Disc Space Research Articles

Is Cervical Disc Degeneration a Compensatory Mechanism in Hirayama Disease? A Retrospective Case‒Control Study.

Retrospective Cohort Study. This study aimed to explore the association between cervical disc degeneration and disease progression in patients with Hirayama disease, with a particular focus on changes in the cervical intervertebral disc space height and potential compensatory mechanisms. This retrospective study included 35 patients diagnosed with Hirayama disease (HD), who were compared with 35 healthy control subjects matched for age and sex. This study focused on collecting and analyzing cervical disc grades and intervertebral space heights from C2 to C7, aiming to assess the extent of cervical disc degeneration between HD patients and the control group. The analysis used independent sample t tests and Mann‒Whitney U tests for demographic data and Spearman's correlation coefficient to explore the relationship between disc degeneration and age. Compared with the control group, patients with Hirayama disease presented significant reductions in intervertebral disc height (P < .01) and increased disc degeneration. Within the HD group, most patients displayed multisegment degeneration (30 out of 35), and more than half presented with full-segment disc degeneration (20 out of 35), which was significantly different from the normal population (P < .01). Patients with Hirayama disease exhibit disc degeneration and reduced intervertebral space height, which may represent a compensatory response.

Bone Density Correlates With Depth of Subsidence After Expandable Interbody Cage Placement: A Biomechanical Analysis.

Biomechanical analysis. To evaluate the depth of subsidence resulting from an expandable interbody cage at varying bone foam densities. Expandable interbody cages have been shown to be associated with increased rates of subsidence. It is critical to evaluate all variables which may influence a patient's risk of subsidence following the placement of an expandable interbody cage. In the first stage of the study, subsidence depth was measured with 1Nm of input expansion torque. In the second stage, the depth of subsidence was measured following 150 N output force exerted by an expandable interbody cage. Within each stage, different bone foam densities were analyzed, including 5, 10, 15, and 20 pounds per cubic foot (PCF). Five experimental trials were performed for each PCF material, and the mean subsidence depths were calculated. Trials which failed to reach 150 N output force were considered outliers and were excluded from the analysis. There was an overall decrease in subsidence depth with increasing bone foam density. The mean subsidence depths at 150 N output force were 2.0±0.3mm for 5 PCF, 1.8±0.2mm for 10 PCF, 1.1±0.2mm for 15 PCF, and 1.1±0.2mm for 20 PCF bone foam. The mean subsidence depths at 1Nm of input torque were 2.3±0.5mm for 5 PCF, 2.3±0.5mm for 10 PCF, 1.2±0.2mm for 15 PCF, and 1.1±0.1mm for 20 PCF bone foam. Depth of subsidence was negatively correlated with bone foam density at both constant input torque and constant endplate force. Because tactile feedback of cage expansion into the subsiding bone cannot be reliably distinguished from true expansion of disc space height, surgeons should take bone quality into account when deploying expandable cages.

Anterior Column Support With Anterior Lumbar Interbody Fusion Cage Through Posterior Approach Maneuver: A Technical Note and Preliminary Radiologic Report.

Retrospective cohort study. To evaluate the feasibility of anterior column support through a posterior approach using an anterior lumbar interbody fusion (ALIF) cage. Anterior fusion is an effective way to maintain spinal lordosis; however, it may be technically difficult in some cases. Conventional lumbar fusion and spinal deformity correction surgeries were performed using a conventional ALIF cage with a modified extratransforaminal lumbar interbody fusion (ExTLIF). Patients with 1 or 2 fusion levels were classified into group 1, and those with spinal deformity correction were classified into group 2. Radiologic parameters were evaluated during the follow-up periods. A total of 51 patients underwent this procedure. Thirty-five patients (19 male and 16 female, 69.4±9.6y old) with 37 fusion sites were in group 1, and 16 patients (3 male and 13 female, 71.4±5.7y old) were in group 2. The mean follow-up periods of groups 1 and 2 were 12.3±3.4 and 10.7±4.7 months, respectively. In group 1, the mean lumbar lordosis and segmental lumbar lordosis increased significantly during the last follow-up (39.9±13.0 and 20.6±6.0 degrees, respectively, both P<0.001), and the mean disc space also increased at the last follow-up (P<0.001). The same was observed in group 2 with significant increases in the mean lumbar lordosis and segmental lumbar lordosis at the last of the follow-up period (46.8±9.3 and 16.9±8.9 degrees, respectively, both P<0.001). The disc space also increased significantly (P<0.001). Fusion rates were 94.2% and 87.5% in groups 1 and 2, respectively, and the corresponding subsidence rates were 85.4% and 68.8%. In group 1, there was a significant correlation between subsidence and cage height (P=0.046). This procedure (ExTLIF) can be applied in cases where an anterior approach is contraindicated as well as for deformity correction. Level III.

