Influence of facetectomy, cross-link augmentation, and interbody procedure on progression of bone fusion in single-level posterior lumbar interbody fusion using the long cortical bone trajectory technique.

OBJECTIVE: When using the cortical bone trajectory (CBT) technique, two technical countermeasures are recommended to promote bone fusion: taking a long CBT screw path directed more anteriorly and improving the stability of the spinal construct by facet joint preservation, cross-link augmentation, and rigid anterior interbody reconstruction. However, there has been no report on how these surgical procedures, which are heavily dependent on the surgeon's preference, contribute to successful bone fusion. The aim of the present study was to investigate the progression of lumbar spinal fusion using the long CBT technique and identify factors contributing to the time taken to achieve bone fusion, with a particular focus on the involvement of surgical procedures. METHODS: A total of 167 consecutive patients with L4 degenerative spondylolisthesis who underwent single-level posterior lumbar interbody fusion at L4-5 using the long CBT technique were included (mean follow-up 42.8 months). Bone fusion was assessed to identify factors contributing to the time to achieve bone fusion. Investigated factors were 1) age, 2) sex, 3) BMI, 4) bone mineral density, 5) intervertebral mobility, 6) screw depth in the vertebra, 7) extent of facetectomy, 8) cross-link augmentation, 9) cage material, 10) cage design, 11) number of cages, and 12) contact area of cages with the vertebral endplate. RESULTS: The bone fusion rate was 89.2% at 2 years postoperatively and 95.8% at the last follow-up, with a mean period to bone fusion of 16.6 ± 9.6 months. Multivariate regression analysis revealed that age (standardized regression coefficient [ß] = 0.25, p = 0.002), female sex (ß = -0.22, p = 0.004), and BMI (ß = 0.15, p = 0.045) were significant independent factors affecting the time to achieve bone fusion. There was no significant effect of surgical procedures (p ≥ 0.364). CONCLUSIONS: This is the first study to investigate the progression of lumbar spinal fusion using the long CBT technique and identify factors contributing to the time taken to achieve bone fusion. Patient factors such as age, sex, and BMI affected the progression of bone fusion, and surgical factors had only weak effects.

Impact of preoperative age-adjusted sagittal imbalance on radiographic and clinical outcomes following 1-level minimally invasive transforaminal lumbar interbody fusion for degenerative spondylolisthesis.

OBJECTIVE: Prior studies investigating the use of minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) for treatment of degenerative lumbar conditions and concomitant sagittal deformity have not stratified patients by preoperative pelvic incidence (PI)-lumbar lordosis (LL) mismatch, which is the earliest parameter to deteriorate in mild sagittal deformity. Thus, the aim of the present study was to determine the impact of preoperative PI-LL mismatch on clinical outcomes and sagittal balance restoration among patients undergoing MI-TLIF for degenerative spondylolisthesis (DS). METHODS: Consecutive adult patients undergoing primary 1-level MI-TLIF between April 2017 and April 2022 for DS with ≥ 6 months radiographic follow-up were included. Patient-reported outcome measures (PROMs) included the Oswestry Disability Index, visual analog scale (VAS), 12-Item Short-Form Health Survey (SF-12), and Patient-Reported Outcomes Measurement Information System at preoperative, early postoperative (< 6 months), and late postoperative (≥ 6 months) time points. The minimal clinically important difference (MCID) for PROMs was also evaluated. Radiographic parameters included PI, LL, pelvic tilt (PT), and sagittal vertical axis (SVA). Patients were categorized into balanced and unbalanced groups based on preoperative PI-LL mismatch according to age-adjusted alignment goals. Changes in radiographic parameters and PROMs were evaluated. RESULTS: Eighty patients were included (L4-5 82.5%, grade I spondylolisthesis 82.5%, unbalanced 58.8%). Mean clinical and radiographic follow-up were 17.0 and 8.3 months, respectively. The average preoperative PI-LL was 18.8° in the unbalanced group and -3.3° in the balanced group. Patients with preoperative PI-LL mismatch had significantly worse preoperative PT (26.2° vs 16.4°, p < 0.001) and SVA (53.2 vs 9.0 mm, p = 0.001) compared with balanced patients. Patients with preoperative PI-LL mismatch also showed significantly worse PI-LL (16.0° vs 0.54°, p < 0.001), PT (25.9° vs 18.7°, p < 0.001), and SVA (49.4 vs 22.8 mm, p = 0.013) at long-term follow-up. No significant radiographic improvement was observed among unbalanced patients. All patients demonstrated significant improvements in all PROMs (p < 0.05) except for SF-12 mental component score. Achievement of MCID for VAS back score was significantly greater among patients with preoperative PI-LL mismatch (85.7% vs 65.5%, p = 0.045). CONCLUSIONS: Although 1-level MI-TLIF did not restore sagittal alignment in patients with preoperative PI-LL mismatch, patients presenting with DS can expect significant improvement in PROMs following 1-level MI-TLIF regardless of preoperative alignment or extent of correction. Thus, attaining good clinical outcomes in patients with mild sagittal imbalance may not require addressing imbalance directly.

