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Purpose: To evaluate the outcomes of Oblique lumbar interbody fusion (OLIF)combined with anterolateral screw fixation (AF) and Stress Endplate Augmentation(SEA) versus OLIF-AF in the treatment of degenerative lumbar spondylolisthesis (DLS)with osteoporosis (OP). Methods: 30 patients underwent OLIF-AF-SEA (SEA group) were matched with 30 patients received OLIF-AF (control group), in terms of sex, age, body mass index (BMI) and bone mineral density (BMD). Clinical outcomes including visual analog scale (VAS) score of the lower back pain (VAS-LBP), leg pain (VAS-LP), and Oswestry Disability Index (ODI) were evaluated at different postoperative intervals and comparedwith their preoperative counterparts. Radiographic outcomes such as disk height (DH), slip distance (SD), lumbar lordosis (LL), segmental lordosis (SL), cage subsidence (CS) rate and fusion rate were evaluated at different postoperative intervals and compared with their preoperative counterparts. Results: SEA group presented to be better at 3-month and 12-month follow-up, the VAS-LBP, VAS-LP and ODI scores of the SEA group were significantly lower than the control group (3-month SEA vs control: 2.30±0.70 vs 3.30±0.75, 2.03±0.72 vs 2.90±0.76,15.60±2.36 vs 23.23±3.07, respectively, all p<0.05. VAS-LBP and ODI 12-month SEA vs control: 1.27±0.74 vs 1.93±0.58, 12.20±1.88 vs 14.43±1.89,respectively, all p<0.05). At 24-month follow-up, both groups showed no difference in fusion rate (83.33% vs 90.00%, p=0.45), while SEA group showed a lower CS rate (13.33% vs 53.33%, p<0.05). Conclusion: OLIF-AF-SEA was safe with no adverse effects and resulted in lower CS rate and better sagittal balance. OLIF-AF-SEA is a promising surgical method for treating patients with DLS-OP. [ABSTRACT FROM AUTHOR]

The study investigates how cage positions in oblique lumbar interbody fusion (OLIF) combined with posterior percutaneous pedicle screw internal fixation (PPSF) affect lumbar canal and foraminal decompression and postoperative outcomes, providing guidance for optimal placement and efficacy assessment. This investigation assesses radiologic outcomes and follow-up data in relation to cage position variability among 80 patients who underwent L4/5 single-segment OLIF + PPSF from 2018 to 2022. In the study involving 80 participants, the combination of OLIF and PPSF significantly improved lower back and leg symptoms in patients, leading to positive clinical outcomes during follow-up. The intervertebral disk height increased from an average of 8.10 ± 2.79 mm before surgery to 11.75 ± 2.14 mm after surgery (P < 0.001). Additionally, this surgical technique notably increased the FH (P < 0.001) and expanded the DCSA from 68.81 ± 53.89 mmˆ2 before surgery to 102.91 ± 60.46 mmˆ2 after surgery (P < 0.001). Linear results suggest that changes in the position of the cage do not affect spinal imaging parameters. There is no significant difference in the correction of spinal parameters or prognosis whether the cage is back, middle, ahead. In the OLIF + PPSF procedure, strict requirements for cage position are not necessary to achieve predetermined spinal biomechanical parameters. The practice of repeated fluoroscopy to adjust cage position postimplantation does not provide added clinical benefits to the patient. [ABSTRACT FROM AUTHOR]

Elderly patients undergoing spinal surgery are at an increased risk of morbidity and mortality. Evaluating frailty and preoperative status is crucial for predicting postoperative outcomes. This study aimed to assess the predictive value of the modified Frailty Index (mFI), sarcopenia, Prognostic Nutritional Index (PNI), and Geriatric Nutritional Risk Index (GNRI) in determining postoperative complications in patients undergoing oblique lumbar interbody fusion (OLIF) over 60 years. Preoperative risk factors were assessed using 11 variables, including mFI, PNI, and GNRI. Complication rates were compared among nonfrail (mFI = 0; n = 50), prefrail (mFI = 0.09–0.18; n = 144), and frail (mFI ≥0.27; n = 80) patients. Demographic and perioperative variables were compared between the complication and noncomplication groups. The incidence of complications was the primary outcome measure. Complications occurred in 36 of 274 patients (13.1%). The frail group exhibited a significantly higher incidence of pneumonia than the nonfrail and prefrail groups. The complication group displayed significant differences in several variables, including age, fusion level, albumin level, lymphocyte count, platelet count, creatinine level, and estimated blood loss. Moreover, mFI, PNI, and GNRI differed significantly between the complication and noncomplication groups. MFI, PNI, and GNRI can be useful for predicting postoperative morbidity and mortality in patients undergoing OLIF. These comprehensive assessment methods enable the identification of high-risk patients and the formulation of tailored strategies to enhance postoperative outcomes. Integrating mFI, PNI, and GNRI into the preoperative evaluation process can help health care providers proactively manage high-risk patients, thus improving the overall quality of care for elderly individuals undergoing OLIF. [ABSTRACT FROM AUTHOR]

Purpose Methods Results Conclusion Oblique lumbar interbody fusion (OLIF) has become a popular technique for treating adult degenerative scoliosis (ADS), but traditional OLIF technology often requires repositioning for one‐stage or staged posterior fixation. The objective of this pilot study was to describe the surgical technique of simultaneous single‐position OLIF and percutaneous pedicle screw fixation (OLIF 360) under O‐Arm navigation for modified MISDEF type II ADS.Between June 2022 and December 2023, six patients classified as having modified MISDEF type II ADS underwent OLIF 360 assisted by O‐Arm navigation at our institution. Intraoperative blood loss, duration of operation, and complications related to the OLIF 360 procedure were recorded. The preoperative and postoperative spinal pelvic parameters were measured using X‐rays. The accuracy of pedicel screws was recorded in accordance with the modified Gertzbein–Robbins classification on CT. Postoperative MRI was performed to evaluate the indirect decompressive effect. The Japanese Orthopedic Association score for low back pain was used to evaluate surgical outcomes.Navigated OLIF 360 were performed in six ADS patients with 44 percutaneous pedicel screws and 16 cages placement, including four women and two men. The mean operation time was 160.83 ± 33.23 min, and the mean blood loss was 111.67 ± 39.71 mL. Postoperative spinal pelvic parameters and spinal stenosis degree improved significantly on X‐ray and MRI. All screws were clinically acceptable according to the Gertzbein–Robbins classification, with 92.7% grade A and 7.3% grade B. No serious intraoperative and postoperative adverse events were recorded in all patients. The JOA scores for low back pain of all patients were significantly improved at postoperative 1 month and the final follow‐up.We report on a case series and describe navigated OLIF 360 in treating modified MISDEF type II ADS patients. Navigation‐assisted OLIF 360 has shown encouraging surgical outcomes with good spinal imbalance correction and indirect decompression. [ABSTRACT FROM AUTHOR]

Background: No consensus has been reached regarding the efficacy of indirect decompression through oblique lumbar interbody fusion (OLIF) in severe lumbar spinal stenosis (LSS). This study investigated the impact of preoperative magnetic resonance imaging (MRI)-based grading of central and foraminal stenosis on OLIF outcomes in LSS patients and identified risk factors for postoperative clinical dissatisfaction. Methods: We retrospectively reviewed LSS patients who underwent OLIF with a minimum 1-year follow-up. Clinical scores obtained preoperatively and at 3, 6, 12, and 24 months postoperatively were analyzed using the substantial clinical benefit (SCB) framework. The severity of central and foraminal stenosis in the initial MRI was assessed through qualitative grading systems. Results: Among the 145 patients, with a mean follow-up of 33.7 months, those with severe central stenosis showed a significantly higher proportion of patients achieving SCB in the visual analog scale for leg pain (94.5% versus 83.1%; p = 0.044) at one year postoperatively than those without. However, those with severe foraminal stenosis showed significantly higher Oswestry Disability Index (ODI) scores (p = 0.024), and lower walking ability scores in the Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ) (p = 0.004) at one year postoperatively than those without. The presence of a foraminal osteophyte of the superior articular process (SAP) was a significant risk factor responsible for not achieving SCB in ODI and walking ability in JOABPEQ at one year postoperatively (odds ratio: 0.20 and 0.22, respectively). Conclusions: After OLIF, patients with severe central stenosis showed clinical outcomes comparable to those without. The improvement in ODI and walking ability in JOABPEQ was limited in patients with severe foraminal stenosis. Surgeons should consider direct decompression in cases with the presence of foraminal osteophytes of SAP. [ABSTRACT FROM AUTHOR]

Purpose: The minimally invasive oblique lumbar interbody fusion (MI-OLIF) L5-S1 was introduced to overcome the limitations of conventional fusion techniques, however, MI-OLIF is not possible using the standard method due to vascular structures in some cases. We aimed to introduce the "lateral corridor" and report the details of the surgical technique with a clinical case series. Methods: We utilized the lateral access route of the left common iliac vein and named it the "lateral corridor", to distinguish the technique from the standard technique (central corridor). The type and frequency of branch vessels that required additional manipulations were reviewed, and the frequency of intraoperative vascular injury was investigated. Results: Among the 107 patients who underwent MI-OLIF L5-S1, 26 patients (24.3%) who received the "lateral corridor" technique were included. Branch vessel ligation was required in 42.3% of the patients. The types of branch vessels that required ligation were seven cases (26.9%) of the iliolumbar vein (ILV) and six cases (23.1%) of ascending lumbar vein (ALV). The ILV and ALV were ligated in two cases. None of the patients developed intraoperative vascular injuries. Conclusion: We introduced the "lateral corridor" as an alternative approach for MI-OLIF L5-S1, implemented it in 24.3% of the patient cohort, and reported favorable outcomes devoid of vascular complications. The "lateral corridor" necessitated ligation of the ILV or ALV in 42.3% of cases. The "lateral corridor" approach appears to be a promising surgical technique, offering feasibility even in instances where the vascular anatomy precludes the employment of the conventional approach. [ABSTRACT FROM AUTHOR]

