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Background: MRI is critical for diagnosing lumbar spine disorders but its complexity challenges diagnostic accuracy. This study proposes a BERT-based large language model (LLM) to enhance precision in classifying lumbar spine disorders through the integration of MRI data, textual reports, and numerical measurements., Methods: The segmentation quality of MRI data is evaluated using dice coefficients (cut-off: 0.92) and intersection over union (IoU) metrics (cut-off: 0.88) to ensure precise anatomical feature extraction. The CNN extracts key lumbar spine features, such as lumbar lordotic angle (LLA) and disc heights, which are tokenized as direct scalar values representing positional relationships. A data source of 28,065 patients with various disorders, including degenerative disc disease, spinal stenosis, and spondylolisthesis, is used to establish diagnostic standards. These standards are refined through post-CNN processing of MRI texture features. The BERT-based spinal LLM model integrates these CNN-extracted MRI features and numerical values through early fusion layers., Results: Segmentation analysis illustrate various lumbar spine disorders and their anatomical changes. The model achieved high performance, with all key metrics nearing 0.9, demonstrating its effectiveness in classifying conditions like spondylolisthesis, herniated disc, and spinal stenosis. External validation further confirmed the model's generalizability across different populations. External validation on 514 expert-validated MRI cases further confirms the model's clinical relevance and generalizability. The BERT-based model classifies 61 combinations of lumbar spine disorders., Conclusions: The BERT-based spinal LLM significantly improves the precision of lumbar spine disorder classification, supporting accurate diagnosis and treatment planning., Competing Interests: Declarations Ethics approval and consent to participate The composite dataset of lumbar spine MRI images, accessed on March 2, 2021, is publicly available at https://data.mendeley.com/datasets/k3b363f3vz/2. Since the dataset does not include any identifiable personal information or sensitive medical data that could compromise patient confidentiality, it falls outside the scope of ethical review requirements typically mandated for studies involving human subjects. The focus of this dataset is strictly on clinically relevant spinal measurements and imaging correlations, without involving patient-specific details or interventions that would necessitate ethical oversight. Therefore, the use of this dataset for research purposes is considered exempt from formal ethical approval processes. Consent for publication Not applicable. Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Introduction: Quantitative parameters for diagnosis of congenital lumbar stenosis (CLS) have yet to be universally accepted. This study establishes parameters for CLS using CT, assessing the influences of patient sex, race, ethnicity, and anthropometric characteristics., Methods: Interpedicular distance (IPD), pedicle length, canal diameter, and canal area were measured using 1,000 patients between 18 and 35 years of age who were without spinal pathology., Results: Irrespective of disk level, threshold values for CLS were 16.1 mm for IPD, 3.9 mm for pedicle length, 11.5 mm for canal diameter, and 142.5 mm 2 for canal area. Notable differences based on patient sex were observed, with men demonstrating larger CLS threshold values with respect to IPD and canal area across all vertebral levels from L1 to L5. Based on patient anthropometric factors, no strong or moderate associations were observed between any spinal measurement and patient height, weight, or body mass index across all levels from L1 to L5. However, notable differences were observed based on patient race and ethnicity from L1 to L5. Asian patients demonstrated the largest pedicle lengths, followed by White, Hispanic, and Black patients in descending order. White patients demonstrated the largest IPD, canal AP diameter, and canal area, followed by Asian, Hispanic, and Black patients in descending order. Black patients demonstrated the smallest values across all anatomic measurements relative to Asian, White, and Hispanic patients., Conclusion: This study reports 25,000 measurements of lumbar central canal dimensions to establish quantitative thresholds for the diagnosis of CLS. Although not influenced by patient height, weight, or body mass index as one might intuit, canal dimensions were influenced by patient sex, race, and ethnicity. These findings may help explain differences in predisposition or prevalence of lumbar nerve root compression among patients of different races, which can be important when considering rates of surgery and access to care., (Copyright © 2024 by the American Academy of Orthopaedic Surgeons.)

Aims: Developmental cervical spinal stenosis (DcSS) is a well-known predisposing factor for degenerative cervical myelopathy (DCM) but there is a lack of consensus on its definition. This study aims to define DcSS based on MRI, and its multilevel characteristics, to assess the prevalence of DcSS in the general population, and to evaluate the presence of DcSS in the prediction of developing DCM., Methods: This cross-sectional study analyzed MRI spine morphological parameters at C3 to C7 (including anteroposterior (AP) diameter of spinal canal, spinal cord, and vertebral body) from DCM patients (n = 95) and individuals recruited from the general population (n = 2,019). Level-specific median AP spinal canal diameter from DCM patients was used to screen for stenotic levels in the population-based cohort. An individual with multilevel (≥ 3 vertebral levels) AP canal diameter smaller than the DCM median values was considered as having DcSS. The most optimal cut-off canal diameter per level for DcSS was determined by receiver operating characteristic analyses, and multivariable logistic regression was performed for the prediction of developing DCM that required surgery., Results: A total of 2,114 individuals aged 64.6 years (SD 11.9) who underwent surgery from March 2009 to December 2016 were studied. The most optimal cut-off canal diameters for DcSS are: C3 < 12.9 mm, C4 < 11.8 mm, C5 < 11.9 mm, C6 < 12.3 mm, and C7 < 13.3 mm. Overall, 13.0% (262 of 2,019) of the population-based cohort had multilevel DcSS. Multilevel DcSS (odds ratio (OR) 6.12 (95% CI 3.97 to 9.42); p < 0.001) and male sex (OR 4.06 (95% CI 2.55 to 6.45); p < 0.001) were predictors of developing DCM., Conclusion: This is the first MRI-based study for defining DcSS with multilevel canal narrowing. Level-specific cut-off canal diameters for DcSS can be used for early identification of individuals at risk of developing DCM. Individuals with DcSS at ≥ three levels and male sex are recommended for close monitoring or early intervention to avoid traumatic spinal cord injuries from stenosis., Competing Interests: J. P. Y. Cheung reports institutional payments from the Theme-based Research Scheme (T12-708/12 N), Area of Excellence Scheme (AoE/M-04/04), and HKU MRes Programme for this study. J. H. M. Leung also reports institutional payments from HKU MRes Programme for this study., (© 2024 Cheung et al.)

Background: This study aimed to compare the muscle thickness and cross-sectional area (CSA), pain, disability, and fear of falling in patients with lumbar spinal stenosis (LSS) with and without balance problems., Methods: Sixty-four patients diagnosed with LSS by magnetic resonance imaging (MRI) were included in this cross-sectional study. The patients were divided into poor (n=31) and normal balance (n=33) groups according to the single leg standing test. Low back pain (Numeric rating scale), dynamic balance (Time up and go test), disability (Oswestry disability index) and fear of falling (International fall efficacy scale) in patients with LSS levels were evaluated. Lumbar (L4/5) multifidus muscle thickness and CSA were obtained from MRI images., Results: The poor balance group had a lower L4/5 multifidus thickness (p<0.05) and CSA (p<0.05) than the normal balance group. It was determined that an increase in left L4/5 multifidus muscle CSA was associated with decreased impaired balance (p=0.036). Also, a significant correlation was detected between static balance and muscle thickness and CSA (p<0.01). In addition, low back pain, disability, and fear of falling were significantly higher in LSS patients in the poor balance group (p<0.05)., Conclusion: Muscle atrophy and decrease in CSA are more common in LSS patients with poor balance. Decreased L4/5 multifidus muscle CSA may increase the risk of balance impairment. Also, LSS patients with poor balance are more likely to experience pain, disability, and fear of falling. Strategies to improve lumbar muscle stability, mass, and pain may reduce impaired balance in LSS., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background Context: Lumbar spinal canal stenosis (LSCS) is the most common spinal degenerative disorder in elderly people and usually first seen by primary care physicians or orthopedic surgeons who are not spine surgery specialists. Magnetic resonance imaging (MRI) is useful in the diagnosis of LSCS, but the equipment is often not available or difficult to read. LSCS patients with progressive neurologic deficits have difficulty with recovery if surgical treatment is delayed. So, early diagnosis and determination of appropriate surgical indications are crucial in the treatment of LSCS. Convolutional neural networks (CNNs), a type of deep learning, offers significant advantages for image recognition and classification, and work well with radiographs, which can be easily taken at any facility., Purpose: Our purpose was to develop an algorithm to diagnose the presence or absence of LSCS requiring surgery from plain radiographs using CNNs., Study Design: Retrospective analysis of consecutive, nonrandomized series of patients at a single institution., Patient Sample: Data of 150 patients who underwent surgery for LSCS, including degenerative spondylolisthesis, at a single institution from January 2022 to August 2022, were collected. Additionally, 25 patients who underwent surgery at 2 other hospitals were included for extra external validation., Outcome Measures: In annotation 1, the area under the curve (AUC) computed from the receiver operating characteristic (ROC) curve, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, positive likelihood ratio (PLR), and negative likelihood ratio (NLR) were calculated. In annotation 2, correlation coefficients were used., Methods: Four intervertebral levels from L1/2 to L4/5 were extracted as region of interest from lateral plain lumbar spine radiographs totaling 600 images were obtained. Based on the date of surgery, 500 images derived from the first 125 cases were used for internal validation, and 100 images from the subsequent 25 cases used for external validation. Additionally, 100 images from other hospitals were used for extra external validation. In annotation 1, binary classification of operative and nonoperative levels was used, and in annotation 2, the spinal canal area measured on axial MRI was labeled as the output layer. For internal validation, the 500 images were divided into each 5 dataset on per-patient basis and 5-fold cross-validation was performed. Five trained models were registered in the external validation prediction performance. Grad-CAM was used to visualize area with the high features extracted by CNNs., Results: In internal validation, the AUC and accuracy for annotation 1 ranged between 0.85-0.89 and 79-83%, respectively, and the correlation coefficients for annotation 2 ranged between 0.53 and 0.64 (all p<.01). In external validation, the AUC and accuracy for annotation 1 were 0.90 and 82%, respectively, and the correlation coefficient for annotation 2 was 0.69, using 5 trained CNN models. In the extra external validation, the AUC and accuracy for annotation 1 were 0.89 and 84%, respectively, and the correlation coefficient for annotation 2 was 0.56. Grad-CAM showed high feature density in the intervertebral joints and posterior intervertebral discs., Conclusions: This technology automatically detects LSCS from plain lumbar spine radiographs, making it possible for medical facilities without MRI or nonspecialists to diagnose LSCS, suggesting the possibility of eliminating delays in the diagnosis and treatment of LSCS that require early treatment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Study Design: Prospective multicentric study., Objective: This study goal was to analyze the clinical and radiographic outcomes of lumbar stenosis and scoliosis (LSS) patients, treated with lumbar decompression (LD), short fusion and decompression (SF) or long fusion with deformity correction (LF)., Hypothesis: Procedures without correction lead to poorer long-term outcomes., Methods: Consecutive patients with two-year minimum follow-up, older than 50, with lumbar scoliosis (Cobb angle>15°), and symptomatic lumbar stenosis were included. Age, gender, Lumbar and Radicular Visual Analog Scale, ODI, SF12 and SRS30 were collected. Main and adjacent curves Cobb angles, C7 coronal tilt (C7CT), spinopelvic parameters, and spino-sacral angle (SSA) were measured preoperatively, at one and two years. Patients were sorted into surgery type groups., Results: In total, 154 patients were included, with respectively 18, 58 and 78 patients in LD, SF and LF groups. Mean age was 69, 85% were women. Clinical scores improved in each group at one year, but only LF group exhibited persistent improvement at 2years. A significant fractional Cobb angle increase was noted in the SF group at 2years (from 12±11° to 18±14°). C7CT significantly increased in the LD group at 2years (from 2.5±1.3° to 5.1±3.5°). LF group presented the highest complication rate (45%, 19% for SF and 0% for LD). The overall revision rate was 14% in SF group and 30% in LF group., Conclusion: LSS is a complex pathology requiring custom-made surgical treatment. LD, SF and LF allow satisfactory clinical outcome, with a better and more sustained clinical improvement for LF despite higher complication and revision rates., Level of Evidence: IV., (Copyright © 2023 Elsevier Masson SAS. All rights reserved.)

