Vertebral Bone Research Articles

Simplified S1 vertebral bone quality (vbq) score to assess proximal junctional kyphosis after Lenke 5 adolescent idiopathic scoliosis surgery.

Proximal junctional kyphosis (PJK) is a common complication following corrective surgery for adolescent idiopathic scoliosis (AIS) with a Lenke 5 curve. Previous studies have suggested that PJK may be associated with osteopenia, which is prevalent in AIS patients. MRI-based vertebral bone quality (VBQ) scores have been proposed as a valuable tool to assess preoperative bone quality. However, accurately measuring VBQ scores in Lenke 5 AIS patients with a structural lumbar curve can be challenging. Recently, a simplified S1 VBQ score has been proposed as an alternative method when the traditional VBQ score is not applicable. This study aims to evaluate the predictive value of the simplified S1 VBQ score in predicting the occurrence of PJK after corrective surgery for Lenke 5 AIS. We conducted a retrospective analysis of patient data to assess the predictive utility of the S1 VBQ score for PJK in Lenke 5 AIS patients. Demographic, radiographic, and surgical data were collected, and S1 VBQ scores were calculated based on preoperative T1-weighted MRI images. Univariate analysis, linear regression, and multivariate logistic regression were performed to identify potential risk factors for PJK and to assess the correlation between other variables and the S1 VBQ score. Receiver operating characteristic analysis and area under the curve values were used to evaluate the predictive efficiency of the S1 VBQ score for PJK. A total of 105 patients (aged 15.50 ± 2.36years) were included in the analysis, of whom 24 (22.9%) developed PJK. S1 VBQ scores were significantly higher in the PJK group compared to the non-PJK group (2.83 ± 0.44 vs. 2.48 ± 0.30, P < 0.001), and there was a significant positive correlation between the S1 VBQ score and proximal junctional angle (PJA) (r = 0.46, P < 0.0001). Multivariate analysis revealed that the S1 VBQ scores and preoperative thoracic kyphosis (TK) were significant predictors of PJK. This study provided evidence that higher S1 VBQ scores were independently associated with PJK occurrence following corrective surgery for Lenke 5 AIS. Preoperative measurement of the S1 VBQ score on MRI may serve as a valuable tool in planning surgical correction for Lenke 5 AIS.

A new vertebrate assemblage from the Matute Formation of the Cameros Basin (Ágreda, Spain): implications for the diversity during the Jurassic/Cretaceous boundary

The Ribota site (Ágreda, Soria, Spain) is a new locality in the Matute Formation (Tithonian–Berriasian) composed of several carbonate layers, outstandingly rich in macrovertebrate remains. Fossils show an unusual replacement of the original bioapatite by quartz, and are found as positive reliefs protruding from lacustrine limestone beds. This type of conservation has allowed the identification of around one hundred vertebrate bone accumulations in an outcrop of more than 10 hectares. Osteichthyans (articulated partial skeletons, cranial material, and isolated postcranial bones and scales), crocodylomorphs (disarticulated cranial material, isolated teeth, vertebrae and osteoderms), turtles (partial carapaces and plastra, but also isolated plates) and pterosaurs (cranial and appendicular elements) have been identified. Around 80 specimens have been collected and a preliminary study of part of the collection (35 specimens) has allowed the identification of at least 5 different taxa: Halecomorphi indet., Neoginglymodi indet., Goniopholididae indet., Testudinata indet., and Pterodactyloidea indet. This new site represents one of the few sites from this time interval preserved in a fully lacustrine environment, so these vertebrate assemblages are unique and composed of different animals that presumably lived around and within the lake. They are dominated by aquatic and amphibian vertebrates and was formed by attrition in this lacustrine environment, possibly far from the lake shoreline. These macrovertebrate assemblages provide new data about the diversity in the faunal ecosystems from the Jurassic/Cretaceous transition of the Iberian Basin Rift System.

Effect of electroacupuncture at "Jiaji" (EX-B2) on senescence of nucleus pulposus cells of degenerated lumbar intervertebral disc in rabbits.

