year follow-up. The overall complication rate was 21% (7/34), including 1 case of plate displacement, 3 cases of cage subsidence, 1 case of psoas weakness, and 2 cases of anterior thigh pain. (5) It is concluded that oblique lateral interbody fusion combined with lateral plate fixation for the treatment of lumbar degenerative diseases has the characteristics of less blood loss, short operation time, rapid postoperative recovery, and significant short-term clinical efficacy with the stable support to a certain extent. The long-term curative effect needs further follow-up observation. [ABSTRACT FROM AUTHOR]

Objective Oblique lateral interbody fusion (OLIF) is a minimally invasive procedure for stabilizing the spine and indirectly decompressing the neural elements. There is sparse data on unsatisfactory outcomes that require additional interventions (surgery or intervention) after OLIF. This study aimed to identify the causes, and risk factors of these reintervention. Methods This was a single-center retrospective study of the patients who underwent the OLIF procedure from June 2016 to March 2023. Several clinical and radiographic parameters were studied. We also analyzed associations between several potential risk factors and the reintervention following OLIF. Results A total of 231 patients were included. Over an average of 2.5 years of follow-up, 28 patients (12.1%) required a reintervention. Adjacent segment disease (ASD) was the most common cause of reintervention. The risk factors associated with reintervention were previous surgery (adjusted odds ratio [aOR], 4.44; 95% confidence interval [CI], 1.21–16.33; p=0.02) and high preoperative Oswestry Disability Index (ODI) scores (aOR, 1.04; 95% CI, 1.00–1.08; p=0.03). Although increasing the duration of follow-up was not statistically significant, the 95% CI was consistent with an increased risk of reintervention with longer follow-up (OR, 1.18; 95% CI, 0.94–1.50). Conclusion This study showed that patients with prior lumbar surgery and high preoperative ODI scores were more likely to require additional intervention after the OLIF procedure. In addition, an increasing duration of follow-up was associated with an increased risk of reintervention. The most common reason for reintervention was ASD after OLIF.

Objective: Oblique lateral interbody fusion (OLIF) is a minimally invasive procedure for stabilizing the spine and indirectly decompressing the neural elements. There is sparse data on unsatisfactory outcomes that require additional interventions (surgery or intervention) after OLIF. This study aimed to identify the causes, and risk factors of these reintervention. Methods: This was a single-center retrospective study of the patients who underwent the OLIF procedure from June 2016 to March 2023. Several clinical and radiographic parameters were studied. We also analyzed associations between several potential risk factors and the reintervention following OLIF. Results: A total of 231 patients were included. Over an average of 2.5 years of follow-up, 28 patients (12.1%) required a reintervention. Adjacent segment disease (ASD) was the most common cause of reintervention. The risk factors associated with reintervention were previous surgery (adjusted odds ratio [aOR], 4.44; 95% confidence interval [CI], 1.21–16.33; p=0.02) and high preoperative Oswestry Disability Index (ODI) scores (aOR, 1.04; 95% CI, 1.00–1.08; p=0.03). Although increasing the duration of follow-up was not statistically significant, the 95% CI was consistent with an increased risk of reintervention with longer follow-up (OR, 1.18; 95% CI, 0.94–1.50). Conclusion: This study showed that patients with prior lumbar surgery and high preoperative ODI scores were more likely to require additional intervention after the OLIF procedure. In addition, an increasing duration of follow-up was associated with an increased risk of reintervention. The most common reason for reintervention was ASD after OLIF. [ABSTRACT FROM AUTHOR]

One of the most common complications of lumbar fusions is cage subsidence, which leads to collapse of disc height and reappearance of the presenting symptomology. However, definitions of cage subsidence are inconsistent, leading to a variety of subsidence calculation methodologies and thresholds. To review previously published literature on cage subsidence in order to present the most common methods for calculating and defining subsidence in the anterior lumbar interbody fusion (ALIF), oblique lateral interbody fusion (OLIF), and lateral lumbar interbody fusion (LLIF) approaches. A search was completed in PubMed and Embase with inclusion criteria focused on identifying any study that provided descriptions of the method, imaging modality, or subsidence threshold used to calculate the presence of cage subsidence. A total of 69 articles were included in the final analysis, of which 18 (26.1%) reported on the ALIF approach, 22 (31.9%) on the OLIF approach, and 31 (44.9%) on the LLIF approach, 2 of which reported on more than one approach. ALIF articles most commonly calculated the loss of disc height over time with a subsidence threshold of > 2 mm. Most OLIF articles calculated the total amount of cage migration into the vertebral bodies, with a threshold of > 2 mm. LLIF was the only approach in which most articles applied the same method for calculation, namely, a grading scale for classifying the loss of disc height over time. We recommend future articles adhere to the most common methodologies presented here to ensure accuracy and generalizability in reporting cage subsidence. [ABSTRACT FROM AUTHOR]

Purpose: 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. Methods: 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. Results: For the left side, the OLIF51 SAW and IL were 12.1 ± 4.6 and 175.1 ± 55.3 mm. For the right side, these measures were 10.0 ± 4.3 and 185.0 ± 52.5 mm. 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. Conclusion: 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. [ABSTRACT FROM AUTHOR]

Abstract Purpose To 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. Method 33 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. Result The 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

Purpose: To 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. Method: 33 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. Result: The 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). Conclusion: The 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. [ABSTRACT FROM AUTHOR]

Abstract Background Finite element analysis (FEA) was performed to investigate the biomechanical differences between different adjunct fixation methods for oblique lumbar interbody fusion (OLIF) and to further analyze its effect on adjacent segmental degeneration. Methods We built a single-segment (Si-segment) finite element model (FEM) for L4-5 and a double-segment (Do-segment) FEM for L3-5. Each complete FEM was supplemented and modified, and both developed two surgical models of OLIF with assisted internal fixation. They were OLIF with posterior bilateral percutaneous pedicle screw (TINA system) fixation (OLIF + BPS) and OLIF with lateral plate system (OLIF + LPS). The range of motion (ROM) and displacement of the vertebral body, cage stress, adjacent segment disc stress, and spinal ligament tension were recorded for the four models during flexion/extension, right/left bending, and right/left rotation by applying follower load. Results For the BPS and LPS systems in the six postures of flexion, extension, right/left bending, and right/left rotation, the ROM of L4 in the Si-segment FEM were 0.32°/1.83°, 0.33°/1.34°, 0.23°/0.47°, 0.24°/0.45°, 0.33°/0.79°, and 0.34°/0.62°; the ROM of L4 in the Do-segment FEM were 0.39°/2.00°, 0.37°/1.38°, 0.23°/0.47°, 0.21°/0.44°, 0.33°/0.57°, and 0.31°/0.62°, and the ROM of L3 in the Do-segment FEM were 6.03°/7.31°, 2.52°/3.50°, 4.21°/4.38°, 4.21°/4.42°, 2.09°/2.32°, and 2.07°/2.43°. BPS system had less vertebral displacement, less cage maximum stress, and less spinal ligament tension in Si/Do-segment FEM relative to the LPS system. BPS system had a smaller upper adjacent vertebral ROM, greater intervertebral disc stress in terms of left and right bending as well as left and right rotation compared to the LPS system in the L3-4 of the Do-segment FEM. There was little biomechanical difference between the same fixation system in the Si/Do-segment FEM. Conclusions Our finite element analysis showed that compared to OLIF + LPS, OLIF + BPS (TINA) is more effective in reducing interbody stress and spinal ligament tension, and it better maintains the stability of the target segment and provides a better fusion environment to resist cage subsidence. However, OLIF + BPS (TINA) may be more likely to cause adjacent segment degeneration than OLIF + LPS.