Cage Obliquity in Oblique Lumbar Interbody Fusion-How Common Is It and What Are the Effects on Fusion Rates, Subsidence, and Sagittal Alignment? A Computed Tomography-Based Analysis.

BACKGROUND: Oblique lumbar interbody fusion (OLIF) through a prepsoas approach was identified as an alternative to alleviate complications associated with direct lateral interbody fusion. Cage placement is known to influence cage subsidence and fusion rates due to suboptimal biomechanics. There are limited studies exploring cage obliquity as a potential factor influencing fusion outcomes. Hence, our objective was to assess the effects of cage obliquity and position on fusion rates, subsidence, and sagittal alignment in patients who underwent OLIF. METHODS: Patients who underwent OLIF for levels L1 to L5 in our center, performed by a single surgeon and with a minimum of 12 months of follow-up, were included in the study. Cage obliquity and sagittal placement were measured, and their correlation with fusion, subsidence, and sagittal alignment correction was assessed. Fusion and subsidence were evaluated using the Bridwell Criteria and Marchi Criteria, respectively. RESULTS: Among the included patients (age, 67.5 ± 7.93 years; 16 men and 37 women), 97 fusion levels were studied. The mean cage obliquity was 4.2° ± 2.8°. Ninety-six levels (99.0%) were considered to have achieved fusion with a Bridwell score of 1 or 2. Eighty-one (83.5%), 14 (14.4%), and 2 (2.06%) operated levels had a Marchi score of 0, 1, and 2, respectively. A Marchi grade of 1 or higher was considered indicative of significant subsidence. There was good improvement in both the segmental lordosis angle (4.2° ± 5.7°; P < 0.0001) and disc height (4.5 ± 3.8 mm; P < 0.0001). Cage placement did not have any statistical correlation with fusion rates, subsidence, or sagittal alignment. CONCLUSIONS: Our results indicate that OLIF facilitates appropriate cage placement with only a minor degree of cage obliquity, typically less than 20°. This minor obliquity does not lead to lower fusion rates, increased subsidence, or sagittal malalignment. Despite subsidence being common, the majority of these cases resulted in complete fusion.

Comparative analysis of tubular retractors and hook retractors in oblique lumbar interbody fusion at the initial stage of the learning curve.

PURPOSE: Oblique lumbar interbody fusion (OLIF) still has a steep learning curve that many spinal surgeons who want to develop are hesitant. The purpose of this study is to provide reference for beginners through the comparative analysis of the application of two kinds of retraction devices in the early stage of learning curve. METHOD: We prospectively included the first 60 patients with lumbar degenerative diseases treated with OLIF by a surgeon in our department. According to the application of different retraction devices during the operation, the patients were divided into hook retractor group and tubular retractor group. The clinical effects and complications of the two groups were compared. RESULT: The average age of hook retractor group was 62 years old, the average age of tubular retractor group was 65 years old. There was no significant difference in age, sex, operative segment, follow-up time and blood loss between the two groups. The operation time in hook retractor group was less than that in tubular retractor group. The incidence of complications in hook retractor group (11.8%) was significantly lower than that in tubular retractor group (38.5%). CONCLUSION: The tubular retractor group has a higher risk of neurovascular injury in the initial stage of learning, as well as the risk of vertebral fracture. In contrast, the hook retractor group has the advantages of simple method, high fault tolerance and relatively low incidence of complications. Therefore, we believe that the application of hook retractor in the early stage of OLIF learning curve is easier to increase the operator's confidence and make OLIF more acceptable.

Experimental Analysis of Stress Shielding Effects in Screw Spacers Placed in Porcine Spinal Tissue.