Study Design: A prospective single-arm clinical study., Objective: To explore the clinical utility of an intervertebral motion metric by determining the proportion of patients for whom it changed their surgical treatment plan from decompression only to decompression with fusion or vice versa ., Summary of Background Data: Lumbar spinal stenosis from degenerative spondylolisthesis is commonly treated with decompression only or decompression with additional instrumented fusion. An objective diagnostic tool capable of establishing abnormal motion between lumbar vertebrae to guide decision-making between surgical procedures is needed. To this end, a metric based on the vertebral sagittal plane translation-per-degree-of-rotation calculated from flexion-extension radiographs was developed., Materials and Methods: First, spine surgeons documented their intended surgical plan. Subsequently, the participants' flexion-extension radiographs were taken. From these, the translation-per-degree-of-rotation was calculated and reported as a sagittal plane shear index (SPSI). The SPSI metric of the spinal level intended to be treated was used to decide if the intended surgical plan needed to be changed or not., Results: SPSI was determined for 75 participants. Of these, 51 (68%) had an intended surgical plan of decompression only and 24 (32%) had decompression with fusion. In 63% of participants, the SPSI was in support of their intended surgical plan. For 29% of participants, the surgeon changed the surgical plan after the SPSI metric became available to them. A suggested change in the surgical plan was overruled by 8% of participants. The final surgical plan was decompression only for 59 (79%) participants and decompression with fusion for 16 (21%) participants., Conclusion: The 29% change in intended surgical plans suggested that SPSI was considered by spine surgeons as an adjunct metric in deciding whether to perform decompression only or to add instrumented fusion. This change exceeded the a priori defined 15% considered necessary to show the potential clinical utility of SPSI., Competing Interests: This study was designed and sponsored by Medical Metrics Inc. (Houston, Texas). The sponsor analyzed the flexion-extension images to produce the SPSI metric. The remaining authors report no conflicts of interest., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.)

Background: Sagittal balance, commonly impaired in lumbar spinal stenosis (LSS) patients, is typically assessed using the sagittal vertical axis (SVA) with EOS imaging. However, to limit X-ray exposure and medical costs, it could be interesting to evaluate the capacity of quantified motion analysis to estimate the 3D modeling of SVA in patients with symptomatic LSS., Methods: An estimation of the SVA in patients with LSS was performed with 3D motion analysis. SVA and "C7&#95;PSI" (orthogonal horizontal distance between the vertical lines through the markers of the C7 vertebra and the middle of the posterosuperior iliac spine) were measured on 37 LSS patients using EOS radiography and postural and 3D motion analysis, respectively. Multiple stepwise linear regressions were performed with EOS SVA according to age, body mass index, C7&#95;PSI and/or postural variables., Results: A highly significant relationship was found between SVA and C7&#95;PSI, mediolateral amplitude of CoP displacements and age (adjusted R²=0.69, p < 0.0001). While the postural analysis did not reveal significant relationships, the model using 3D parameters revealed significant relationships between radiographic SVA and C7&#95;PSI and age (adjusted R²=0.65, p < 0.0001). 3D motion parameters with or without postural parameters may explain more than 65% of the variance seen in EOS imaging performed on LSS patients., Conclusions: These promising results in LSS patients suggest that the estimation of SVA with 3D motion analysis offers an alternative to EOS. In addition, SVA could be assessed at rest and during dynamic tasks., Trial Registration: This study has been published in Clinical Trial registration (reference NCT03194607)., (© 2024. The Author(s).)

This study aimed to determine the prevalence of lumbar ligamentum flavum lesions and identify correlations between radiological and pathological findings. We conducted an observational cross-sectional study of 349 patients (lumbar: n = 296, thoracic: n = 39, lumbar and thoracic: n = 14, mean age: 69 ± 12 years, male: 74%) who underwent posterior surgery for thoracolumbar spinal canal stenosis between January 2008 and April 2023 at our hospital.Computed tomography (CT) revealed that the prevalence of ligamentum flavum lesions defined as a high-density area with a CT value of 200 Hounsfield Unit or higher in the lumbar and thoracic spine was 47% (147/310) and 85% (45/53), respectively. CT showed that most patients had radiologically suspected ossification in the lumbar (90%) and thoracic spine (98%) than radiologically suspected calcification. Lumbar lesions were thinner than the thoracic lesions (2.5 vs 3.7 mm, p < 0.01). Pathological examinations were performed in specimens collected from 34 cases (lumbar: n = 13, thoracic: n = 21), and ossification was found in 62% (8/13) and 95% (20/21) of lumbar and thoracic lesions (p = 0.02), respectively. Lastly, ossification was confirmed pathologically in 72% (8/11) and 95% (19/20) of lumbar and thoracic lesions that showed ossification on imaging (p = 0.13), respectively. The literature review revealed that the prevalence of the lumbar ligamentum flavum lesions varied from 1.5 to 35% and the patient population was mostly asymptomatic.Collectively, we found that the prevalence of lumbar ligamentum flavum lesions in symptomatic patients was greater than previously reported. Histologically confirmed ossification was less common in lumbar lesions than in thoracic lesions.

Objective: Redundant nerve roots (RNRs) seen in conjunction with lumbar spinal stenosis (LSS) are well-described radiographic findings. Several studies suggest their presence may be a negative prognostic indicator of postoperative outcome. Our hypothesis was that severe RNR (informally known as the spaghetti sign [SS]) can serve as a reliable marker of LSS that would benefit from surgical decompression. We sought to evaluate a grading scale for RNR, characterize the association with stenosis, and investigate the clinical implications of RNR., Methods: We conducted a retrospective chart review of 72 patients who underwent lumbar spine surgery from 2016 to 2018 at 1 institution. Preoperative T2 magnetic resonance imaging scans were graded by 3 reviewers for severity of stenosis (0-4), severity of RNR (0-3), and rostral versus caudal RNR. SS was defined as RNR score ≥2 (clear-cut or marked nerve root irregularity). Preoperative and postoperative Oswestry Disability Index scores were analyzed by stenosis and RNR severity., Results: Seventy-one (98%) patients had severe stenosis (score ≥3) and 25 (35%) had a SS. SS was 100% specific for high-grade stenosis. If patients had a SS, it was more likely rostral (P=0.02). Postoperative Oswestry Disability Index scores improved significantly, but there were no differences related to RNR score, presence of SS, or stenosis severity., Conclusions: The study demonstrated that there is a significant association between SS and severe LSS and that presence of RNR is not a negative prognostic indicator for postoperative outcomes., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The aim of this study was to investigate whether super-resolution deep learning reconstruction (SR-DLR) is superior to conventional deep learning reconstruction (DLR) with respect to interobserver agreement in the evaluation of neuroforaminal stenosis using 1.5T cervical spine MRI. This retrospective study included 39 patients who underwent 1.5T cervical spine MRI. T2-weighted sagittal images were reconstructed with SR-DLR and DLR. Three blinded radiologists independently evaluated the images in terms of the degree of neuroforaminal stenosis, depictions of the vertebrae, spinal cord and neural foramina, sharpness, noise, artefacts and diagnostic acceptability. In quantitative image analyses, a fourth radiologist evaluated the signal-to-noise ratio (SNR) by placing a circular or ovoid region of interest on the spinal cord, and the edge slope based on a linear region of interest placed across the surface of the spinal cord. Interobserver agreement in the evaluations of neuroforaminal stenosis using SR-DLR and DLR was 0.422-0.571 and 0.410-0.542, respectively. The kappa values between reader 1 vs. reader 2 and reader 2 vs. reader 3 significantly differed. Two of the three readers rated depictions of the spinal cord, sharpness, and diagnostic acceptability as significantly better with SR-DLR than with DLR. Both SNR and edge slope (/mm) were also significantly better with SR-DLR (12.9 and 6031, respectively) than with DLR (11.5 and 3741, respectively) (p < 0.001 for both). In conclusion, compared to DLR, SR-DLR improved interobserver agreement in the evaluations of neuroforaminal stenosis using 1.5T cervical spine MRI., (© 2024. The Author(s) under exclusive licence to Society for Imaging Informatics in Medicine.)

