L5 Vertebral Body Research Articles

Optimal cutoff point of vertebral body cross-sectional area as a morphological parameter for predicting lumbar spondylolysis.

The relationship between vertebral body cross-sectional area (VBCSA) and spinal conditions associated with increased lumbar lordosis, such as lumbar spondylolysis (LSL), is not known. We investigated the morphological parameter, VBCSA, to predict LSL. The VBCSA on MRI has not been studied for its association with LSL. We hypothesized that VBCSA is an important morphological parameter for LSL prediction. We collected VBCSA data from 90 patients (43 males and 47 females) with LSL and 91 control subjects (44 males and 47 females) who underwent lumbar spine magnetic resonance imaging (LS-MRI). Axial T2-weighted LS-MRI images were obtained from all participants. Using our picture archiving and communications system, we analyzed the VBCSA at the level of the L5 vertebral body by utilizing MRI. The average VBCSA was 2263.51 ± 306.02 mm2 in the male control group and 1820.92 ± 224.89 mm2 in the male LSL group. LSL patients had significantly lower VBCSAs (P < .001) than did the male controls. The average VBCSA was 1985.21 ± 258.05 mm2 in the female control group and 1553.73 ± 250.02 mm2 in the female LSL group, and the LSL patients also had significantly lower VBCSAs (P < .001) than did the female controls. The optimal VBCSA cutoff value in the male group was 2014.69 mm2 with 76.7% sensitivity, 75.0% specificity, and an area under the receiver operating curve (AUC) of 0.89 (95% CI: 0.82-0.95). In the female group, the optimal cutoff score was 1814.11 mm2 with 76.6% sensitivity, 76.6% specificity, and an AUC of 0.88 (95% CI: 0.82-0.95). VBCSA is a sensitive objective morphological parameter for assessing LSL, and a lower VBCSA is associated with a higher possibility of LSL. We believe that these results will be useful in diagnostic radiology for evaluating patients with LSL.

Phlpp1 Expression in Osteoblasts Plays a Modest Role in Bone Homeostasis.

Prior work demonstrated that Phlpp1 deficiency alters limb length and bone mass, but the cell types involved and requirement of Phlpp1 for this effect were unclear. To understand the function of Phlpp1 within bone-forming osteoblasts, we crossed Phlpp1 floxed mice with mice harboring type 1 collagen (Col1a12.3kb)-Cre. Mineralization of bone marrow stromal cell cultures derived from Phlpp1 cKOCol1a1 was unchanged, but levels of inflammatory genes (eg, Ifng, Il6, Ccl8) and receptor activator of NF-κB ligand/osteoprotegerin (RANKL/OPG) ratios were enhanced by either Phlpp1 ablation or chemical inhibition. Micro-computed tomography of the distal femur and L5 vertebral body of 12-week-old mice revealed no alteration in bone volume per total volume, but compromised femoral bone microarchitecture within Phlpp1 cKOCol1a1 conditional knockout females. Bone histomorphometry of the proximal tibia documented no changes in osteoblast or osteoclast number per bone surface but slight reductions in osteoclast surface per bone surface. Overall, our data show that deletion of Phlpp1 in type 1 collagen-expressing cells does not significantly alter attainment of peak bone mass of either males or females, but may enhance inflammatory gene expression and the ratio of RANKL/OPG. Future studies examining the role of Phlpp1 within models of advanced age, inflammation, or osteocytes, as well as functional redundancy with the related Phlpp2 isoform are warranted. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Finite element study of sagittal fracture location on thoracolumbar fracture treatment.

Background: Posterior internal fixation is the main method used for the treatment of thoracolumbar fractures. Fractures often occur in the upper 1/3 of the vertebral body. However, they can also occur in the middle or lower 1/3 of the vertebral body. At present, there is no report discussing the potential effects of sagittal location on instrument biomechanics or surgical strategy. The object of this study was to investigate the effect of the sagittal location of the fracture region of the vertebral body on the biomechanics of the internal fixation system and surgical strategy. Methods: A finite element model of the T11-L3 thoracolumbar segment was established based on a healthy person's CT scan. Different sagittal fracture location finite element models were created by resection of the upper 1/3, middle 1/3, and lower 1/3 of the L1 vertebral body. Three surgical strategies were utilized in this study, namely, proximal 1 level and distal 1 level (P1-D1), proximal 2 level and distal 1 level (P2-D1), and proximal 1 level and distal 2 levels (P1-D2). Nine fixation finite element models were created by combining fracture location and fixation strategies. Range of motion, von Mises stress, and stress distribution were analyzed to evaluate the effects on the instrument biomechanics and the selection of surgical strategy. Results: In all three different fixation strategies, the maximum von Mises stress location on the screw did not change with the sagittal location of the fracture site; nevertheless, the maximum von Mises stress differed. The maximum rod stress was located at the fracture site, with its value and location changed slightly. In the same fixation strategy, a limited effect of sagittal location on the range of motion was observed. P2D1 resulted in a shorter range of motion and lower screw stress for all sagittal locations of the fracture compared with the other strategies; however, rod stress was similar between strategies. Conclusion: The sagittal location of a fracture may affect the intensity and distribution of stress on the fixation system but does not influence the selection of surgical strategy.