There are 2 surgical corridors to L5-S1 lumbar interbody fusion via the left oblique approach: anterior to psoas−oblique lateral interbody fusion (ATP-OLIF) and oblique−anterior lumbar interbody fusion (O-ALIF). The aim of this study was to evaluate criteria to guide the selection of surgical corridors for L5-S1 lumbar interbody fusion via the left oblique approach. According to the structure of L5-S1 segment left common iliac vein (LCIV) in axial magnetic resonance image, the LCIV was divided into 6 types. O-ALIF was performed for type I and type II. ATP-OLIF was performed for type A and type B. For sexually active men, ATP-OLIF was chosen. Between April 2020 and April 2022, 22 patients were assigned to ATP-OLIF or O-ALIF based on the type of LCIV. Clinical outcomes and radiographic outcomes were assessed. There were 11 cases in O-ALIF group (type I, n = 10; type II, n = 1) and 11 cases in ATP-OLIF group (type A, n = 8; type B, n = 3). No differences were observed in clinical outcomes (Oswestry Disability Index, VAS, and complication rate); radiographic outcomes (mean disk height and segmental lordosis angle); length of hospital stay; operation time; and blood loss. No vascular injury occurred in either group. This may be an appropriate criterion to guide the selection of surgical corridor for L5-S1 lumbar interbody fusion through the left oblique approach. O-ALIF was performed for type I and type II. ATP-OLIF was performed for type A and type B. For sexually active men, ATP-OLIF was chosen. According to this standard, the operation can be performed safely and with good clinical results. [ABSTRACT FROM AUTHOR]

The aim of this systematic review was to evaluate the risk factors for cage subsidence (CS) after oblique lumbar interbody fusion (OLIF). The cohort and case-control studies which reporting potential risk factors for CS following OLIF were searched in PubMed, Embase, and Web of Science from database inception to June 17, 2023. Two researchers independently screened the literature, extracted data, and evaluated the quality of the literature according to the Newcastle Ottawa Scale. RevMan5.3 software was used for Meta analysis. χ2 statistics and I 2 statistics were used to evaluate heterogeneity, and the analysis results were represented by forest plots. A total of 8 studies with 280 cases of CS from 832 patients who underwent OLIF met the inclusion criteria. Elderly patients over 60 years old (odds ratio [OR] 2.44, 95% CI 1.38–4.31, P = 0.002), osteoporosis (OR 4.18, 95% CI 2.30–7.61, P = 0.002), end plate injury (OR 5.72, 95% CI 2.32–14.11, P = 0.0002), and overdistraction of intervertebral space (OR 1.67, 95% CI 1.3 2–2.11, P < 0.0001) were potential risk factors, while Hounsfield units value of the vertebral body (OR 0.97, 95% CI 0.95–1.00, P = 0.02) is a protective factor. The number of operative segments did not increase the risk of CS. Older age, osteoporosis, endplate injury, and overdistraction of the intervertebral space may increase the risk of CS after OLIF. Although the incidence rate of CS is low, implementing effective preventions is a priority for clinicians based on these risk factors. [ABSTRACT FROM AUTHOR]

Purpose: In combined anterior–posterior adult spinal deformity surgery, the optimal combination of anterior and posterior procedures remains unclear. We aimed to demonstrate the radiological outcomes and relevant factors in oblique lateral interbody fusion (OLIF) for lumbosacral fractional curve (FC) correction combined with open posterior surgery in degenerative lumbar scoliosis (DLS). Methods: This study involved 42 consecutive patients with DLS who had a major curve (MC) ≥ 20° and an FC (L4 to S1) ≥ 10°, and underwent a combined anterior–posterior surgery Changes in the MC, FC, coronal balance distance, type of coronal imbalance, coronal/sagittal disc angle at L4-5 and L5-S1, L4 and L5 tilt, and sagittal parameters were examined. The associations between FC correction and demographic, surgical, and radiological factors were analysed. Results: The FC decreased from 16.9 ± 7.3° preoperatively to 6.6 ± 4.4° at the last follow-up (P < 0.001). The coronal disc angle at L4-5 and L5-S1 were, respectively, 6.8 ± 2.2° and 6.0 ± 4.1° preoperatively and decreased to 2.2 ± 2.1 and 1.2 ± 1.3° at the last follow-up (both P < 0.001). The changes in FC were greater in uppermost instrumented level > T10 (P < 0.001), and associated with the preoperative FC (r = 0.820, P < 0.001), L4 tilt (r = 0.434, P = 0.007), and L5 tilt (r = 0.462, P = 0.003). Conclusion: OLIF at the FC combined with open posterior surgery is an effective combined anterior–posterior correction strategy in DLS. [ABSTRACT FROM AUTHOR]

Background and Objectives: Although adult spinal deformity (ASD) surgery brought about improvement in the quality of life of patients, it is accompanied by high invasiveness and several complications. Specifically, mechanical complications of rod fracture, instrumentation failures, and pseudarthrosis are still unsolved issues. To better improve these problems, oblique lateral interbody fusion at L5/S1 (OLIF51) was introduced in 2015 at my institution. The objective of this study was to compare the clinical and radiologic outcomes of anterior–posterior combined surgery for ASD between the use of OLIF51 and transforaminal interbody fusion (TLIF) at L5/S1. Materials and Methods: A total of 117 ASD patients received anterior–posterior correction surgeries either with the use of OLIF51 (35 patients) or L5/S1 TLIF (82 patients). In both groups, L1–5 OLIF and minimally invasive posterior procedures of hybrid or circumferential MIS were employed. The sagittal and coronal spinal alignment and spino-pelvic parameters were recorded preoperatively and at follow-up. The quality-of-life parameters and visual analogue scale were evaluated, as well as surgical complications at follow-up. Results: The average follow-up period was thirty months (13–84). The number of average fused segments was eight (4–12). The operation time and estimated blood loss were significantly lower in OLIF51 than in TLIF. The PI-LL mismatch, LLL, L5/S1 segmental lordosis, and L5 coronal tilt were significantly better in OLIF51 than TLIF. The complication rate was statistically equivalent between the two groups. Conclusions: The introduction of OLIF51 for adult spine deformity surgery led to a decrease in operation time and estimated blood loss, as well as improvement in sagittal and coronal correction compared to TLIF. The circumferential MIS correction and fusion with OLIF51 serve as an effective surgical modality which can be applied to many cases of adult spinal deformity. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Objective Cage subsidence is a common morbidity after oblique lumbar interbody fusion (OLIF), with risk of compromising clinical and radiographic outcomes. The study aims to describe an innovative reverse lumbar pedicle screw (RLPS) technique in OLIF and compare its effect on restricting cage subsidence with classical lateral fixation (LF) in radiological and clinical evaluation. Method Consecutive patients having undergone single‐level OLIF‐LF/RLPS from 2018 to 2020 were retrospectively reviewed. In OLIF‐RLPS, the upper entry point was determined at the intersection between one horizontal line (1 cm above inferior endplate) and one vertical line (dissecting anterior and middle thirds of the vertebra) while the inferior entry point between one horizontal line (5 mm below superior endplate) and the same vertical line. Trajectories were from vertebrae reverse into contralateral pedicle. Radiological evaluation included disc height (DH) and segmental lordosis (SL); cage subsidence was evaluated by DH loss. Clinical assessment included visual analogue scale (VAS) and Oswestry disability index (ODI). Student t or Mann–Whitney U test was used for continuous variation according to normality analysis while Chi‐square test for category variation. Results A total of 29 patients had been enrolled in the study including 14 cases in the RLPS group and 15 cases in the LF group. The DH in the OLIF‐RLPS group had increased from the preoperative 9.07 ± 1.73 mm to 13.73 ± 1.83 mm postoperatively, without significant difference compared with the OLIF‐LF group during the perioperative, but decreased to 12.53 ± 1.74 mm in 3 months and maintained at 12.00 ± 1.45 mm in 12 months, significantly higher than the OLIF‐LF group (p

Objective We introduced a new preoperative method, the “expanded surgical corridor,” to evaluate the actual safety corridor, which may expand the possibility of performing oblique lateral interbody fusion (OLIF). Methods Axial T2-weighted magnetic resonance images at the L4–5 disc level of 511 lumbar degenerative disease patients was evaluated. The distance between the medial edge of the left-sided psoas muscle and the major artery was measured as the conventional surgical corridor (CSc). The distance between the major vein and lumbar plexus was measured as the expanded surgical corridor (ESc). Results The mean CSc and ESc were 13.9 ± 8.20 and 37.43 ± 10.1 mm, respectively. No surgical corridor was found in 7.05% of CSc and 1.76% of ESc, small corridor (≤ 1 cm) was found in 27.40% of CSc and 0.59% of ESc, moderate corridor (1–2 cm) was found in 42.07% of CSc and 1.96% of ESc, and large corridor (> 2 cm) was found in 23.48% of CSc and 95.69% of ESc. A total of 33.83% (45 of 133) of whom were preoperatively categorized as having a limited surgical corridor by conventional measurement, underwent OLIF L4–5 successfully. Conclusion By using the ESc, only 2.35% were categorized as having a limited surgical corridor. The other 97.65% of the patients had an approachable corridor that could be successfully operated by experienced spine surgeons who employ meticulous surgical dissection and thorough understanding of the anatomical structures. The ESc may represent true accessibility to the disc space for OLIF, particularly at the L4–5 level.