Study Design: Retrospective study., Objective: (1) To compare cervical magnetic resonance imaging (MRI) radiology reports to a validated grading system for cervical foraminal stenosis (FS) and (2) to evaluate whether the severity of cervical neural FS on MRI correlates to motor weakness or patient-reported outcomes., Background: Radiology reports of cervical spine MRI are often reviewed to assess the degree of neural FS. However, research looking at the association between these reports and objective MRI findings, as well as clinical symptoms, is lacking., Patients and Methods: We retrospectively identified all adult patients undergoing primary 1 or 2-level anterior cervical discectomy and fusion at a single academic center for an indication of cervical radiculopathy. Preoperative MRI was assessed for neural FS severity using the grading system described by Kim and colleagues for each level of fusion, as well as adjacent levels. Neural FS severity was recorded from diagnostic radiologist MRI reports. Motor weakness was defined as an examination grade <4/5 on the final preoperative encounter. Regression analysis was conducted to evaluate whether the degree of FS by either classification was related to patient-reported outcome measure severity., Results: A total of 283 patients were included in the study, and 998 total levels were assessed. There were significant differences between the MRI grading system and the assessment by radio-logists ( P < 0.001). In levels with moderate stenosis, 28.9% were classified as having no stenosis by radiology. In levels with severe stenosis, 29.7% were classified as having mild-moderate stenosis or less. Motor weakness was found similarly often in levels of moderate or severe stenosis (6.9% and 9.2%, respectively). On regression analysis, no associations were found between baseline patient-reported outcome measures and stenosis severity assessed by radiologists or MRI grading systems., Conclusion: Radiology reports on the severity of cervical neural FS are not consistent with a validated MRI grading system. These radiology reports underestimated the severity of neural foraminal compression and may be inappropriate when used for clinical decision-making., Level of Evidence: Level III., Competing Interests: Dr Schroeder has received funds to travel from AOSpine and Medtronic. Dr Vaccaro has consulted or has done independent contracting for DePuy, Medtronic, Stryker Spine, Globus, Stout Medical, Gerson Lehrman Group, Guidepoint Global, Medacorp, Innovative Surgical Design, Orthobullets, Ellipse, and Vertex. He has also served on the scientific advisory board/board of directors/committees for Flagship Surgical, AO Spine, Innovative Surgical Design, and Association of Collaborative Spine Research. Dr Vaccaro has received royalty payments from Medtronic, Stryker Spine, Globus, Aesculap, Thieme, Jaypee, Elsevier, and Taylor Francis/Hodder and Stoughton. He has stock/stock option ownership interests in Replication Medica, Globus, Paradigm Spine, Stout Medical, Progressive Spinal Technologies, Advanced Spinal Intellectual Properties, Spine Medica, ComputationalBiodynamics, Spinology, In Vivo, Flagship Surgical, Cytonics, BonovoOrthopaedics, Electrocore, Gamma Spine, Location Based Intelligence, FlowPharma, R.S.I., Rothman Institute and Related Properties, InnovativeSurgical Design, and Avaz Surgical. In addition, Dr Vaccaro has also provided expert testimony. He has also served as deputy editor/editor of Clinical Spine Surgery. The remaining authors declare no conflict of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: To elucidate the effect of global spinal alignment on cervical degeneration in patients with degenerative lumbar scoliosis (DLS)., Methods: This study included 117 patients with DLS and 42 patients with lumbar spinal stenosis as a control group. Patients with DLS (study group) were categorized according to the Scoliosis Research Society-Schwab classification. Spinopelvic parameters were measured in cervical and full-length spine radiographs. Cervical degeneration was assessed using the cervical degeneration index (CDI) scoring system., Results: There were significant differences in C2-C7 sagittal vertical axis, T1 slope, thoracic kyphosis, lumbar lordosis (LL), and pelvic tilt between DLS and control groups. Although the DLS and control groups did not differ significantly with regard to CDI scores, a striking difference was noted when sagittal spinopelvic modifiers were considered individually. Patients with a pelvic incidence (PI)-LL mismatch modifier grade of ++ had significantly higher CDI scores than patients with grade 0, and patients with a PI-LL or sagittal vertical axis modifier grade of ++ had significantly higher CDI scores than the control group. Disk narrowing scores were highest in patients with a PI-LL modifier grade of ++ followed by patients with a grade of +. Additionally, CDI scores were more associated with LL rather than cervical lordosis., Conclusions: Patients with DLS may be at greater risk of cervical spine degeneration, especially patients with a PI-LL or sagittal vertical axis modifier grade of ++. A surgical strategy for patients with DLS should be carefully selected considering the restoration of LL., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: To analyze the characteristics of an unnamed interlaminar ligaments(ILL) through magnetic resonance image (MRI), endoscopy and pathological examination., Method: A retrospective study was conducted to analyze the clinical data of patients who underwent posterior endoscopic surgery for lumbar disc herniation or lumbar spinal stenosis from January 2021 to February 2022 at our medical center. The height, width and cross-sectional thickness of the ligament was analyzed using T2 weighted MRI. Meanwhile, the morphological and pathological characteristics were also compared with those of the ligamentum flavum to highlight the differences between above mentioned ligaments., Result: Forty-three patients were included in this study, including 27 males and 16 females, with an average age of 46.6 ± 12.1y. There were 20 cases of lumbar disc herniation and 23 cases of lumbar spinal stenosis. The width, length, thickness of the ILL, the thickness of LF and surgical time in the lumbar disc group were 17.7 ± 3.5 mm, 4.3 ± 1.3 mm, 18.3 ± 3.5 mm, 5.3 ± 1.9 mm, 53.2 ± 14.5 min, respectively. In the lumbar spinal stenosis group, the corresponding parameters were 16.0 ± 3.1 mm, 4.1 ± 1.6 mm, 17.6 ± 4.8 mm, 6.3 ± 0.8 mm, 61.8 ± 12.4 min, respectively. The intergroup difference in thickness of the ligamentum flavum was statistically significant (P = 0.02). The difference in surgical time was also established(P = 0.04). Endoscopic differences were identified as to the location of the anchor points and appearances among the two ligaments. Significant differences in the density and direction of fibrous structures were also observed under biopsy. Under endoscopy, significant difference as to the grade of ILL thickness was established when compared regarding disease spectrum (P = 0.09.) CONCLUSION: The interlaminar ligament is a structure that has not yet been officially named, which has significant structural differences from those of the ligamentum flavum. For posterior endoscopic procedure, its clinical significance lies in its ability to serve as the endpoint of soft tissue channel establishment. The thickness of the ligamentum flavum in MRI and the thickness of ILL under endoscopy vary according to the disease spectrum., (© 2024. The Author(s).)

Background: Unilateral laminotomy for bilateral decompression (ULBD) has yielded positive results in the treatment of lumbar spinal stenosis (LSS). Unilateral biportal ULBD (UB-ULBD) and percutaneous endoscopic ULBD (PE-ULBD) are gaining popularity because of the progress that has been made in minimally invasive surgery (MIS). The objective of this study was to evaluate and compare the radiographic and clinical results of UB-ULBD and PE-ULBD., Methods: This study retrospectively enrolled patients who underwent ULBD surgery for LSS. The patients were categorized into two groups on the basis of the surgical method: the UB-ULBD group and the PE-ULBD group. Data on the general demographic data, surgical details, clinical efficacy, radiography and complications were compared between the two groups were compared. The minimum follow-up duration was 12 months., Results: A total of 113 LSS patients who had undergone ULBD at our institution were included, of whom 61 patients underwent UB-ULBD surgery and 52 underwent PE-ULBD surgery. The UB-ULBD group had a significantly shorter operation time (P < 0.05). The facet was significantly better preserved in the UB-ULBD group than in the PE-ULBD group, and the angle of ipsilateral facet joint resection in the UE-ULBD group was significantly smaller (P < 0.05). The ODI score, VAS score and modified Macnab criteria improved postoperatively in both groups. The UB-ULBD group had a 95.08% rate of excellent or good patient outcomes, whereas the PE-ULBD group had a 92.30% rate., Conclusion: Both UB-ULBD and PE-ULBD can provide favourable clinical outcomes when used to treat LSS. UB-ULBD is beneficial because of its shorter operation time, smaller angle of ipsilateral facet joint resection and better facet preservation, making it a viable and safe option for treating LSS while ensuring spinal stability., (© 2024. The Author(s).)

Background: Posterolateral decompression and fusion with internal fixation is a commonly used surgical approach for treating degenerative lumbar spinal stenosis (DLSS). This study aims to evaluate the impact of preserving a portion of the unilateral facet joint during decompression on surgical outcomes and long-term recovery in patients., Methods: This study analyzed 73 patients with DLSS accompanied by bilateral lower limb neurological symptoms who underwent single-level L4/5 posterolateral decompression and fusion surgery from January 2022 to March 2023. Patients were categorized into two groups based on the type of surgery received: Group A comprised 31 patients who underwent neural decompression without facet joint preservation, while Group B consisted of 42 patients who underwent neural decompression with preservation of partial facet joints on one side. Regular follow-up evaluations were conducted, including clinical and radiological assessments immediately postoperatively, and at 3 and 12 months thereafter. Key patient information was documented through retrospective chart reviews., Results: Most patients in both groups experienced favorable surgical outcomes. However, four cases encountered complications. Notably, during follow-up, Group B demonstrated superior 1-year postoperative interbody fusion outcomes (P < 0.05), along with a trend towards less interbody cage subsidence and slower postoperative intervertebral disc height loss. Additionally, Group B showed significantly reduced postoperative hospital stay (P < 0.05)., Conclusion: Under strict adherence to surgical indications, the posterior lateral lumbar fusion surgery, which preserves partial facet joint unilaterally during neural decompression, can offer greater benefits to patients., (© 2024. The Author(s).)

Symptoms arise when narrowing of the spinal canal, lateral recesses, or intervertebral foramina impinge upon the neural structures that traverse the spinal column. Pathology involving the structures that make up the spine can narrow the relevant spaces. Here a description of percutaneous procedures that address narrowing from disc disease, ligamentum Flavum hypertrophy, and devices that open and stabilize the spine at individual levels are presented., Competing Interests: Disclosures The authors have no relevant disclosures., (Copyright © 2024. Published by Elsevier Inc.)

Study Design: Experimental study., Objective: We sought to elucidate the association between ligamentum flavum thickening and tissue buckling, and the clinical and imaging factors related to buckling by comparing the ligamentum flavum thickness on MRI images and within the actual tissue., Summary of Background Data: Ligamentum flavum thickening is a main contributor to lumbar spinal canal stenosis. Buckling of the tissue may contribute to ligamentum flavum thickening along with tissue hypertrophy; however, this association has not been established conclusively., Materials and Methods: Ligamentum flavum samples (135 ligament samples) from 70 patients with lumbar spinal canal stenosis were evaluated. The ligamentum flavum thicknesses on magnetic resonance imaging (MRI) and in the tissue samples were compared to assess for the presence of buckling. The ligamentum flavum samples were divided into groups with or without buckling based on the difference between their thicknesses on MRI and in the tissues. The Pearson correlation coefficient test was used to assess the relationships between the LF thicknesses on MRI and in the tissues, MRI-tissue difference and LF thickness in the tissues, and MRI-tissue difference and LF thickness on MRI. Further, differences between the buckling+ and buckling- groups were compared using the unpaired t-test (LF thickness on MRI, LF thickness in the tissues, age, disc angle, and disc height) and χ2 (disc level, disc degeneration, and receival/nonreceival of dialysis) test., Results: The ligamentum flavum thickness on MRI and in the tissues had a positive linear relationship, although the thickness was estimated to be significantly larger on MRI than in the tissues themselves. The ligamentum flavum with buckling had a larger thickness on MRI, less tissue hypertrophy, more severe disc degeneration, and was present in patients with a higher rate of dialysis. There were no differences in age and disc height, angle, or level between the two groups., Conclusions: Buckling of the ligamentum flavum coexists with tissue hypertrophy and contributes to perceived ligamentum thickening on imaging. Buckling of the ligamentum flavum tends to occur in less hypertrophied tissues and is associated with the grade of disc degeneration and the presence of other characteristics associated with spinal degeneration., Competing Interests: The authors report no conflicts of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Hip-spine syndrome (HSS) was first described in 1983 to describe the symptomatology resulting from concomitant lumbar degenerative stenosis and hip osteoarthritis. Numerous studies have sought to understand the underlying pathology and appropriate management of this syndrome. The purpose of this article is to review the literature for the specific imaging characteristics and the optimal surgical treatment of HSS., Methods: A systematic review was conducted via an electronic database search through PubMed to identify all publications related to HSS. All publications that contained data on patients who underwent surgical treatment for HSS and reported patient-reported outcome measures or radiographic data were included. Exclusion criteria consisted of publications in a language other than English, review articles, and technique articles., Results: Fifteen articles that focused on the surgical management of HSS were identified. Of these 15 articles, 8 reported radiographic outcomes, with most reporting no significant change in spinopelvic parameters before and after surgery. Thirteen articles reported clinical outcomes, with 8 of those 13 articles identifying patient-reported outcome measures to be significantly improved following surgery., Conclusions: The data on the surgical management of HSS remains sparse. While there is some evidence that total hip arthroplasty in patients who previously underwent spinal fusion may have higher complication rates, there remains debate regarding which surgical problem to address first, the hip or the spine., (Copyright © 2024. Published by Elsevier Inc.)