Radiation-induced changes in load-sharing and structure-function behavior in murine lumbar vertebrae

In this study, we used micro-CT-based finite element analysis to investigate the biomechanical effects of radiation on the microstructure and mechanical function of murine lumbar vertebrae. Specifically, we evaluated vertebral microstructure, whole-bone stiffness, and cortical-trabecular load sharing in the L5 vertebral body of mice exposed to ionizing radiation 11 days post exposure (5 Gy total dose; n = 13) and controls (n = 14). Our findings revealed the irradiated group exhibited reduced trabecular bone volume and microstructure (p < 0.001) compared to controls, while cortical bone volume remained unchanged (p = 0.91). Axially compressive loads in the irradiated group were diverted from the trabecular centrum and into the vertebral cortex, as evidenced by a higher cortical load-fraction (p = 0.02) and a higher proportion of cortical tissue at risk of initial failure (p < 0.01). Whole-bone stiffness was lower in the irradiated group compared to the controls, though the difference was small and non-significant (2045 ± 142 vs. 2185 ± 225 vs. N/mm, irradiated vs. control, p = 0.07). Additionally, the structure-function relationship between trabecular bone volume and trabecular load fraction differed between groups (p = 0.03), indicating a less biomechanically efficient trabecular network in the irradiated group. We conclude that radiation can decrease trabecular bone volume and result in a less biomechanically efficient trabecular structure, leading to increased reliance on the vertebral cortex to resist axially compressive loads. These findings offer biomechanical insight into the effects of radiation on structure-function behavior in murine lumbar vertebrae independent of possible tissue-level material effects.

Finite Element Analysis of Cortical Bone Trajectory Screw Resistance to Pullout During Exposure to Different Cortical Layers Based on AbaqusCEA Software.

To investigate the maximum anti-pullout force and stress distribution of cortical bone trajectory (CBT) screws during screw pullout after contacting different cortical bone layers by finite element analysis (FEA) based on Abaqus software, and to provide evidence for increasing screw holding force during CBT screw implantation in clinical practice. Based on the plain CT data of lumbar spine of a healthy male volunteer who visited the Fourth People's Hospital of Guiyang in June 2022, and the standard screw parameters according to cortical bone trajectory screws. A three-dimensional model of L4 vertebral body and CBT screw was established. The diagnostic criteria of osteoporosis by quantitative CT of lumbar spine in China were set as 120mg/cm3 low bone mass model. According to the number of contact layers between screws and cortical bone, the models were divided into group A: CBT screws produced one layer of cortical bone contact with the vertebral body (screw implantation point); group B: CBT pedicle screws produced two layers of cortical bone contact with the vertebral body (screw implantation point + pedicle inner edge); group C: CBT pedicle screws produced three layers of cortical bone contact with the vertebral body (screw implantation point + pedicle inner edge + outer edge of the vertebral body); group D: CBT pedicle screws produced four layers of cortical bone contact with the vertebral body (screw implantation point + pedicle upper wall + pedicle lateral wall + upper edge of the vertebral body); group E: CBT pedicle screws produced five layers of cortical bone contact with the vertebral body (screw implantation point + pedicle posteromedial medial wall + anterolateral wall of the pedicle + upper edge of the vertebral body + outer edge of the vertebral body). According to the reference, after the material assignment was completed, the axial pullout force experiment of screws was simulated on Abaqus CEA engineering software for five groups of finite element models established to observe the maximum axial pullout force of each group of models and the stress distribution of screws and vertebral bodies. For the comparative analysis between each group of models corresponding to the measured data, one-way analysis of variance was used. The stress of cancellous bone failure in finite element model of group E was (8.6 ± 0.9), (8.4 ± 0.9), (8.1 ± 0.9), (8.3 ± 0.8), and (8.8 ± 0.7) MPa, respectively, and there was no significant difference between any group (P > 0.05); the maximum principal stress in the tail of screw was (195.1 ± 35.8), (290.9 ± 32.1), (317.3 ± 44.5), (396.3 ± 51.2), and (526.5 ± 53.1) MPa, respectively, and the stress in cortical bone destruction was (40.6 ± 3.5), (52.6 ± 4.2), (89.4 ± 4.9), (109.0 ± 8.3), and (129.4 ± 6.4) MPa, respectively, and there was significant difference between any group (P < 0.05); the maximum axial pullout force in group A-E was (1890.5 ± 45.0), (1913.4 ± 53.8), (2371.0 ± 108.3), (237.2 ± 43.0), and (119.5 ± 43.0), respectively. The increases were 2%, 16%, 5%, and 7%. There were significant differences between each group and group E (P < 0.05). Axial pullout force increases as the number of contact layers between CBT screws and cortical bone increases. The axial pullout force increases most when the cortical trajectory screw contacts the vertebral body with three layers of cortical bone, and reaches the maximum value when the number of contact layers reaches five layers, regardless of the screw tail stress and the maximum axial pullout force, so it is clinically desirable to make the screw contact more than three layers of cortical bone to obtain higher stability during screw implantation, improve screw stability, and increase the surgical fusion rate.