The 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. Thirty-five patients with degenerative disc disease were surgically treated with one-level OLIF and were followed up for more than 6 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. Radiologic evaluation using computed tomography (CT) and magnetic resonance imaging (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 6 months postoperatively. The 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 and VAS scores for leg numbness were significantly better in the Expandable group (P < 0.05). Compared 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. [ABSTRACT FROM AUTHOR]

Purpose: 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). Methods: 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. Results: 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. Conclusion: 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. [ABSTRACT FROM AUTHOR]

Objective To compare the clinical and radiographic outcomes following lateral lumbar interbody fusion (LLIF) between direct and indirect decompression in the treatment of patients with degenerative lumbar diseases. Methods Patients who underwent single-level LLIF were randomized into 2 groups: direct decompression (group D) and indirect decompression (group I). Clinical outcomes including the Oswestry Disability index and visual analogue scale of back and leg pain were collected. Radiographic outcomes including cross-sectional area (CSA) of thecal sac, disc height, foraminal height, foraminal area, fusion rate, segmental, and lumbar lordosis were measured. Results Twenty-eight patients who met the inclusion criteria were eligible for the analysis, with a distribution of 14 subjects in each group. The average age was 66.1 years. Postoperatively, significant improvements were observed in all clinical parameters. However, these improvements did not show significant difference between both groups at all follow-up periods. All radiographic outcomes were not different between both groups, except for the increase in CSA which was significantly greater in group D (77.73 ± 20.26 mm2 vs. 54.32 ± 35.70 mm2, p = 0.042). Group I demonstrated significantly lower blood loss (68.13 ± 32.06 mL vs. 210.00 ± 110.05 mL, p < 0.005), as well as shorter operative time (136.35 ± 28.07 minutes vs. 182.18 ± 42.67 minutes, p = 0.002). Overall complication rate was not different. Conclusion Indirect decompression through LLIF results in comparable clinical improvement to LLIF with additional direct decompression over 1-year follow-up period. These findings suggest that, for an appropriate candidate, direct decompression in LLIF might not be necessary since the ligamentotaxis effect achieved through indirect decompression appears sufficient to relieve symptoms while diminishing blood loss and operative time.

(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. [ABSTRACT FROM AUTHOR]

Objective: To compare the clinical and radiographic outcomes following lateral lumbar interbody fusion (LLIF) between direct and indirect decompression in the treatment of patients with degenerative lumbar diseases. Methods: Patients who underwent single-level LLIF were randomized into 2 groups: direct decompression (group D) and indirect decompression (group I). Clinical outcomes including the Oswestry Disability index and visual analogue scale of back and leg pain were collected. Radiographic outcomes including cross-sectional area (CSA) of thecal sac, disc height, foraminal height, foraminal area, fusion rate, segmental, and lumbar lordosis were measured. Results: Twenty-eight patients who met the inclusion criteria were eligible for the analysis, with a distribution of 14 subjects in each group. The average age was 66.1 years. Postoperatively, significant improvements were observed in all clinical parameters. However, these improvements did not show significant difference between both groups at all follow-up periods. All radiographic outcomes were not different between both groups, except for the increase in CSA which was significantly greater in group D (77.73 ± 20.26 mm2 vs. 54.32 ± 35.70 mm2, p = 0.042). Group I demonstrated significantly lower blood loss (68.13 ± 32.06 mL vs. 210.00 ± 110.05 mL, p < 0.005), as well as shorter operative time (136.35 ± 28.07 minutes vs. 182.18 ± 42.67 minutes, p = 0.002). Overall complication rate was not different. Conclusion: Indirect decompression through LLIF results in comparable clinical improvement to LLIF with additional direct decompression over 1-year follow-up period. These findings suggest that, for an appropriate candidate, direct decompression in LLIF might not be necessary since the ligamentotaxis effect achieved through indirect decompression appears sufficient to relieve symptoms while diminishing blood loss and operative time. [ABSTRACT FROM AUTHOR]

A variety of different lumbar spinal fusion techniques have been developed. In this study, we review published medical literature highlighting the differences between lumbar interbody fusion techniques with regard to their surgical technique, clinical outcomes, and complications. PubMed, ScienceDirect, and Google Scholar searches were performed for studies published between January 1990 to April 2018 reporting spinal fusion surgery clinical outcomes of at least one fusion technique. Clinical outcomes were extracted and pooled by surgical technique. Chi-squared analyses and Fisher Exact Tests were used to determine differences in rates between groups. PLIF had the highest rate of successful fusion (97% [155/159]) and the lowest rate of complications (4% [6/131]). A chi square analysis revealed a significant difference in fusion success in PLIF compared to PLF (84% [278/330], p <.001). PLIF also had significantly fewer complications compared to PSF (14.7% [251/1709], p =.001), PLF (13.4% [47/351], p =.008), ALIF (14.2% [22/155], p =.008), and LIC (13.9% [47/339], p =.005). Additionally, there were significant differences in the rate of successful fusion when comparing lateral interbody cage (LIC) techniques (p =.041), which include OLIF (100% [63/63]), DLIF (92% [24/26]), and XLIF (87% [67/77]). LIC techniques overall had higher fusion success rates (93.0% [154/166] compared to PLF (p =.01), but a higher rate of complications (14% [47/339]) compared to PLIF (p =.005) and TLIF (6% [17/259], p =.005). Overall, PLF and XLIF have the lowest fusion success rates, and OLIF demonstrated a trend of higher fusion rates among LIC. Techniques that utilized interbody fusion tended to increase the rate of fusion. While interbody fusion techniques offer higher rates of fusion, complication rates also tend to rise with the increase in complexity of the surgical technique, as with OLIF which notably has the highest fusion rate and complication rate. [ABSTRACT FROM AUTHOR]

Objectives Cage subsidence (CS) has been reported to be one of the most common complications following oblique lumbar interbody fusion (OLIF). To reduce the incidence of CS and improve intervertebral fusion rates, anterolateral fixation (AF) has been gradually proposed. However, the incidence of CS in patients with oblique lumbar interbody fusion combined with anterolateral fixation (OLIF‐AF) is still controversial. Additionally, there is a lack of consensus regarding the optimal placement of screws for OLIF‐AF, and the impact of screw placement on the incidence of CS has yet to be thoroughly investigated and validated. The objective of this investigation was to examine the correlation between screw placements and CS and to establish an optimized approach for implantation in OLIF‐AF. Methods A retrospective cohort study was undertaken. From October 2017 to December 2020, a total of 103 patients who received L4/5 OLIF‐AF for lumbar spinal stenosis or spondylolisthesis or degenerative instability in our department were followed up for more than 12 months. Demographic and radiographic data of these patients were collected. Additionally, screw placement related parameters, including trajectory and position, were measured by anterior–posterior X‐ray and axial CT. Analysis was done by chi‐square, independent t‐test, univariable and multivariable binary logistic regression to explore the correlation between screw placements and CS. Finally, the receiver operating characteristic (ROC) curve analysis was used to evaluate the predictive ability of screw placement‐related parameters. Results A total of 103 patients were included, and CS was found in 28 (27.18%) patients. Univariable analysis was firstly performed for each parameter. Next, variables with p‐value of

Objective Although several studies have reported successful fusion rates after oblique lumbar interbody fusion (OLIF) using allografts or dimerized bone matrix (DBM) instead of autografts, whether OLIF can achieve satisfactory solid fusion without the use of autografts remains unclear. This study investigated the real fusion rates after OLIF using allografts and DBM, which were evaluated using both dynamic radiographs and computed tomography scans. Methods We enrolled 79 consecutive patients who underwent minimally invasive OLIF followed by percutaneous pedicle screw fixation. All patients were treated with OLIF between L2 and L5 and underwent radiographic and clinical follow-ups at 12, 18, and 24 months after surgery. Radiographic assessment of fusion was performed using the modified BrantigaSteffee-Fraser (mBSF) scale, which was categorized as follows: grades I (radiographic pseudoarthrosis), II (indeterminate fusion), and III (solid radiographic fusion). Other radiologic and clinical outcomes were evaluated using the following parameters: vertebral slippage distance, disc height, subsidence, Oswestry Disability Index (ODI), and visual analogue scale (VAS). Results Clinical outcomes demonstrated significant improvements in the VAS scores for back pain, leg pain, and ODI after surgery. Subsidence was present in 34 cases (35.4%) at 12 months postoperatively, which increased to 47.9% and reached 50.0% at 1.5 years and 2 years after surgery, respectively. The solid fusion rate after OLIF was 32.3% at 1 year, increased to 58.3% at 1.5 years, and reached 72.9% at 2 years. Radiographic pseudoarthrosis was 24.0% at 1 year, which decreased to 6.3% at 1.5 years and 3.1% at 2 years. Conclusion OLIF is a safe and effective surgical procedure for the treatment of degenerative lumbar diseases. The mBSF scale, which simultaneously evaluates both dynamic angles and bone bridge formation, offers great reliability for the radiological assessment of fusion. Moreover, OLIF using allografts and DBM, which is performed on one or 2 levels at L2–5, can achieve satisfactory fusion rates within 2 years after surgery.

Abstract Background Oblique lateral lumbar fusion (OLIF) is widely used in spinal degeneration, deformity and other diseases. The purpose of this study was to investigate the biomechanical differences between two different shapes of OLIF cages on whether to add posterior internal fixation system, using finite element analysis. Methods A complete three-dimensional finite element model is established and verified for L3–L5. Surgical simulation was performed on the verified model, and the L4–L5 was the surgical segment. A total of the stand-alone group (Model A1, Model B1) and the BPSF group (Model A2, Model B2) were constructed. The four OLIF surgical models were: A1. Stand-alone OLIF with a kidney-shaped Cage; B1. Stand-alone OLIF with a straight cage; A2. OLIF with a kidney-shaped cage + BPSF; B2. Stand-alone OLIF with a straight cage + BPSF, respectively. The differences in the range of motion of the surgical segment (ROM), equivalent stress peak of the cage (ESPC), the maximum equivalent stress of the endplate (MESE) and the maximum stress of the internal fixation (MSIF) were compared between different models. Results All OLIF surgical models showed that ROM declines between 74.87 and 96.77% at L4–L5 operative levels. The decreasing order of ROM was Model A2 > Model B2 > Model A1 > Model A2. In addition, the ESPC and MESE of Model A2 are smaller than those of other OLIF models. Except for the left-bending position, the MSIF of Model B2 increased by 1.51–16.69% compared with Model A2 in each position. The maximum value of MESE was 124.4 Mpa for Model B1 in the backward extension position, and the minimum value was 7.91 Mpa for Model A2 in the right rotation. Stand-alone group showed significantly higher ROMs and ESPCs than the BPSF group, with maximum values of 66.66% and 70.59%. For MESE, the BPSF group model can be reduced by 89.88% compared to the stand-alone group model. Conclusions Compared with the traditional straight OLIF cage, the kidney-shaped OLIF cage can further improve the stability of the surgical segment, reduce ESPC, MESE and MSIF, and help to reduce the risk of cage subsidence.