The association of limited or painful spinal range of motion with lumbar disc degeneration: the back complaints in older adults (BACE) study

BackgroundWe currently lack clear definitions for structural and symptomatic spinal osteoarthritis (OA). To define spinal OA and create diagnostic criteria for this condition, it is necessary to determine the relationship between clinical signs and symptoms of back pain and radiographic features of OA. Notably, recent studies suggest a defining sign of spinal OA could be a limited or painful spinal range of motion (ROM). Therefore, our objective was to assess the association between restricted or painful active spinal ROM, and multilevel structural features of lumbar disc degeneration (LDD) (i.e., disc space narrowing, osteophytes) on radiographs.MethodsWe used the baseline data from the’Back Complaints in Older Adults’ (BACE) study. The association between a limited or painful active spinal ROM, and multilevel disc space narrowing or osteophytes was assessed using multivariable logistic regression adjusted for age, mean pain intensity in the previous week, sex, BMI, and the Fear Avoidance Belief Questionnaire score. Primary analyses were performed on imputed datasets.ResultsWe included 675 patients with a mean age of 66.52 years (SD 7.69). Limited latero-flexion (fingertip that at best reached halfway up the upper leg) was associated with increased odds of having multilevel osteophytes (OR 1.85; 95% CI: 1.13 to 3.01). However, a limited or painful ROM in other directions (i.e., rotation, ante-flexion) was not associated with multilevel osteophytes, and a limited or painful active ROM in any direction was found to have no association with multilevel disc space narrowing.ConclusionsOur study indicates that a restricted ROM in latero-flexion could potentially be a defining sign in future definitions of symptomatic spinal OA. However, since our results partially differ from previous studies, further research is needed to explore the association between active ROM and LDD.

Comparing ACDF Outcomes by Cervical Spine Level: A Single Center Retrospective Cohort Study.

Previous research suggests a relationship between complications associated with anterior cervical discectomy and fusion and level involvement; however, there is limited research comparing postoperative outcomes of upper cervical fusions (UCFs) with middle-to-lower cervical fusions (MLCFs). This study aims to compare the outcomes of UCF with MLCF. A retrospective medical record review was conducted on 835 anterior cervical discectomy and fusion patients from 2012 to 2022. Patients were classified as UCF, defined as inclusion of C3 to C4 disc space, or MLCF, defined as lacking C3 to C4 disc space. Demographics were compared using χ 2 or Fisher exact tests. Clinical characteristics were compared in univariable analysis using χ 2 tests, linear-mixed effects models, or generalized linear-mixed models depending on distribution. Significant pre- and intraoperative characteristics were included in multivariable models to minimize confounding. Of the 835 patients included, 562 underwent MLCF and 281 underwent UCF. Median follow-up time was 211 days for UCF and 200 days for MLCF. UCF led to a 1.5-day longer length of stay in both univariable (1.5 vs 3.1, P < 0.0001) and multivariable analysis (2.3 days [95% CI: 1.8, 3.0] vs 3.3 days [2.6, 4.2], P < 0.0001). MLCF patients reported symptom improvement or resolution more often than UCF patients (0.43 [95% CI: 0.30, 0.62] and 0.46 [95% CI: 0.30, 0.70]). Additionally, a significantly higher rate of dysphagia was reported in the UCF group on both univariate and multivariable analysis, respectively (1.72 [95% CI: 1.18, 2.49] and 1.66 [95%CI: 1.08, 2.56]). To our knowledge, this is the first study to investigate the link between cervical fusion level and outcomes. UCF patients demonstrated greater rates of dysphagia, longer length of stay, and lower likelihood of improvement in neurological symptoms postoperatively both before and after controlling for differences in pre- and intraoperative characteristics. This study highlights that UCFs may be associated with worse postoperative outcomes when compared to MLCFs, which can inform surgical decision-making and patient counseling. The study represents Level 3 evidence due to its retrospective design and potential biases, indicating a need for future prospective randomized controlled trials to validate these findings.