Telerehabilitation of spinal cord injury in limited resources setting during COVID-19 pandemic: A case report

Link of Video Abstract: https://youtu.be/f6IaLnu3sz8 Introduction: Spinal cord injury (SCI) rehabilitation is a resource-intensive and time-consuming process and this is problem in particular for patients from a rural, remote areas, or low socioeconomic backgrounds. This problem is further exacerbated by social restriction policies in place due to coronavirus disease 2019 (COVID-19). This case report aimed to describe how telerehabilitation could overcome these challenges Case presentation: A 20-year-old female involved in a motor vehicle accident. Preoperative magnetic resonance imaging (MRI) indicated a complete burst fracture of the L1 vertebral body. The patient experiences paraplegia and loss of autonomic control. Long spine fusion was performed. After being discharged, the patient could only visit the hospital once one-month post-surgery due to personal financial reasons and COVID-19-related social distancing policy. Telerehabilitation was used for the remaining follow-ups and rehabilitation programs were monitored through instant messaging platform between the patient, the operating surgeon, and the rehabilitation specialist. Telerehabilitation using instant messaging was an affordable and practical platform of communication for patient self-reporting and monitoring of progress. With intensive telerehabilitation program, the patient’s functional abilities recovered from Frankel B to D after 6 months of following the domiciliary telerehabilitation plan. Conclusion: We report a case of satisfactory functional outcome of SCI rehabilitation following the use of instant messaging to assist the rehabilitation. This highlights that instant messaging may be utilized to guide the rehabilitation process with the consideration of other factors such as the patient's engagement and the healthcare provider’s commitment. We recommend for further refinements in the adoption and use of telerehabilitation for orthopaedic and traumatology cases that need long-term rehabilitation.

Localizing tip of conus medullaris in hospital visiting adults using MRI

Introduction: Generally, the spinal cord ends at the level between the first and second lumbar vertebrae. There are many studies published globally, yet no article has been published concerning this title in our settings. The objective of this study was to determine the tip level of conus medullaris by the Magnetic Resonance Imaging (MRI) in living humans in Nepalese population. Methods: Images of the MRI done between August 2019 to June 2021 were accessed through the database of the radiology department for defining the level of conus medullaris. The termination level of conus medullaris was rescored in relation to the upper, mid, and lower third of the adjacent vertebrae and the intervertebral disc. Input data was processed in Microsoft Excel which was later analyzed by SPSS 20.0. Results: Of the total, 202 study population, a higher number of spinal cords terminated at lower one-third of L1 vertebrae, accounting for 51 (females 26 and males 25) followed by L1-L2 intervertebral disc comprising only 35 (males 19; females 16). No significant differences in number existed between the two sexes having conus medullaris termination at both levels. Most of the cases who were in the age group of 40-49 years old, termination of CM was noted in L1 with the most common shape being the central type C, accounting for 38% (78/202). Conclusions: The conus medullaris was terminated mostly at lower one third of L1 vertebral body in our settings with no gender difference.

T2*-corrected Q-Dixon and reduced-FOV diffusion kurtosis imaging (DKI) parameters: correlation with QCT-derived bone mineral density (BMD) and ability to identify abnormal BMD and osteoporosis in postmenopausal women.