Objectives: To determine the characteristics of lumbar foraminal stenosis (LFS) on magnetic resonance (MR) images and their association with back pain and radiating leg pain in a population-based sample of Chinese subjects., Methods: This study was an extension of the Hangzhou Lumbar Spine Study, a cross-sectional study focusing on back pain and lumbar spine MR imaging findings. Questionnaire data, including demographics, lifestyle, occupational exposures, back pain and radiating leg pain were included. On lumbar spine MR images, disc degeneration was assessed using Pfirrmann grade and Modic changes were evaluated. Using Lee's scale, the L3-S1 intervertebral foramina were evaluated, with grade 2-3 representing substantial LFS and grade 0-1 no LFS. Characteristics of LFS were noted, and associations of LFS with back pain and radiating leg pain were examined., Results: Among the 644 study subjects, 141 (21.9%) had at least one LFS, and its occurrence was associated with greater age (OR = 1.93 for each 10 years, p < 0.001). Substantial LFS was associated with the presence of back pain (OR = 1.92, p = 0.001) and the intensity of the worst back pain (Coef = 8.30, p < 0.001) over the past 12 months, and disabling back pain during their lifetime (OR = 2.25, p < 0.001). Substantial LFS was also associated with leg pain (OR = 14.27, p < 0.001), with a sensitivity of 75.7% for the presence of radiating leg pain and a specificity of 81.4%., Conclusion: Substantial LFS on MR images was a common age-related degenerative phenotype in adults, and appears to be an independent risk factor for back pain and leg pain., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objectives: The aim of this study was to clinically validate a fully automated AI model for magnetic resonance imaging (MRI)-based quantifications of lumbar spinal canal stenosis., Materials and Methods: This retrospective study included lumbar spine MRI of 100 consecutive clinical patients (56 ± 17 years; 43 females, 57 males) performed on clinical 1.5 (51 examinations) and 3 T MRI scanners (49 examinations) with heterogeneous clinical imaging protocols. The AI model performed segmentations of the thecal sac on axial T2-weighted sequences. Based on these segmentations, the anteroposterior (AP) and mediolateral (ML) distance, and the area of the thecal sac were measured in a fully automated manner. For comparison, 2 fellowship-trained musculoskeletal radiologists performed the same segmentations and measurements independently. Statistics included 1-sample t tests, the intraclass correlation coefficient (ICC), Bland-Altman plots, and Dice coefficients. A P value of <0.05 was considered statistically significant., Results: The average measurements of the AI model, reader 1, and reader 2 were 194 ± 72 mm 2 , 181 ± 71 mm 2 , and 179 ± 70 mm 2 for thecal sac area, 13 ± 3.3 mm, 12.6 ± 3.3 mm, and 12.6 ± 3.2 mm for AP distance, and 19.5 ± 3.9 mm, 20 ± 4.3 mm, and 19.4 ± 4 mm for ML distance, respectively. Significant differences existed for all pairwise comparisons, besides reader 1 versus AI model for the ML distance and reader 1 versus reader 2 for the AP distance ( P = 0.1 and P = 0.21, respectively). The pairwise mean absolute errors among reader 1, reader 2, and the AI model ranged from 0.59 mm and 0.75 mm for the AP distance, from 1.16 mm to 1.37 mm for the ML distance, and from 7.9 mm 2 to 15.54 mm 2 for the thecal sac area. Pairwise ICCs among reader 1, reader 2, and the AI model ranged from 0.91 and 0.94 for the AP distance and from 0.86 to 0.9 for the ML distance without significant differences. For the thecal sac area, the pairwise ICC between both readers and the AI model of 0.97 each was slightly, but significantly lower than the ICC between reader 1 and reader 2 of 0.99. Similarly, the Dice coefficient and Hausdorff distance between both readers and the AI model were significantly lower than the values between reader 1 and reader 2, overall ranging from 0.93 to 0.95 for the Dice coefficients and 1.1 to 1.44 for the Hausdorff distances., Conclusions: The investigated AI model is reliable for assessing the AP and the ML thecal sac diameters with human level accuracies. The small differences for measurement and segmentation of the thecal sac area between the AI model and the radiologists are likely within a clinically acceptable range., Competing Interests: Conflicts of interest and sources of funding: M. Staib, M. Schleiniger, L. Steiner, and L. Schwarz are employees of ScanDiags AG. For S.B., C.G., R.S., and B.F., Balgrist University Hospital has an academic research collaboration with Siemens Healthineers, Bayer, and Balzano Informatik., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.)

Objective: To explore the clinical effect of percutaneous kyphoplasty (PKP) via process-rib-pedicle approach for upper and middle thoracic osteoporosis fractures with pedicle stenosis., Methods: This study is a retrospective observational study. In this study, we retrospectively analyzed the data of 62 patients with upper thoracic vertebral bone loss compression fracture treated via the process-rib-pedicle pathway PKP at the First Affiliated Hospital of Soochow University from January 2020 to December 2022. The patients were divided into group A (unilateral PKP, 38 cases) and group B (bilateral PKP, 24 cases). The aspects of surgical safety, clinical efficacy, and radiological outcome were investigated., Results: All 62 patients successfully completed the surgery without any spinal cord, nerve, or vascular injury, and there were no complications such as infection and vascular embolism. The differences in visual analog scale scores（P < 0.05）, Oswestry disability index functional index（P < 0.05）, and Cobb angle（P < 0.05） were significant when comparing preoperative and postoperative periods, and the differences were not significant when comparing the postoperative periods (P > 0.05). There were no statistically significant differences in days of hospital stay (P = 0.653) and the rate of bone cement leakage (P = 0.537) between the 2 groups., Conclusions: For upper middle osteoporotic thoracic vertebral fractures with pedicle stenosis, puncture via the process-rib-pedicle path is a safe and reliable puncture route, and more than 2.5 ml of cement can achieve good clinical outcomes, regardless of bilateral or unilateral PKP., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Tubular retractors in minimally invasive lumbar stenosis permit surgeons to achieve satisfactory neural decompression while minimizing the morbidity of the surgical access. 1-3 Transtubular lumbar decompression requires intraoperative image guidance and microscopic magnification to achieve precise and reproductible surgical results. Use of 2-dimensional image guidance in transtubular lumbar decompression has a major limitation due to the lack of multiplanar orientation. Consequently, there is a risk of incomplete decompression and excessive bone removal resulting in iatrogenic instability. Furthermore, available microscopes have limited optics (short focal lengths) and unsatisfactory surgeon ergonomics. To overcome these limitations, the authors present a step-by-step video of the navigated exoscopic transtubular approach (NETA) for spinal canal decompression (Video 1). The patient suffers from bilateral L5 radiculopathy due to L4-L5 bilateral synovial cysts responsible for severe L4-L5 canal stenosis. During the entire surgical procedure, NETA implements the use of navigation based on intraoperative 3-dimensional (3D) fluoroscopic images for retractor placement, bone mapping, and neural decompression. 4 NETA represents a modification of the "standard" MIS transtubular technique for bilateral lumbar decompression. NETA is based on the use of neuronavigation during each surgical step to guide the placement of tubular retractor. This tailors the bone resection to achieve adequate neural decompression while minimizing the risks of potential spine instability. After precise placement of the tubular retractor, bone removal and neural decompression are accomplished under robotic exoscope magnification with 4k 3D images. Using a 3D robotic exoscope (Modus V, Synaptive, Toronto, Canada) allows better tissue magnification and improves surgeon ergonomics during lumbar decompression through tubular retractors. 5 , 6 ., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background and Objectives: Adjacent segment disease is a relatively common late complication after lumbar fusion. If symptomatic, certain patients require fusion of the degenerated adjacent segment. Currently, there are no posterior completely minimally invasive techniques described for fusion of the adjacent segment above or below a previous fusion. We describe here a novel minimally invasive technique for both implant removal (MIS-IR) and adjacent level transforaminal lumbar interbody fusion (MIS-TLIF) for lumbar stenosis., Methods: Demographic, surgical, and radiographic outcome data were collected for patients with lumbar stenosis and previous lumbar fusion, who were treated with MIS-IR and MIS-TLIF through the same incision. Radiographic outcomes were assessed postoperatively and complications were assessed at the primary end point of 3 months., Results: A total of 14 patients (7 female and 7 male), with average age 64.6 years (SD 13.4), were included in this case series. Nine patients had single-level MIS-IR with single-level MIS-TLIF. Three patients had 2-level MIS-IR with single-level MIS-TLIF. Two patients had single-level MIS-IR with 2-level MIS-TLIF. Only 1 patient had a postoperative complication-hematoma requiring same-day evacuation. There were no other complications at the primary end point and no fusion failure at the hardware removal levels to date (average follow-up, 11 months). Average increases in posterior disk height and foraminal height after MIS-TLIF were 4.44, and 2.18 mm, respectively., Conclusion: Minimally invasive spinal IR can be successfully completed along with adjacent level TLIF through the same incisions, via an all-posterior approach., (Copyright © Congress of Neurological Surgeons 2024. All rights reserved.)