Abstract Background While there have been previous studies on the surgical efficacy of patients with redundant nerve roots (RNRs), a persistent issue is that some patients continue to experience redundancy even after surgery. Furthermore, the clinical significance of RNRs remains unclear. Notably, there is a lack of research regarding RNRs within the context of oblique lumbar interbody fusion (OLIF) combined with percutaneous internal fixation. Therefore, the primary objective of this study is to investigate the correlation between RNRs and clinical outcomes following OLIF combined with percutaneous internal fixation. Methods Eighty-seven patients diagnosed with lumbar spinal stenosis (LSS) who underwent single-segment OLIF combined with percutaneous internal fixation were categorized into three groups. Group 1 comprised patients with positive RNRs both before and after the operation. Group 2 included patients with positive RNRs preoperatively but negative RNRs postoperatively. Group 3 consisted of patients with consistently negative RNRs before and after the operation. Comprehensive patient data were collected, including operation time, intraoperative blood loss, and any recorded complications. Radiographic parameters, both pre- and post-operative, were assessed, encompassing the number of stenosis segments, disc height (DH), lumbar lordotic angle, dural sac cross-sectional area, and the placement of the fusion cage. Furthermore, the Visual Analogue Scale was applied to gauge back and leg pain, while the Oswestry Disability Index was employed to appraise daily living activities. A comparative analysis was carried out among the three patient groups. Results In this study, all 87 LSS patients successfully underwent surgery. Among them, 35 patients (40.2%) showed preoperative MRI assessment indicating positive RNRs. In the postoperative MRI assessment, 14 of these patients maintained positive RNRs status, and they were grouped into Group 1. The remaining 21 patients saw a transition to negative RNRs status and were included in Group 2. Among the 52 patients who had preoperative MRI assessments showing negative RNRs, their postoperative RNRs status remained negative, forming Group 3. All patients received follow-up, which ranged from 8 to 18 months, and no complications occurred during this period. In this study, the postoperative efficacy and parameters such as DH and Dural Sac CSA significantly improved compared to preoperative values for all 87 patients. Patients with preoperative RNRs had more stenosis segments, smaller dural sac CSA, and more severe symptoms. In all three groups, postoperative efficacy scores significantly improved compared to preoperative scores. Group 2 patients had their fusion cages placed more in the middle, while Group 1 patients had their fusion cages more anteriorly located. Group 2 patients exhibited greater recovery in dural sac CSA postoperatively compared to Group 1 patients. Additionally, Group 2 patients had better ODI efficacy scores compared to Group 1 patients. Conclusions Irrespective of the presence or absence of RNRs, patients experienced improvement after undergoing OLIF combined with percutaneous internal fixation. Preoperative RNRs appear to be linked to multi-segmental lumbar spinal stenosis, a reduction in dural sac CSA, and symptom severity. Patients with negative postoperative RNRs demonstrated better treatment efficacy. Furthermore, the placement of the fusion cage appears to have a significant impact on postoperative efficacy and RNRs outcomes.

Abstract Background Oblique lumbar interbody fusion (OLIF) is an internationally popular minimally invasive technology for the treatment of various lumbar diseases. Since its introduction to China in 2014, OLIF technology has clearly shown its superiority in reconstructing intervertebral stability, restoring intervertebral space height, achieving indirect decompression, and restoring normal lumbar sequence. However, some patients still suffer from persistent symptoms after OLIF, including low back pain and soreness, which indirectly affect the overall surgical efficacy and patient satisfaction. Therefore, some clinicians recommend that patients routinely use spinal orthoses after OLIF to reduce the stress on the lower back muscles and ligaments, thereby relieving or avoiding postoperative residual symptoms or new symptoms. Accordingly, spinal orthosis use after OLIF has emerged as an essential option. However, the role of spinal orthoses in OLIF and their specific impact on postoperative patient clinical outcomes have remained unclear, and there is a lack of strong clinical evidence to indirectly or directly support the role of spinal orthoses in OLIF and demonstrate their impact on patient clinical outcomes. This study aims to investigate the role of spinal orthoses in OLIF by grouping patients based on the use or nonuse of spinal orthosis after OLIF, thus providing a better basis for the majority of patients and physicians. Methods/design We plan to conduct a 1-year randomized controlled trial involving 60 subjects. The subjects will be randomized into two groups: group A (those wearing spinal orthoses after surgery) and group B (those not wearing spinal orthoses after surgery). The clinical outcomes of these patients will be evaluated using the Oswestry disability index, visual analog scale, and Brantigan, Steffee, Fraser 1 day before surgery and 2 weeks and 1, 6, and 12 months after surgery. Discussion This randomized controlled trial aims to provide a reference for further comprehensive trial design. The findings of this study will provide a better and more scientific basis for the choice of postoperative rehabilitation and treatment for patients undergoing such a procedure. Trial registration This study has been registered in the Chinese Clinical Trial Registry (Registration No.: ChiCTR2200059000). Registration date: April 22, 2022. Registration website: http://www.chictr.org.cn/showproj.aspx?proj=166310

Abstract Purpose To compare the outcomes and characteristics of oblique lumbar interbody fusion stand-alone (OLIF-SA) and OLIF with posterior pedicle screw fixation (OLIF-PPS) in the treatment of Grade I or Grade II degenerative lumbar spondylolisthesis. Patients and methods Between January 2019 and May 2022, 139 patients with degenerative spondylolisthesis were treated with OLIF-SA (n = 85) or OLIF-PPS (n = 54). The clinical and radiographic records were reviewed. Results The clinical and radiographic outcomes were similar in both groups. The operative time and intraoperative blood loss in the OLIF-SA group were lower than those in the OLIF-PPS group (P

Abstract Purpose To compare the clinical efficacy of oblique lateral interbody fusion (OLIF) combined with unilateral (UPSF) and bilateral pedicle screw internal fixation (BPSF) in patients with osteoporosis. Methods Clinical data of 57 patients who underwent single-segment OLIF surgery with a clear diagnosis of osteoporosis from December 2018 to May 2021 were retrospectively analyzed, of which 27 patients underwent OLIF + UPSF and 30 patients underwent OLIF + BPSF. Surgical technique-related indexes were recorded, including operative time, operative blood loss and postoperative hospital stay; clinical outcome-related indexes included postoperative complications, Visual analogue scale (VAS) and Oswestry disability index (ODI) at preoperative, 1 week, 1 month, 3 months, and 12 months postoperative follow-up; and imaging outcome-related indexes included the measurement of preoperative and postoperative segmental lordosis (SL), and observation of the degree of cage subsidence and bone graft fusion. Results The surgery was successfully performed in 57 patients, and there was no statistical difference in operative blood loss and postoperative hospital stay between UPSF group and BPSF group (P > 0.05). In terms of operative time, there was a significant difference (UPSF group: 92.30 ± 11.03 min, BPSF group: 119.67 ± 16.41, P 0.05). At 1 year postoperatively, the rate and degree of cage subsidence was higher in the UPSF group than in the BPSF group (P

Background: No consensus has been reached regarding the efficacy of indirect decompression through oblique lumbar interbody fusion (OLIF) in severe lumbar spinal stenosis (LSS). This study investigated the impact of preoperative magnetic resonance imaging (MRI)-based grading of central and foraminal stenosis on OLIF outcomes in LSS patients and identified risk factors for postoperative clinical dissatisfaction. Methods: We retrospectively reviewed LSS patients who underwent OLIF with a minimum 1-year follow-up. Clinical scores obtained preoperatively and at 3, 6, 12, and 24 months postoperatively were analyzed using the substantial clinical benefit (SCB) framework. The severity of central and foraminal stenosis in the initial MRI was assessed through qualitative grading systems. Results: Among the 145 patients, with a mean follow-up of 33.7 months, those with severe central stenosis showed a significantly higher proportion of patients achieving SCB in the visual analog scale for leg pain (94.5% versus 83.1%; p = 0.044) at one year postoperatively than those without. However, those with severe foraminal stenosis showed significantly higher Oswestry Disability Index (ODI) scores (p = 0.024), and lower walking ability scores in the Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ) (p = 0.004) at one year postoperatively than those without. The presence of a foraminal osteophyte of the superior articular process (SAP) was a significant risk factor responsible for not achieving SCB in ODI and walking ability in JOABPEQ at one year postoperatively (odds ratio: 0.20 and 0.22, respectively). Conclusions: After OLIF, patients with severe central stenosis showed clinical outcomes comparable to those without. The improvement in ODI and walking ability in JOABPEQ was limited in patients with severe foraminal stenosis. Surgeons should consider direct decompression in cases with the presence of foraminal osteophytes of SAP.