Design and implementation of HDF5-format neutron nuclear database in RMC code

This study developed a new structured nuclear database to improve the readability and extensibility of the ACE (A Compact ENDF) nuclear database, save disk space, reduce memory usage, and enhance the computational efficiency of the Reactor Monte Carlo (RMC) code. A Python package was developed to store nuclear data in HDF5 format. Compared to the ACE database, the HDF5-format database shows significant improvements: an 80% reduction in disk space for continuous energy neutron data and a 60% reduction for neutron thermal scattering data. The HDF5-format database was implemented in RMC’s criticality calculation mode and validated through VERA benchmark problem 2B, demonstrating perfect agreement with the ACE results in keff and neutron flux counts. The Computational results indicate a 7.7% reduction in memory usage and a 20.1% improvement in computational efficiency with the HDF5-format database. Additional tests show that using the database at a single temperature point reduces memory usage by 5.4% and running time by 13.2%. At two temperature points, memory usage decreases by 35.2% and running time by 18.0%. The new data structure reduces temperature-independent redundant data and improves indexing efficiency, leading to greater savings with more temperature points. This development enhances performance of criticality calculation of RMC and addresses ACE database limitations.

Biportal Endoscopic Transforaminal Lumbar Interbody Fusion: The Double-Cage Technique

Biportal endoscopic transforaminal lumbar interbody fusion (BETLIF) is a novel spinal fusion procedure using the unilateral biportal endoscopic technique. The hydrostatic pressure of saline irrigation suppresses bleeding, enabling us to perform delicate surgery in a crystal-clear and magnified surgical field with almost no bleeding. Adequate neural decompression, disc space preparation, and bony endplate preservation can be achieved safely. The sturdy endplate reduces the incidence of cage subsidence and provides good initial stability. We use 2 interbody fusion cages and a large amount of bone graft to promote fusion. Reduction of the spondylolisthesis can also be achieved using a modern pedicle screw system. This article presents a step-by-step demonstration of the BETLIF technique in a 68-year-old patient with degenerative scoliosis and spondylolisthesis at L4-5, including his clinical presentation and treatment results. BETLIF is a safe, effective, and revolutionary minimally invasive solution for spinal fusion. Its advantages include a magnificent surgical field, direct decompression, minimum blood loss, radical discectomy, meticulous endplate preparation, cage insertion under direct visual control, and excellent treatment results with a high fusion rate and few complications.

Contralateral Sublaminar Approach in Lumbar Spine With Unilateral Biportal Endoscopy

Unilateral biportal endoscopy (UBE) can be used to treat common lumbar pathologies, such as synovial facet cysts, foraminal disc herniations, and foraminal stenosis via a contralateral sublaminar approach. Due to the ultra-minimally invasive technique, UBE can reduce damage to anatomical structures, thereby reducing postoperative pain and allowing faster recovery. The patient is placed prone on a Wilson frame or bolsters. Fluoroscopy is used to identify the midline and medial pedicle line in the anterior-posterior projection. Spinal needles can aid to identifying portals’ trajectory in the lateral fluoroscopic projection. The procedure is performed via 2 separate portal incisions. The endoscope is introduced through the viewing portal and the surgical instruments through the working portal. Soft tissue dissector is used to create a working area over the spinous process-lamina junction. Bony shaving and drilling start at the target area and continue medially underneath the base of the spinous process until the midline and contralateral ligamentum flavum are identified. Contralateral ligamentum flavum is excised, exposing thecontralateral thecal sac, traversing nerve root, and lateral recess. The contralateral disc space, annulus, and superior articulating process are then identified and the offending pathology can be addressed under direct visualization. Meticulous hemostasis and close attention to outflow should be maintained to reduce the risk of complications. The steps of this procedure closely resemble those of traditional microscopic “over-the-top” techniques, including the surgical instruments used through the working portal. In this video, authors present the surgical technique of the contralateral sublaminar approach in the lumbar spine with UBE.