Bone cortical tissues reorganize and remodel in response to tensile forces acting on them, while compressive forces cause atrophy. However, implants support most of the payload. Bones do not regenerate, and stress shielding occurs. The aim is to analyze the biomechanical behavior of a lumbar cage to study the implant's stress shielding. The ASTM E-9 standard was used with the necessary adjustments to perform compression tests on lumbar and thoracic porcine spinal vertebrae. Twelve cases were analyzed: six with the metal prosthesis and six with the PEEK implant. A mathematical model based on the Hertz contact theory is proposed to assess the stress shielding for endoprosthesis used in spine pathologies. The lumbar spacer (screw) helps to reduce the stress shielding effect due to the ACME thread. The best interspinous spacer is the PEEK screw. It does not embed in bone. The deformation capability increases by 11.5% and supports 78.6 kg more than a system without any interspinous spacer.

Sacrolumbar Interbody Fusion (SLIF): Feasibility, Technical Nuances, Biomechanical Assessment, and Clinical Outcomes.

Introduction: S1-L5 transdiscal screw fixation is a direct stabilization technique used for surgical treatment of high-grade (III-IV) L5-S1 spondylolisthesis. It has not been used for nonspondylolisthetic cases or in combination with an interbody cage (IC). This study aimed to develop a novel, direct S1-L5 sacrolumbar interbody fusion (SLIF) technique, a combination of IC and sacrolumbar transdiscal screw. Methods: SLIF was tested in cadaveric, clinical, and finite element analysis settings. Three cadaveric lumbar spines were used to test the SLIF procedure before clinical application. Eight patients underwent the SLIF procedure. Clinical outcomes were evaluated by visual analog score for leg and back pain, short form 36, Oswestry disability index, and neurological examination. CT scans of the lumbar spine were used to assess the hardware placement and subsequent fusion. Finite element analysis was performed on a healthy human CT-based L5-S1 model. Intact segment, unilateral facetectomy and discectomy, SLIF, and transforaminal lumbar interbody fusion (TLIF) procedures were compared in terms of the range of motion (ROM), von Mises stress on hardware, and shear-induced directional deformity. Additionally, the same set of tests were conducted in an osteoporotic model. Results: Excellent hardware placement was feasible in three cadavers and eight patients. Preoperative neurological deficits improved in all patients. Statistically significant improvements were obtained on all self-reported questionnaire scores. All patients developed solid, Bridwell grade I fusions. Biomechanical testing revealed similar outcomes for TLIF and SLIF regarding the ROM. However, the screw's von Mises stress and shear-induced directional deformity were low for SLIF of healthy and osteoporotic bone. Conclusions: SLIF is a feasible, safe, and effective L5-S1 fusion option suitable for all clinical scenarios. It provides several biomechanical advantages, yielding excellent clinical outcomes.

Animal Model for Anterior Lumbar Interbody Fusion: A Literature Review.

Lumbar interbody fusion (LIF) is a surgical procedure for treating lumbar spinal stenosis and deformities. It removes a spinal disc and insert a cage or bone graft to promote solid fusion. Extensive research on LIF has been supported by numerous animal studies, which are being developed to enhance fusion rates and reduce the complications associated with the procedure. In particular, the anterior approach is significant in LIF research and regenerative medicine studies concerning intervertebral discs, as it utilizes the disc and the entire vertebral body. Several animal models have been used for anterior LIF (ALIF), each with distinct characteristics. However, a comprehensive review of ALIF models in different animals is currently lacking. Medium-sized and large animals, such as dogs and sheep, have been employed as ALIF models because of their suitable spine size for surgery. Conversely, small animals, such as rats, are rarely employed as ALIF models because of anatomical challenges. However, recent advancements in surgical implants and techniques have gradually allowed rats in ALIF models. Ambitious studies utilizing small animal ALIF models will soon be conducted. This review aims to review the advantages and disadvantages of various animal models, commonly used approaches, and bone fusion rate, to provide valuable insights to researchers studying the spine.

Clinical Effectiveness of Anterior Cervical Discectomy and Fusion Using Tritanium C Anterior Cervical Cage vs. PEEK Cage.