Bone marrow fat increases when the bone volume decreases. The composition of the bone marrow microenvironment can also become altered. Assessments of bone marrow fat and bone marrow structural heterogeneity have the potential to predict abnormal bone mineral density (BMD) and osteoporosis. This study aimed to investigate the diagnostic performance of T2*-corrected Q-Dixon and reduced-field-of-view (FOV) diffusion kurtosis imaging (DKI) parameters in determining abnormal BMD and osteoporosis in postmenopausal women. In this prospective study, the individuals who were eligible for inclusion included postmenopausal women (over 50-year-old) with suspected osteoporosis based on experiencing low back pain. This mono-center study was conducted in tertiary care in China. All of the patients were recruited by using the consecutive sampling method. Subjects who underwent T2*-corrected Q-Dixon and reduced-FOV DKI sequences were enrolled. Fat fraction (FF), T2*, mean kurtosis (MK), and mean diffusivity (MD) values were measured on L1, L2, and L3 vertebral bodies. Quantitative computed tomography (QCT) examinations served as the reference standard. All of the subjects were divided into three groups: normal (BMD >120 mg/cm3), osteopenia (BMD 80-120 mg/cm3), and osteoporosis (BMD <80 mg/cm3). One-way analysis of variance, correlation coefficient analysis, and receiver operating characteristic curve analysis were performed. Among all of the enrolled subjects, 52 were in the normal group, 51 were in the osteopenia group, and 52 were in the osteoporosis group. There were significant differences in FF, T2*, MK, and MD values between the three groups (P<0.001, P<0.001, P<0.001, and P=0.003, respectively). FF, T2*, and MK values exhibited significant negative correlations with BMD values (r=-0.739, P<0.001; r=-0,676, P<0.001; and r=-0.626, P<0.001, respectively). Excellent discriminatory capacity was observed in the Q-Dixon [area under the curve (AUC): 0.976, 95% confidence interval (CI): 0.955-0.997] differentiation between normal and abnormal BMD subjects. It was significantly better than the DKI (AUC: 0.812, 95% CI: 0.741-0.882) parameter combination (P<0.001), whereas the DKI model (AUC: 0.825, 95% CI: 0.739-0.910) performed comparably to the Q-Dixon model (AUC: 0.798, 95% CI: 0.710-0.886) for screening osteoporosis (P=0.57). FF and T2* values measured by using T2*-corrected Q-Dixon, as well as MK and MD values measured by using reduced-FOV DKI, may serve as potential imaging biomarkers in assessing abnormal BMD and osteoporosis in postmenopausal women.

Computer navigation-guided transpedicular excision of L4 vertebral body osteoblastoma

Abstract Osteoblastoma is a benign bone tumor that accounts for 10% of all spinal tumors and mostly arises from the posterior spinal elements. Isolated vertebral body osteoblastoma is relatively rare and generally requires extensive surgery. We report a rare case of L4 vertebral body osteoblastoma, which was managed successfully by computer navigation-guided transpedicular excision. A 22-year-old female presented with progressive lower back pain for the past six months. Radiological investigation revealed a sclerotic lesion involving the anterior cortex with a prominent central nidus in the anterior part of the L4 vertebral body. Based on the lesion size, a diagnosis of benign osteoblastoma (Enneking stage 2) was made, and she underwent computer navigation-assisted intralesional excision of the lesion by the bilateral transpedicular route. Histopathological examination confirmed the diagnosis of osteoblastoma. In the immediate postoperative period, the patient was completely relieved of symptoms, and the final follow-up magnetic resonance imaging showed no evidence of recurrence at the end of seven years. The intraoperative 3D navigation technology allowed a transpedicular minimal access approach to excise an osteoblastoma of the L4 vertebral body while preserving intervertebral stability and decreasing morbidity.

Prediction of the 3D shape of the L1 vertebral body from adjacent vertebrae.

The aim of treatments of vertebral fractures is the anatomical reduction to restore the physiological biomechanics of the spine and the stabilization of the fracture to allow bone healing. However, the three-dimensional shape of the fractured vertebral body before the fracture is unknown in the clinical setting. Information about the pre-fracture vertebral body shape could help surgeons to select the optimal treatment. The goal of this study was to develop and validate a method based on Singular Value Decomposition (SVD) to predict the shape of the vertebral body of L1 from the shapes of T12 and L2. The geometry of the vertebral bodies of T12, L1 and L2 vertebrae of 40 patients were extracted from CT scans available from the VerSe2020 open-access dataset. Surface triangular meshes of each vertebra were morphed onto a template mesh. The set of vectors with the node coordinates of the morphed T12, L1 and L2 were compressed with SVD and used to build a system of linear equations. This system was used to solve a minimization problem and to reconstruct the shape of L1. A leave-one-out cross-validation was performed. Moreover, the approach was tested against an independent dataset with large osteophytes. The results of the study show a good prediction of the shape of the vertebral body of L1 from the shapes of the two adjacent vertebrae (mean error equal to 0.51±0.11mm on average, Hausdorff distance equal to 2.11±0.56mm on average), compared to current CT resolution typically used in the operating room. The error was slightly higher for patients presenting large osteophytes or severe bone degeneration (mean error equal to 0.65±0.10mm, Hausdorff distance equal to 3.54±1.03mm). The accuracy of the prediction was significantly better than approximating the shape of the vertebral body of L1 by the shape of T12 or L2. This approach could be used in the future to improve the pre-planning of spine surgeries to treat vertebral fractures.