Platelet Rich Plasma in the Management of Recurrent Lumbar Disc Surgery; A Study of Ten Cases

Low back pain (LBP) is a very common entity, now regarded as the first cause of disability worldwide. Intervertebral disc (IVD) degeneration leads to posterior rupture annulus fibrosus (AF) with extrusion of Central Nucleus pulposus (NP) through the injured area which has little potential to repair as it has no blood supply and causes mechanical pressure and inflammatory changes in the nerve root causing LBP. Autologous platelet rich plasma (PRP) contain concentrate blood that contain a natural concentration of autologous growth factors and cytokines and currently widely used in the clinical setting for tissue regeneration and repair. PRP had great potential to stimulate cell proliferation and metabolic activity of IVD effectively restoring structural change, improving matrix integrity, IVD regeneration, reducing discogenic back pain. Our Study of 10 cases, where repeat or re-exploration surgery (after primary PLID Surgery, fenestration and discectomy) was done, where removal of recurrent disc 5, release of epidural fibrosis and perineural scarring 4 and surgical debridement for discitis 1 was done. In addition, PRP was given in the disc space &amp; around the nerve root which provides lots of growth factor, cytokines which helps in disc regeneration and prevent adhesion &amp; fibrosis. These dual actions enhance symptomatic recovery of all cases. Large scale studies may be required to confirm the clinical evidence of PRP for the treatment of discogenic LBP Bang. J Neurosurgery 2024; 13(2): 70-74

Evaluation of Intervertebral Disc Space Width Between 10th and 11th Thoracic Vertebrae in Cats Using Radiography and Magnetic Resonance Imaging.

It is well known that the T10-T11 intervertebral disc space is usually narrower than the adjacent intervertebral disc spaces in most dogs. However, whether the T10-T11 disc space is narrower than the adjacent disc spaces is not well-established in cats. To measure the intervertebral disc space width of the T10-T11 disc space and to compare it with that of the adjacent disc spaces using radiography and magnetic resonance imaging (MRI). In Groups 1 (101 clinically normal cats) and 2 (32 cats without spinal diseases from T8 to T13), dorsal width (DW), central width (CW) and ventral width (VW) of the T8-T13 disc spaces were measured by radiography or MRI. Significant differences of the DW, CW and VW among disc spaces measured by radiography and MRI were evaluated. Intra- and interobserver reliabilities were measured by intraclass correlation coefficient. In Groups 1 and 2 using radiography, the DW and CW of the T10-T11 disc space were significantly narrower than those of adjacent disc spaces (p<0.05). The DW of the T8-T12 disc spaces was significantly narrower than that of the T12-T13 disc space in Group 1 using radiography. In Groups 1 and 2 using radiography, the CW and VW of the T8-T11 disc spaces were significantly narrower than those of the T11-T13 disc spaces. In Group 2 using MRI, the DW of the T10-T11 disc space was significantly narrower than that of the T11-T13 disc spaces. The VW of the T8-T11 disc spaces was significantly narrower than that of the T11-T13 disc spaces. The T10-T11 intervertebral disc space on radiography is statistically narrower than the adjacent intervertebral disc spaces in normal cats. The cranial thoracic intervertebral disc spaces (T8-T11) are usually narrower than the caudal thoracic intervertebral disc spaces (T11-T13) on radiography and MRI.

The association of spinal morning stiffness with lumbar disc degeneration and C-reactive protein: The back complaints in older adults (BACE) study