Objective To illustrate a simultaneous single-position oblique lateral interbody fusion (SP-OLIF) combined with unilateral percutaneous pedicle screw fixation in treating single-level lumbar tuberculosis, compared with posterior-only approach in clinical and radiographic evaluations. Methods Consecutive patients who had undergone surgeries for single-level lumbar tuberculosis from January 2018 to December 2020 were retrospectively reviewed. The patients included were divided into SP-OLIF and posterior-only groups according to surgical methods applied, with follow-up for at least 36 months. Outcomes included estimated blood loss, operative time, and complications for safety evaluation; visual analogue scale (VAS), Oswestry Disability Index (ODI) for efficacy evaluation; erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) for evaluating tuberculosis activity; x-ray and computed tomography scan were used for radiographic evaluation. Results A total of 136 patients had been enrolled in the study (60 for SP-OLIF and 76 for Posterior-only). The median operative time, blood loss, and hospital stay in SP-OLIF group were significantly less, with a lower complication rate. Meanwhile, the SP-OLIF group showed substantially lower VAS in 1 and 7 days and decreased ODI in the first month postoperatively, without significant difference afterward. Similarly, the median CRP and ESR in SP-OLIF group were significantly lower in 3 and 7 days postoperatively. All indicators had reduced to normal after 3 months. No recurrence had been reported throughout the whole follow-up. Conclusion SP-OLIF was an efficient minimally invasive protocol for single-level lumbar tuberculosis, facilitating earlier clinical improvement, with decreased blood loss, operative time and hospital stay compared with posterior-only approach.

Abstract Objective To compare the surgical trauma and outcomes between oblique lateral interbody fusion (OLIF) and posterior fixation and posterior lumbar interbody fusion (PLIF) with fixation for adult degenerative scoliosis (ADS). Methods We included ADS patients who underwent OLIF with fixation or PLIF with fixation treatment from June 2020 to December 2022. The preoperative and postoperative spinal pelvic parameters were measured using X-rays. Clinical symptoms were measured using the Oswestry Disability Index and a visual analog scale. We recorded operation time, intraoperative blood loss, blood transfusion, albumin infusion, surgical fixation segment, surgical osteotomy segment, time, and drainage volume. Results Forty patients with ADS were included: 20 with OLIF with posterior fixation and 20 with PLIF matched for age, sex, pelvic incidence, and Cobb angle with the OLIF group. There were no significant differences in age, gender, BMI, preoperative spinal parameters, or preoperative clinical symptoms between the groups (p > 0.05). There were no statistical differences in postoperative spinal parameters or clinical symptoms (p > 0.05). Patients in the OLIF group had less intraoperative blood loss (p

Objective: Cage subsidence is a common morbidity after oblique lumbar interbody fusion (OLIF), with risk of compromising clinical and radiographic outcomes. The study aims to describe an innovative reverse lumbar pedicle screw (RLPS) technique in OLIF and compare its effect on restricting cage subsidence with classical lateral fixation (LF) in radiological and clinical evaluation. Method: Consecutive patients having undergone single‐level OLIF‐LF/RLPS from 2018 to 2020 were retrospectively reviewed. In OLIF‐RLPS, the upper entry point was determined at the intersection between one horizontal line (1 cm above inferior endplate) and one vertical line (dissecting anterior and middle thirds of the vertebra) while the inferior entry point between one horizontal line (5 mm below superior endplate) and the same vertical line. Trajectories were from vertebrae reverse into contralateral pedicle. Radiological evaluation included disc height (DH) and segmental lordosis (SL); cage subsidence was evaluated by DH loss. Clinical assessment included visual analogue scale (VAS) and Oswestry disability index (ODI). Student t or Mann–Whitney U test was used for continuous variation according to normality analysis while Chi‐square test for category variation. Results: A total of 29 patients had been enrolled in the study including 14 cases in the RLPS group and 15 cases in the LF group. The DH in the OLIF‐RLPS group had increased from the preoperative 9.07 ± 1.73 mm to 13.73 ± 1.83 mm postoperatively, without significant difference compared with the OLIF‐LF group during the perioperative, but decreased to 12.53 ± 1.74 mm in 3 months and maintained at 12.00 ± 1.45 mm in 12 months, significantly higher than the OLIF‐LF group (p < 0.05). At the last follow‐up, 7.1% (1/14) cases in the OLIF‐RLPS group had shown subsidence of grade I, significantly less than 46.7% (7/15) cases in the OLIF‐LF group. Pain and disability had improved similarly in two groups, without significant difference detected between two groups at the last follow‐up. Conclusion: RLPS technique with modified entry points and prolonged trajectory could effectively restrict cage subsidence in OLIF postoperatively compared with traditional lateral fixation. [ABSTRACT FROM AUTHOR]

Objective: We introduced a new preoperative method, the "expanded surgical corridor," to evaluate the actual safety corridor, which may expand the possibility of performing oblique lateral interbody fusion (OLIF). Methods: Axial T2-weighted magnetic resonance images at the L4-5 disc level of 511 lumbar degenerative disease patients was evaluated. The distance between the medial edge of the left-sided psoas muscle and the major artery was measured as the conventional surgical corridor (CSc). The distance between the major vein and lumbar plexus was measured as the expanded surgical corridor (ESc). Results: The mean CSc and ESc were 13.9 ± 8.20 and 37.43 ± 10.1 mm, respectively. No surgical corridor was found in 7.05% of CSc and 1.76% of ESc, small corridor (= 1 cm) was found in 27.40% of CSc and 0.59% of ESc, moderate corridor (1-2 cm) was found in 42.07% of CSc and 1.96% of ESc, and large corridor (> 2 cm) was found in 23.48% of CSc and 95.69% of ESc. A total of 33.83% (45 of 133) of whom were preoperatively categorized as having a limited surgical corridor by conventional measurement, underwent OLIF L4-5 successfully. Conclusion: By using the ESc, only 2.35% were categorized as having a limited surgical corridor. The other 97.65% of the patients had an approachable corridor that could be successfully operated by experienced spine surgeons who employ meticulous surgical dissection and thorough understanding of the anatomical structures. The ESc may represent true accessibility to the disc space for OLIF, particularly at the L4-5 level. [ABSTRACT FROM AUTHOR]

Background: The kidneys, ribs, liver, spleen, and iliac crests can pose access-related issues to the disc space during both anterior-to-psoas (ATP) and transpsoas (TP) surgical approaches. The aim of this study was to identify and compare the presence and degree of obstruction caused by these structures for the ATP and TP approaches bilaterally from L1 to S1 using abdominal computed tomography. Methods: Presence of obstruction by a given structure was recorded if the structure was within ATP or TP borders. Degree of obstruction was calculated as the quotient of the structure measurement within the ATP or TP approach divided by the entire corridor length at the point of obstruction. Results: The percentage of time the left kidney was present during the ATP vs TP approaches at L1 to L2 was 44% vs 89% (P < 0.001), at L2 to L3 was 26% vs 75% (P < 0.001), and at L3 to L4 was 5% vs 19% (P < 0.001). For the right kidney, these values were 37% vs 78% (P < 0.001), 43% vs 71% (P < 0.001), and 11% vs 18% (P < 0.001). The percentage of time the left rib was present during ATP vs TP approaches was 41% vs 81% (P < 0.001) at L1 to L2 and 11% vs 26% (P = 0.413) at L2 to L3. With respect to the liver, the ATP approach was obstructed 56%, 30%, and 9% of the time at the levels of L1 to L2, L2 to L3, and L3 to L4; the liver was not present in L1 to L4 TP approach. Conclusions: This study is the first to both characterize and compare nonneurological structures at risk during ATP and TP fusion approaches bilaterally from L1 to S1 using abdominal computed tomography. Findings suggest the ATP approach poses less structures at risk relative to the TP approach with respect to the kidneys, ribs, and iliac crests bilaterally. The TP approach offers advantages compared with ATP approach with respect to the liver and spleen. [ABSTRACT FROM AUTHOR]