In adult patients affected by degenerative disc disease with lumbar instability and chronic low back pain, spine surgery with lumbar fixation aims to reduce segmental instability and pain. Different techniques have been developed, but the optimal surgical technique remains controversial. No studies have compared the clinical and radiological outcomes between stand-alone pedicle screw fixation (SAPF) and minimally invasive transforaminal lumbar interbody fusion (MI-TLIF). This was a retrospective study. All patients who underwent surgery for single-level L4-L5 or L5-S1 lumbar stenosis, associated with minor lumbar instability and treated with SAPF or MI-TLIF techniques were included in the study. Data were collected preoperatively and at 24 monts follow-up. Clinical primary outcomes were Oswestry Disability Index (ODI) and Numerical Rating Scale (NRS). Secondary outcomes were patient satisfaction, walking ability and self reported back and leg pain. In addition, perioperative data and complications were recorded. Segmental lordosis (L4-L5 and L5-S1) and overall lumbar lordosis (L1-S1) were measured on lumbar X-Rays preoperatively and at least 24 months postoperatively. 277 patients were firstly identified. Baseline data and a minimum of two-year follow-up were available for 62 patients. After the propensity score matching, 44 patients (22 patients in the SAPF group and 22 patients in the MI-TLIF group) were matched. At 24 months follow-up, no difference between the two groups of patients in NRS (p = 0.11) and ODI scores (p = 0.21) were observed. Patients' satisfaction at follow-up was also not significantly different between the two groups. In both groups, a significant improvement in the walked distance was observed after surgery (p = 0.05) while no difference was observed regarding the type of surgery performed (p = 1.00). No differences were found in the pre- and post-operative median lumbar lordosis (p = 0.91 and p = 0.67) and the same findings were observed for lumbar segmental lordosis (p = 0.65 and p = 0.41 respectively). Significant improvements in ODI and NRS-scores were recorded after 24 months follow-up with both SAPF and MI-TLIF. No significant differences in postoperative PROMs and patients' satisfaction were observed between the groups. The results of our study indicate no superiority of either surgical technique concerning pain and functional outcomes after 24 months., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Objective: To perform a systematic literature review on the diagnostic utility of 3D MRI sequences in the assessment of central canal, recess and foraminal stenosis in the spine., Methods: The databases PubMed, MEDLINE (via OVID) and The Cochrane Central Register of Controlled Trials, were searched for studies that investigated the diagnostic use of 3D MRI to evaluate stenoses in various parts of the spine in humans. Three reviewers examined the literature and conducted systematic review according to PRISMA 2020 guidelines., Results: Thirty studies were retrieved from 2 595 publications for this systematic review. The overall diagnostic performance of 3D MRI outperformed the conventional 2D MRI with reported sensitivities ranging from 79 to 100% and specificities ranging from 86 to 100% regarding the evaluation of central, recess and foraminal stenoses. In general, high level of agreement (both intra- and interrater) regarding visibility and pathology on 3D sequences was reported. Studies show that well-optimized 3D sequences allow the use of higher spatial resolution, similar scan time and increased SNR and CNR when compared to corresponding 2D sequences. However, the benefit of 3D sequences is in the additional information provided by them and in the possibility to save total protocol scan times., Conclusion: The literature on the spine 3D MRI assessment of stenoses is heterogeneous with varying MRI protocols and diagnostic results. However, the 3D sequences offer similar or superior detection of stenoses with high reliability. Especially, the advantage of 3D MRI seems to be the better evaluation of recess stenoses., (© 2024. The Author(s).)

Objective: To analyze the relational factors influencing the formation of cauda equina redundant nerve roots (RNRs) of the lumbar spinal stenosis., Methods: Clinical data of 116 patients with lumbar spinal stenosis treated from January 2016 to June 2019 were retrospectively analyzed. The patients were divided into redundant nerve roots(RNRs) group and non-RNRs group based on the presence or absence of RNRs on sagittal T2-weighted MRI. In the non-RNRs group, there were 74 patients, including 38 males and 36 females with an average age of (62.00±10.41) years old, the body mass index (BMI) was (23.09±2.22) kg·m -2 ;the maximum stenosis segment was L 2 -L 3 in 12 cases, L 3 -L 4 in 38, L 4 -L 5 in 20, and L 5 S 1 in 4, respectively. In the RNRs group, there were 42 patients, including 18 males and 24 females with an average age of (63.36±8.73) years old, the BMI was (22.63±2.60) kg·m -2 ;the maximum stenosis segment was L 2 -L 3 in 3 cases, L 3 -L 4 in 9, L 4 -L 5 in 27 and L 5 S 1 in 3, respectively. MRI was performed in the supine position to observe the conshape and morphology of the redundant nerve in the sagittal position. The preoperative low back and leg pain visual analogue scale(VAS), and preoperative Oswestry disability index(ODI) were analyzed, and the rate of spondylolisthesis and ligamentum flavum hypertrophy were compared. Simultaneously, the inter-vertebral height, intervertebral foramen height, inter-vertebral height+vertebral height, median sagittal diameter at the inter-vertebral space level(DIW-MSD), median sagittal diameter at the pedicel level(DV-MSD), range of motion(ROM) of the stenotic segment were measured and analyzed., Results: Among the 116 patients with lumbar spinal stenosis, 42 patients developed RNRs, with an incidence of 36.2%. There were no significant differences in gender, age, BMI, preoperative VAS for lumbar and leg pain and ODI between two groups( P >0.05). There were statistically significant differences regard to the duration of symptoms and the rate of spondylolisthesis and ligamentum flavum hypertrophy ( P <0.05);the inter-vertebral height, intervertebral foramen height, inter-vertebral height+vertebral height, DIW-MSD, ROM of the stenotic segment were also significantly different between two groups( P <0.05). However, there was no significant difference in DV-MSD between two groups( P >0.05)., Conclusion: The inter-vertebral height, inter-vertebral foramen height, inter-vertebral height+vertebral height, DIW-MSD and ROM of the stenotic segment were the crucial factors related to RNRs in lumbar spinal stenosis.

Background: Morphometric analysis of the psoas major muscle has shown utility in predicting postoperative morbidity in various surgical fields, but its usefulness in predicting complications in elderly patients undergoing multilevel lumbar fusion surgery has not been studied. The study aimed to investigate if psoas major parameters are independent risk factors of early postoperative complication among elderly patients., Methods: Patients who underwent multilevel lumbar fusion for degenerative lumbar spinal stenosis (DLSS) were included. The psoas major was measured at the lumbar 3/4 intervertebral disc level in three ways on computed tomography image: psoas muscle mass index, mean muscle attenuation, and morphologic change of the psoas major. Early complications were graded using the Clavien-Dindo classification system and the Comprehensive complication index (CCI). A CCI ≥ 26.2 indicated severe complications. Logistic regression was performed to identify independent risk factors., Results: This retrospective study reviewed 108 patients (mean age 70.9 years, female to male ratio 1.8:1). Complications were observed in 72.2% of patients, with allogeneic blood transfusion being the most frequent (66.7%), followed by wound infection, acute heart failure (2.8% each). Severe complications occurred in 13.9% of patients. After multivariable regression analysis, those in the lowest psoas muscle attenuation tertile had higher odds of experiencing early postoperative complications (OR: 3.327, 95% CI 1.134-9.763, p = 0.029) and severe complications (OR: 6.964, 95% CI 1.928-25.160, p = 0.003)., Conclusion: The psoas muscle attenuation can be used as a predictor of early postoperative complications in elderly patients undergoing multilevel lumbar fusion surgery for DLSS., (© 2024. The Author(s).)

Background: Spinal cord stimulation (SCS) is an efficacious treatment for various refractory chronic pain syndromes. Serious complications including spinal cord compression (SCC) are rare with 19 previous reports which are mainly attributed to fibrotic scar tissue formation at the distal end of the leads at the location of the contacts. We report a case of SCC following SCS implantation at the lead entry location secondary to a delayed progression of spinal canal stenosis., Case Presentation: A patient in her early 70s underwent SCS implantation with adequate therapeutic benefit for approximately 2 years before citing complaints of increasing lower back pain and lower extremity radicular pain. Lumbar spine X-rays excluded lead migration as a causative factor. An MRI of the lumbar spine obtained 30 months following SCS implantation demonstrated a marked interval progression of central canal stenosis secondary to facet and ligamentous hypertrophy manifesting in compression of the spinal cord at the lead entry location. An L1-L2 decompressive laminectomy with hardware removal resulted in the resolution of her symptoms. A literature search conducted with the PubMed database identified previously published cases of SCC following SCS implantation which highlighted the rarity of this complication., Conclusion: Our case report urges physicians of SCS patients, noting a loss of therapeutic benefit with their device, to investigate new pathologies including SCC. Furthermore, our case highlights clinical symptoms and surgical treatments of SCC. Paddle leads are more commonly implicated in published cases of SCC than percutaneous leads. Lastly, MRI conditionality is critical to identifying cases of SCC., Competing Interests: Competing interests: DAP has consulted for Avanos, Boston Scientific, Medtronic, Nevro, and SI Bone. Pain Diagnostics and Interventional Care received research support from Avanos, Medtronic, Nevro, Stimgenics, and Abbott. HXL, DO-S and LD have no conflicts to report., (© American Society of Regional Anesthesia & Pain Medicine 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Degenerative lumbar spinal stenosis (LSS) is a common condition that involves the narrowing of the spinal canal. Diagnosing instability traditionally requires standing lateral radiographs to detect dynamic translation, but there is debate about relying solely on radiographs due to challenges like patient discomfort and radiation exposure. This study aimed to evaluate if Magnetic Resonance Imaging (MRI) findings could effectively diagnose instability observed on radiographs., Methods: We reviewed 478 consecutive patients with degenerative LSS who had surgery at our institution. Instability was defined as a sagittal translation exceeding 3 mm on standing lateral radiographs in both extension and flexion. Patients were divided into stable (those with < 3 mm translation) and unstable groups (those with > 3 mm translation). The study assessed potential variables for instability, including MRI findings like facet joint effusion, facet joint angle, disk height index, intradiscal vacuum presence, endplate sclerosis, ligamentum flavum hypertrophy, and multifidus muscle fatty degeneration, comparing these factors between the two groups., Results: A total of 478 consecutive patients diagnosed with degenerative Lumbar Spinal Stenosis (LSS) were included. The average age of the patients was 66.32 years, with 43.3% being male. Approximately 27.6% of the cases exhibited signs of instability on the standing lateral radiograph during extension and flexion. The multivariate analysis using binary logistic regression revealed that facet joint effusion (odds ratio [OR] 2.73; 95% confidence interval [CI] 1.27-3.94; P = 0.002), disk height index (OR 2.22; 95% CI 1.68-3.35; P = 0.009), and the presence of the Vacuum sign (OR 1.77; 95% CI 1.32-2.84; P = 0.021) were identified as factors associated with instability., Conclusions: Our findings showed thata higher facet joint effusion, the presence of Vacuum sign, and a greater Disk Height Index were associated with the presence of instability on the standing lateral radiograph in extension and flexion in patients with degenerative LSS., (© 2024. The Author(s).)