ObjectiveTo determine the association between patient-reported spinal morning stiffness and lumbar disc degeneration (LDD) and systemic inflammation, as measured by C-reactive protein (CRP), in older patients with non-specific back pain. The ultimate objective is to help shape a future definition of spinal osteoarthritis (OA). DesignBaseline data from the Dutch “Back Complaints in the Older Adults” (BACE) study was used. The relationship between the severity and duration of patient-reported spinal morning stiffness, LDD (i.e., multilevel disc space narrowing and multilevel osteophytes), and CRP was assessed. Regression models adjusted for confounding variables were performed. ResultsSix hundred and seventy-five patients were included. The mean age was 66.52 years (SD 7.69), with a mean CRP of 3.20 ​mg/L (SD 7.61). The severity of spinal morning stiffness was associated with multilevel disc space narrowing: OR 2.89 (95 ​% CI: 1.24 to 6.74) for ‘mild’, OR 2.97 (95 ​% CI: 1.18 to 7.44) for ‘moderate’, OR 3.23 (95 ​% CI: 1.17 to 8.90) for ‘severe’, and OR 5.62 (95 ​% CI: 1.70 to 18.60) for ‘extreme’ morning stiffness severity. However, spinal morning stiffness severity was not associated with multilevel osteophytes, and both multilevel features of LDD showed no associations with the duration of spinal morning stiffness. No associations were found between spinal morning stiffness severity or duration, and CRP levels. ConclusionsOur results suggest that the severity of patient-reported spinal morning stiffness might be considered in future definitions of symptomatic spinal OA and that spinal morning stiffness is probably a symptom of a degenerative process in the spine rather than a symptom of systemic inflammation in patients with back pain.

The utility of disc space and vertebral body specimens cell count differential for the diagnosis of native vertebral osteomyelitis: a prospective cohort study.

Diagnostic methods for native vertebral osteomyelitis (NVO) often yield inconclusive results. Image-guided spine biopsies for culture are specific but diagnose NVO in only 50% of cases. Pre-exposure to antimicrobials further reduces diagnostic yield. Our study assesses the value of neutrophil percentage in disc space fluid and vertebral body (DS/VB) samples for diagnosing NVO. Adults referred for spine biopsy at Mayo Clinic from August 2022 to September 2023 were consented and enrolled at the time of biopsy. Following routine specimen collection, the biopsy needle was rinsed in saline into an EDTA tube for cell analysis. NVO diagnosis required organism identification in spine tissue or blood and/or positive histopathology, and consistent symptoms and imaging. Sixty-eight patients were prospectively enrolled, comprising 14 with NVO and 54 with alternative diagnoses. The median biopsy sample polymorphonuclear (PMN) percentage for NVO patients was 80.5% (IQR 72.5-85.2), compared to 64.5% (IQR 54.0-69.0) for those without NVO (p < 0.001). Nine (64.3%) NVO patients received antibiotics within 10 days prior to spine biopsy. As a continuous measure, PMN differential showed a moderately strong ability in classifying NVO status with an area under ROC curve of 0.795; an optimal point on the curve of 71.5% corresponded to a sensitivity of 78.6%, specificity of 79.6%, negative predictive value of 93.5% and positive predictive value of 50.0%. PMN differential in DS/VB biopsies may serve as an effective diagnostic tool in the evaluation of patients with NVO particularly in ambiguous cases with an initially negative spine biopsy. Future efforts will aim to implement these findings within routine clinical practice.

Could indirect decompression occur for cord compression by the ligamentum flavum with anterior cervical discectomy and fusion?

Cord compression by the ligamentum flavum (CCLF) has been reported to adversely affect the clinical outcomes of anterior cervical discectomy and fusion (ACDF). While indirect decompression does occur for foraminal stenosis with ACDF, whether ACDF could improve CCLF with the distraction of disc space remains unclear. This study aimed to identify 1) whether indirect decompression occurs for CCLF with ACDF, and 2) risk factors that hinder the improvement of CCLF. This retrospective cohort study included 119 patients who underwent ACDF for the treatment of cervical myelopathy and CCLF was detected on preoperative MRI. Patients who demonstrated improvement in CCLF grade after ACDF were included in the improved group, while those who did not show improvement were classified as the unimproved group. Patient characteristics, cervical sagittal parameters, neck and arm pain visual analog scale score, and Japanese Orthopaedic Association (JOA) score were assessed. A comparison between the improved and unimproved groups was performed. Regression analyses were performed to identify factors associated with CCLF grade improvement. Overall, 58.0% (69/119) of patients showed improvement in CCLF grade after ACDF. CCLF grade did not improve in the remaining 42.0% (50/119) of patients, and 3.4% (4/119) of patients experienced aggravation of CCLF after ACDF. Preoperative spondylolisthesis (OR 0.252, 95% CI 0.090-0.711; p = 0.009) and greater segmental lordosis 3 months postoperatively (OR 0.835, 95% CI 0.731-0.953; p = 0.008) were the factors that hindered the improvement of CCLF after ACDF. Furthermore, patients with higher pre- or postoperative CCLF grades showed significantly less improvement in JOA score 2 years postoperatively. Indirect decompression for CCLF with ACDF is not reliable because 42.0% of patients did not demonstrate improvement in CCLF grade after the operation. Preoperative spondylolisthesis and postoperative increased segmental lordosis were risk factors for failure of CCLF improvement. Both pre- and postoperative higher CCLF grades were associated with poor neurological recovery 2 years postoperatively.