Study Design. Retrospective radiological study. Objective. This study aimed to examine whether cage obliquity affects radiological outcomes in oblique lateral interbody fusion (OLIF). Summary of Background Data. The OLIF cage enters the disk space in the oblique direction and is then turned to the true orthogonal orientation. However, orthogonal cage placement is often hindered by cage rotation limitations. Few studies have examined the degree of cage obliquity and its effects in OLIF. Materials and Methods. This study involved 171 levels in 118 consecutive patients who underwent OLIF between L2--L3 and L4--L5 with a minimum two-year follow-up. Cage obliquity was divided into three groups on postoperative axial computed tomography images; cage obliquity <10° (group 1), cage obliquity ≥ 10° and <20° (group 2), and cage obliquity ≥20° (group 3). The radiological outcomes included anterior/posterior disk height, intervertebral disk angle, foraminal height, fusion, and cage subsidence. Postoperative complications related to cage obliquity were examined. Results. The mean cage obliquity of the 171 cages was 11.3± 6.9°. Cage obliquity was greater at the L4--L5 level (13.4± 6.4°) than at other levels (L2--L3 and L3--L4: 6.5± 7.0° and 10.1± 6.2°, respectively) (P<0.05). There were no significant differences in radiological outcomes among the groups. There were two cases of postoperative contralateral neurological symptoms in group 3. Conclusions. Our study showed that the orthogonal cage rotation in OLIF achieved adequate lateral cage placement. Although accurate cage rotation can be limited at the lower lumbar segments, radiological outcomes were not affected by cage obliquity. [ABSTRACT FROM AUTHOR]

Abstract Purpose To advance a modified oblique lumbar interbody fusion (M-OLIF) achieving anterior debridement and posterior freehand instrumentation simultaneously in circumferential approach via dynamic position and compare with traditional combined anterior–posterior surgery (CAPS) in clinical and radiological evaluation. Patients and methods Innovative freehand instrumentation in floating position was described. Consecutive patients having undergone surgeries for lumbar tuberculosis from 2017 January to 2019 December had been retrospectively reviewed. Patients with follow-ups for at least 36 months were included and divided into M-OLIF or CAPS group according to surgical methods applied. Outcomes included operation time, estimated blood loss, complication profile for safety evaluation; Vascular Analogue Scale (VAS) and Oswestry Disability Index (ODI) for efficacy evaluation; C-reactive protein and Erythrocyte Sedimentation Rate for tuberculosis activity and recurrence evaluation; X-ray and CT scan for radiological evaluation. Results Totally 56 patients had been enrolled in the study (26 for M-OLIF and 30 for CAPS). Compared with CAPS group, M-OLIF group illustrated significantly decreased estimated blood loss, operation time, hospital stay, and less postoperative morbidities. Meanwhile, M-OLIF group showed earlier improvement in VAS in 3 days and ODI in the first month postoperatively, without obvious discrepancy in further follow-ups. The overall screw accuracy in M-OLIF and CAPS group was 93.8% and 92.3% respectively, without significant difference in perforation distribution. Conclusion M-OLIF was efficient for lumbar tuberculosis requiring multilevel fixation, with reduced operation time and iatrogenic trauma, earlier clinical improvement compared with traditional combined surgery.

Objective Lumbar sympathetic trunk (LST) injury is one of the major complications after oblique lumbar interbody fusion (OLIF). LST injury often manifests as unequal skin temperature in lower limbs after operation, and there may be a large number of missed diagnoses due to the lack of attention and different diagnostic methods. The study aimed to investigate the incidence and clinical characteristics of LST injury after OLIF. Methods The data of patients with lumbar degenerative diseases who underwent OLIF in our hospital from April 2016 to October 2017 were retrospectively analyzed. Finally, a total of 54 patients were included. There were 10 males and 44 females, aged 58.4 ± 10.9 years. The skin temperature of lower limbs was measured before and a day after surgery. The patients were followed up at 1 week, 6 weeks, 6 months, and 2 years after the surgery. Likert five‐point scale was used to evaluate the discomfort caused by LST injury. Injury severity score was introduced to grade injury degree according to the recovery time of postoperative symptoms. The chi‐square test was used to analyze the association of incidence of lumbar sympathetic trunk (LST) injury with contributing factors, such as gender and number of surgical segments. Results The unequal temperature was not found before surgery in all the patients. Postoperatively, 16 cases (29.6%) had difference of skin temperature more than 0.5 °C and were diagnosed with LST injury. Eight patients (14.8%) had self‐perception of skin temperature differences, and 12 patients (22.2%) had other symptoms, such as muscle pain, numbness, and weakness, which were not statistically different between patients with and without lumbar sympathetic trunk injury (p > 0.05). In the 16 patients with LST injury, the difference of skin temperature between the two legs was 0.6 ± 0.1 °C on the first day, and the temperature difference lasted for 1.5–~12 months. According to Likert five‐point scale, two cases (12.5%) were poor, and 14 cases (87.5%) were moderate immediately after surgery. Fifteen cases improved to some extent 6 weeks to 12 months after surgery. Conclusion Postoperative LST injury is mainly manifested by different temperature of lower limbs. The incidence was higher in patients with multi‐segment OLIF than in those with single‐segment OLIF, and the subjective experience of most patients with LST injury was moderate discomfort.

Background: Oblique lumbar interbody fusion (OLIF) offers indirect decompression of stenotic lesions of the spinal canal and foramen through immediate disc height restoration. Only a few studies have reported the effect of cage position and associated intraoperatively modifiable factors for successful immediate indirect decompression following OLIF surgery. This study aimed to investigate the intraoperatively modifiable factors for successful radiological outcomes of OLIF. Methods: This study included 46 patients with 80 surgical levels who underwent OLIF without direct posterior decompression. Preoperative and postoperative radiological parameters were evaluated and intraoperatively modifiable radiologic parameters for successful immediate radiologic decompression on magnetic resonance image (MRI) were determined. Radiologic parameters were preoperative and postoperative radiological parameters including anterior disc height (ADH), posterior disc height (PDH) lumbar lordotic angle (LLA), segmental lordotic angle (SLA), foraminal height (FH), cage position, cross-sectional area (CSA) of the thecal sac, cross-sectional foraminal area (CSF), facet distance (FD) Results: All radiologic outcomes significantly improved. Comparing preoperative and postoperative values, mean CSA increased from 99.63±40.21 mm2 to 125.02±45.90 mm2 (p