Lipomeningocele with Tethered Cord Syndrome in an Adult: A Case Report

Lipomeningocele is a closed neural tube defect characterized by the presence of spinal tissue within the spinal cord, with a junction between the spinal cord and a lipoma. It has a prevalence of 0.6 per 10,000 live births. A 29-year-old female presented to the outpatient clinic with complaints of weakness in both legs (more on the right) and tingling sensation and pain over her right thigh and legs for 1 year. She also mentioned swelling in her lower back since birth, which has been growing progressively since childhood. Magnetic resonance imaging of the spine revealed a low-lying spinal cord with the conus lying at the lower end of the L2 vertebral body. Spinal decompression with detethering of the cord and excision of the lipomeningocele was undertaken via a posterior midline incision. Prompt surgical intervention are crucial for symptom relief and prevention of neurological deterioration.

Correlation analysis between morphologic characteristics of the thoracolumbar basivertebral foramen and Kummell’s disease in patients with osteoporosis using imaging techniques

BackgroundThe aging of the population is a social problem faced by many countries in the world. With the increase in the elderly population, the number of patients with Kummell’s disease is also gradually increasing. No study has demonstrated that Kummell’s disease has a clear correlation with the foramen of a vertebrobasilar vein.ObjectivesThe research was conducted to describe and evaluate the morphological characteristics of a basivertebral foramen in patients with osteoporosis and Kummell’s disease by CT; to infer whether the specific morphological characteristics of basivertebral foramen may be one of the risk factors of Kummell’s disease; to provide clinical suggestions for the treatment of Kummell’s disease.DesignRetrospective analysis from January 2020 to December 2021 on 83 patients with 83 vertebral bodies (T8-L5) diagnosed with senile osteoporosis and Kummell’s disease hospitalized in our hospital due to chronic low back pain, including 57 women and 23 men. Group A was assigned for the following patients: the age ranged from 59 to 86 years old, with the average age of 67.30 ± 7.32 years old; the body mass index ranged from 20.01 to 29.46 kg/m2, with the average body mass index of 23.51 ± 3.03 kg/m2.Group B was assigned for the following patients: 83 patients diagnosed with senile osteoporosis in our outpatient department from January 2020 to December 2021, including 41 males and 42 females; the age ranged from 60 to 85 years, with an average age of 68.52 ± 4.68 years old; the height to weight ratio met the normal reference standard (except 20% above or 10% below the standard weight). Through the lanwon PACS imaging system, the related parameters of the vertebrobasilar foramen in patients with osteoporosis and Kummell’s disease were measured to evaluate and analyze the correlation between the morphological characteristics of the vertebrobasilar foramen in patients with osteoporosis and Kummell’s disease.ResultsIn patients with osteoporosis, the distribution of incidence rate of Kummell’s disease in the spine was consistent with that of osteoporotic compression fractures. Sagittal view of the vertebral body on CT scan and the triangular-shaped, trapezoidal-shaped, and irregular-shaped basivertebral foramen in group A accounted for 18%,57%,and 36%,respectively. In group B, triangular-shaped, trapezoidal-shaped, and irregular-shaped foramen accounted for 51%,17%,and 26%,respectively.The distribution of triangular-shaped, trapezoidal-shaped, and irregular-shaped foramen was compared between groups A and B, and the difference was recorded as statistically significant (P < 0.05). Additionally, the difference in the distribution of triangular-shaped, trapezoidal-shaped, and irregular-shaped foramen in group A was found statistically significant (P < 0.05),while that of Group B was found statistically insignificant (P > 0.05).On a horizontal CT scan of the vertebra of group A, triangles, trapezoids, and irregularities accounted for 28%, 26%, and 47%, respectively. In group B, triangles,trapezoids,and irregularities accounted for 31%, 37%, and 30%, respectively. The difference in the distribution of the triangular-shaped and trapezoidal-shaped foramen in groups A and B was statistically insignificant (P > 0.05), while that of irregular-shaped was statistically significant (P < 0.05). Additionally, there was no statistical significance (P > 0.05) in the difference in the morphological distribution of triangular-shaped and trapezoidal-shaped foramen in group A, while that of irregular-shaped was found to be statistically significant (P < 0.05). Further, the difference in the morphological distribution of triangular-shaped, trapezoidal-shaped, and irregular-shaped foramen in group B was not statistically significant (P > 0.05).In general, about 8% of the vertebral body of BF has an osseous septum. In group A, 97% are single-holed while the remaining 3% are porous; in group B, those with single holes accounted for 76%, while the remaining 24% are porous. In groups A and B, the difference in the morphological distribution of single-holed and multi-holed T8, T11, T12, L1, L2, L4, and L5 vertebral bodies was statistically significant (P < 0.05). In group A, the difference in the distribution of single-holed and multi-holed L1 and L5 vertebral bodies was statistically significant (P < 0.05). Similarly, the difference in the distribution of single-holed and multi-holed T8, T11, T12, L1, L2, and L4 basivertebral foramen was statistically significant (P < 0.05).ConclusionsIn patients with osteoporosis, the incidence of vertebral Kummell’s disease can be associated with the morphological characteristics of the basivertebral foramen, as observed in the CT scan. Furthermore, the vertebral body with trapezoidal-shaped and irregular-shaped basivertebral foramen and boneless septum in the foramen is highly susceptible to Kummell’s disease.