Background: Oblique lateral lumbar fusion (OLIF) is widely used in spinal degeneration, deformity and other diseases. The purpose of this study was to investigate the biomechanical differences between two different shapes of OLIF cages on whether to add posterior internal fixation system, using finite element analysis. Methods: A complete three-dimensional finite element model is established and verified for L3–L5. Surgical simulation was performed on the verified model, and the L4–L5 was the surgical segment. A total of the stand-alone group (Model A1, Model B1) and the BPSF group (Model A2, Model B2) were constructed. The four OLIF surgical models were: A1. Stand-alone OLIF with a kidney-shaped Cage; B1. Stand-alone OLIF with a straight cage; A2. OLIF with a kidney-shaped cage + BPSF; B2. Stand-alone OLIF with a straight cage + BPSF, respectively. The differences in the range of motion of the surgical segment (ROM), equivalent stress peak of the cage (ESPC), the maximum equivalent stress of the endplate (MESE) and the maximum stress of the internal fixation (MSIF) were compared between different models. Results: All OLIF surgical models showed that ROM declines between 74.87 and 96.77% at L4–L5 operative levels. The decreasing order of ROM was Model A2 > Model B2 > Model A1 > Model A2. In addition, the ESPC and MESE of Model A2 are smaller than those of other OLIF models. Except for the left-bending position, the MSIF of Model B2 increased by 1.51–16.69% compared with Model A2 in each position. The maximum value of MESE was 124.4 Mpa for Model B1 in the backward extension position, and the minimum value was 7.91 Mpa for Model A2 in the right rotation. Stand-alone group showed significantly higher ROMs and ESPCs than the BPSF group, with maximum values of 66.66% and 70.59%. For MESE, the BPSF group model can be reduced by 89.88% compared to the stand-alone group model. Conclusions: Compared with the traditional straight OLIF cage, the kidney-shaped OLIF cage can further improve the stability of the surgical segment, reduce ESPC, MESE and MSIF, and help to reduce the risk of cage subsidence. [ABSTRACT FROM AUTHOR]

Background: Oblique lumbar interbody fusion (OLIF) is an internationally popular minimally invasive technology for the treatment of various lumbar diseases. Since its introduction to China in 2014, OLIF technology has clearly shown its superiority in reconstructing intervertebral stability, restoring intervertebral space height, achieving indirect decompression, and restoring normal lumbar sequence. However, some patients still suffer from persistent symptoms after OLIF, including low back pain and soreness, which indirectly affect the overall surgical efficacy and patient satisfaction. Therefore, some clinicians recommend that patients routinely use spinal orthoses after OLIF to reduce the stress on the lower back muscles and ligaments, thereby relieving or avoiding postoperative residual symptoms or new symptoms. Accordingly, spinal orthosis use after OLIF has emerged as an essential option. However, the role of spinal orthoses in OLIF and their specific impact on postoperative patient clinical outcomes have remained unclear, and there is a lack of strong clinical evidence to indirectly or directly support the role of spinal orthoses in OLIF and demonstrate their impact on patient clinical outcomes. This study aims to investigate the role of spinal orthoses in OLIF by grouping patients based on the use or nonuse of spinal orthosis after OLIF, thus providing a better basis for the majority of patients and physicians. Methods/design: We plan to conduct a 1-year randomized controlled trial involving 60 subjects. The subjects will be randomized into two groups: group A (those wearing spinal orthoses after surgery) and group B (those not wearing spinal orthoses after surgery). The clinical outcomes of these patients will be evaluated using the Oswestry disability index, visual analog scale, and Brantigan, Steffee, Fraser 1 day before surgery and 2 weeks and 1, 6, and 12 months after surgery. Discussion: This randomized controlled trial aims to provide a reference for further comprehensive trial design. The findings of this study will provide a better and more scientific basis for the choice of postoperative rehabilitation and treatment for patients undergoing such a procedure. Trial registration: This study has been registered in the Chinese Clinical Trial Registry (Registration No.: ChiCTR2200059000). Registration date: April 22, 2022. Registration website: http://www.chictr.org.cn/showproj.aspx?proj=166310 [ABSTRACT FROM AUTHOR]

Objectives: Cage subsidence (CS) has been reported to be one of the most common complications following oblique lumbar interbody fusion (OLIF). To reduce the incidence of CS and improve intervertebral fusion rates, anterolateral fixation (AF) has been gradually proposed. However, the incidence of CS in patients with oblique lumbar interbody fusion combined with anterolateral fixation (OLIF‐AF) is still controversial. Additionally, there is a lack of consensus regarding the optimal placement of screws for OLIF‐AF, and the impact of screw placement on the incidence of CS has yet to be thoroughly investigated and validated. The objective of this investigation was to examine the correlation between screw placements and CS and to establish an optimized approach for implantation in OLIF‐AF. Methods: A retrospective cohort study was undertaken. From October 2017 to December 2020, a total of 103 patients who received L4/5 OLIF‐AF for lumbar spinal stenosis or spondylolisthesis or degenerative instability in our department were followed up for more than 12 months. Demographic and radiographic data of these patients were collected. Additionally, screw placement related parameters, including trajectory and position, were measured by anterior–posterior X‐ray and axial CT. Analysis was done by chi‐square, independent t‐test, univariable and multivariable binary logistic regression to explore the correlation between screw placements and CS. Finally, the receiver operating characteristic (ROC) curve analysis was used to evaluate the predictive ability of screw placement‐related parameters. Results: A total of 103 patients were included, and CS was found in 28 (27.18%) patients. Univariable analysis was firstly performed for each parameter. Next, variables with p‐value of <0.05, including bone mineral density (BMD), concave morphology, and screw placement‐related parameters were included in the multivariate logistic regression analysis. Significant predictor factors for subsidence were coronal plane angle (CPA) (OR 0.580 ± 0.208, 95% CI 1.187–2.684), implantation point (IP) (L4) (OR 5.732 ± 2.737, 95% CI 1.445–12.166), and IP (L5) (OR 7.160 ± 3.480, 95% CI 1.405–28.683). Furthermore, ROC curves showed that the predictive accuracy of CS was 88.1% for CPA, 77.6% for IP (L4) and 80.9% for IP (L5). Conclusions: We demonstrate that the trajectory of vertebral screws, including angle and position, was closely related to CS. Inserting screws parallel to each other and as close to the endplate as possible while keeping the cage inside the range of the superior and inferior screws are an optimal implantation strategy for OLIF‐AF. [ABSTRACT FROM AUTHOR]

This meta-analysis compared the efficacy of oblique lumbar interbody fusion (OLIF) and minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) in the treatment of lumbar degenerative diseases. A computer search for the published literature on OLIF and MIS-TLIF for the treatment of lumbar degenerative diseases in the PubMed, Web of Science, Embase, CINAHL, MEDLINE, Cochrane Library, and other databases was performed, from which 522 related articles were retrieved and 13 were finally included. Two reviewers independently extracted data from the included studies and analyzed them using RevMan 5.4. The quality of the studies was assessed using the Cochrane systematic analysis and the Newcastle–Ottawa scale. Meta-analysis showed that the blood loss [95% confidence intervals (CI) (− 121.01, − 54.56), P < 0.001 ], hospital stay [95% CI (− 1.98, − 0.85), P < 0.001 ], postoperative fusion rate [95%CI (1.04, 3.60), P = 0.04 ], postoperative disc height [95% CI (0.50, 3.63), P = 0.01 ], and postoperative foraminal height [95% CI (0.96, 4.13), P = 0.002 ] were all better in the OLIF group; however, the complication rates were significantly lower in the MIS-TLIF group [95% CI (1.01, 2.06), P = 0.04 ]. However, there were no significant differences between the two in terms of surgery time, patient satisfaction, or postoperative functional scores. The OLIF group had the advantages of lower blood loss, a shorter hospital stay, a higher postoperative fusion rate, and better recovery of the disc and foraminal heights, whereas MIS-TLIF had a relatively lower complication rate. [ABSTRACT FROM AUTHOR]

Background and Objectives: The implementation of intraoperative imaging in the procedures performed under the guidance of the same finds its history dating back to the early 1990s. This practice was abandoned due to many deficits and practicality. Later, fluoroscopy-dependent techniques were developed and have been used even in the present time, albeit with several disadvantages. With the recent advancement of several complex surgical techniques, which demand higher accuracy and are in conjunction with the existence of radiation exposure hazard, C-arm-free techniques were introduced. In this review study, we aim to demonstrate the various types of these techniques performed in our hospital. Materials and Methods: We have retrospectively analyzed and collected imaging data of C-arm-free, minimally invasive techniques performed in our hospital. The basic steps of the procedures are described, following with a discussion, along with the literature of findings, enlisting the merits and demerits. Results: MIS techniques of the thoracolumbar and lumbar spine that do not require the use of the C-arm can offer excellent results with high precision. However, several disadvantages may prevail in certain circumstances such as the navigation accuracy problem where in the possibility of perioperative complications comes a high morbidity rate. Conclusions: The accustomedness of performing these techniques requires a steep learning curve. The increase in accuracy and the decrease in radiation exposure in complex spinal surgery can overcome the burden hazards and can prove to be cost-effective. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of the study was to evaluate the efficacy of OLIF combined with pedicle screw internal fixation in the treatment of lumbar spinal stenosis by assessing the changes in spinal canal before and after surgery. Methods: In this retrospective study, we included sixteen patients who underwent a combination of single-segment OLIF and pedicle screw internal fixation for the treatment of lumbar spinal stenosis at the Affiliated Hospital of Jiangxi University of Chinese Medicine between February 2018 and August 2022. The patients' pre- and post-operative data were compared. Intraoperative bleeding, duration of surgery, visual analogue score (VAS), Oswestry Disability Index (ODI), disc height (DH), cross-sectional area of vertebral canal (CSAVC), cross-sectional area of dural sac (CSADS), cross-sectional area of intervertebral foramen (CSAIF), spinal canal volume (SCV), spinal canal volume expansion rate, lumbar lordosis, and sagittal vertical axis were observed and recorded. The efficacy of OLIF combined with pedicle screw internal fixation for lumbar spinal stenosis on spinal canal changes before and after surgery was summarized. Results: The results showed that OLIF combined with pedicle screw internal fixation effectively restored disc height and increased the cross-sectional area of the spinal canal. It also had an indirect decompression effect. The intraoperative bleeding and duration of surgery were within acceptable ranges. The VAS and ODI scores significantly improved after surgery, indicating a reduction in pain and improvement in functional disability. The CSAVC, CSADS, CSAIF, SCV, and spinal canal volume expansion rate were all increased postoperatively. Additionally, there was improvement in lumbar lordosis and sagittal vertical axis. We conducted a follow-up of all patients at 1 year after the surgery. The results revealed that the parameter values at 1 year post-surgery showed varying degrees of decrease or increase compared to the immediate postoperative values. However, these values remained statistically significant when compared to the preoperative parameter values (P < 0.05). Conclusions: OLIF combined with pedicle screw internal fixation effectively restores disc height and increases the cross-sectional area of the vertebral canal in patients with LSS, reflecting the indirect decompression effect. Measuring parameters such as DH, CSAVC, CSADS, CSAIF, SCV, and SCV expansion rate before and after surgery provides valuable information for evaluating the efficacy and functional recovery of the lumbar spine in LSS patients treated with OLIF surgery. [ABSTRACT FROM AUTHOR]