Study Design: Retrospective review of a prospectively collected multisurgeon registry., Objective: To evaluate the outcomes of minimally invasive (MI) decompression in patients with severe degenerative scoliosis (DS) and identify factors associated with poorer outcomes., Summary of Background Context: MI decompression has gained widespread acceptance as a treatment option for patients with lumbar canal stenosis and DS. However, there is a lack of research regarding the clinical outcomes and the impact of MI decompression location in patients with severe DS exhibiting a Cobb angle exceeding 20°., Materials and Methods: Patients who underwent MI decompression alone were included and categorized into the DS or control groups based on Cobb angle (>20°). Decompression location was labeled as "scoliosis-related" when the decompression levels were across or between end vertebrae and "outside" when the operative levels did not include the end vertebrae. The outcomes, including the Oswestry Disability Index (ODI), were compared between the propensity score-matched groups for improvement and minimal clinical importance difference (MCID) achievement at ≥1 year postoperatively. Multivariable regression analysis was conducted to identify factors contributing to the nonachievement of MCID in ODI of the DS group at the ≥1-year time point., Results: A total of 253 patients (41 DS) were included in the study. Following matching for age, sex, osteoporosis status, psoas muscle area, and preoperative ODI, the DS groups exhibited a significantly lower rate of MCID achievement in ODI (DS: 45.5% vs. control 69.0%, P =0.047). The "scoliosis-related" decompression (odds ratio: 9.9, P =0.028) was an independent factor of nonachievement of MCID in ODI within the DS group., Conclusions: In patients with a Cobb angle >20°, lumbar decompression surgery, even in the MI approach, may result in limited improvement of disability and physical function. Caution should be exercised when determining a surgical plan, especially when decompression involves the level between or across the end vertebrae., Level of Evidence: 3., Competing Interests: S.A.Q. has the following disclosures: AMOpportunities: Other financial or material support; Annals of Translational Medicine: Editorial or governing board; Association of Bone and Joint Surgeons: Board or committee member; Cervical Spine Research Society: Board or committee member; Contemporary Spine Surgery: Editorial or governing board; Globus Medical: IP royalties; Paid consultant; Paid presenter or speaker; Hospital Special Surgery Journal: Editorial or governing board; HS2, LLC: Stock or stock Options; International Society for the Advancement of Spine Surgery (ISASS) - Program Committee member: Board or committee member; Lifelink.com: Other financial or material support; Lumbar Spine Research Society: Board or committee member; Minimally Invasive Spine Study Group: Board or committee member; North American Spine Society: Board or committee member; Simplify Medical Inc.: Other financial or material support; Society of Minimally Invasive Spine Surgery (SMISS) - Program Committee member: Board or committee member; Spinal Simplicity: Other financial or material support; SpineGuard Inc.: Paid consultant; Stryker: IP royalties; Paid consultant; Surgalign: Paid consultant; Tissue Differentiation Intelligence: Stock or stock Options; Viseon Inc.: Paid consultant; Research support. S.I. has the following disclosures: Globus Medical: Paid presenter or speaker; Stryker: Paid presenter or speaker; Vertebral Columns/International Society for the Advancement of Spine Surgery (ISASS): Editorial or governing board. The remaining authors report no conflicts of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Introduction: Lumbar foraminal stenosis is a key contributor to low back pain. Imaging, particularly MRI, is commonly used in the assessment of foraminal stenosis, contributing to treatment planning. The adoption of a standardised grading system to try and improve inter-rater agreement is thought to be of importance. Our study aims to assess the variability of grading lumbar foraminal stenosis amongst reporting doctors, determine whether education about a validated grading scale increases agreement, and determine if these changes persist over time., Methods: A single-site study involving MRI reporting registrars/radiologists was performed. Participants were shown select MRI images and asked to grade the degree of stenosis in each on a 4-point scale. Subsequently, they were educated about Lee et al's grading system and asked to re-grade the cases 1 and 6 weeks later. The level of agreement was calculated using Gwet's AC1 coefficient and Krippendorff's Alpha., Results: The baseline level of agreement was substantial (AC1 = 0.71). This decreased to a moderate level of agreement post-intervention (AC1 = 0.575 at 1-week, P-value 0.033 and AC1 = 0.598 at 6 weeks, P-value 0.012). A grading of severe stenosis was 21% more likely 6 weeks post-education., Conclusion: The baseline agreement at our institution was substantial, thought to be due to the single-centre nature of the study. Moderate agreement was achieved after education regarding the Lee et al.'s scale, in-line with other studies, with changes maintained at 6 weeks, showing retention of the scale parameters. Grading of severe stenosis was more common post intervention., (© 2024 The Royal Australian and New Zealand College of Radiologists.)

Objective: To evaluate the therapeutic effect of transforaminal selective nerve root sleeve injections (TFSNRIs) in a specific subset of patients with clinical symptoms and presentation consistent with spinal stenosis., Design: Retrospective review., Setting: Tertiary academic spine center., Participants: A total of 176 patients with radicular leg pain with or without low back pain as well as ≥3 clinical features of spinal stenosis and corroborative radiographic features of spinal stenosis on lumbar spine magnetic resonance imaging without confounding spinal pathology (N=176)., Interventions: Fluoroscopically guided transforaminal selective nerve root sleeve injections., Main Outcome Measures: Patient Reported Outcome Measurement Information System (PROMIS) Physical Function (PF) v1.2/v2.0, Pain Interference (PI) v1.1, and PROMIS (D) v1.0 were collected at baseline and post-procedure short term (<3-months) and long-term (6-12 month) follow-up. Statistical analysis comparing baseline and postprocedural PROMIS scores was performed. Differences were compared with previously established minimal clinically important differences in the spine population., Results: For patients with spinal stenosis treated with TFSNRI, no statistically significant improvement was observed short- and long-term follow-up in PROMIS PF (P=.97, .77) and PROMIS Depression (P=.86, .85) scores. At short-term follow-up, PROMIS PI scores did significantly improve (P=.01) but the average difference of pre- and post-procedure scores did not reach clinical significance. No significant difference in PROMIS PI was noted at long-term follow-up (.75)., Conclusions: Although a statistically significant difference was observed for improvement in pain, in this retrospective study, TFSNRI did not provide clinically significant improvement in patients' function, pain, or depression for lumbar spinal stenosis at short- and long-term follow-up., (Copyright © 2024 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)

Purpose: This study aimed to compare and analyze the effectiveness of unilateral biportal endoscopic (UBE) decompressive laminectomy plus fusion and microscope-assisted open decompressive laminectomy plus fusion., Methods: A total of 143 patients with lumbar spinal stenosis were enrolled in this study between March 2020 and February 2021 with a minimum 2 years follow-up visit to our hospital. Sixty-five patients underwent the unilateral biportal endoscopic technique and were assigned to the UBE group, and the remaining 78 patients with microscope assistant were assigned to the Microscope group. The baseline characteristics, clinical outcomes, and radiological data were retrospectively collected and analyzed, as well as Clinical outcomes, radiological data and complications., Results: There were no significant differences between the two groups in terms of baseline characteristics (P > 0.05). The UBE group was demonstrated to be significantly superior in CRP, drainage, blood loss, treatment cost and Hospital stay than the Microscope group (P < 0.05), whereas a significant longer operation time was observed (P < 0.05). The VAS-B, ODI, and JOA-L scores of the UBE group at 1 year follow-up were significantly greater than those of the Microscope group (P < 0.05). Regarding radiological data, there were no significant differences in the section area of the spinal canal and fusion grade between the two groups (P > 0.05)., Conclusion: In view of the satisfactory clinical outcomes of patients and notable decompression at the stenosed segment, UBE is a feasible, minimally invasive technique for single level lumbar canal stenosis., (Copyright © 2024 Asian Surgical Association and Taiwan Society of Coloproctology. Published by Elsevier B.V. All rights reserved.)

Background: The purpose of this study is to determine whether preoperative facet fluid on MRI can help predict segmental instability (SI) after decompression surgery., Methods: We analyzed 34 patients (14 men and 20 women, a total of 37 segments) who underwent decompression for degenerative lumbar spinal stenosis from June 2011 to August 2019 at a single institution. Mean age at the time of operation was 67.8. Postoperative assessment was performed uniformly 12 months (11~15 months) after the surgery. Preoperative facet fluid on MRI, pre- and postoperative slip percentage, and segmental motion on lumbar lateral neutral and flexion-extension (LFE) radiographic images were measured. Visual Analog Scale (VAS) and necessities of interventional procedure or medication was also assessed for clinical outcomes., Results: No significant association was found between preoperative facet fluid indices and pre- or postoperative slip percentage (P=0.134) and segmental motion (P=0.936). There were no significant association also between facet fluid indices and VAS of back or leg (P=0.997 and P=0.437 respectively)., Conclusions: Preoperative facet fluid is not a predictive index of postoperative segmental instability or clinical outcome. Without segmental instability on LFE radiographic images, the presence of facet fluid in MRI is not an absolute indication for fusion.

Introduction: Lumbar foraminal stenosis (LFS) occurs primarily due to degenerative changes in older adults, affecting the spinal foramina and leading to nerve compression. Characterized by pain, numbness, and muscle weakness, LFS arises from structural changes in discs, joints, and ligaments, further complicated by factors like inflammation and spondylolisthesis. Diagnosis combines patient history, physical examination, and imaging, while management ranges from conservative treatment to surgical intervention, underscoring the need for a tailored approach., Materials and Methods: This multicenter study, conducted over six years at a tertiary hospital, analyzed the volumetric dimensions of lumbar foramina and their correlation with nerve structures in 500 patients without lumbar pathology. Utilizing high-resolution MRI with a standardized imaging protocol, eight experienced researchers independently reviewed the images for accurate measurements. The study emphasized quality control through the calibration of measurement tools, double data entry, validation checks, and comprehensive training for researchers. To ensure reliability, interobserver and intraobserver agreements were analyzed, with statistical significance determined by kappa statistics and the Student's t -test. Efforts to minimize bias included blinding observers to patient information and employing broad inclusion criteria to mitigate referral and selection biases. The methodology and findings aim to enhance the understanding of normal lumbar foramina anatomy and its implications for diagnosing and treating lumbar conditions., Results: The study's volumetric analysis of lumbar foramina in 500 patients showed a progressive increase in foraminal volume from the L1/L2 to the L5/S1 levels, with significant enlargement at L5/S1 indicating anatomical and biomechanical complexity in the lumbar spine. Lateral asymmetry suggested further exploration. High interobserver and intraobserver agreement levels (ICC values of 0.91 and 0.95, respectively) demonstrated the reliability and reproducibility of measurements. The patient cohort comprised 58% males and 42% females, highlighting a balanced gender distribution. These findings underscore the importance of understanding foraminal volume variations for lumbar spinal health and pathology., Conclusion: Our study significantly advances spinal research by quantifying lumbar foraminal volumes, revealing a clear increase from the L1/L2 to the L5/S1 levels, indicative of the spine's adaptation to biomechanical stresses. This provides clinicians with a precise tool to differentiate between pathological narrowing and normal variations, enhancing the detection and treatment of lumbar foraminal stenosis. Despite limitations like its cross-sectional design, the strong agreement in measurements underscores the method's reliability, encouraging future research to further explore these findings' clinical implications.