Visible trephine-based foraminoplasty in PTED leads to asymmetrical stress changes and instability in the surgical and adjacent segments: a finite element analysis

This study aimed to construct a multi-segment lumbar finite element model (FEM) of PTED surgery to analyze the changes in stress and ROM after visible trephine-based foraminoplasty. The CT scans of a 35-year-old healthy male were used to develop a multi-segment lumbar FEM with Mimic, Geomagic Studio, Hypermesh and MSC.Patran. Different foraminoplasty was performed on the model, and these were grouped into normal group (A), the ventral resection group (B), the apex resection group (C), the ventral + apex + isthmus resection group (D), and the SAP + isthmus + lateral recess resection group (E). A vertical load of 500N and a torque of 10N·M were applied to the upper surface of the L3 vertebral body to simulate the biomechanical characteristics under the motion of flexion, extension, lateral bending, and rotation. The von Mises stress maps of the intervertebral f, vertebral body, facet joints, and the ROM of the L3-S1 intervertebral disk were calculated and analyzed. The changes of peak stress on the vertebral body for each group were not significant in the same motion state. Significant stress differences were observed in the L4/5 intervertebral disks, while no obvious stress changes were observed for the L3/4 and L5/S1 intervertebral disks. The stress of the L3/4 and L5/S1 facet joints decreased after L4/5 foraminoplasty, while the stress of L4/5 facet joints displayed an overall increasing trend. Significant asymmetrical stress changes of bilateral facet joints were observed in all three segments, particularly during bilateral rotation movements. The ROM of L3-S1 gradually increased from Group A to Group E, especially during flexion, left lateral bending, and right rotation, with the highest elevation observed for the L45 ROM. Our FEM indicated that enlarged resection and exposure of the articular surface could lead to significant asymmetrical stress changes in the bilateral facet joints and ROM instability of the surgical and adjacent segments. These findings suggested that unnecessary and excessive resection should be avoided in PTED to reduce the incidence of low back pain and the risk of postsurgical degeneration.

Development and validation of a machine learning model to predict imminent new vertebral fractures after vertebral augmentation

BackgroundAccurately predicting the occurrence of imminent new vertebral fractures (NVFs) in patients with osteoporotic vertebral compression fractures (OVCFs) undergoing vertebral augmentation (VA) is challenging with yet no effective approach. This study aim to examine a machine learning model based on radiomics signature and clinical factors in predicting imminent new vertebral fractures after vertebral augmentation.MethodsA total of 235 eligible patients with OVCFs who underwent VA procedures were recruited from two independent institutions and categorized into three groups, including training set (n = 138), internal validation set (n = 59), and external validation set (n = 38). In the training set, radiomics features were computationally retrieved from L1 or adjacent vertebral body (T12 or L2) on T1-w MRI images, and a radiomics signature was constructed using the least absolute shrinkage and selection operator algorithm (LASSO). Predictive radiomics signature and clinical factors were fitted into two final prediction models using the random survival forest (RSF) algorithm or COX proportional hazard (CPH) analysis. Independent internal and external validation sets were used to validate the prediction models.ResultsThe two prediction models were integrated with radiomics signature and intravertebral cleft (IVC). The RSF model with C-indices of 0.763, 0.773, and 0.731 and time-dependent AUC (2 years) of 0.855, 0.907, and 0.839 (p < 0.001 for all) was found to be better predictive than the CPH model in training, internal and external validation sets. The RSF model provided better calibration, larger net benefits (determined by decision curve analysis), and lower prediction error (time-dependent brier score of 0.156, 0.151, and 0.146, respectively) than the CPH model.ConclusionsThe integrated RSF model showed the potential to predict imminent NVFs following vertebral augmentation, which will aid in postoperative follow-up and treatment.