Study Design: Retrospective study Objectives: The combination of oblique lateral interbody fusion (OLIF) with grade 2 posterior column osteotomy (PCO) is an effective treatment for adult spinal deformity. However, grade 2 PCO may lead to pseudoarthrosis because it involves complete removal of the bilateral posterior facet joints. The main study objective was to determine the achievement rate of anterior and posterolateral fusion resulting in circumferential fusion in patients who underwent combined OLIF and grade 2 PCO. Methods: This retrospective study included consecutive patients who underwent OLIF and grade 2 PCO. The group comprised a long fusion group, with fusion from the thoracic level to the ilium, and a short fusion group, with fusion within the lumbar region. The OLIF with percutaneous pedicle screw insertion group was also used for reference. The Brantigan–Steffee–Fraser classification was used to assess interbody fusion and Lenke classification for assessment of posterolateral fusion. Results: Sixty-six patients with 109 lumbar levels were included in the study. We observed 100% anterior fusion in all 3 groups. The fusion rate for posterolateral fusion between the OLIF-grade 2 PCO group was 97%, with very low (3%) non-circumferential fusion (pseudoarthrosis only at the osteotomy site). In most cases, solid posterolateral fusions (Lenke A) occurred within 24 months. Conclusions: The combination of OLIF and grade 2 PCO resulted in circumferential fusion for most (97%) of the cases within 24 months. OLIF and grade 2 PCO are considered a good combination treatment to achieve sufficient lumbar lordosis and solid bone fusion. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective cohort study Objectives: This study aimed to report the incidence and potential risk factors of polyetheretherketone (PEEK) cage subsidence following oblique lateral interbody fusion (OLIF) for lumbar degenerative diseases. We proposed also an algorithm to minimize subsidence following OLIF surgery. Methods: The study included a retrospective cohort of 107 consecutive patients (48 men and 59 women; mean age, 67.4 years) who had received either single- or multi-level OLIF between 2012 and 2019. Patients were classified into subsidence and non-subsidence groups. PEEK cage subsidence was defined as any violation of either endplate from the computed tomography scan in both sagittal and coronal views. Preoperative variables such as age, sex, body mass index, bone mineral density (BMD) measured by preoperative dual-energy X-ray absorptiometry, smoking status, corticosteroid use, diagnosis, operative level, multifidus muscle cross-sectional area, and multifidus muscle fatty degeneration were collected. Age-related variables (height and length) were also documented. Univariate and multivariate logistic regression analyses were used to analyze the risk factors of subsidence. Results: Of the 107 patients (137 levels), 50 (46.7%) met the subsidence criteria. Higher PEEK cage height had the strongest association with subsidence (OR = 9.59, P <.001). Other factors significantly associated with cage subsistence included age >60 years (OR = 3.15, P =.018), BMD <−2.5 (OR = 2.78, P =.006), and severe multifidus muscle fatty degeneration (OR = 1.97, P =.023). Conclusions: Risk factors for subsidence in OLIF were age >60 years, BMD < −2.5, higher cage height, and severe multifidus muscle fatty degeneration. Patients who had subsidence had worse early (3 months) postoperative back and leg pain. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective clinical case series. Objectives: To investigate the risk factors for intraoperative endplate violations and delayed cage subsidence after oblique lateral interbody fusion (OLIF) surgery. Secondly, to examine whether low Hounsfield unit (HU) values at different regions of the endplate are associated with intraoperative endplate violation or delayed cage subsidence. Methods: 61 patients (aged 65.1 ± 9.5 years; 107 segments) who underwent OLIF with or without posterior instrumentation from May 2015 to April 2019 were retrospectively studied. Intraoperative endplate violation was measured on sagittal reconstructed computerized tomography (CT) images immediate postoperatively, while delayed cage subsidence was evaluated using lateral radiographs and defined at 1-month follow-up or later. Demographic information and clinical parameters such as age, body mass index, bone mineral density, number of surgical levels, cage dimension, disc height restoration, visual analogue scale (VAS), and HU at different regions of the endplate were obtained. Results: Total postoperative cage subsidence was identified in 45 surgical levels (42.0%) in 26 patients (42.6%) up till postoperative 1-year follow-up. Low HU value at the ipsilateral epiphyseal ring was an independent risk factor for intraoperative endplate violation (P =.008) with a cut-off value of 326.21 HUs. Low HU values at the central endplate had a significant correlation with delayed cage subsidence in stand-alone cases (P =.013) with a cut-off value of 296.42 HUs. VAS scores were not different at 1 week postoperatively in cases with or without intraoperative endplate violation (3.12 ±.73 vs 2.89 ±.72, P =.166) and showed no difference at 1 year with or without delayed cage subsidence (1.95 ±.60 vs 2.26 ±.85, P =.173). Conclusions: Intraoperative endplate violation and delayed cage subsidence are not uncommon with OLIF surgery. HUs of the endplate are good predictors for intraoperative endplate violation and cage subsidence since they can represent the regional bone quality of the endplate in contact with the implant. VAS improvements were not affected by intraoperative endplate violation or delayed cage subsidence at 1-year follow-up. Level of Evidence: Level III. [ABSTRACT FROM AUTHOR]

Abstract Background To perform a comparative assessment of percutaneous transfacet screws (TFS) and percutaneous bilateral pedicle screws (BPS) in oblique lateral interbody fusion (OLIF) for the treatment of single-level degenerative lumbar spine diseases in terms of radiological examinations and clinical outcomes. Methods Sixty-six patients who received single-level OLIF with percutaneous supplementary fixation assisted by the robot for the treatment of degenerative lumbar spine diseases were selected. There were 16 cases of OLIF with TFS and 50 cases of OLIF with BPS. The propensity score matching method selected 11 patients in each group with matched characteristics to perform a clinical comparison. Results The estimated blood loss was 68.2 ± 25.2 ml in the OLIF with TFS group compared to 113.6 ± 39.3 ml in the OLIF with BPS group (P 0.05). Quantitative assessments of back/leg pain of the two groups reached a healthy level in the late period of the follow-up. Conclusion Both TFS and BPS techniques for the OLIF surgery relieve back pain caused by degenerative lumbar spine diseases. The TFS technique exhibits less blood loss compared with the BPS. A moderate cage subsidence is present in TFS but no complication is reported.

Objective Adjacent segment disease (ASD) is considered any abnormal process that develops in the mobile segment next to spinal fusion, accompanied by related symptoms. To evaluate the efficacy and complications of oblique lateral interbody fusion (OLIF) combined with bridge‐locking fusion on ASD after lumbar fusion. Methods A total of 35 ASD patients who required re‐operation after lumbar fusion in our hospital from March 2014 to March 2020 were retrospectively analyzed, among which 13 cases (seven males and six females; 62.3 ± 11.3 years old) received the treatment of OLIF + bridge‐locking cage internal fixation (OLIF group), and 22 cases (14 males and eight females; 52.3 ± 17.8 years old) received the treatment of transforaminal lumbar interbody fusion (TLIF) + pedicle screw fixation (TLIF group). The comparison of the operation time, intraoperative blood loss, postoperative drainage volume, and length of hospital stay between the two groups of patients was performed using the t‐test. The comparison of Visual Analogue Scale (VAS) and Oswestry Disability Index (ODI) at different time points before and after the operation was performed using analysis of variance for repeated measurement data. The fusion rate and postoperative complications of the two groups of patients were also evaluated. Results The operation time of patients in the OLIF group (55.4 ± 12.4 min) was significantly shorter than that of patients in the TLIF group (94.3 ± 22.9 min) (P

Background Andersson lesion (AL) refers to a destructive vertebral or disco‐vertebral lesion of the spine in patients with ankylosing spondylitis (AS). Against the backdrop that the best surgical option for AL remains controversial, this work serves as the first case report of oblique lateral interbody fusion (OLIF) combined with posterior pedicle screw fixation to treat AL of the lumbar spine under minimal invasion. Case presentation In this case report, the patient involved was a female aged 37 diagnosed with AL (L3‐L4). OLIF combined with pedicle screw fixation was carried out to achieve stabilization of the lumbar spine. It turned out that the patient experienced significant pain relief in her excellent post‐operative recovery, with her post‐surgical radiographs indicating good stability and bony fusion. The patient now remains disease‐free with no low back pain or neurological deficit at the two‐year follow‐up. Conclusion OLIF combined with pedicle screw fixation thus has proven to be an ideal therapeutic option for treating AL of the lumbar spine.