Photometric redshifts probability density estimation from recurrent neural networks in the DECam local volume exploration survey data release 2

Photometric wide-field surveys are imaging the sky in unprecedented detail. These surveys face a significant challenge in efficiently estimating galactic photometric redshifts while accurately quantifying associated uncertainties. In this work, we address this challenge by exploring the estimation of Probability Density Functions (PDFs) for the photometric redshifts of galaxies across a vast area of 17,000 square degrees, encompassing objects with a median 5σ point-source depth of g= 24.3, r=23.9, i= 23.5, and z= 22.8 mag. Our approach uses deep learning, specifically integrating a Recurrent Neural Network architecture with a Mixture Density Network, to leverage magnitudes and colors as input features for constructing photometric redshift PDFs across the whole DECam Local Volume Exploration (DELVE) survey sky footprint. Subsequently, we rigorously evaluate the reliability and robustness of our estimation methodology, gauging its performance against other well-established machine learning methods to ensure the quality of our redshift estimations. Our best results constrain photometric redshifts with the bias of −0.0013, a scatter of 0.0293, and an outlier fraction of 5.1%. These point estimates are accompanied by well-calibrated PDFs evaluated using diagnostic tools such as Probability Integral Transform and Odds distribution. We also address the problem of the accessibility of PDFs in terms of disk space storage and the time demand required to generate their corresponding parameters.We present a novel Autoencoder model that reduces the size of PDF parameter arrays to one-sixth of their original length, significantly decreasing the time required for PDF generation to one-eighth of the time needed when generating PDFs directly from the magnitudes.

A novel lightweight deep learning framework with knowledge distillation for efficient diabetic foot ulcer detection

Diabetic Foot Ulcers (DFUs) are a critical healthcare issue requiring early detection. Although deep learning models show promise in DFU diagnosis, their large parameter sizes and high computational demands limit their practical use. This work addresses these challenges by introducing DFU-LWNet, a lightweight, knowledge-distilled model that maintains or even surpasses the performance of existing models while drastically reducing computing costs. The DFU-LWNet model synergistically integrates the MBConv Block, leveraging its capabilities in feature expansion, depthwise convolution for parameter efficiency, and adaptive feature recalibration through the Squeeze-and-Excitation (SE) mechanism. The methodology commences with the fine-tuning of seven pre-trained models, ultimately selecting InceptionV3 as the optimal teacher model based on experimental results. Subsequently, knowledge distillation (KD) is applied, leveraging the insights from this robust teacher model to enhance the performance of the student model, DFU-LWNet. The primary objective is to reduce the student model's parameter size and computational complexity while maintaining diagnostic accuracy. Through comprehensive evaluations, DFU-LWNet achieves an impressive classification accuracy of 96.23 % on a publicly available dataset comprising 1055 foot images. Notably, this achievement is accomplished with a remarkably low parameter size of only 0.49 million, consuming 2MB of disk space. This reduction in parameter size not only improves inference speed but also significantly reduces computational costs compared to pre-trained models. Moreover, the study employs Grad-CAM visualizations to demonstrate the model's enhanced saliency and interpretability in predictions post-KD, thereby offering valuable insights to clinicians. Additionally, the efficacy of DFU-LWNet extends to thermal imagery domains, as validated by experiments on a diverse dataset of thermal images of diabetic foot cases. The proposed approach achieves remarkable accuracy of 93.13 % on a separate thermal image dataset, demonstrating cross-domain success and reinforcing the model's practical utility in real-world scenarios. Compared to existing state-of-the-art methods, this work demonstrates promising practical viability. DFU-LWNet’s minimal parameter count and low prediction times make it well-suited for deployment in resource-limited healthcare settings.