A comparative study of establishing rabbit vertebral tumor model by two ways of CT-guided percutaneous puncture

ObjectiveTo investigate the difference of tumor formation rate of rabbit vertebral tumor model established by percutaneous injection of V×2 tumor tissue suspension and tumor mass under computed tomography (CT) guidance, and the imaging findings of CT, magnetic resonance images (MRI) and positron emission tomography with computed tomography (PET/CT) at 7 days, 14 days and 21 days after implantation, and preliminarily verify the safety and feasibility of microwave ablation (MWA), percutaneous vertebroplasty (PVP) and microwave ablation combined with percutaneous vertebroplasty (MWA + PVP) in rabbit VX2 vertebral tumor model. MethodsThirty healthy New Zealand rabbits were randomly allocated to tissue suspension group and tumor block group, with 15 rabbits for each group. The VX2 tumor block and mixed suspension were inoculated into the L5 vertebral body under CT-guided percutaneous puncture. The PET/CT, MRI and CT examinations were performed at 7, 14 and 21 days after implantation. Fisher exact probability test was used to compare the success rate of the two implantation methods and the tumor display rate at each time point of the three examination methods. Observe the paralysis of tumor-forming rabbits, and immediately perform MWA/PVP/MWA + PVP treatment according to groups after paralysis to verify the safety and feasibility of treatment. ResultsA total of 18 experimental rabbits were successfully modeled in two groups, of which the success rate was 26.6% (4/15) in tissue suspension group and 93.3% (14/15) in tumor block group, with statistically significant differences between two groups (P < 0.01). The tumor display rates by PET/CT, MRI and CT at each time point after implantation were: 83.3% (15/18), 16.6% (3/18), and 0% (0/18) at 7 days after implantation; 100% (18/18), 88.8% (16/18), and 11.1% (2/18) at 14 days after implantation; and 100% (18/18), 100% (18/18), 77.7% (14/18) at 21 days after implantation. The average paralysis time of 18 experimental rabbits successfully modeled was 24.44 ± 2.38 days, and MWA/PVP/MWA + PVP treatment was performed in groups immediately after paralysis. Except for 2 rabbits who died due to anesthesia overdose during anesthesia before treatment, the remaining 16 rabbits were successfully treated with MWA/PVP/MWA + PVP, and the technical success rate was 100% (16/16). In MWA group, one experimental rabbit was randomly selected and killed after ablation, and histopathological examination (H and E staining) was performed together with 2 experimental rabbits who died of anesthesia. The pathological changes before and after ablation were compared. The survival time of the remaining 15 experimental rabbits varied from 3 to 8 days after treatment. ConclusionThe success rate of establishing rabbit vertebral tumor model by injecting tumor masses under the CT-guided percutaneous puncture is high, and the following MWA and PVP treatment can be successfully conducted. PET/CT is the most sensitive method for early detection of tumor compared with MRI and CT. Spectral Presaturation with Inversion Recovery (SPIR) sequence can significantly improve the detection rate of smaller tumors by MRI and shorten the detection time.

Endovascular Repair of Traumatic Infrarenal Aortic Injury in an 8-Year-Old.

The patient is an 8 year-old male presenting to outside facility following high-speed motor vehicle collision in which he was a restrained passenger. CT imaging at that time demonstrated a traumatic infrarenal aortic pseudoaneurysm, extensive pneumoperitoneum and free fluid, and an unstable L2 vertebral body fracture. He underwent exploratory laparotomy with small bowel resection prior to transfer. The patient was left in discontinuity and temporary closed. Vascular surgery was consulted upon arrival to tertiary care children's hospital. The decision was made to proceed with emergent endovascular repair. An aortogram confirmed the location of the aortic disruption well below the renal arteries, superior to the bifurcation. An 11 mm × 5 cm Viabahn covered stent was placed across the injury with adequate proximal and distal seal. This is a case of seatbelt-related pediatric infrarenal aortic injury in the setting of polytrauma. Endovascular repair was pursued in this damage-control setting.

Importance of computed tomography Hounsfield units in predicting S1 screw loosening after lumbosacral fusion