The success of spinal fusion surgery relies on the precise placement of bone grafts and minimizing scatter. This study aims to optimize cage design and bone substitute filling methods to enhance surgical outcomes. A 3D printed lumbar spine model was utilized to implant 3D printed cages of different heights (8 mm, 10 mm, 12 mm, and 14 mm) filled with BICERA® Bone Graft Substitute mixed with saline. Two filling methods, SG cage (side hole for grafting group, a specially designed innovative cage with side hole, post-implantation filling) and FP cage (finger-packing group, pre-implantation finger packing, traditional cage), were compared based on the weight of the implanted bone substitute. The results showed a significantly higher amount of bone substitute implanted in the SG cage group compared to the FP cage group. The quantity of bone substitute filled in the SG cage group increased with the height of the cage. However, in the FP cage group, no significant difference was observed between the 12 mm and 14 mm subgroups. Utilizing oblique lumbar interbody fusion cages with side holes for bone substitute filling after implantation offers several advantages. It reduces scatter and increases the amount of implanted bone substitute. Additionally, it effectively addresses the challenge of insufficient fusion surface area caused by gaps between the cage and endplates. The use of cages with side holes facilitates greater bone substitute implantation, ultimately enhancing the success of fusion. This study provides valuable insights for future advancements in oblique lumbar interbody fusion cage design, highlighting the effectiveness of using cages with side holes for bone substitute filling after implantation. [ABSTRACT FROM AUTHOR]

Oblique lumbar interbody fusion (OLIF) and percutaneous posterior approach for screw fixation (PPS) is the latest minimal invasive treatment for spinal deformity in adult patients (ASD). This study aims to design and highlight key points for ASD correction. We retrospectively analyzed 54 patients who had undergone OLIF with PPS for ASD from October 2019 to January 2022 (average 71.5 ± 6.2 years-old, male 4, female 50) with a mean follow-up period of 29.2 months. Clinical outcomes are expressed by values including the Oswestry disability index (ODI) and visual analogue scale (VAS) for back pain. The imagistic assessment was also performed preoperatively and at 12, and 24 months postoperatively. For OLIF51, CT- MRI fusion images were obtained before surgery. Postoperative ODI and VAS were 30.5 ± 18.9% and 31.2 ± 6.9 mm, respectively. The average operating time and blood loss during the surgical exposure was 490.9 ± 85.4 min and 1195.2 ± 653.8 ml. Preoperative SVA, PI-LL, and PT were 96.5 ± 55.9 mm, 39.3 ± 22.1°, 34.5 ± 11.0°, respectively. Postoperatively, SVA and PT became normal (24.1 ± 39.0 mm, 17.1 ± 10.3°) and PI-LL was ideal (2.4 ± 12.6°). Postoperative ODI and VAS were 30.5 ± 18.9% and 31.2 ± 6.9 mm. For OLIF51, the results revealed gain in L5-S1 lordosis and intervertebral disc height 9.4° and 4.2 mm respectively. The complications consisted of PJK in 21 cases (38.9%), rod breakage in 5 cases (9.3%), deep or superficial wound infection in 2 cases (3.7%). Clinical and imagistic results of OLIF and PPS for ASD were excellent. The radiographic measurements revealed that OLIF51 created good L5-S1 lordosis and significant L5-S1 disc height. CT-MRI fusion images were very useful for evaluating vascular anatomy for OLIF51. [ABSTRACT FROM AUTHOR]

Purpose: To compare the outcomes and characteristics of oblique lumbar interbody fusion stand-alone (OLIF-SA) and OLIF with posterior pedicle screw fixation (OLIF-PPS) in the treatment of Grade I or Grade II degenerative lumbar spondylolisthesis. Patients and methods: Between January 2019 and May 2022, 139 patients with degenerative spondylolisthesis were treated with OLIF-SA (n = 85) or OLIF-PPS (n = 54). The clinical and radiographic records were reviewed. Results: The clinical and radiographic outcomes were similar in both groups. The operative time and intraoperative blood loss in the OLIF-SA group were lower than those in the OLIF-PPS group (P < 0.05). However, the OLIF-PPS group had significantly better disc height (DH) and postoperative forward spondylolisthesis distance (FSD) improvement at 6 months (P < 0.05). The OLIF-PPS group had a significantly lower cage subsidence value than the OLIF-SA group (P < 0.05). Improvement of the lumbar lordotic angle (LA) and fusion segmental lordotic angle (FSA) in the OLIF-PPS group was significantly better than that in the OLIF-SA group (P < 0.05). In terms of fusion types, the OLIF-SA group tended to undergo fusion from the edge of the vertebral body. Fusion in the OLIF-PPS group began more often in the bone graft area of the central cage of the vertebral body. The fusion speed of the OLIF-SA group was faster than that of the OLIF-PPS group. Conclusion: OLIF-SA has the advantages of a short operative time, less intraoperative blood loss, and reduced financial burden, while PPS has incomparable advantages in the reduction of spondylolisthesis, restoration of lumbar physiological curvature, and long-term maintenance of intervertebral DH. In addition, the SA group had a unique vertebral edge fusion method and faster fusion speed. [ABSTRACT FROM AUTHOR]

Purpose: To compare the clinical efficacy of oblique lateral interbody fusion (OLIF) combined with unilateral (UPSF) and bilateral pedicle screw internal fixation (BPSF) in patients with osteoporosis. Methods: Clinical data of 57 patients who underwent single-segment OLIF surgery with a clear diagnosis of osteoporosis from December 2018 to May 2021 were retrospectively analyzed, of which 27 patients underwent OLIF + UPSF and 30 patients underwent OLIF + BPSF. Surgical technique-related indexes were recorded, including operative time, operative blood loss and postoperative hospital stay; clinical outcome-related indexes included postoperative complications, Visual analogue scale (VAS) and Oswestry disability index (ODI) at preoperative, 1 week, 1 month, 3 months, and 12 months postoperative follow-up; and imaging outcome-related indexes included the measurement of preoperative and postoperative segmental lordosis (SL), and observation of the degree of cage subsidence and bone graft fusion. Results: The surgery was successfully performed in 57 patients, and there was no statistical difference in operative blood loss and postoperative hospital stay between UPSF group and BPSF group (P > 0.05). In terms of operative time, there was a significant difference (UPSF group: 92.30 ± 11.03 min, BPSF group: 119.67 ± 16.41, P < 0.05). Postoperative VAS and ODI scores exhibited significant improvement (P < 0.05). At the 12 months postoperative follow-up, the VAS and ODI scores in the BPSF group were significantly better than those in the UPS group (P < 0.05). Compared with the preoperative images, the SL was significantly improved in both groups after surgery (P < 0.05). At 6 months postoperatively, the fusion rate in the UPSF group was significantly lower than that in the BPSF group (P < 0.05). At 1 year postoperatively, the fusion rate in the UPSF group was not significantly different from that in the BPSF group (P > 0.05). At 1 year postoperatively, the rate and degree of cage subsidence was higher in the UPSF group than in the BPSF group (P < 0.05). Conclusion: In the long term, OLIF combined with bilateral posterior fixation applied to the osteoporosis patients is superior to OLIF surgery combined with unilateral posterior fixation in terms of clinical and imaging outcomes. It is effective in improving pain relief and functional improvement, accelerating bone graft fusion, and reducing cage subsidence compared with UPSF. [ABSTRACT FROM AUTHOR]

Background and Objectives: C-arm-free MIS techniques can offer significantly reduced rates of postoperative complications such as inadequate decompression, blood loss, and instrumentation misplacement. Another advantageous long-term aspect is the notably diminished exposure to radiation, which is known to cause malignant changes. This study emphasizes that, in some cases of spinal conditions that require a procedural intervention, C-arm-free MIS techniques hold stronger indications than open surgeries guided by image intensifiers. Materials and Methods: This study includes a retrospective analysis and review of various cervical and thoracic spinal procedures, performed in our hospital, applying C-arm-free techniques. The course of this study explains the basic steps of the procedures and demonstrates postoperative and intraoperative results. For anterior cervical surgery, we performed OPLL resection, while for posterior cervical surgery, we performed posterior fossa decompression for Chiari malformation, minimally invasive cervical pedicle screw fixation (MICEPS), and modified Goel technique with C1 lateral mass screw for atlantoaxial subluxation. Regarding the thoracic spine, we performed anterior correction for Lenke type 5 scoliosis and transdiscal screw fixation for diffuse idiopathic skeletal hyperostosis fractures. Results: C-arm-free techniques are safe procedures that provide precise and high-quality postoperative results by offering sufficient spine alignment and adequate decompression depending on the case. Navigation can offer significant assistance in the absence of normal anatomical landmarks, yet the surgeon should always appraise the quality of the information received from the software. Conclusions: Navigated C-arm-free techniques are safe and precise procedures implemented in the treatment of surgically demanding conditions. They can significantly increase accuracy while decreasing operative time. They represent the advancement in the field of spine surgery and are hailed as the future of the same. [ABSTRACT FROM AUTHOR]