Introduction: Anterior cervical discectomy and fusion (ACDF) has proven to be a clinically efficient and cost-effective method for treating patients with degenerative cervical spine conditions. New intervertebral implant products are being developed to improve fusion and stability while decreasing complications. This study assesses the effectiveness of Tritanium C (Tri-C) Anterior Cervical Cage (Stryker) in the treatment of degenerative disk disease (DDD) of the cervical spine compared with polyetheretherketone (PEEK) cages. Methods: A retrospective cohort analysis was conducted using data prospectively collected from two institutions. Patients who underwent ACDFs for DDD using either the Tri-C cage or PEEK cage were identified. The patients' demographics, comorbidities, operative variables, and baseline patient-reported outcomes (PROs) were collected. PROs included the Neck Disability Index (NDI) and numeric rating scale (NRS) for neck and arm pain. The primary outcomes included 3- and 12-month PROs as well as the rates of 90-day readmission, 90-day reoperation, and perioperative complication. The radiographic outcomes included rates of subsidence, cage movement, and successful fusion within 12 months. Multivariate linear regression models were run to identify variables predictive of 12-month PROs. Results: A total of 275 patients who underwent ACDF were included in this study and were divided into two groups: PEEK (n=213) and Tri-C (n=62). Both groups showed improvement in neck and arm pain and NDI postoperatively. When Tri-C and PEEK were compared, no significant differences were observed in the 3- or 12-month changes in neck or arm pain or NDI. Furthermore, there were no differences in the rates of 90-day readmission, 90-day reoperation, and perioperative complication. Regression analysis revealed that Tri-C vs. PEEK was not a significant predictor of any outcome. Conclusions: Our results indicate that the use of porous titanium Tri-C cage during ACDFs is an effective method for managing cervical DDD in terms of PROs, perioperative morbidity, and radiologic parameters. No significant difference was observed in any clinical outcome between patients undergoing ACDF using the Tri-C cage and those in whom the PEEK cage was used. Level of Evidence: III.

Minimally-invasive lateral thoracic and lumbar interbody fusion (LLIF) with expandable interbody cages - Considerations, complications & outcomes.

Introduction: Reports about lateral lumbar or thoracic interbody fusion (LLIF) using expandable interbody spacers are sparse. Research question: To report our experience with the use of expandable spacers for LLIF. Material and methods: We reviewed all consecutive LLIF patients with use of an expandable titanium interbody implant (ELSA® Expandable Integrated LLIF Spacer, Globus Medical Inc, PA (USA)) between September 2018 and January 2024. Results: We identified 503 patients, in which we performed LLIF at 732 levels. In 63 patients (12.5%) and 70 levels (9.6%) an expandable spacer was used. The mean age was 61.4 years, 57.1% were females. LLIF was performed between T11/12 - L4/5 in the setting of fusion procedures (mono-/bisegmental (20; 28.6%), 3-7 segments (29; 41.4%); >7 segments (21; 30.0%)), of which 21 (33.3%), 20 (31.8%) and 22 (34.9%) were for traumatic, deformity/revision and other diagnoses. Surgery included release of the anterior longitudinal ligament in 30 cases (42.9%). Intraoperative adverse events (AEs) were noted in 2 (3.2%), postoperative AEs in 27 (42.9%) at discharge, 17 (27.0%) at 3 months and 14 (22.2%) at 12 months. Segmental sagittal Cobb angle changed from 1.3° (preoperative) to 13.0° at discharge (p < 0.001), 12.7° at 3 months (p < 0.001) and 13.3° at 12 months (p < 0.001). Functional outcome was excellent/good in 43 (68.3%; 5 missing) at 3 months and in 37 (58.7%; 10 missing) at 12 months. Discussion and conclusion: The use of LLIF with an expandable spacer was safe, promoted solid fusion and enabled powerful correction of sagittal segmental Cobb angle, which was maintained during follow-up.

Comparison of mMO-TLIF via Midline Incision Versus MIS-TLIF via Wiltse Approach in Lumbar Degenerative Disease.