Purpose: To advance a modified oblique lumbar interbody fusion (M-OLIF) achieving anterior debridement and posterior freehand instrumentation simultaneously in circumferential approach via dynamic position and compare with traditional combined anterior–posterior surgery (CAPS) in clinical and radiological evaluation. Patients and methods: Innovative freehand instrumentation in floating position was described. Consecutive patients having undergone surgeries for lumbar tuberculosis from 2017 January to 2019 December had been retrospectively reviewed. Patients with follow-ups for at least 36 months were included and divided into M-OLIF or CAPS group according to surgical methods applied. Outcomes included operation time, estimated blood loss, complication profile for safety evaluation; Vascular Analogue Scale (VAS) and Oswestry Disability Index (ODI) for efficacy evaluation; C-reactive protein and Erythrocyte Sedimentation Rate for tuberculosis activity and recurrence evaluation; X-ray and CT scan for radiological evaluation. Results: Totally 56 patients had been enrolled in the study (26 for M-OLIF and 30 for CAPS). Compared with CAPS group, M-OLIF group illustrated significantly decreased estimated blood loss, operation time, hospital stay, and less postoperative morbidities. Meanwhile, M-OLIF group showed earlier improvement in VAS in 3 days and ODI in the first month postoperatively, without obvious discrepancy in further follow-ups. The overall screw accuracy in M-OLIF and CAPS group was 93.8% and 92.3% respectively, without significant difference in perforation distribution. Conclusion: M-OLIF was efficient for lumbar tuberculosis requiring multilevel fixation, with reduced operation time and iatrogenic trauma, earlier clinical improvement compared with traditional combined surgery. [ABSTRACT FROM AUTHOR]

Purpose: The primary aim was to measure the safe corridor (SC), surgical incision anterior margin (AM), and posterior margin (PM) for OLIF bilaterally from L1 to L5. The secondary aim was to determine the feasibility of approach via the SC. The tertiary aim was to analyze the influence of demographic and anthropometric factors on OLIF parameters. Methods: We performed a radiographic analysis of 100 subjects who received an abdominal CT. Measurements of the AM, PM, and SC were obtained as well as patient age, sex, height, weight, and BMI. The intraclass correlation coefficient was used to evaluate interrater reliability. To assess associations among variables, Pearson's correlation tests and multivariate linear regression models were constructed. Sex differences were analyzed using Student's t tests. Results: At L1-2, L2-3, L3-4, and L4-5, the PM was 6.6, 8.2, 9.4, and 10.2 cm on the left side and 7.2, 7.7, 8.8, and 9.5 cm on the right side in relation to the disk space center. The SC was less than 1 cm 1%, 3%,3%, and 18% of the time on the left side, and 15%, 12%,29%, and 60% on the right side. None of the anthropometric factors demonstrated a strong correlation with incision location. SC was larger on the left side. Interrater ICC was.934. Conclusions: This study is the first to provide guidelines on the appropriate location of the incision line during OLIF based on SC from L1 to L5. SC measurements do not vary by sex. OLIF is more feasible via a left-sided approach. [ABSTRACT FROM AUTHOR]

BACKGROUND: Cortical bone trajectory screw is a new type of spinal minimally invasive internal fixation technology. Compared with traditional pedicle screws, it has the characteristics of less trauma and strong pullout resistance, and has strong biomechanical properties for patients with osteoporosis. However, studies on the application of cortical bone trajectory screws combined with oblique lateral interbody fusion and fixation are still rare. OBJECTIVE: To evaluate the effect of oblique lateral interbody fusion combined with various fixation methods on stress distribution and range of motion of cage and L4-5 lower endplate by constructing three kinds of finite element models including oblique lateral interbody fusion (OLIF stand-alone) model, OLIF combined with bilateral pedicle screw (OLIF+BPS) model and OLIF combined with cortical bone trajectory screw (OLIF+CBT) model. METHODS: The CT images of adult lumbar spine were used to establish the three kinds of OLIF finite element models: OLIF stand alone, OLIF+BPS, and OLIF+CBT. Ansys workbench was used to simulate the application of six different motion loads of human body flexion and extension, left and right bending, and left and right rotation to calculate stress distribution and the changes in the range of motion of the lumbar spine of the cage and endplate of the three lumbar spine surgery models and to compare the effects of three surgical options on the biomechanical effects of the lumbar spine. RESULTS AND CONCLUSION: (1) The OLIF stand-alone model, OLIF+BPS model and OLIF+CBT model were constructed successfully. (2) In terms of range of motion, OLIF+CBT model presented no obvious difference with that of OLIF stand-alone model in flexion and extension, left and right lateral bending, and left and right rotation motions. (3) In flexion, extension, and lateral bending conditions, the maximum stress of cage of OLIF+CBT model was smaller than that of OLIF stand-alone model and slightly greater than that of OLIF+BPS model. When it came to rotating condition, the maximum stress of cage in OLIF+CBT model was bigger than that of two other models. (4) The maximum stress of the lower end plate of OLIF+CBT model was smaller than that of OLIF stand-alone model but slightly greater than that of OLIF+BPS model at various conditions. (4) It is concluded that OLIF combined with CBT fixation provides a good stable support for the vertebral body of the fusion segment on the premise of ensuring the mobility of the lumbar spine, and has a relatively good biomechanical effect. [ABSTRACT FROM AUTHOR]

To identify cage and end plate factors of cage subsidence (CS) in patients who underwent oblique lateral interbody fusion (OLIF) and their association with patient-reported outcomes. Sixty-one patients (43 women and 18 men), with a total of 69 segments (138 end plates) which underwent OLIF at a single academic institution between November 2018 and November 2020, were included. All the end plates were separated into CS and nonsubsidence groups. Cage-related parameters (cage height, cage width, cage insertion level, and cage position) and end plate-related parameters (position of end plate, Hounsfield unit value of the vertebra, end plate concave angle [ECA], end plate injury, and angular mismatch measured with cage/end plate angle [C/EA]) were compared and analyzed using logistic regression to predict CS. Receiver operating characteristic curve analysis was used to determine the cutoff points of the parameters. Postoperative CS was identified in 50 of the 138 end plates (36.2%). The CS group had significantly lower mean Hounsfield unit values of the vertebra, higher rate of end plate injury, lower ECA, and higher C/EA than the nonsubsidence group. ECA and C/EA were identified as independent risk factors for developing CS. The optimal cutoff points for ECA and C/EA were 176.9° and 5.4°, respectively. An ECA greater than 176.9° and a cage/end plate angular mismatch greater than 5.4° were found to be independent risk factors of postoperative CS after the OLIF procedure. These findings aid in preoperative decision-making and intraoperative technical guidance. [ABSTRACT FROM AUTHOR]

BACKGROUND: For the treatment of single-level lumbar degenerative disc disease (DDD), oblique lateral interbody fusion (OLIF) has clinical advantages. Whether internal fixation needs to be combined for treatment has been the subject of debate. OBJECTIVE: To compare the early clinical effects of standalone oblique lateral interbody fusion (S-OLIF) versus OLIF combined with lateral screw fixation of the vertebral body (F-OLIF) on single-level lumbar DDD. METHODS: A retrospective analysis was performed on the data of 34 patients for whom the OLIF technique was applied to treat single-level lumbar DDD from August 2018 to May 2021. Patients were divided into the S-OLIF (n = 18) and F-OLIF groups (n = 16). Intraoperative blood loss, operative time, and length of hospital stay were recorded. The pain visual analogue scale (VAS) and Oswestry disability index (ODI) before and after the operation were evaluated. The disc height (DH), foraminal height (FH), fused segment lordosis (FSL), lumbar lordosis (LL), cage subsidence, and fusion by CT examination were measured before and after the operation. RESULTS: The S-OLIF group experienced a shorter operative time and less intraoperative blood loss than the F-OLIF group, and the differences were statistically significant (p < 0.05), but the difference in the length of hospital stay was not statistically significant. The postoperative VAS score and ODI of the two groups were significantly lower than those before the operation, but the postoperative differences between the two groups were not statistically significant. Differences were not statistically significant in postoperative FH, DH, FSL and LL of the two groups. Both groups were followed up for no less than 12 months. In the two groups, fusion was achieved at the last follow-up visit. CONCLUSION: According to short-term follow-up results, both S-OLIF and F-OLIF can achieve reliable and stable fusion and good clinical effect in the treatment of single-level lumbar DDD. [ABSTRACT FROM AUTHOR]