Biportal Endoscopic Transforaminal Lumbar Interbody Fusion: How to Improve Fusion Rate?

Biportal endoscopic transforaminal lumbar interbody fusion (BE-TLIF) is a minimally invasive surgical technique for treating degenerative lumbar spine conditions. It offers advantages such as reduced soft tissue trauma and lower infection rates, but certain technical aspects may be challenging. The current study aims to identify strategies to enhance the fusion rate in BE-TLIF by addressing these specific challenges. A literature review was conducted on techniques to improve fusion rates in BE-TLIF. The review suggests that lateral-based portals supplemented with medial portals allowed for safe insertion of interbody cages with large footprint. Direct visualization of the disc space with a 30° endoscope assisted with better disc space preparation. Facetectomies performed with osteotomes, rather than burrs, ensured maximum retrieval of autologous bone graft. Utilizing bone morphogenetic proteins with sustained release carriers such as hydroxyapatite can be useful to increase fusion rates of BE-TLIF. To our knowledge, the current literature is the first comprehensive review of strategies to enhance fusion rates in BE-TLIF. The proposed techniques and biological adjuncts are effective means to address key challenges associated with the procedure, and such strategies would potentially shorten the learning curve and improve clinical outcomes. Further clinical studies are required to validate these findings and establish standardized protocols. These findings provide practical solutions to overcome common challenges in BE-TLIF. The suggested techniques would reduce the incidence of pseudarthrosis, improve patient outcomes, and ultimately offer a safer and more reliable option for lumbar interbody fusion patients.

Are the Umbilicus and Iliac Crests Truly at the Level of L4 to L5? A Computed Tomography-Based Study of Surface Anatomy of the Anterior Lumbar Spine.

This study aimed to determine whether the iliac crests are truly at the level of L4 to L5, accounting for patient demographic and anthropometric characteristics. We measured the umbilicus and iliac crests relative to the lumbar spine using computed tomography of patients without spinal pathology, accounting for the influences of patient height, weight, body mass index (BMI), sex, race, and ethnicity. A total of 834 patients (391 men and 443 women) were reviewed. The location of the umbilicus relative to the lumbar spine demonstrated a unimodal distribution pattern clustered at L4, while the iliac crests were most frequently located from L4 to L5. Iliac crests were located above the L4 to L5 disc space 26.5% of the time. Iliac crests were located at the L4 to L5 disc space 29.8% of the time. No correlations were observed between the umbilicus and iliac crests with patient height, weight, or BMI. There was no difference in the location of the umbilicus with respect to patient sex, race, and ethnicity. The locations of the iliac crests were cephalad in women compared with men and in Hispanics compared with African American, Caucasian, and Asian patients. The iliac crests were located above the level of the L4 to L5 disc space approximately 26% of the time. The umbilicus is most frequently at the level of the L4 vertebral body. Patient height, weight, and BMI do not influence the location of the umbilicus or the iliac crests relative to the lumbar spine. Patient sex and ethnicity influence the location of the iliac crests but not the umbilicus relative to the lumbar spine. Modern neurosurgical techniques require clearance of the iliac crests during anterior and anterolateral approaches. Understanding the level of the iliac crests is crucial in planning for transpsoas fusion approaches.

A Comparative Study of Text-Based Lossless Compression

Lossless data compression is a critical technique used to reduce file sizes without any loss of information during the encoding and decoding processes. This study presents a comparative analysis of two widely-used lossless compression algorithms: Huffman Encoding and Lempel-Ziv-Welch (LZW). The primary objective is to evaluate the performance of these algorithms in terms of compression ratio, compression time, decompression time, and space savings. The analysis was conducted on 100 files of varying sizes. The results demonstrate that the LZW algorithm outperforms Huffman Encoding, offering superior compression ratios, faster compression and decompression times, and greater disk space savings. These findings highlight the effectiveness of LZW for efficient data compression in practical applications.