Background: To compare the clinical and radiological outcomes of modified mini-open transforaminal lumbar interbody fusion (mMO-TLIF) via posterior midline incision for "targeted limited dissection" versus minimal invasive transforaminal lumbar interbody fusion (MIS-TLIF) via Wiltse approach in lumbar degenerative diseases. Methods: A total of 60 consecutive patients in our center from January 2019 to March 2020 were enrolled, including 30 patients who were treated with mMO-TLIF via posterior midline incision and 30 treated with MIS-TLIF through the Wiltse approach. Perioperative parameters were recorded. The questionnaires of Oswestry Disability Index (ODI) and Visual Analogue Score (VAS) were conducted before the operation and after the operation (3 days, 1 week, and 2 years). CT and MRI radiological outcomes were evaluated before the operation and at a 2-year follow-up. Results: There were no significant differences in the general data, gender, age, and BMI between the two groups. All patients were successfully operated without intraoperative complications. There were significant differences between the two groups in the operation time (p < 0.001) and intraoperative bleeding (p < 0.05). There was no difference in ODI and VAS scores between groups pre- and post-operatively, but they were both significantly improved compared to those before the operation (p < 0.01). At a 2-year follow-up, the paraspinal muscle atrophy and fat infiltration were increased comparing to pre-operation, but the difference was also not statistically significant (p > 0.05). In addition, both the two groups' fusion rates were more than 90% at a 2-year follow-up, however, no difference was detected between the two groups. Conclusion: mMO-TLIF via midline incision for "targeted limited dissection" could achieve similar clinical and radiological outcomes as MIS-TLIF for lumbar degenerative disease.

Surgical Innovation: Comparative Efficacy of Navigation-Assisted Modified MIS-TLIF and Traditional MIS-TLIF in Treating Low-Grade Isthmic Spondylolisthesis in the Elderly.

OBJECTIVE: To compare the efficacy of navigation-assisted modified MIS-TLIF (Minimally invasive transforaminal lumbar interbody fusion) and MIS-TILF in the treatment of low-grade isthmic spondylolisthesis in the elderly. METHODS: We retrospectively included elderly patients with low-grade isthmic spondylolisthesis who underwent surgical treatment at our hospital from January 2019 to January 2022. Based on the surgical method chosen according to the patient's personal preference, the patients were divided into the modified MIS-TLIF group and the MIS-TLIF group. The modified MIS-TLIF group underwent navigation-assisted MIS-TLIF, while the MIS-TLIF group underwent conventional MIS-TLIF. A total of 54 patients (34 males and 20 females) were included in this study, with 26 cases in the modified MIS-TLIF group and 28 cases in the MIS-TLIF group. Relevant data for this study were collected by an independent observer. The demographic characteristics, including age, gender, BMI, comorbidities, surgical level, Meyerding grade, and duration of symptoms before admission, were recorded and compared between the two groups. Perioperative parameters, such as operative time, intraoperative blood loss, postoperative drainage volume, bed rest time, and hospital stay, were also recorded and compared. The lumbar pain visual analog scale (BP-VAS), Oswestry Disability Index (ODI), and lumbar JOA scores were recorded preoperatively and at 1 week, 1 month, 3 months, 6 months, and 12 months postoperatively to evaluate functional recovery in both groups. At 12 months postoperatively, patient satisfaction was assessed using the Macnab criteria (with satisfaction defined as the number of excellent and good outcomes divided by the total number in the group × 100%). The rate of vertebral slippage was recorded preoperatively, at 1 week postoperatively, and at 12 months postoperatively. The accuracy of screw placement was evaluated by CT scan at 1 week postoperatively, and interbody fusion was assessed by CT scan at 12 months postoperatively. Surgical complications were recorded, and their incidence was calculated. RESULTS: The intraoperative blood loss, postoperative drainage volume, bed rest time and hospital stay in the modified MIS-TLIF group were less than those in the MIS-TLIF group (P< 0.05). The BP-VAS (Back Pain Visual Analogue Scale), ODI (Oswestry Disability Index), and JOA (Japanese Orthopaedic Association) modified MIS-TLIF groups improved significantly compared with the MIS-TLIF group at 1 week, 1 month, 3 months, and 6 months after surgery, and the differences between groups were statistically significant (P<0.05). The excellent and good rate of modified MIS-TLIF group was higher than that of MIS-TLIF group, and the difference had statistical significance (P<0.05). The accuracy of screw placement in the modified MIS-TLIF group was higher than that in the MIS-TLIF group, and the difference was statistically significant (P<0.05). The fusion rate in the modified MIS-TLIF group was higher than that in the MIS-TLIF group at 12 months after surgery, and the difference was statistically significant (P<0.05). No statistical difference in the incidence rate of complications between the two groups. CONCLUSION: Compared with MIS-TLIF, navigation-assisted modified MIS-TLIF has the advantages of less trauma, rapid recovery, accurate screw placement, high fusion rate, high surgical satisfaction and good safety.