OBJECTIVE: The aim of this study was to assess the clinical efficacy of oblique lateral interbody fusion (OLIF) and posterior lumbar interbody fusion (PLIF) for lumbar brucellosis spondylitis. PATIENTS AND METHODS: Between April 2018 and December 2021, 80 cases of lumbar brucellosis spondylitis admitted to our institution were evaluated for eligibility and randomly assigned to either PLIF (group A, lesion removal by posterior approach + interbody fusion + percutaneous pedicle screw internal fixation) or OLIF (group B, lesion removal by anterior approach + interbody fusion + percutaneous pedicle screw internal fixation). The outcome measures included operative time, intraoperative bleeding, hospital stay, preoperative and postoperative visual analogue scale (VAS) ratings, American Spinal Injury Association (ASIA) classification, Cobb angle, and interbody fusion time. RESULTS: PLIF resulted in shorter operative time and hospital stay and less intraoperative bleeding vs. OLIF (p<0.05). All eligible patients showed significantly lower VAS scores, and smaller ESR values and Cobb angles after treatment (p<0.05), but no significant intergroup differences were observed (p>0.05). The two groups showed similar preoperative ASIA (American Spinal Injury Association) classification and interbody fusion time (p>0.05). PLIF was associated with better ASIA classification at three months postoperatively vs. OLIF (p<0.05). CONCLUSIONS: Both surgical techniques are efficient at removing the lesion, relieving pain, maintaining spinal stability, promoting implant fusion, and facilitating prognostic inflammation control. PLIF features a shorter surgical duration and hospital stay, less intraoperative bleeding, and greater neurological improvement vs. OLIF. Nevertheless, OLIF outperforms PLIF in the excision of peri-vertebral abscesses. PLIF is indicated for posterior spinal column lesions, particularly those with spinal nerve compression in the spinal canal, whereas OLIF is indicated for structural bone deterioration in the anterior column, particularly for those with perivascular abscesses. [ABSTRACT FROM AUTHOR]

Objective: Lumbar sympathetic trunk (LST) injury is one of the major complications after oblique lumbar interbody fusion (OLIF). LST injury often manifests as unequal skin temperature in lower limbs after operation, and there may be a large number of missed diagnoses due to the lack of attention and different diagnostic methods. The study aimed to investigate the incidence and clinical characteristics of LST injury after OLIF. Methods: The data of patients with lumbar degenerative diseases who underwent OLIF in our hospital from April 2016 to October 2017 were retrospectively analyzed. Finally, a total of 54 patients were included. There were 10 males and 44 females, aged 58.4 ± 10.9 years. The skin temperature of lower limbs was measured before and a day after surgery. The patients were followed up at 1 week, 6 weeks, 6 months, and 2 years after the surgery. Likert five‐point scale was used to evaluate the discomfort caused by LST injury. Injury severity score was introduced to grade injury degree according to the recovery time of postoperative symptoms. The chi‐square test was used to analyze the association of incidence of lumbar sympathetic trunk (LST) injury with contributing factors, such as gender and number of surgical segments. Results: The unequal temperature was not found before surgery in all the patients. Postoperatively, 16 cases (29.6%) had difference of skin temperature more than 0.5 °C and were diagnosed with LST injury. Eight patients (14.8%) had self‐perception of skin temperature differences, and 12 patients (22.2%) had other symptoms, such as muscle pain, numbness, and weakness, which were not statistically different between patients with and without lumbar sympathetic trunk injury (p > 0.05). In the 16 patients with LST injury, the difference of skin temperature between the two legs was 0.6 ± 0.1 °C on the first day, and the temperature difference lasted for 1.5–~12 months. According to Likert five‐point scale, two cases (12.5%) were poor, and 14 cases (87.5%) were moderate immediately after surgery. Fifteen cases improved to some extent 6 weeks to 12 months after surgery. Conclusion: Postoperative LST injury is mainly manifested by different temperature of lower limbs. The incidence was higher in patients with multi‐segment OLIF than in those with single‐segment OLIF, and the subjective experience of most patients with LST injury was moderate discomfort. [ABSTRACT FROM AUTHOR]

Background and Objectives: Although adult spinal deformity (ASD) surgery brought about improvement in the quality of life of patients, it is accompanied by high invasiveness and several complications. Specifically, mechanical complications of rod fracture, instrumentation failures, and pseudarthrosis are still unsolved issues. To better improve these problems, oblique lateral interbody fusion at L5/S1 (OLIF51) was introduced in 2015 at my institution. The objective of this study was to compare the clinical and radiologic outcomes of anterior–posterior combined surgery for ASD between the use of OLIF51 and transforaminal interbody fusion (TLIF) at L5/S1. Materials and Methods: A total of 117 ASD patients received anterior–posterior correction surgeries either with the use of OLIF51 (35 patients) or L5/S1 TLIF (82 patients). In both groups, L1–5 OLIF and minimally invasive posterior procedures of hybrid or circumferential MIS were employed. The sagittal and coronal spinal alignment and spino-pelvic parameters were recorded preoperatively and at follow-up. The quality-of-life parameters and visual analogue scale were evaluated, as well as surgical complications at follow-up. Results: The average follow-up period was thirty months (13–84). The number of average fused segments was eight (4–12). The operation time and estimated blood loss were significantly lower in OLIF51 than in TLIF. The PI-LL mismatch, LLL, L5/S1 segmental lordosis, and L5 coronal tilt were significantly better in OLIF51 than TLIF. The complication rate was statistically equivalent between the two groups. Conclusions: The introduction of OLIF51 for adult spine deformity surgery led to a decrease in operation time and estimated blood loss, as well as improvement in sagittal and coronal correction compared to TLIF. The circumferential MIS correction and fusion with OLIF51 serve as an effective surgical modality which can be applied to many cases of adult spinal deformity.

Objective Oblique lumbar interbody fusion (OLIF) involves inserting large cages into the interbody disc space. This expands the spinal canal and neural foramen by stretching the ligament flavum and releasing the facet joint, resulting in indirect neural decompression. Our objective was to investigate the changes in the spinal canal and ligament flavum over time after OLIF. Methods This was a prospective observational study involving 30 patients who underwent OLIF L4–5 between 2015 and 2018. In total, 27 of the 30 patients underwent preoperative, early follow-up (< 5 days), and late follow-up (10–14 months) magnetic resonance imaging to measure the area of the spinal canal and ligament flavum. Based on the results, the patients were divided into subsidence and nonsubsidence groups for further analysis. Results After OLIF, the spinal canal area gradually increased during the preoperative, early postoperative, and late postoperative periods (p

PurposeWith advancements in minimally invasive techniques, oblique lumbar interbody fusion (OLIF) has gained widespread acceptance and is now commonly performed for adult degenerative scoliosis (ADS). The objective of this research paper is to evaluate three-dimensional (3D) intervertebral motions in EOS models before and after surgery and subsequently assess the efficacy of the 3D correction achieved through staged OLIF.MethodsIn this retrospective study, 29 consecutive patients diagnosed with ADS were included, with a mean age of 63.6 years, who underwent staged OLIF surgery between 2018 and 2021. Spinopelvic parameters were assessed using EOS images, and 3D models were reconstructed to measure intervertebral motion angles (IMAs) in 70 surgical intervertebral segments, comprising wedge, lordosis, and axial rotation angles. Regression analysis was conducted to compare IMAs in different planes before and after the staged OLIF surgery.ResultsSignificant three-dimensional correction was observed in 70 intervertebral segments following the first-stage OLIF. The wedge angles decreased from 5.2°± 4.2° to 2.7°± 2.4° (P

ObjectiveThe oblique lateral interbody fusion (OLIF) technique is a promising interbody fusion technique. This study summarizes the technical aspects of OLIF as a salvage surgery and the preliminary outcomes of a series of cases.Patients and methodsA retrospective review of patients with leg or back pain induced by pseudoarthrosis or adjacent segment disease after posterior lumbar interbody fusion/transforaminal lumbar interbody fusion was done. These patients underwent salvage OLIF surgeries in our institution from January 2021 to March 2022. Variables such as the demographic, clinical, surgical, and radiological characteristics of the enrolled patients were recorded and analyzed.ResultsEight patients (five females and three males; mean age 69.1 ± 5.7 years, range 63–80 years) were enrolled in this study. The mean operative time was 286.25 min (range: 230–440 min), and the estimated blood loss was 90 ml (range: 50–150 ml). Only one of the eight patients experienced a complication of lower limb motor weakness, which disappeared within 5 days after surgery. The latest data showed that the mean intervertebral space height increased from 8.36 mm preoperatively to 12.70 mm and the mean segmentary lordosis increased from 8.92° preoperatively to 15.05°. Bone fusion was achieved in all but one patient, who was followed up for only 3 months. The JOA scores Japanese Orthopaedic Association (JOA) Scores for low back pain of all patients significantly improved at the final follow-up.ConclusionOLIF provides a safe and effective salvage strategy for patients with failed posterior intervertebral fusion surgery. Patients effectively recovered intervertebral and foraminal height with no additional posterior direct decompression.