To observe the effect of electroacupuncture (EA) at "Jiaji"(EX-B2) on body mass, motor function, expression of caveolin-1 (Cav-1) in nucleus pulposus cells and annulus fibrosus tissue, telomerase activi-ty, relative telomere length and different cell cycle ratio of nucleus pulposus cells in rabbits with intervertebral disc degeneration(IVDD), so as to investigate its mechanism underlying delaying senescence of the degenerated lumbar intervertebral disc nucleus pulposus cells. Twenty-five male New Zealand rabbits with mature bones were divided into control, sham operation, model, EA, and acupuncture groups, with 5 rabbits in each group. The IVDD model was established by inserting kirschner wires to the vertebral bone surface between the lumbar (L)4 and L5 vertebrae, followed by applying continuous axial pressure for 28 d. EA (2 Hz/15 Hz, 1-2 mA) or acupuncture (only insertion of acupuncture needles into bilateral EX-B2, but without electrical stimulation) was applied to bilateral EX-B2 for 20 min, once daily, 6 times a week for 4 weeks. The hindlimb locomotor function (locomotor score) was assessed by using Faden's and colleagues' methods. The general conditions of rabbits in each group were observed, and their body weight changes were measured every week. Nucleus pulposus cells were isolated using enzyme digestion method. After the treatment, the Cav-1 positive cell counts in nucleus pulposus cells and annulus fibrosus tissues were detected by immunohistochemistry, and the telomerase activity of nucleus pulposus cells was detected by PCR-ELISA. The relative telomere length of nucleus pulposus cells was measured by real-time quantitative polymerase chain reaction (real-time qPCR), and the cell cycle of nucleus pulposus was detected by flow cytometry. Compared with the sham operation group, the body mass from 4 to 11 week, locomotor score at 4, 7 and 11 week, telomerase activity, relative telomere length and the proportion of cells in G2/M phase of nucleus pulposus cells were significantly decreased (P<0.01), while Cav-1 positive cell counts of nucleus pulposus and annulus fibrosus tissue, and the proportion of nucleus pulposus cells in the G0/G1 phase considerably increased (P<0.01) in the model group. Relevant to the model group, the EA group rather than the acupuncture group had an increase in the body mass from 8 to 11 week, locomotor score at 11 week, telomerase activity, relative telomere length of nucleus pulposus cells, and the proportion of nucleus pulposus cells in G2/M phase (P<0.01), and a decrease in the Cav-1 positive cell counts of nucleus pulposus and annulus fibrosus tissue and the proportion of cells in G0/G1 phase (P<0.01). No significant differences were found between the model and acupuncture groups in all the indexes mentioned above. EA at EX-B2 has a bene-ficial effect in improving motor function in rabbits with IVDD, which may be related to its functions in reducing the expression of Cav-1 in nucleus pulposus cells and annulus fibrosus, improving cycle arrest, enhancing the telomerase activity and the relative telomere length of nucleus pulposus cells, delaying the senescence of nucleus pulposus cells of the degenerated lumbar intervertebral discs.

Automated vertebral bone mineral density measurement with phantomless internal calibration in chest LDCT scans using deep learning.

To develop and evaluate a fully automated method based on deep learning and phantomless internal calibration for bone mineral density (BMD) measurement and opportunistic low BMD (osteopenia and osteoporosis) screening using chest low-dose CT (LDCT) scans. A total of 1175 individuals were enrolled in this study, who underwent both chest LDCT and BMD examinations with quantitative computed tomography (QCT), by two different CT scanners (Siemens and GE). Two convolutional neural network (CNN) models were employed for vertebral body segmentation and labeling, respectively. A histogram technique was applied for vertebral BMD calculation using paraspinal muscle and surrounding fat as references. 195 cases (by Siemens scanner) as fitting cohort were used to build the calibration function. 698 cases as validation cohort I (VCI, by Siemens scanner) and 282 cases as validation cohort II (VCII, by GE scanner) were performed to evaluate the performance of the proposed method, with QCT as the standard for analysis. The average BMDs from the proposed method were strongly correlated with QCT (in VCI: r = 0.896, in VCII: r = 0.956, p < 0.001). Bland-Altman analysis showed a small mean difference of 1.1 mg/cm3, and large interindividual differences as seen by wide 95% limits of agreement (-29.9 to +32.0 mg/cm3) in VCI. The proposed method measured BMDs were higher than QCT measured BMDs in VCII (mean difference = 15.3 mg/cm3, p < 0.001). Osteoporosis and low BMD were diagnosed by proposed method with AUCs of 0.876 and 0.903 in VCI, 0.731 and 0.794 in VCII, respectively. The AUCs of the proposed method were increased to over 0.920 in both VCI and VCII after adjusting the cut-off. Without manual selection of the region of interest of body tissues, the proposed method based on deep learning and phantomless internal calibration has the potential for preliminary screening of patients with low BMD using chest LDCT scans. However, the agreement between the proposed method and QCT is insufficient to allow them to be used interchangeably in BMD measurement. This study proposed an automated vertebral BMD measurement method based on deep learning and phantomless internal calibration with paraspinal muscle and fat as reference.

Intraoperative Surgeon Assessment of Bone: Correlation to Bone Mineral Density, CT Hounsfield Units, and Vertebral Bone Quality.