[Orthopedic robot-assisted endoscopic transforaminal lumbar interbody fusion for lumbar disc herniation with lumbar instability].

OBJECTIVE: To explore the safety and effectiveness of the robot-assisted system for transforaminal percutaneous endoscopic in the treatment of lumbar disc herniation with lumbar instability. METHODS: From October 2021 to March 2023, 26 patients with single-segment lumbar disc herniation and lumbar spinal instability were treated with robot-assisted system for transforaminal percutaneous endoscopic. The operation time, intraoperative blood loss, incision length, postoperative drainage volume, postoperative ambulation activity time, postoperative hospitalization time were record. The intervertebral space height and the lumbar lordosis angle before and after surgery were observed and compared. Pain level was evaluated using the visual analogue scale(VAS). The clinical efficacy was evaluated by Oswestry disability index(ODI). The interbody fusion was evaluated by Brantigan Steffee criteria. RESULTS: All patients successfully completed the operation, the operation time ranged form 105 to 109 min with an average of (150.8±24.1) min. Intraoperative blood loss ranged form 35 to 88 ml with an average of (55.5±16.4) ml. Incision length ranged form 1.4 to 3.5 cm with an average of (2.3±0.8) cm. Postoperative drainage volume ranged form 15 to 40 ml with an average of (28.5±7.8) ml. Postoperative ambulation time ranged form 15 to 30 h with an average of (22.8±4.5) h. Postoperative hospitalization time was 3 to 7 d with an average of (4.2±1.3) d. Total of 26 patients were followed up, the duration ranged from 12 to 16 months with an average of (14.0±1.3) months. The VAS and ODI at 1 week [(2.96±0.72) points, (41.63±4.79)%] and 12 months[(1.27±0.60) points, (13.11±2.45)%] were significantly different from those before surgery[(6.69±0.93) points, (59.12±5.92)%], P<0.01. The height of the intervertebral space (11.95±1.47) mm and lumbar lordosis (57.46±7.59)° at 12 months were significantly different from those before surgery [(6.67±1.20) mm, (44.08±7.79)°], P<0.01. At 12 months after surgery, all patients had no pedicle screw rupture or dislocation of the fusion cage, and the intervertebral fusion was successful. According to Brantigan-Steffee classification, 17 cases were grade D and 9 cases were grade E. CONCLUSION: Robot-assisted system for transforaminal percutaneous endoscopic for the treatment of single-segment lumbar disc herniation with lumbar instability improved the accuracy and safety of the operation, and the clinical effect of early follow-up is accurate.

[Reasons and strategies of reoperation after oblique lateral interbody fusion].

OBJECTIVE: To summarize the reasons and management strategies of reoperation after oblique lateral interbody fusion (OLIF), and put forward preventive measures. METHODS: From October 2015 to December 2019, 23 patients who underwent reoperation after OLIF in four spine surgery centers were retrospectively analyzed. There were 9 males and 14 females with an average age of (61.89±8.80) years old ranging from 44 to 81 years old. The index diagnosis was degenerative lumbar intervertebral dics diseases in 3 cases, discogenic low back pain in 1 case, degenerative lumbar spondylolisthesis in 6 cases, lumbar spinal stenosis in 9 cases and degenerative lumbar spinal kyphoscoliosis in 4 cases. Sixteen patients were primarily treated with Stand-alone OLIF procedures and 7 cases were primarily treated with OLIF combined with posterior pedicle screw fixation. There were 17 cases of single fusion segment, 2 of 2 fusion segments, 4 of 3 fusion segments. All the cases underwent reoperation within 3 months after the initial surgery. The strategies of reoperation included supplementary posterior pedicle screw instrumentation in 16 cases;posterior laminectomy, cage adjustment and neurolysis in 2 cases, arthroplasty and neurolysis under endoscope in 1 case, posterior laminectomy and neurolysis in 1 case, pedicle screw adjustment in 1 case, exploration and decompression under percutaneous endoscopic in 1 case, interbody fusion cage and pedicle screw revision in 1 case. Visual analogue scale (VAS) and Oswestry disability index (ODI) index were used to evaluate and compare the recovery of low back pain and lumbar function before reoperation and at the last follow-up. During the follow-up process, the phenomenon of fusion cage settlement or re-displacement, as well as the condition of intervertebral fusion, were observed. The changes in intervertebral space height before the first operation, after the first operation, before the second operation, 3 to 5 days after the second operation, 6 months after the second operation, and at the latest follow-up were measured and compared. RESULTS: There was no skin necrosis and infection. All patients were followed up from 12 to 48 months with an average of (28.1±7.3) months. Nerve root injury symptoms were relieved within 3 to 6 months. No cage transverse shifting and no dislodgement, loosening or breakage of the instrumentation was observed in any patient during the follow-up period. Though the intervertebral disc height was obviously increased at the first postoperative, there was a rapid loss in the early stage, and still partially lost after reoperation. The VAS for back pain recovered from (6.20±1.69) points preoperatively to (1.60±0.71) points postoperatively(P<0.05). The ODI recovered from (40.60±7.01)% preoperatively to (9.14±2.66)% postoperatively(P<0.05). CONCLUSION: There is a risk of reoperation due to failure after OLIF surgery. The reasons for reoperation include preoperative bone loss or osteoporosis the initial surgery was performed by Stand-alone, intraoperative endplate injury, significant subsidence of the fusion cage after surgery, postoperative fusion cage displacement, nerve damage, etc. As long as it is discovered in a timely manner and handled properly, further surgery after OLIF surgery can achieve better clinical results, but prevention still needs to be strengthened.