We investigated whether computed tomography (CT) Hounsfield unit (HU) values of the S1 screw trajectory can predict screw loosening after lumbosacral fixation. We analysed 102 patients (58 men and 44 women) who underwent L5–S1 interbody fusion between April 2018 and October 2019. We reviewed the characteristics of patients including body mass index, smoking, comorbidity with diabetes mellitus, and interbody fusion types. Bone mineral density (BMD) was obtained from the lumbar spine and total hip using dual-energy X-ray absorptiometry. Additionally, we reviewed the S1 screw lengths and diameters. HU values of both L1 vertebral bodies and bilateral S1 screw trajectories were measured on preoperative CT. At six months postoperatively, S1 screws on CT were assessed. Screws with a 1 mm or more radiolucent zone were defined as “loosening”. Seventeen patients had loosened screws, and 85 patients did not. The patient characteristics did not significantly differ between the two groups. Both total hip BMD and L1 HU values were low in the loosening patient group (both p = 0.03). Of the 204 total S1 screws, 25 screws were loosened, and 179 screws were not. The screw length was short (p = 0.01), and the HU value of the S1 screw trajectory was low (p < 0.001) in the loosening screw group. Based on receiver operating characteristic analyses of these factors, the area under the curve of HU value of the S1 screw trajectory was the highest (0.79). Measuring the HU value of both the L1 vertebral body and S1 screw trajectory aids in predicting screw loosening.

Pneumocephalus After Anterior Lumbar Spinal Surgery Due to Trauma: A Case Report

Pneumocephalus as a complication of anterior lumbar spinal surgery is extremely rare. A 53-year-old male patient presented with L4 fracture. Posterior fixation from L3 to L5 was conducted one day after the trauma. As the patient’s neurological deficit persisted, additional anterior surgery by L4 vertebral body replacement was performed on the 19th day. Both surgeries were completed without obvious intraoperative complications. Two weeks after the anterior lumbar surgery, the patient complained of severe headaches, and computed tomography scan revealed pneumocephalus and massive fluid retention in the abdomen. The symptoms improved with conservative treatment, including bed rest, spinal drainage, intravenous drip infusion, and prophylactic administration of antibiotics. Due to the lack of tamponade effect in the soft tissues, a large amount of cerebrospinal fluid leakage may induce and cause progression of pneumocephalus in anterior dural injury.

CLINICAL AND RADIOLOGICAL CORRELATION IN ACUTE AND SUBACUTE LOW BACK PAIN IN ADULT MALES OF 20 TO 30 YEAR AGE GROUP

Low back pain (LBP) is one of the most common health problems affecting 75% to 85% of the general population. Young adults are suffering from LBP more frequently than in the past, where loss of working days is a great personal and national loss. This study aims to determine the correlation of clinical features with plain radiograph and Magnetic resonance imaging (MRI) ndings in adult males of 20 to 30 years age group. 100 male patients with acute or subacute low backache were enrolled in the present study. Personal details and history noted and clinical examination was performed. The Oswestry disability index was used for quantication of pain. Plain radiograph and MRI was done. The plain radiograph and MRI ndings were correlated with the clinical ndings. The mean age of patients was 25.18±3.28 years. Sensory loss was found in 15% and paraesthesia in 18% cases. The mean Oswestry lower back pain score was 16.66±10.44. The most common abnormality found on plain radiograph was abnormal disc intensity followed by reduced disc height. The most common abnormality found on MRI was disc bulge followed by abnormal disc intensity. The most common site for osteophytes was anterior of L4 vertebral body followed by anterior of L3. There was a poor agreement between clinical ndings and radiological ndings. Both plain x-ray and MRI imaging found a signicantly higher rate of spine changes which did not correlate well with clinical &amp; neurological ndings

Opportunistic screening for osteoporosis by abdominal CT in a British population

BackgroundIt has previously been shown that CT scans performed for other indications can be used to identify patients with osteoporosis. This has not yet been tested in a British population. We sought to evaluate the use of vertebral CT attenuation measures for predicting osteoporosis in a British cohort, using dual-energy X-ray absorptiometry (DEXA) as a reference standard.MethodsPatients who underwent abdominal CT in 2018 and concomitantly underwent DEXA within a six-month interval were retrospectively included. CT attenuation values in Hounsfield units (HU) were measured by placement of a region-of-interest at the central portion of the L1 vertebral body and then compared to their corresponding DEXA score. Receiver operating characteristic (ROC) curves were generated to evaluate the performance of a logistic regression model and to determine sensitivity and specificity thresholds.Results536 patients (394 females, mean age 65.8) were included, of which 174 had DEXA-defined osteoporosis. L1 attenuation measures were significantly different (p < 0.01) between the three DEXA-defined groups of osteoporosis (118 HU), osteopenia (143 HU) and normal bone density (178 HU). The area under the ROC curve was 0.74 (95% CI 0.69–0.78). A threshold of 169 HU was 90% sensitive, and a threshold of 104 HU was 90% specific for diagnosing osteoporosis.ConclusionsRoutine abdominal CT can be used to opportunistically screen for osteoporosis without additional cost or radiation exposure. The thresholds identified in this study are comparable with previous studies in other populations. We recommend radiologists engage with primary care and rheumatology providers to determine appropriate cut-off values for further investigation.