Study Design: Clinical experimental diagnostic study., Objective: The objective of the study was to investigate cervical spine dynamics including changes in the cervical foramina in patients experiencing intermittent arm radiculopathy., Background: Cervical foraminal stenosis is a frequent cause of radicular arm pain. The Spurling test, while specific, lacks the precision to identify symptomatic nerve roots. The relationship among vertebral motion, foraminal changes, and radiculopathy during a Spurling test remains underexplored., Patients and Methods: Ten patients with positive Spurling tests and magnetic resonance imaging (MRI) confirmed 1 or 2-level cervical foraminal stenosis were scanned using the Dynamic MRI Compression System enabling a simulated Spurling test inside the MRI gantry of a 3T MRI scanner with a dedicated neck coil. First, a relaxed image acquisition was undertaken, followed by slowly applying the Spurling test until the patient reported aggravation of radiculopathy or discomfort, where the next image series was taken. Zero echo time MRI was employed to obtain computed tomography (CT)-like images. The images were thereafter analyzed using the Sectra® CT-based Micromotion Analysis software for motion analysis., Results: The C4/C5 level exhibited the most significant movements both in translation and rotation, with less movements observed in C5 to C6 and C6 to C7 levels. No uniform pattern emerged that differentiated suspected stenotic levels from nonsuspected levels. Despite relatively small vertebral movements, 9/10 of patients reported arm pain during provocation, indicating extremely narrow margins of tolerance., Conclusion: This study demonstrates the utility of zero echo time MRI and CT-based Micromotion Analysis in detecting subtle yet clinically relevant vertebral motions influencing the foramina in the cervical spine during the Spurling maneuver. These findings could lead to a better understanding and potentially improved diagnostic strategies for cervical foraminal stenosis, although further research with a larger cohort is necessary to confirm these results., Competing Interests: J.H., H.H., K.L., and H.B. have partial ownership in patent holding company of the DMRICS compressive device. The remaining author reports no conflicts of interest.., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

The prognoses of patients who undergo open spinal endoscopy (OSE) decompression significantly differ by scoliosis type and symptom despite the use of uniform standards and procedures for the decompression surgery. These differences may be directly related to the selection and formulation of surgical strategies but their cause remains unclear. The aim of this study was to verify and evaluate the efficacy of the "Symptom, Stenosis and Segment classification (SSS classification)" in determining an appropriate surgical strategy and to analyze the differences in the outcomes of different patients after receiving the selected surgical strategy. The results of this study ultimately provide a theoretical basis for the specific optimization of surgical strategies guided by the "SSS classification". This work was a retrospective study. We reviewed 55 patients with scoliosis and spinal stenosis who underwent "pear-shaped" decompression under OSE from May 2021 to June 2023 treated by our surgical team. To classify different types of patients, we defined the "SSS classification" system. The permutation and combination of subtypes in Symptom (including three subtypes: Convex = v, Concave = c and Bilateral = b), Stenosis (including three subtypes: Convex = v, Concave = c and Bilateral = b), and Segment (including two subtypes: Edge = e and Inside = i) yields 18 possible types (details in Table 1) in this classification system. To classify different types of surgeries, we also defined the operation system. The VAS Back and VAS Leg scores after surgical treatment were significantly lower in all patients 3 months after surgery than before surgery. (**P < 0.05). The Svve type accounted for the greatest proportion of patients (62.50%) in the VAS back remission group, and the Scce type accounted for the greatest proportion (57.14%) in the VAS back ineffective group. According to the VAS leg score, the percentage of patients in whom Svve was detected in the VAS leg remission group reached 60.87%, and the percentage of patients in whom Svve was detected in the VAS leg ineffective group reached 44.44%. Svve accounted for the greatest proportion of cases (61.22%) in the JOA-effective group, and Scce accounted for the greatest proportion of cases (50.00%) in the JOA-ineffective group. In the JOA-effective group, the Ovv type accounted for the greatest proportion (up to 79.59%), while in the JOA-ineffective group, Occ and Ovv accounted for 50.00% of the cases each. The proportions of Svve type were the highest in the healthy group (up to 60.00%) and the ODI-effective group (up to 50.00%). The Ovv type accounted for the greatest proportion of patients in the ODI-effective group (up to 80.00%), and the Occ type accounted for the greatest proportion of patients in the ODI-ineffective group (up to 60.00%). Most of the surgical plans formulated by the "SSS classification" method were considered appropriate, and only when the symptoms of patients were located on the concave side did the endoscopic decompression plan used in the present study have a limited ability to alleviate symptoms., (© 2024. The Author(s).)

Objective: To determine the occurrence of degenerative changes affecting the vertebral column in cats, assess their clinical significance, and determine the occurrence in cats with intervertebral disk herniation compared to other spinal diseases., Animals: 114 client-owned cats., Methods: Hospital records were retrospectively reviewed for cats with suspected myelopathy that had undergone spinal MRI. Signalment; history; neurological examination; neurolocalization; primary diagnosis; presence, type, and location of intervertebral disk herniation; and presence and location of other degenerative spinal changes (intervertebral disk degeneration [IVDD], spondylosis deformans [SD], end plate changes, dorsal compressions [DC], and foraminal stenosis [FS]) were recorded., Results: 70% of cats showed at least 1 spinal degenerative change. The most common change was IVDD, followed by SD and intervertebral disk protrusion (IVDP), while intervertebral disk extrusion (IVDE), end plate changes, DC, and FS were uncommon to rare. Primary complaint was attributed to a degenerative condition in 22% of cats, including 100% with IVDE, 9% with IVDP, and 43% with degenerative lumbosacral stenosis (DLSS). The occurrence of degenerative spinal changes and number of intervertebral disks affected by IVDD significantly increased with age and body weight. Age was positively correlated with the occurrence of SD and DLSS. Intervertebral disk degeneration, IVDP, SD, DC, and FS were more prevalent in the lumbosacral junction. Cats with IVDD were significantly more likely to show IVDE and IVDP., Clinical Relevance: This study revealed that in a population of cats presenting for signs of myelopathy, IVDE was always responsible for the clinical presentation, DLSS was commonly considered incidental, and IVDP was infrequently related to neurological signs.

Design: Prospective diagnostic study., Objectives: Anatomical evaluation and graduation of the severity of spinal stenosis is essential in degenerative cervical spine disease. In clinical practice, this is subjectively categorized on cervical MRI lacking an objective and reliable classification. We implemented a fully-automated quantification of spinal canal compromise through 3D T2-weighted MRI segmentation., Setting: Medical Center - University of Freiburg, Germany., Methods: Evaluation of 202 participants receiving 3D T2-weighted MRI of the cervical spine. Segments C2/3 to C6/7 were analyzed for spinal cord and cerebrospinal fluid space volume through a fully-automated segmentation based on a trained deep convolutional neural network. Spinal canal narrowing was characterized by relative values, across sever segments as adapted Maximal Canal Compromise (aMCC), and within the index segment as adapted Spinal Cord Occupation Ratio (aSCOR). Additionally, all segments were subjectively categorized by three observers as "no", "relative" or "absolute" stenosis. Computed scores were applied on the subjective categorization., Results: 798 (79.0%) segments were subjectively categorized as "no" stenosis, 85 (8.4%) as "relative" stenosis, and 127 (12.6%) as "absolute" stenosis. The calculated scores revealed significant differences between each category (p ≤ 0.001). Youden's Index analysis of ROC curves revealed optimal cut-offs to distinguish between "no" and "relative" stenosis for aMCC = 1.18 and aSCOR = 36.9%, and between "relative" and "absolute" stenosis for aMCC = 1.54 and aSCOR = 49.3%., Conclusion: The presented fully-automated segmentation algorithm provides high diagnostic accuracy and objective classification of cervical spinal stenosis. The calculated cut-offs can be used for convenient radiological quantification of the severity of spinal canal compromise in clinical routine., (© 2024. The Author(s).)

Purpose: This study was conducted to develop a convolutional neural network (CNN) algorithm that can diagnose cervical foraminal stenosis using oblique radiographs and evaluate its accuracy., Materials and Methods: A total of 997 patients who underwent cervical MRI and cervical oblique radiographs within a 3-month interval were included. Oblique radiographs were labeled as "foraminal stenosis" or "no foraminal stenosis" according to whether foraminal stenosis was present in the C2-T1 levels based on MRI evaluation as ground truth. The CNN model involved data augmentation, image preprocessing, and transfer learning using DenseNet161. Visualization of the location of the CNN model was performed using gradient-weight class activation mapping (Grad-CAM)., Results: The area under the curve (AUC) of the receiver operating characteristic curve based on DenseNet161 was 0.889 (95% confidence interval, 0.851-0.927). The F1 score, accuracy, precision, and recall were 88.5%, 84.6%, 88.1%, and 88.5%, respectively. The accuracy of the proposed CNN model was significantly higher than that of two orthopedic surgeons (64.0%, p <0.001; 58.0%, p <0.001). Grad-CAM analysis demonstrated that the CNN model most frequently focused on the foramen location for the determination of foraminal stenosis, although disc space was also frequently taken into consideration., Conclusion: A CNN algorithm that can detect neural foraminal stenosis in cervical oblique radiographs was developed. The AUC, F1 score, and accuracy were 0.889, 88.5%, and 84.6%, respectively. With the current CNN model, cervical oblique radiography could be a more effective screening tool for neural foraminal stenosis., Competing Interests: The authors have no potential conflicts of interest to disclose., (© Copyright: Yonsei University College of Medicine 2024.)