Anterior and posterior surgical approach for vertebral lumbar Mycobacterium abscessus osteomyelitis.

Mycobacterium abscessus (M. abscessus) infections primarily affect immunocompromised patients who commonly present with non-orthopedic infections. We present a case of a 63-year-old female presented with persistent back pain and radicular pain. Computed tomography and magnetic resonance imaging showed a large multiloculated anterior epidural abscess. We show here the unique occurrence of lumbar M. abscessus vertebral osteomyelitis, which was treated with L2 and L3 corpectomies, anterior lumbar interbody fusion, and posterior instrumentation via an anterolateral thoracoabdominal (TA) incision. Vascular surgery provided L1-L4 spine exposure via a left anterolateral TA incision, whereas orthopedic surgery performed L2 and L3 corpectomies with lumbar cage placement and posterior instrumentation in two separate procedures. The patient was discharged to a skilled nursing facility, retaining all neurological function, and is progressing well on follow-up.

Factors that influence the results of indirect decompression employing oblique lumbar interbody fusion.

BACKGROUND: Indirect decompression is one of the potential benefits of anterior reconstruction in patients with spinal stenosis. On the other hand, the reported rate of revision surgery after indirect decompression highlights the necessity of working out prediction models for the radiographic results of indirect decompression with assessing their clinical relevance. AIM: To assess factors that influence radiographic and clinical results of the indirect decompression in patients with stenosis of the lumbar spine. METHODS: This study is a single-center cross-sectional evaluation of 80 consecutive patients (17 males and 63 females) with lumbar spinal stenosis combined with the instability of the lumbar spinal segment. Patients underwent single level or bisegmental spinal instrumentation employing oblique lumbar interbody fusion (OLIF) with percutaneous pedicle screw fixation. Radiographic results of the indirect decompression were assessed using computerized tomography, while MacNab scale was used to assess clinical results. RESULTS: After indirect decompression employing anterior reconstruction using OLIF, the statistically significant increase in the disc space height, vertebral canal square, right and left lateral canal depth were detected (Р < 0.0001). The median (M) relative vertebral canal square increase came to М = 24.5% with 25%-75% quartile border (16.3%; 33.3%) if indirect decompression was achieved by restoration of the segment height. In patients with the reduction of the upper vertebrae slip, the median of the relative increase in vertebral canal square accounted for 49.5% with 25%-75% quartile border (2.35; 99.75). Six out of 80 patients (7.5%) presented with unsatisfactory results because of residual nerve root compression. The critical values for lateral recess depth and vertebral canal square that were associated with indirect decompression failure were 3 mm and 80 mm2 respectively. CONCLUSION: Indirect decompression employing anterior reconstruction is achieved by the increase in disc height along the posterior boarder and reduction of the slipped vertebrae in patients with degenerative spondylolisthesis. Vertebral canal square below 80 mm2 and lateral recess depth less than 3 mm are associated with indirect decompression failures that require direct microsurgical decompression.

The insert and revolve technique: a novel approach for inserting cages during unilateral biportal endoscopic assisted fusion surgery for effective spinal alignment restoration.