Abstract Purpose The purpose of the study was to evaluate the efficacy of OLIF combined with pedicle screw internal fixation in the treatment of lumbar spinal stenosis by assessing the changes in spinal canal before and after surgery. Methods In this retrospective study, we included sixteen patients who underwent a combination of single-segment OLIF and pedicle screw internal fixation for the treatment of lumbar spinal stenosis at the Affiliated Hospital of Jiangxi University of Chinese Medicine between February 2018 and August 2022. The patients' pre- and post-operative data were compared. Intraoperative bleeding, duration of surgery, visual analogue score (VAS), Oswestry Disability Index (ODI), disc height (DH), cross-sectional area of vertebral canal (CSAVC), cross-sectional area of dural sac (CSADS), cross-sectional area of intervertebral foramen (CSAIF), spinal canal volume (SCV), spinal canal volume expansion rate, lumbar lordosis, and sagittal vertical axis were observed and recorded. The efficacy of OLIF combined with pedicle screw internal fixation for lumbar spinal stenosis on spinal canal changes before and after surgery was summarized. Results The results showed that OLIF combined with pedicle screw internal fixation effectively restored disc height and increased the cross-sectional area of the spinal canal. It also had an indirect decompression effect. The intraoperative bleeding and duration of surgery were within acceptable ranges. The VAS and ODI scores significantly improved after surgery, indicating a reduction in pain and improvement in functional disability. The CSAVC, CSADS, CSAIF, SCV, and spinal canal volume expansion rate were all increased postoperatively. Additionally, there was improvement in lumbar lordosis and sagittal vertical axis. We conducted a follow-up of all patients at 1 year after the surgery. The results revealed that the parameter values at 1 year post-surgery showed varying degrees of decrease or increase compared to the immediate postoperative values. However, these values remained statistically significant when compared to the preoperative parameter values (P

Objects Oblique lumbar interbody fusion (OLIF) has gained increasing popularity recently. However, complications resulting from intraoperative retraction of psoas major (PM) sometimes occur. The aim of this study is to evaluate the degree of PM swelling by developing a scoring system called the Psoas Major Swelling Grade (PMSG), and to investigate the correlation between the PMSG and clinical outcomes after OLIF. Methods Patients who underwent L4‐5 OLIF at our hospital from May 2019 to May 2021 were reviewed and all data were recorded. The extent of postoperative PM swelling was determined by calculating the percentage of change in the PM area before and after surgery on MRI and divided into three grades subsequently. Swelling within the range of 0% to 25% was defined as grade I, 25%–50% was grade II, and more than 50% was grade III. All patients were grouped into the new grade system and followed up for at least 1 year, during which the visual analog scale (VAS) and Oswestry disability index (ODI) scores were recorded. Categorical data were analyzed using chi‐square and Fisher's exact tests, while continuous variables were assessed with one‐way ANOVA and paired t‐tests. Results Eighty‐nine consecutive patients were enrolled in this study, with a mean follow‐up duration of 16.9 months. The proportion of female patients in the PMSG I, II, and III groups was 57.1%, 58.3%, and 84.1%, respectively (p = 0.024). Furthermore, the total complication rate was 43.2% in the PMSG III group, significantly higher than 9.5% and 20.8% in the PMSG I and II groups (p = 0.012). The incidence of thigh paraesthesia was also considerably higher in the PMSG III group at 34.1% (p = 0.015), compared to 9.5% and 8.3% in the PMSG I and II groups. Among the patients, 12.4% exhibited a teardrop‐shaped PM, with the majority (90.9%) belonging to the PMSG III group (p = 0.012). Additionally, the PMSG III group demonstrated a higher estimated blood loss (p = 0.007) and significantly worse clinical scores at the 1‐week follow‐up assessment (p

Abstract Objectives We reported thirteen cases of percutaneous transforaminal endoscopic surgery (PTES) under local anesthesia and mini-incision L5/S1 OLIF (OLIF51) with a self-lock cage for the treatment of L5 spondylolisthesis. Methods From Jan 2019 to Feb 2020, the patients with L5 spondylolisthesis with nerve root symptoms undergoing PTES and OLIF51 were included in this study. PTES under local anesthesia was performed in a prone position, and OLIF51 with a self-lock cage and allograft was then undertaken through a left abdominal mini-incision and oblique retroperitoneal approach between bilateral iliac vessels with the external oblique, internal oblique and transverse abdominal muscles bluntly separated in turn for L5/S1 in a right oblique position under general anesthesia. Back and leg pain were preoperatively and postoperatively evaluated using the VAS, and the clinical outcomes were evaluated with the ODI before surgery and at the 2-year follow-up. The anterior and posterior intervertebral space height (AISH, PISH), lumbar lordotic, and surgical segmental lordotic angle (SLA) were measured on lumbar spine X-rays preoperatively and postoperatively. The fusion status was assessed according to Bridwell’s fusion grades. Results Thirteen cases of L5 spondylolisthesis were included. The operation duration was 49.1 ± 5.6 min for PTES and 73.6 ± 8.2 min for OLIF. There was blood loss of 25 (15–45) ml. The incision length was 7.5 ± 1.1 mm for PTES and 46.8 ± 3.8 mm for OLIF. The hospital stay was 5 (4–6) days, and the follow-up duration was 29 (24–37) months. For the clinical evaluation, the VAS of back and leg pain significantly dropped after surgery (p

Objectives To compare the clinical and radiographic outcomes of oblique lateral lumbar interbody fusion and minimally invasive transforaminal lumbar interbody fusion in patients with grade‐1 L4/5 degenerative spondylolisthesis. Methods Based on the inclusion and exclusion criteria, the comparative analysis included consecutive patients with grade‐1 degenerative spondylolisthesis who underwent oblique LIF (OLIF, n = 36) or minimally invasive transforaminal LIF (MI‐TLIF, n = 45) at the Department of Spine Surgery, Beijing Jishuitan Hospital from January 2016 to August 2017. Patient satisfaction Japanese Orthopaedic Association score, visual analog scale (VAS) scores for back and leg pain, Oswestry disability index (ODI), radiographic outcomes including anterior/posterior disc heights (ADH/PDH), foraminal height (FH), foraminal width (FW), cage subsidence, cage retropulsion, and fusion rate were assessed during a 2‐year follow‐up. Continuous data are presented as mean ± standard deviation and were compared between groups using the independent sample t‐test. Categorical data are presented as n (%) and were compared between groups using the Pearson chi‐squared test or Fisher's exact test. Repetitive measurement and analysis of variance was employed in the analysis of ODI, back pain VAS score, and leg pain VAS score. Statistical significance was defined as p

Objective One well‐liked less invasive procedure is oblique lumbar interbody fusion (OLIF). The biomechanical characteristics of double‐level oblique lumbar interbody fusion in conjunction with various internal fixations are poorly understood. The purpose of this study was to clarify the biomechanical characteristics of double‐level oblique lumbar interbody fusion for osteoporosis spines using various internal fixation techniques. Methods Based on CT scans of healthy male volunteers, a complete finite element model of osteoporosis in L1–S1 was established. After validation, L3–L5 was selected as the surgical segment to construct four surgical models: (a) two stand‐alone cages (SA); (b) two cages with unilateral pedicle screws (UPS); (c) two cages with bilateral pedicle screws (BPS); and (d) two cages with bilateral cortical bone trajectory screws (CBT). Segmental range of motion (ROM), cage stress, and internal fixation stress were studied in all surgical models and compared with the intact osteoporosis model. Results The SA model had a minimal reduction in all motions. The CBT model had the most noticeable reduction in flexion and extension activities, while the reduction in the BPS model was slightly less than that in the CBT model but larger than that in the UPS model. The BPS model had the greatest limitation in left–right bending and rotation, which was greater than the UPS and CBT models. CBT had the smallest limitation in left–right rotation. The cage stress of the SA model was the highest. The cage stress in the BPS model was the lowest. Compared with the UPS model, the cage stress in the CBT model was larger in terms of flexion and LB and LR but slightly smaller in terms of RB and RR. In the extension, the cage stress in the CBT model is significantly smaller than in the UPS model. The CBT internal fixation was subjected to the highest stress of all motions. The BPS group had the lowest internal fixation stress in all motions. Conclusions Supplemental internal fixation can improve segmental stability and lessen cage stress in double‐level OLIF surgery. In limiting segmental mobility and lowering the stress of cage and internal fixation, BPS outperformed UPS and CBT.

Oblique lumbar interbody fusion is a minimally invasive procedure for treating degenerative lumbar disease. Its advantages include correcting coronal and sagittal spinal alignment and indirect neural decompression. However, achieving a successful outcome is limited in some patients who need direct decompression for central canal lesions including hard stenotic lesions (endplate or facet articular osteophytes and ossification of posterior longitudinal ligaments) and sequestration of the disk. Biportal endoscopic spinal surgery is a minimally invasive technique, which directly decompresses the lesion. By taking advantage of two procedures, in a long-level lumbar lesion, alignment correction and direct decompression can be both achieved. Herein, the authors introduce multilevel lumbar fusion through oblique lumbar interbody fusion and selective direct decompression through biportal endoscopic spinal surgery and discuss the surgical indications, surgical pitfalls, and recommendations for application. Consequently, it is regarded as a minimally invasive interbody fusion method for patients with multilevel lumbar degenerative degeneration.