Psoas muscle cross sectional area relates to bone density and microarchitecture in candidates for spine fusion surgery

Prior studies demonstrate that muscle and bone health are integrally related, and both independently impact orthopedic surgery outcomes. However, relationships between bone density, in vivo microarchitecture, and muscle area have not been previously investigated in orthopedic surgery patients. This study assessed associations between psoas cross sectional area (CSA), bone mineral density (BMD), and microstructure in a cohort undergoing spine fusion. Pre-operatively, bilateral psoas CSA was measured on axial lumbar spine CT in the L3-L4 disc space. To adjust for body size, Psoas Muscle Index (PMI) was calculated (CSA divided by the square of patient height). High resolution peripheral quantitative CT (HR-pQCT, XtremeCT2) assessed volumetric BMD (vBMD), cortical (Ct) and trabecular (Tb) microarchitecture at the distal radius and tibia. Areal BMD (aBMD) was measured by DXA at the lumbar spine (LS), total hip (TH), femoral neck (FN), and the 1/3 radius (1/3R). Pearson correlations related psoas CSA and bone imaging parameters before and after correcting for height and weight. Among 88 patients included, mean age was 63 ± 12 years, BMI was 28 ± 7 kg/m2, 47 (53 %) were female. Larger psoas CSA was associated with higher vBMD, greater Ct thickness and better Tb microarchitecture (higher Tb number and lower Tb separation) at the tibia and radius. Larger psoas CSA was also associated with greater aBMD at TH and FN bilaterally and 1/3R (r 0.33 to 0.61; p < 0.002 for all comparisons). Psoas CSA was not associated with aBMD at the LS. Similar results were observed when relating PMI, and adjusting for age, height and weight to HR-pQCT and DXA measurements. Investigation of subgroups by sex demonstrated that relationships were similar magnitude among women but not the men. Patients who underwent primary compared to revision spine surgery had similar associations. Our results demonstrate a link between psoas muscle size and peripheral bone microarchitecture among patients undergoing posterior lumbar spinal fusion. Given the importance of both muscle and skeletal integrity to the success of spine surgery, further study regarding the associations between measurements of psoas muscle, bone microarchitecture, and surgical outcomes is warranted.

Lumbar fusion efficacy with local bone grafting and platelet-rich plasma: a clinical investigation in treating degenerative lumbar spinal stenosis in the elderly.

The focus of this study was to comprehensively assess the clinical outcomes of lumbar fusion utilizing autogenous bone grafting and platelet-rich plasma (PRP) for the management of degenerative lumbar spinal stenosis (DLSS) in elderly individuals. A cohort of 40 senior individuals diagnosed with DLSS, who underwent treatment at our hospital between January 2020 and March 2022. The control group consisted of 20 participants who underwent local bone grafting for intervertebral fusion, while the observation group comprised 20 individuals who received a combination of local bone grafting and PRP for lumbar fusion. MRI imaging was employed for a comprehensive assessment of spinal structure. The efficacy of spinal fusion was evaluated through MRI imaging. Clinical treatment outcomes were assessed using the Japanese Orthopaedic Association (JOA) and Oswestry Disability Index (ODI) scoring systems. Postoperative low back pain was quantified using a Visual Analog Scale (VAS). During the final follow-up, the observation group demonstrated a significant increase in the inner diameter of the spinal canal and the height of the disc space compared to the control group (P < 0.05).Moreover, the observation group displayed a larger spinal canal than the control group (P < 0.05).A reduced lesion score in the bone grafting region was observed in the observation group compared to the control group during the final follow-up (P < 0.05). Furthermore, the observation group displayed a higher intervertebral fusion continuity score than the control group (P < 0.05).The JOA score in the observation group was significantly higher than in the control group (P < 0.05), while the ODI score was significantly lower (P < 0.05). Of note, the back pain VAS score in the observation group was lower than in the control group at both the three months post-surgery mark and the final follow-up (P < 0.05).The satisfaction rate and overall satisfaction rate in the observation group were significantly higher than those in the control group (P < 0.05), while the dissatisfaction rate in the observation group was evidently lower than in the control group (P < 0.05). In the management of DLSS in elderly individuals, the utilization of local bone grafting and PRP in lumbar spinal fusion yields notable outcomes.