BACKGROUND: The clinical application of stand-alone oblique lateral interbody fusion is greatly affected by the bone mineral density of patients, but there is no relevant report on the specific bone mineral density at home and abroad. OBJECTIVE: To compare the biomechanical performance of an oblique lateral interbody fusion cage among different bone density models. METHODS: Based on the CT data of healthy adult male volunteers, there were L3-S1 normal control finite element model (M0 group), the normal bone mineral density (T value>-1.0 SD) L4-5 stand-alone oblique lateral interbody fusion finite element model (M1 group), osteopenia (-2.5 SD-2.5 SD, stand-alone oblique lateral interbody fusion surgery can improve biomechanical stability. [ABSTRACT FROM AUTHOR]

The study aimed to explore the recent efficacy of oblique lateral interbody fusion (OLIF) combined with Wiltse approach pedicle screw fixation in the treatment of single-level degenerative lumbar spondylolisthesis (DLS). This is a retrospective study. The study enrolled 54 patients with single-level DLS who were treated at the Affiliated Jiangnan Hospital of Zhejiang Chinese Medical University from May 2018 to June 2020. (OLIF group) 24 cases operated using OLIF combined with Wiltse approach pedicle screw fixation, and (PLIF group) 30 cases operated by PLIF. The primary outcome measures were visual analog scale (VAS) pain scores, Oswestry dysfunction index (ODI), and the lower lumbar spine anterior convexity angle. There were significant differences in VAS (2.63 ± 0.58 vs. 3.57 ± 0.63, P < 0.001) and ODI (9.67 ± 0.92 vs. 10.63 ± 1.40, P < 0.05) between the OLIF group and PLIF group on postoperative 3 days. And there was a significant decrease in VAS (2.63 ± 0.58 vs. 1.08 ± 0.28, P < 0.05) and ODI (3.57 ± 0.63 vs. 1.10 ± 0.31, P < 0.05) in both groups on postoperative 3 days and at 6 months postoperative comparisons. OLIF group showed better intervertebral space height and the lower lumbar spine anterior convexity angle scores on postoperative 3 days and 6 months, the difference was statistically significant(all P < 0.05). OLIF combined with the Wiltse approach pedicle screw fixation can achieve good short-term clinical results in the treatment of single-level DLS. This surgical approach is less invasive, promotes early functional recovery, shortens hospitalization time, and improves the quality of life. [ABSTRACT FROM AUTHOR]

Abstract Background Little is known about the biomechanical performance of different internal fixations in oblique lumbar interbody fusion (OLIF). Here, finite element (FE) analysis was used to describe the biomechanics of various internal fixations and compare and explore the stability of each fixation. Methods CT scans of a patient with lumbar degenerative disease were performed, and the l3-S1 model was constructed using relevant software. The other five FE models were constructed by simulating the model operation and adding different related implants, including (1) an intact model, (2) a stand-alone (SA) model with no instrument, (3) a unilateral pedicle screw model (UPS), (4) a unilateral pedicle screw contralateral translaminar facet screw model (UPS-CTFS), (5) a bilateral pedicle screw (BPS) model, and (6) a cortical bone trajectory screw model (CBT). Various motion loads were set by FE software to simulate lumbar vertebral activity. The software was also used to extract the range of motion (ROM) of the surgical segment, CAGE and fixation stress in the different models. Results The SA group had the greatest ROM and CAGE stress. The ROM of the BPS and UPS-CTFS was not significantly different among motion loadings. Compared with the other three models, the BPS model had lower internal fixation stress among loading conditions, and the CBT screw internal fixation had the highest stress among loads. Conclusions The BPS model provided the best biomechanical stability for OLIF. The SA model was relatively less stable. The UPS-CTFS group had reduced ROM in the fusion segments, but the stresses on the internal fixation and CAGE were relatively higher in the than in the BPS group; the CBT group had a lower flexion and extension ROM and higher rotation and lateral flexion ROM than the BPS group. The stability of the CBT group was poorer than that of the BPS and LPS-CTFS groups. The CAGE and internal fixation stress was greater in the CBT group.

Introduction: Lateral lumbar fusion via the trans-psoas approach is popular in adult deformity reconstruction. To overcome its limitations (neurological damage to the plexus and lack of applicability to the lumbosacral junction), a modified anterior-to-psoas (ATP) approach has been described and used. Research question: To investigate the results of ATP lumbar and lumbosacral fusion, in a cohort of adult patients treated with combined anteroposterior approaches for adult spinal deformity (ASD). Materials and methods: ASD patients surgically treated at two tertiary spinal centres were followed up. Forty patients were treated with combined ATP and posterior surgery: 11 with open lumbar lateral interbody-fusions (lumbotomy LLIF) and 29 with lesser invasive oblique lateral interbody-fusions (OLIF). Preoperative demographics, aetiology, clinical characteristics, and spinopelvic parameters were comparable between the two cohorts. Results: At a minimum 2-year follow-up, both cohorts showed significant improvements in patient reported outcome measures (PROMs), i.e. Visual Analogue Scale and Core Outcome Measures Index, as well as radiological parameters, with no significant differences based on the type of surgical approach. No significant differences were found in major (P ​= ​0.457) and minor (P ​= ​0.071) complications between the two cohorts. Discusson and conclusion: Anterolateral lumbar interbody fusions, whether performed via a direct or oblique approach, proved to be safe and effective adjuvants to posterior surgery in patients with ASD. No significant complication differences were noted between techniques. In addition, the anterior-to-psoas approaches limited the risks of post-operative pseudoarthrosis by providing solid anterior support to lumbar and lumbosacral segments, demonstrating a positive impact on PROMS.

Background: To perform a comparative assessment of percutaneous transfacet screws (TFS) and percutaneous bilateral pedicle screws (BPS) in oblique lateral interbody fusion (OLIF) for the treatment of single-level degenerative lumbar spine diseases in terms of radiological examinations and clinical outcomes. Methods: Sixty-six patients who received single-level OLIF with percutaneous supplementary fixation assisted by the robot for the treatment of degenerative lumbar spine diseases were selected. There were 16 cases of OLIF with TFS and 50 cases of OLIF with BPS. The propensity score matching method selected 11 patients in each group with matched characteristics to perform a clinical comparison. Results: The estimated blood loss was 68.2 ± 25.2 ml in the OLIF with TFS group compared to 113.6 ± 39.3 ml in the OLIF with BPS group (P < 0.05). The intervertebral disc height raised from 8.6 to 12.9 mm in the TFS group and from 8.9 to 13.9 mm in the BPS group in the immediate postoperative period, and dropped to 10.8 and 12.9 mm at the twelfth month, respectively (P < 0.05). The fusion rates were 91% and 100% for TFS and BPS groups (P > 0.05). Quantitative assessments of back/leg pain of the two groups reached a healthy level in the late period of the follow-up. Conclusion: Both TFS and BPS techniques for the OLIF surgery relieve back pain caused by degenerative lumbar spine diseases. The TFS technique exhibits less blood loss compared with the BPS. A moderate cage subsidence is present in TFS but no complication is reported. [ABSTRACT FROM AUTHOR]