Objects: Oblique lumbar interbody fusion (OLIF) has gained increasing popularity recently. However, complications resulting from intraoperative retraction of psoas major (PM) sometimes occur. The aim of this study is to evaluate the degree of PM swelling by developing a scoring system called the Psoas Major Swelling Grade (PMSG), and to investigate the correlation between the PMSG and clinical outcomes after OLIF. Methods: Patients who underwent L4‐5 OLIF at our hospital from May 2019 to May 2021 were reviewed and all data were recorded. The extent of postoperative PM swelling was determined by calculating the percentage of change in the PM area before and after surgery on MRI and divided into three grades subsequently. Swelling within the range of 0% to 25% was defined as grade I, 25%–50% was grade II, and more than 50% was grade III. All patients were grouped into the new grade system and followed up for at least 1 year, during which the visual analog scale (VAS) and Oswestry disability index (ODI) scores were recorded. Categorical data were analyzed using chi‐square and Fisher's exact tests, while continuous variables were assessed with one‐way ANOVA and paired t‐tests. Results: Eighty‐nine consecutive patients were enrolled in this study, with a mean follow‐up duration of 16.9 months. The proportion of female patients in the PMSG I, II, and III groups was 57.1%, 58.3%, and 84.1%, respectively (p = 0.024). Furthermore, the total complication rate was 43.2% in the PMSG III group, significantly higher than 9.5% and 20.8% in the PMSG I and II groups (p = 0.012). The incidence of thigh paraesthesia was also considerably higher in the PMSG III group at 34.1% (p = 0.015), compared to 9.5% and 8.3% in the PMSG I and II groups. Among the patients, 12.4% exhibited a teardrop‐shaped PM, with the majority (90.9%) belonging to the PMSG III group (p = 0.012). Additionally, the PMSG III group demonstrated a higher estimated blood loss (p = 0.007) and significantly worse clinical scores at the 1‐week follow‐up assessment (p < 0.001). Conclusion: PM swelling adversely affects the OLIF prognosis. Female patients with teardrop‐shaped PM are more likely to develop swelling after OLIF. A higher PMSG is associated with a higher complication rate of thigh pain or numbness and worse short‐term clinical outcomes. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to explore the relationship between intraoperative somatosensory evoked potential (SEP) amplitude changes and clinical outcomes of OLIF indirect decompression for degenerative lumbar spinal stenosis (DLSS). Methods: A prospective study was performed on 201 patients who received oblique lumbar interbody fusion (OLIF) in our hospital from July 2017 to May 2021 due to single segmental DLSS. The patients were divided into three groups: group A (mild DLSS), group B (moderate DLSS), and group C (severe DLSS). The P40 amplitude during operation were recorded, and the clinical efficacy was evaluated by JOA score 1 year postoperative. ROC curves for satisfactory efficacy of P40 amplitude improvement rate and CSA improvement rate were established. Pearson correlation was used to analyze the relationship between P40 improvement rate and JOA improvement rate. Results: In group A and group B, the improvement rate of JOA in P40 significantly improved group was significantly greater that in improved group and unimproved group (Pa = 0.009; Pb < 0.000). No significant among-subgroup differences in group C (all P > 0.05). In both groups A and B, there was a significant difference in the improvement rate of P40 amplitude between the satisfactory group and the ineffective group (Pa = 0.013; Pb = 0.001), while in group C, there was no statistical significance (Pc = 0.107). By variable Person correlation analysis, a significant positive correlation was obtained between JOA improvement rate and P40 amplitude improvement rate in groups A and B (r1 = 0.27, P1 = 0.02; r2 = 0.508, P2 = 0.001), no correlation between the two in group C (r3 = 0.243, P3 = 0.056). The area under the ROC for assessing surgical efficacy in terms of CSA improvement rate was 0.813 (95% CI: 0.737–0.889, P < 0.001) and 0.767 (95% CI: 0.677–0.856, P < 0.001) in group A and group B, respectively, with satisfactory efficacy cutoff points of 50.18% and 67.89%. Conclusion: For mild and moderate DLSS, the intraoperative P40 amplitude improvement rate can predict the improvement of clinical symptoms after surgery and can be used as a reference index to assess the effect of indirect decompression. For severe DLSS, the P40 amplitude improvement rate has limited significance in guiding indirect decompression, and OLIF indirect decompression is not the right treatment for this type of patients. [ABSTRACT FROM AUTHOR]

Purpose: The retrospective study aimed to report the surgical technique and clinic-radiological outcomes of endoscopic anterior to psoas interbody lumbar fusion through the retroperitoneal approach with direct and indirect decompression. Methods: We retrospectively analyzed the results of clinical parameters of patients who underwent endoscopic anterior to psoas interbody lumbar fusion between June 2013 and June 2022. Clinical outcomes were evaluated by the visual analog scale (VAS) and Oswestry Disability Index (ODI) scores. The radiological outcomes were measured and statistically compared in disc height index (DHI), whole lumbar lordosis (WLL), pelvic Incidence (PI), pelvic tilt (PT), Segmental lordosis (SL), the sagittal vertical axis (SVA). Results: A total of 35 patients were selected for the procedure ranging in age from 51 to 84 years with 17.83 ± 8.85 months follow-up. The mean operation time in lateral position for one level was 162.96 ± 35.76 min (n = 24), and 207.73 ± 66.60 min for two-level fusion. The mean endoscopic time was 32.83 ± 17.71 min per level, with a total estimated blood loss of 230.57 ± 187.22 cc. The mean postoperative VAS back, leg pain score and ODI improved significantly compared to the preoperative values; Radiological data showed significant change in WLL, SL, DHI, PI, PT, and SS; however, there is no significant difference in SVA postoperatively. Subgroup analysis for the radiographic data showed 50 mm length cage has significantly improved for the DHI, SS and SVA compare to 40 mm length cage. The subgroup analysis results showed that hypertensive patients had significantly higher proportion in the incomplete fusion group compare to complete fusion group at one-year follow-up. Outcomes: The endoscopic anterior to psoas interbody lumbar fusion achieves satisfactory indirect and direct decompression. This convergent technique presents an effective choice for treating lumbar instability associated with disc herniations and foraminal stenosis, thus complementing the indications for oblique lumbar interbody fusion. [ABSTRACT FROM AUTHOR]

Objectives: We reported thirteen cases of percutaneous transforaminal endoscopic surgery (PTES) under local anesthesia and mini-incision L5/S1 OLIF (OLIF51) with a self-lock cage for the treatment of L5 spondylolisthesis. Methods: From Jan 2019 to Feb 2020, the patients with L5 spondylolisthesis with nerve root symptoms undergoing PTES and OLIF51 were included in this study. PTES under local anesthesia was performed in a prone position, and OLIF51 with a self-lock cage and allograft was then undertaken through a left abdominal mini-incision and oblique retroperitoneal approach between bilateral iliac vessels with the external oblique, internal oblique and transverse abdominal muscles bluntly separated in turn for L5/S1 in a right oblique position under general anesthesia. Back and leg pain were preoperatively and postoperatively evaluated using the VAS, and the clinical outcomes were evaluated with the ODI before surgery and at the 2-year follow-up. The anterior and posterior intervertebral space height (AISH, PISH), lumbar lordotic, and surgical segmental lordotic angle (SLA) were measured on lumbar spine X-rays preoperatively and postoperatively. The fusion status was assessed according to Bridwell's fusion grades. Results: Thirteen cases of L5 spondylolisthesis were included. The operation duration was 49.1 ± 5.6 min for PTES and 73.6 ± 8.2 min for OLIF. There was blood loss of 25 (15–45) ml. The incision length was 7.5 ± 1.1 mm for PTES and 46.8 ± 3.8 mm for OLIF. The hospital stay was 5 (4–6) days, and the follow-up duration was 29 (24–37) months. For the clinical evaluation, the VAS of back and leg pain significantly dropped after surgery (p < 0.001), and the ODI significantly decreased from 64.7 ± 7.8% to 12.9 ± 4.3% 2 years after surgery (p < 0.001). AISH, PISH and SLA significantly improved after surgery (p < 0.05). Fusion grades based on the Bridwell grading system at the 2-year follow-up were grade I in 9 segments (69.2%) and grade II in 4 segments (30.8%). No patients had any form of permanent iatrogenic nerve damage or major complications. No failure of instruments was observed. Conclusions: PTES and mini-incision OLIF51 with a self-lock cage is a viable option of minimally invasive surgery for L5 spondylolisthesis, which can achieve direct neurologic decompression, satisfactory fusion and hardly destroys the rectus abdominis and its sheath, paraspinal muscles and bone structures. [ABSTRACT FROM AUTHOR]

We sought to assess the lumbar sympathetic chain (LSC) relation to the surgical corridor for the oblique lumbar approach and the ability to mobilize the LSC. Forty-three cadavers were included. A left-sided anterior retroperitoneal approach was performed in supine position. The distances between the great vessels and psoas muscle (oblique corridor) and distance between great vessels and LSC at the L2/3, L3/4, and L4/5 disk levels were measured. Mobilization of LSC at each disk level was done either close to or away from the psoas muscle, and each mobilization distance was measured. The presence rates of LSC in oblique corridor were 19.5%, 43%, and 75.7% at L2/3, L3/4, and L4/5 levels, respectively. At the L2/3 disk level, the mean distance between the psoas muscle and LSC and its mobility were 0.61 mm ± 1.31 mm and 2.72 mm ± 1.24 mm, respectively. At the L3/4 disk level, the mean distance between the psoas muscle and LSC and its mobility were 1.72 mm ± 2.53 mm and 3.11 mm ± 1.02 mm, respectively. At the L4/5 disk level, the mean distance between the psoas muscle and LSC and its mobility were 2.94 mm ± 3.52 mm and 2.53 mm ± 1.03 mm, respectively. The mean width of corridor of L2/3, L3/4, and L4/5 were 10.73 mm ± 5.82 mm, 12.63 mm ± 5.02 mm, and 15.43 mm ± 6.31 mm, respectively. The LSC tract usually lies in the oblique corridor in L4/5 but keeps decreasing in prevalence when approaching L3/4 and L2/3 levels. It can be mobilized a few millimeters close to or away from the psoas muscle. Care should be taken to prevent an LSC injury, particularly when the LSC needs to be retracted along with the psoas muscle. [ABSTRACT FROM AUTHOR]

This study aimed to identify factors that can predict the need for rib resection in a minimally invasive, oblique retroperitoneal approach for upper lumbar interbody fusion (OLIF at L1-3) using modern tubular retractors. Eighty-six patients, who underwent L1-2 and/or L2-3 OLIF at a single institution, were included. Decision for rib resection was made through intraoperative fluoroscopic view (true lateral view of the desired level). Patients were divided into two groups according to rib resection (rib resection and non-rib resection groups). Baseline demographics, surgical and radiographic data, including coronal/sagittal spinopelvic parameters and perioperative complications, were compared between the groups. Logistic regression analysis was performed to identify the factors predicting the need for rib resection. The study cohort comprised 31 patients in the rib resection group and 55 patients in the non-rib resection group. There was no significant inter-group difference in terms of the baseline demographics. A total of 79% patients undergoing the two-level (both L1-2 and L2-3) procedures were rib-resected, while 81.6% of the patients undergoing the L2-3 level alone were not rib-resected. Endplate injuries occurred more commonly in the non-rib resection group (3% vs. 14%). Pleural laceration was observed in 6% of the patients in the rib resection group. The mean T10-L2 kyphosis was larger in the rib resection group than in the non-rib resection group (14.9° vs. 6.6°, P = 0.031). Multivariate logistic regression analysis identified the following independent predictors of the need for rib resection: an L1-2 inclusive procedure; T10-L2 kyphosis > 15.9°; and the apex of the coronal curve located above L2. : The need for rib resection should be expected when performing L1-2 inclusive procedure. Even in the L2-3 alone case, aggressive decision-making for intraoperative rib resection might be required for an appropriate tubular retractor position, especially for patients with thoracolumbar kyphosis and apex vertebra of the major coronal curve located above L2. [ABSTRACT FROM AUTHOR]