Retrospective observational study of consecutive patients. The purpose of the study is to determine if a surgeon's qualitative assessment of bone intraoperatively correlates with radiologic parameters of bone strength. Preoperative radiologic assessment of bone can include modalities such as computed tomography (CT) Hounsfield units (HUs), dual-energy x-ray absorptiometry (DXA) bone mineral density with trabecular bone score (TBS) and magnetic resonance imaging vertebral bone quality (VBQ). Quantitative analysis of bone with screw insertional torque and pull-out strength measurement has been performed in cadaveric models and has been correlated to these radiologic parameters. However, these quantitative measurements are not routinely available for use in surgery. Surgeons anecdotally judge bone strength, but the fidelity of the intraoperative judgment has not been investigated. All adult patients undergoing instrumented posterior thoracolumbar spine fusion by one of seven surgeons at a single center over a 3-month period were included. Surgeons evaluated the strength of bone based on intraoperative feedback and graded each patient's bone on a 5-point Likert scale. Two independent reviewers measured preoperative CT HUs and magnetic resonance imaging VBQ. Bone mineral density, lowest T-score, and TBS were extracted from DXA within 2 years of surgery. Eighty-nine patients were enrolled and 16, 28, 31, 13, and 1 patients had Likert grade 1 (strongest bone), 2, 3, 4, and 5 (weakest bone), respectively. The surgeon assessment of bone correlated with VBQ (τ=0.15, P =0.07), CT HU (τ=-0.31, P <0.01), lowest DXA T-score (τ=-0.47, P <0.01), and TBS (τ=-0.23, P =0.06). Spine surgeons' qualitative intraoperative assessment of bone correlates with preoperative radiologic parameters, particularly in posterior thoracolumbar surgeries. This information is valuable to surgeons as this supports the idea that decisions based on feel in surgery have a statistical foundation.

Cervical Vertebral Bone Quality Score Independently Predicts Distal Junctional Kyphosis After Posterior Cervical Fusion.

Posterior cervical fusion is the surgery of choice when fusing long segments of the cervical spine. However, because of the limited presence of this pathology, there is a paucity of data in the literature about the postoperative complications of distal junctional kyphosis (DJK). We aimed to identify and report potential associations between the preoperative cervical vertebral bone quality (C-VBQ) score and the occurrence of DJK after posterior cervical fusion. The authors retrospectively reviewed records of patients who underwent posterior cervical fusion at a single hospital between June 1, 2010, and May 31, 2020. Patient data were screened to include patients who were >18 years old, had baseline MRI, had baseline standing cervical X-ray, had immediate postoperative standing cervical X-ray, and had clinical and radiographic follow-ups of >1 year, including a standing cervical X-ray at least 1 year postoperatively. Univariate analysis was completed between DJK and non-DJK groups, with multivariate regression completed for relevant clinical variables. Simple linear regression was completed to analyze correlation between the C-VBQ score and total degrees of kyphosis angle change. Ninety-three patients were identified, of whom 19 (20.4%) had DJK and 74 (79.6%) did not. The DJK group had a significantly higher C-VBQ score than the non-DJK group (2.97 ± 0.40 vs 2.26 ± 0.46; P < .001). A significant, positive correlation was found between the C-VBQ score and the total degrees of kyphosis angle change (r 2 = 0.26; P < .001). On multivariate analysis, the C-VBQ score independently predicted DJK (odds ratio, 1.46; 95% CI, 1.27-1.67; P < .001). We found that the C-VBQ score was an independent predictive factor of DJK after posterior cervical fusion.

Survival prediction nomogram for patients with vertebral bone metastases treated with palliative radiotherapy.

In the treatment of vertebral bone metastases, estimating patient prognosis is important to select the optimal treatment strategy. The purpose of this study was to identify prognostic factors for vertebral bone metastases treated with palliative radiotherapy and to establish a nomogram for predicting patient survival. We analyzed patients who underwent palliative radiotherapy for vertebral bone metastasis between January 2010 and December 2020 at a single institution. Exclusion criteria were as follows: (1) primary bone malignancy, (2) stereotactic body radiotherapy, (3) concurrent radiotherapy to sites other than the vertebral bone, (4) radiotherapy to other sites within 12 weeks before or after the current radiotherapy, and (5) lack of more than half of blood test data before radiotherapy. A total of 487 patients met the inclusion criteria. Clinical and hematologic data were collected from the patient record system. Patients were divided into training and test groups in a 7:3 ratio. Multivariate Cox regression analysis in the training cohort revealed six significant factors, including a history of chemotherapy, primary site (breast cancer, prostate cancer, or hematologic malignancy), use of analgesics, neutrophil-lymphocyte ratio, serum albumin, and lactate dehydrogenase. A prognostic nomogram was developed and validated in the test cohort. The area under the curve (AUC) values in predicting survival at 6, 24, and 60 months were 0.83, 0.88, and 0.88 in the training cohort and 0.85, 0.81, and 0.79 in the test cohort, respectively. This nomogram may help to select the treatment strategy for vertebral bone metastases.