Study Design: Retrospective study. Purpose: This study aimed to propose a method of performing unilateral biportal endoscopy (UBE)-assisted interbody cage insertion for fusion using the "insert and revolve" technique and analyze the clinico-radiological outcomes. Overview of Literature: UBE-assisted lumbar interbody fusion (ULIF) is a rapidly evolving technique combining the advantages of minimally invasive technique with ease of learning. The limited size of cages was a result of the narrow insertion channel. We propose a technique in which large extreme lateral interbody fusion cages can be inserted through the same opening. Methods: This study included 104 patients who underwent ULIF using the "insert and revolve technique" between July 2019 and September 2022. The patients were followed up for at least 12 months postoperatively. The clinical outcomes were assessed using the Visual Analog Scale (VAS) for leg pain and back pain, Oswestry Disability Index (ODI), and modified McNab's criteria. Changes in segmental lordosis (SL), intervertebral disc height (IVDH), segmental coronal alignment (SCA), cage subsidence, and fusion grade were evaluated at 6- and 12-month follow-up. Results: The VAS scores for leg and back pain and ODI score showed significant improvement. Based on the Macnab's criteria, 97 patients showed excellent outcomes and seven demonstrated good outcomes at 12 months. The mean IVDH increased from 6.3±2 to 10±2.1 mm immediately after surgery and 10±1.1 mm at 6 months. SL improved from 9.3°±11.5° to 17.78°±8.1°, while SCA improved from 7.7°±2.1° to 3.4°±1.2° at 1 year. Moreover, 92 and 11 patients showed grade 1 and 2 fusion, respectively, according to the Bridwell grading at 1 year. Conclusions: The "insert and revolve technique" facilitates the successful insertion of large cages, contributing to the restoration of disc height and coronal and sagittal spinal correction with favorable fusion rates.

Prospective Analysis of Incisional Morbidity Associated With Anterior Surgical Approaches to the Lumbar Spine.

OBJECTIVE: Anterior approaches to the lumbar spine have been used extensively for various indications but they are also associated with unique complications and have been linked with higher incisional morbidity.This study aimsto evaluate incisional morbidity related to anterior lumbar surgeries and to assess how incisional outcomes correlate with patient and surgery-related factors. METHODS: Patients ≥18 years old and with planned anterior lumbar fusions from L1 to S1 were prospectively enrolled. Follow-up ended at two years, and patients who did not complete the follow-up were excluded. Incision was assessed for general appearance, width, color, cross-hatching, hypertrophy, and pain by using a validated scoring system and a visual analog scale (VAS). Patient and surgery-related factors were analyzed for possible correlations with complications or wound-related parameters. RESULTS: A total of 205 patients with a mean age of 54.4 ± 11.5 were included. Significant improvements were seen in color, hypertrophy, pain, and appearance of the incision. At two years, the mean patient-based VAS for appearance was 8.6 while surgeon-based VAS was 8.8. The total rate of complications was 9%, with no incisional hernia or bulging. No significant relation was found between incision-related parameters and the demographic and surgical variables. CONCLUSION: This study reports acceptable cosmetic results and no chronic pain after anterior lumbar surgery, which is contrary to previous reports. Together with a low total rate of complications, anterior approaches are safe when carefully executed, and have low morbidity.

Oblique lumbar interbody fusion combined with anterolateral screw fixation and stress endplate augmentation for treating degenerative lumbar spondylolisthesis with osteoporosis.

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.

A novel technique for posterior lumbar interbody fusion to obtain a good local lordosis angle: anterior-release posterior lumbar interbody fusion.

Herein, we describe a novel posterior lumbar interbody fusion (PLIF) technique with annulus fibrosus (AF) release and the use of expandable cages (called "anterior-release PLIF" [ARPLIF]). In this technique, posterior column osteotomy (PCO) and AF release provide excellent intervertebral mobility. AF release involves circumferentially peeling off the AF above or below the endplate between the fixed vertebrae under radiographic guidance without cutting the AF and anterior longitudinal ligament. Subsequently, high-angle variable-angle expandable cages are used to simultaneously expand both sides before inserting the percutaneous pedicle screws and correcting to achieve good local lumbar lordosis. PCO and AF release achieve excellent intervertebral mobility. Intervertebral mobility and simultaneous expansion of both cages disperse the force on the endplates, reducing cage subsidence, and the high-angle cages facilitate high intervertebral angle creation. The novel ARPLIF intervertebral manipulation technique can promote good local lumbar lordosis formation.