Abstract Background Current evidence suggests that the magnetic resonance imaging (MRI)-based vertebral bone quality (VBQ) score is a good parameter for evaluating bone quality. We aimed to assess whether the VBQ score can predict the occurrence of postoperative cage subsidence after oblique lumbar interbody fusion (OLIF) surgery. Methods Patients (n = 102) who had undergone single-level OLIF with a minimal follow-up for 1 year were reviewed in this study. Demographic and radiographic data of these patients were collected. Cage subsidence was defined as ≥ 2 mm of cage migration into the inferior endplate, superior endplate, or both. Further, the MRI-based VBQ score was measured on T1-weighted images. Moreover, univariable and multivariable binary logistic regression analyses were performed. Meanwhile, Pearson analysis was used to evaluate the correlation among the VBQ score, average lumbar dual-energy X-ray absorptiometry (DEXA) T-score, and degree of cage subsidence. Furthermore, ad-hoc analysis was used along with receiver operating characteristic curve analysis to assess the predictive ability of the VBQ score and average lumbar DEXA T-score. Results Of 102 participants, cage subsidence was observed in 39 (38.24%) patients. According to the univariable analysis, patients with subsidence had older age, higher antiosteoporotic drug use, larger disk height change, a more concave morphology of inferior and superior endplates, higher VBQ score, and lower average lumbar DEXA T-score compared to patients without subsidence. In the multivariable logistic regression analysis, a higher VBQ score was significantly associated with an increased risk of subsidence (OR = 23.158 ± 0.849, 95% CI 4.381–122.399, p

Abstract Background and objective Anterior lumbar interbody fusion (ALIF) and oblique lumbar interbody fusion (OLIF) have shown a great surgical potential, while it has always been controversial which surgical approach and which type of fixation system should be selected. This study investigated the biomechanical response of ALIF and OLIF with various supplementary fixation systems using the finite element method. Materials and methods Lumbar L4–L5 ALIF and OLIF models stabilized by different supplementary fixation systems (stand-alone cage, integrated stand-alone cage, anterior plate, and bilateral pedicle screw) were developed to assess the segmental range of motion (ROM), endplate stress (EPS), and screw-bone interface stress (SBIS). Experimental results ALIF showed lower ROM and EPS than OLIF in all motion planes and less SBIS in the most of motion planes compared with OLIF when the anterior plate or pedicle screw was used. ALIF induced higher ROM, while lower EPS and SBIS than OLIF in the majority of motion planes when integrated stand-alone cage was utilized. Using a stand-alone cage in ALIF and OLIF led to cage migration. Integrated stand-alone cage prevented the cage migration, whereas caused significantly larger ROM, EPS, and SBIS than other fixation systems except for the rotation plane. In the most of motion planes, the pedicle screw had the lowest ROM, EPS, and SBIS. The anterior plate induced a slightly larger ROM, EPS, and SBIS than the pedicle screw, while the differences were not significant. Conclusion ALIF exhibited a better performance in postoperative segmental stability, endplate stress, and screw-bone interface stress than OLIF when the anterior plate or the pedicle screw was used. The pedicle screw could provide the greatest postoperative segmental stability, less cage subsidence incidence, and lower risk of fixation system loosening in ALIF and OLIF. The anterior plate could also contribute to the stability required and fewer complications, while not as effectively as the pedicle screw. Extreme caution should be regarded when the stand-alone cage is used due to the risk of cage migration. The integrated stand-alone cage may be an alternative method; however, further optimization is needed to reduce complications and improve postoperative segmental stability.

(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.

Objectives: To compare the clinical and radiographic outcomes of oblique lateral lumbar interbody fusion and minimally invasive transforaminal lumbar interbody fusion in patients with grade‐1 L4/5 degenerative spondylolisthesis. Methods: Based on the inclusion and exclusion criteria, the comparative analysis included consecutive patients with grade‐1 degenerative spondylolisthesis who underwent oblique LIF (OLIF, n = 36) or minimally invasive transforaminal LIF (MI‐TLIF, n = 45) at the Department of Spine Surgery, Beijing Jishuitan Hospital from January 2016 to August 2017. Patient satisfaction Japanese Orthopaedic Association score, visual analog scale (VAS) scores for back and leg pain, Oswestry disability index (ODI), radiographic outcomes including anterior/posterior disc heights (ADH/PDH), foraminal height (FH), foraminal width (FW), cage subsidence, cage retropulsion, and fusion rate were assessed during a 2‐year follow‐up. Continuous data are presented as mean ± standard deviation and were compared between groups using the independent sample t‐test. Categorical data are presented as n (%) and were compared between groups using the Pearson chi‐squared test or Fisher's exact test. Repetitive measurement and analysis of variance was employed in the analysis of ODI, back pain VAS score, and leg pain VAS score. Statistical significance was defined as p < 0.05. Results: The OLIF and MI‐TLIF groups comprised 36 patients (age, 52.1 ± 7.2 years; 27 women) and 45 patients (age, 48.4 ± 14.4 years; 24 women), respectively. Satisfaction rates at 2 years post procedure exceeded 90% in both groups. The OLIF group had less intraoperative blood loss (140 ± 36 vs 233 ± 62 mL), lower back pain VAS score (2.42 ± 0.81 vs 3.38 ± 0.47), and ODI score (20.47 ± 2.53 vs 27.31 ± 3.71) at 3 months follow‐up (with trends toward lower values at 2 years follow‐up), but higher leg pain VAS scores at all postoperative time points than the MI‐TLIF group (all p < 0.001). ADH, PDH, FD, and FW improved in both groups post‐surgery. At the 2 year follow‐up, the OLIF group had a higher rate of Bridwell grade‐I fusion (100% vs 88.9%, p = 0.046) and lower incidences of cage subsidence (8.33% vs 46.67%, p < 0.001) and retropulsion (0% vs 6.67%, p = 0.046) than the MI‐TLIF group. Conclusions: In patients with grade‐I spondylolisthesis, OLIF was associated with lower blood loss and greater improvements in VAS for back pain and ODI and radiologic outcomes than MI‐TLIF. The OLIF is more suitable for these patients with low back pain as the main symptoms are accompanied by mild or no leg symptoms before operation. [ABSTRACT FROM AUTHOR]

BACKGROUND: In vitro experiments have confirmed that although the integrated interbody cage can be implanted from the side, it does not have the ability to adjust the height of the intervertebral cage and adjust the reduction function of lumbar spondylolisthesis after implantation. Therefore, the present study designed a new lumbar surgical procedure: oblique lumbar interbody fusion with an integrated expandable repositionable cage fixation (OLIF+IERC), and studied the biomechanical performance of OLIF+IERC. OBJECTIVE: To explore the biomechanical performance differences of the OLIF+IERC surgical model in this study, compared with the normal lumbar spine finite element model, OLIF stand-alone without fixation system (stand-alone OLIF) model, and OLIF with posterior bilateral pedicle screws fixation (OLIF+BPS) model. METHODS: The established and validated normal model (L3-S1) was suitably modified to establish three kinds of OLIF surgical models: stand-alone OLIF, OLIF+BPS, and OLIF+IERC designed in this study. By applying a 500 N follower load and a moment load of 7.5 N·m in different directions (flexion, extension, lateral bending, and axial rotation) to each model, the various biomechanical indicators of the different models were compared. RESULTS AND CONCLUSION: (1) For range of motion, maximum cage stress, and maximum endplate stress at L4-L5, OLIF+IERC was lower than other surgical models in axial rotation; stand-alone OLIF was highest in all motion postures; OLIF+BPS was lowest in flexion, extension, and lateral bending. (2) Taken together, the biomechanical stability, resistance to cage subsidence, and disc height reduction of OLIF+IERC were superior to stand-alone OLIF in all motion postures and superior to OLIF+BPS in motion posture of axial rotation. (3) This study suggests that OLIF+IERC may be considered as a surgical procedure for future surgical treatment of patients with degenerative disease of the lumbar spine. This study provides a valuable reference for the treatment of lumbar degenerative diseases. [ABSTRACT FROM AUTHOR]

Objective: One well‐liked less invasive procedure is oblique lumbar interbody fusion (OLIF). The biomechanical characteristics of double‐level oblique lumbar interbody fusion in conjunction with various internal fixations are poorly understood. The purpose of this study was to clarify the biomechanical characteristics of double‐level oblique lumbar interbody fusion for osteoporosis spines using various internal fixation techniques. Methods: Based on CT scans of healthy male volunteers, a complete finite element model of osteoporosis in L1–S1 was established. After validation, L3–L5 was selected as the surgical segment to construct four surgical models: (a) two stand‐alone cages (SA); (b) two cages with unilateral pedicle screws (UPS); (c) two cages with bilateral pedicle screws (BPS); and (d) two cages with bilateral cortical bone trajectory screws (CBT). Segmental range of motion (ROM), cage stress, and internal fixation stress were studied in all surgical models and compared with the intact osteoporosis model. Results: The SA model had a minimal reduction in all motions. The CBT model had the most noticeable reduction in flexion and extension activities, while the reduction in the BPS model was slightly less than that in the CBT model but larger than that in the UPS model. The BPS model had the greatest limitation in left–right bending and rotation, which was greater than the UPS and CBT models. CBT had the smallest limitation in left–right rotation. The cage stress of the SA model was the highest. The cage stress in the BPS model was the lowest. Compared with the UPS model, the cage stress in the CBT model was larger in terms of flexion and LB and LR but slightly smaller in terms of RB and RR. In the extension, the cage stress in the CBT model is significantly smaller than in the UPS model. The CBT internal fixation was subjected to the highest stress of all motions. The BPS group had the lowest internal fixation stress in all motions. Conclusions: Supplemental internal fixation can improve segmental stability and lessen cage stress in double‐level OLIF surgery. In limiting segmental mobility and lowering the stress of cage and internal fixation, BPS outperformed UPS and CBT. [ABSTRACT FROM AUTHOR]