Objectives: No standardized magnetic resonance imaging (MRI) parameters have defined the 3-dimensional morphoanatomy and relevant spinal cord occupation ratios (occupation of spinal cord dimensions/similar dimensions within the spinal canal) in congenital cervical stenosis (CCS)., Methods: A retrospective, comparative analysis was conducted on 200 patients >18 years of age with myelopathy and CCS (mean age, 52.4 years) and 200 age-matched controls with no myelopathy or radiculopathy. The variables assessed from high resolution MRI included sagittal and axial spinal canal dimensions (MRI Torg-Pavlov ratios) from C3 to C7. Morphometric dimensions from the sagittal retrodiscal and retrovertebral regions as well as axial MRI dimensions were compared. Sagittal and axial spinal cord occupation ratios were defined and correlated with spinal canal dimensions., Results: Multivariate analyses indicated reduced sagittal and axial anteroposterior (AP) spinal canal dimensions and a large reduction in transverse spinal canal dimensions at all spinal levels. There was a small significant correlation between AP sagittal spinal canal dimensions and axial transverse spinal canal dimensions at C3-C5, but not at C5-C6. Small correlations were noted between AP sagittal spinal canal dimensions and AP axial spinal cord and axial cross-sectional area occupation ratios at C3-C6, but there was no correlation with axial mediolateral spinal cord occupation ratios., Conclusions: The stenosis effect can involve any dimension, including the transverse spinal canal dimension, independent of other dimensions. Owing to the varied observed morphoanatomies, a classification algorithm that defines CCS specific phenotypes was formulated. Objectivizing the stenosis morphoanatomy may allow for data-driven patient-focused decompression approaches in the future., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Purposes: To propose a new lumbar degenerative staging system using the current radiological classification system., Methods: A cross-sectional analysis of retrospective databases between January 2018 and December 2022 was performed. Total of 410 patients for Modic changes, paravertebral muscle fat infiltration, disc degeneration, articular process degeneration, vertebral endplate degeneration and other structures, and disc displacement, Spondylolisthesis, and stenosis, and grouped patients according to stage were assessed. Visual analog scale, Japanese Orthopaedic Association, and Oswestry Disability Index scores were used to assess low back pain strength, neurological function, and quality of life, respectively., Results: The lumbar degeneration staging system consists of 8 variables, which can be divided into 3 steps: early, middle and late, and the correlation between each variable is strong (P < 0.05). The later the staging, the worse the Japanese Orthopaedic Association, visual analog scale, and Oswestry Disability Index scores., Conclusions: Patients with later stages have worse clinical scores. This staging system recommends a uniform classification to assess lumbar degeneration., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Objectives: Alkaptonuria is a rare inborn disorder of phenylalanine and tyrosine metabolism. It is characterized by an accumulation of homogentisic acid and its oxidation products, possibly resulting into connective tissue damaging. "Ochronosis" is a main feature, which is characterized by tissue discoloration and even alkaptonuric arthropathy. Cervical spine involvement is exceptional and there is a paucity of reports on surgical interventions in these patients. We explored the literature concerning cervical spine involvement in patients with alkaptonuria., Patients and Methods: We performed a review of the literature, in which patients with alkaptonuric degenerative changes of the cervical spine were examined. Articles were obtained from MEDLINE. Search terms included: "cervical", "alkaptonuria", "alkaptonuric changes" and "black disc". Additional studies were identified by checking reference lists. Furthermore, we present the case of a 46 year old patient with critical cervical spinal canal stenosis who underwent C6-C7 anterior cervical microdiscectomy and interbody fusion, in order to prevent myelopathic changes. CARE statement guidelines were followed., Results: Peroperatively, we did not encounter any macroscopic abnormalities of the skin, muscles or ligaments. A black discoloration of the nucleus pulposus was observed. Peroperative and postoperative course was uneventful., Conclusion: Alkaptonuric degenerative abnormalities most commonly involve the lumbar spine, although the cervical spine can be affected in rare cases. Most frequently, the diagnosis of alkaptonuria can be made based on the clinical phenotype many years before symptoms secondary to ochronotic arthropathy develop. A retrospective diagnosis based on peroperative black discoloration of spinal structures has been described. A black discoloration of the intervertebral disc should encourage the neurosurgeon to further explore the possibility of alkaptonuria, even in the absence of a clear phenotype. Surgical results are mostly satisfactory. Further studies are required in order to better understand this pathology and its postoperative course., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: The diagnosis of lumbar spinal stenosis (LSS) can be challenging because radicular pain is not often present in the culprit-level localization. Accurate segmentation and quantitative analysis of the lumbar dura on radiographic images are key to the accurate differential diagnosis of LSS. The aim of this study is to develop an automatic dura-contouring tool for radiographic quantification on computed tomography myelogram (CTM) for patients with LSS., Methods: A total of 518 CTM cases with or without lumbar stenosis were included in this study. A deep learning (DL) segmentation algorithm 3-dimensional (3D) U-Net was deployed. A total of 210 labeled cases were used to develop the dura-contouring tool, with the ratio of the training, independent testing, and external validation datasets being 150:30:30. The Dice score (DCS) was the primary measure to evaluate the segmentation performance of the 3D U-Net, which was subsequently developed as the dura-contouring tool to segment another unlabeled 308 CTM cases with LSS. Automatic masks of 446 slices on the stenotic levels were then meticulously reviewed and revised by human experts, and the cross-sectional area (CSA) of the dura was compared., Results: The mean DCS of the 3D U-Net were 0.905 ± 0.080, 0.933 ± 0.018, and 0.928 ± 0.034 in the five-fold cross-validation, the independent testing, and the external validation datasets, respectively. The segmentation performance of the dura-contouring tool was also comparable to that of the second observer (the human expert). With the dura-contouring tool, only 59.0% (263/446) of the automatic masks of the stenotic slices needed to be revised. In the revised cases, there were no significant differences in the dura CSA between automatic masks and corresponding revised masks (p = 0.652). Additionally, a strong correlation of dura CSA was found between the automatic masks and corresponding revised masks (r = 0.805)., Conclusions: A dura-contouring tool was developed that could automatically segment the dural sac on CTM, and it demonstrated high accuracy and generalization ability. Additionally, the dura-contouring tool has the potential to be applied in patients with LSS because it facilitates the quantification of the dural CSA on stenotic slices., (© 2024 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, LLC on behalf of The American Association of Physicists in Medicine.)

Objective: To quantify the distribution of cauda equina nerve roots in supine and upright positions using manual measurements and radiomics features both in normal subjects and in lumbar spinal canal stenosis (LSCS) patients., Methods: We retrospectively recruited patients who underwent weight-bearing MRI in supine and upright positions for back pain. 3D T2-weighted isotropic acquisition (3D-HYCE) sequences were used to develop a 3D convolutional neural network for identification and segmentation of lumbar vertebrae. Para-axial reformatted images perpendicular to the spinal canal and parallel to each vertebral endplate were automatically extracted. From each level, we computed the maximum antero-posterior (AP) and latero-lateral (LL) dispersion of nerve roots; further, radiomics features were extracted to quantify standardized metrics of nerve root distribution., Results: We included 16 patients with LSCS and 20 normal subjects. In normal subjects, nerve root AP dispersion significantly increased from supine to upright position (p < 0.001, L2-L5 levels), and radiomics features showed an increase in non-uniformity. In LSCS subjects, in the upright position AP dispersion of nerve roots and entropy-related features increased caudally to the stenosis level (p < 0.001) and decreased cranially (p < 0.001). Moreover, entropy-related radiomics features negatively correlated with pre-operative Pain Numerical Rating Scale. Comparison between normal subjects and LSCS patients showed a difference in AP dispersion and increase of variance cranially to the stenosis level (p < 0.001) in the upright position., Conclusions: Nerve root distribution inside the dural sac changed between supine and upright positions, and radiomics features were able to quantify the differences between normal and LSCS subjects., Clinical Relevance Statement: The distribution of cauda equina nerve roots and the redundant nerve root sign significantly varies between supine and upright positions in normal subjects and spinal canal stenosis patients, respectively. Radiomics features quantify nerve root dispersion and correlates with pain severity., Key Points: • Weight-bearing MRI depicts spatial distribution of the cauda equina in both supine and upright positions in normal subjects and spinal stenosis patients. • Radiomics features can quantify the effects of spinal stenosis on the dispersion of the cauda equina in the dural sac. • In the orthostatic position, dispersion of nerve roots is different in lumbar spinal stenosis patients compared to that in normal subjects; entropy-related features negatively correlated with pre-operative Pain Numerical Rating Scale., (© 2023. The Author(s), under exclusive licence to European Society of Radiology.)

Purpose: This study aims to observe the safety and effectiveness of 10-mm endoscopic minimally invasive interlaminar decompression in the treatment of ossified lumbar spinal stenosis., Methods: The clinical data of 50 consecutive patients with ossified lumbar spinal stenosis were retrospectively analyzed. All patients underwent minimally invasive interlaminar decompression with 10-mm endoscope. Patient demographics, perioperative data, and clinical outcomes were recorded. Visual analog scale scores, Oswestry disability index scores, and modified Macnab criteria were used to assess clinical outcomes. The lateral recess angle, real spinal canal area, and effective intervertebral foramen area were used to assess the effect of decompression., Results: The mean age of all patients was 59.0 ± 12.3 years. The mean operative time and intraoperative blood loss were 43.7 ± 8.7 minutes and <20 ml, respectively. Two years after surgery, the leg pain Visual analog scale score decreased from 7.4 ± 1.0 to 1.6 ± 0.6 (P < 0.05) and the Oswestry disability index score decreased from 63.8 ± 7.6 to 21.7 ± 3.4 (P < 0.05). The lateral recess angle, real spinal canal area and effective intervertebral foramen area were significantly larger than before surgery (P < 0.05). The overall excellent and good rate at the last follow-up was 92.0% according to the modified Macnab criteria., Conclusions: The 10-mm endoscopic minimally invasive interlaminar decompression can safely and effectively remove the ossification in the spinal canal and achieve adequate decompression in patients with ossified lumbar spinal stenosis., (Copyright © 2024 Elsevier Inc. All rights reserved.)

An observational study to discover the common conditions affecting the lumbosacral region that may affect lumbosacral position and tension. All the patients, underwent MRI exaamination (magnetic resonance imaging) in the supine position, were examined by the same consultant radiologist. The article was revised by the institutional ethical approval committee. The position of the nerve roots was observed, and the number of nerve roots was calculated anterior to a line passing between the mid-transvers process of L3(third lumbar vertebra). The number of nerve roots ahead of this line was calculated by the radiologist at the level of the right intervertebral foramen and at the left one. This procedure was applied to the normal group, and 5 common pathological diseases were repeated including single-level lumbar disc prolapse, multiple-disc prolapse, multiple bulge, spinal stenosis and spondylolisthesis (at the level of L45 (fourth to fifth lumbar vertebrae) or L5S1 (fifth lumbar to first sacral vertebrae) being outside the study area, i.e., L3). We noticed significant difference in the number of the nerve roots between the cases with herniated discs, spinal stenosis, and spondylolisthesis with the normal group and the significance was in ascending increment in significance being the highest in cases with spondylolisthesis, and even in the groups of other pathologies which are statistically not significant, we noticed that the significance is proportional to the severity of the disease being the least in single level cases (p 0.427), to be more significant on cases with multiple prolapses(p 0.319) to be more in cases with multiple bulges to start to be statistically significant in herniated, higher significance in cases with spinal stenosis to be the highest in cases with spondylolisthesis., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Study Design: Retrospective, observational study., Objective: To determine the relationship between the Goutallier classification system (GS) and anthropometric, clinical, and radiologic features in 168 patients with lumbar spinal stenosis (LSS)., Background: There is no agreement on a classification system that is both reliable and easy to use for describing the severity of fatty degeneration in the paravertebral muscles of the lower back in patients with symptomatic LSS. This study aimed to determine the statistical relationship between the GS and anthropometric, clinical, and radiologic factors in 168 patients with LSS., Materials and Methods: This study was conducted on 168 patients with LSS scheduled for elective decompressive surgery. A control group of 110 healthy individuals was enrolled. The study assessed paralumbar musculature fatty infiltration using GS on preoperative magnetic resonance imaging. The authors evaluated the statistical association between patient age, body mass index (BMI), preoperative Oswestry disability index (ODI) questionnaire, and cross-sectional areas (CSAs) of the dural sac and lumbar paraspinal muscles. Multivariate analysis was performed to adjust for confounding., Results: This study enrolled 168 patients with symptomatic LSS (95 men, 73 women); mean±SD age: 67.81±9.38 (range: 32.78-92.34) years; BMI: 28.29±3.36 (19.95-38.10) kg/m 2 . The control group was comprised of 110 healthy patients (61 men and 49 women). Age, sex, BMI, and erector spinae (ES)-CSA were not significantly different between the two groups. The authors found a direct relationship between GS grade and age and an inverse relationship between GS grade and dural sac-, multifidus lumbaris (LM)-, ES-, and psoas muscle (PM)-CSAs. Univariate analyses showed the variables statistically related to a higher GS grade included patient age ( P <0.001), ODI ( P =0.136), dural sac-CSA ( P =0.011), LM-CSA ( P < 0.001), ES-CSA ( P <0.001), and PM-CSA ( P <0.001). Multivariate least squares analysis showed the GS grade to be influenced by patient age ( P =0.01), LM-CSA ( P =0.002), ES-CSA ( P =0.002), and PM-CSA ( P =0.003)., Conclusions: GS shows great potential as a tool for evaluating fat infiltration in the paralumbar muscles. This measure does not correlate with the ODI and BMI but is related to all radiologic parameters and patient age. Further prospective studies are required to establish a link between preoperative and postoperative outcomes in the setting of paraspinal fat infiltration., Competing Interests: The authors report no conflicts of interest.​, (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)