OR27-02 The Bone Anabolic Effect Of An Antibody Blocking Oxidized Phospholipids Is Associated With An Increase In Wnt10b In Osteoblasts.

Abstract Disclosure: M. Palmieri: None. I. Nookaew: None. M.J. Schuller-Almeida: None. H. Kim: None. T.E. Jospeh: None. S.C. Manolagas: None. C.A. O'Brien: None. E. Ambrogini: None. Oxidized phospholipids containing phosphatidylcholine (PC-OxPLs) are toxic molecules present on oxidized low-density lipoproteins (OxLDL) and apoptotic cells; and are pathogenic in many diseases, including osteoporosis. OxPLs decrease Wnt and BMP2 signaling, induce ferroptosis and stimulate pro-inflammatory cytokine production, in atherosclerosis and nonalcoholic steatohepatitis. The natural antibody E06 blocks PC-OxPLs. Transgenic expression of a single chain (scFv) form of the antigen-binding domain of E06 IgM (E06-scFv) increases bone mass in 6-month-old mice and attenuates high fat diet- and age-induced bone loss by increasing osteoblast number and bone formation rate and reducing osteoblast apoptosis. To elucidate the mechanism(s) mediating the bone anabolic effect of E06-scFv we performed bulk-RNA sequencing (bulk-RNA-seq) of vertebral bone and single cell RNA-sequencing (scRNA-seq) of mesenchymal and myeloid cells from long bones of WT and E06-scFv transgenic mice. Earlier bulk-RNA-seq performed in vertebral bone of 22- month-old females had shown that E06-scFv upregulates Wnt10b, but not other Wnt ligands, and the Wnt signaling pathway. We report now that scRNA-seq of mesenchymal cells isolated from 7-month-old female mice revealed that Wnt10b expression is increased by 3-fold (adj-P=3.04E-11) in pre-osteoblasts and osteoblasts from E06-scFv transgenic mice as compared to cells from WT mice. Wnt target genes were also upregulated. An integrated analysis of 9 published scRNA-seq datasets from bone resident mesenchymal and hematopoietic cell types revealed that the majority of Wnt10b in the bone microenvironment originates from cells of the osteoblast lineage. Further, OxLDL decreased Wnt10b and Wnt target genes in calvaria- or bone marrow-derived osteoblastic cell cultures. In contrast, OxLDL did not cause the ferroptosis associated upregulation of Chac1, Ptgs2, Slc7A11, and Acsl4, and the downregulation of Rgs4 in calvaria cells. In addition, no changes in the expression of these genes were detected in the scRNA-seq of mesenchymal cells from E06-scFv compared to WT mice. BMP signaling pathways were also unchanged in this scRNA-seq analysis. Finally, using bulk-RNA-seq of vertebral bone and scRNA-seq of myeloid cells, we could not detect changes in the expression of pro-inflammatory cytokines, such as Tnf-α, Il-6, Il1-α, Il-β, Il-4, Il-12, Lif, Il-23, interferon-α, and interferon-β, between WT and E06-scFv mice. Together, these findings indicate the PC-OxPLs decrease Wnt10b and E06-scFv increases Wnt10b in bone but has no effect on other pathways shown to be affected by OxPLs in other tissues. Thus, Wnt10b may be a critical mediator of the bone anabolic effects of E06-scFv. Presentation: Saturday, June 17, 2023

Osteoplasty of vertebral bone defects caused by pedicle screw loosening using orthobiological approaches: a pilot study of case series

Objective. To analyze the effectiveness and safety of using an orthobiological product in osteoplasty of bone defects of the vertebrae with simultaneous reosteosynthesis.Material and Methods. The results of screw augmentation technology using thrombogel-enriched allogeneic bone were studied in a retrospective, single-center, non-randomized study, which included 17 patients (10 women, 7 men) with instability of the hardware in the form of screw loosening and osteolysis around screws. Results within 12 months were followed up in 17 patients (100 %). We compared preoperative and postoperative instrumental data, clinical parameters in dynamics.Results. The mean age of the patients was 59 (43–75) years. The distribution of patients, according to the primary pathology, was as follows: 11 patients (64.7 %) had a degenerative-dystrophic pathology of the spine, 4 patients (23.5 %) had a traumatic injury, and 2 patients had a kyphotic deformity on the background of Bechterew’s disease (11.8 %). The mean time from primary to revision surgery was 7.06 months (3.1–12.1), mean CRP was 4.48 (0.5–15.0). When observing patients for 12 months, all patients showed a positive trend in the form of a statistically significant regression of back pain according to VAS from 7.0 (6.0; 7.3) to 1.0 (0.0; 1.0) points (χ2 = 47.9, df 3, р &lt; 0.0001). A positive trend was also noted in the form of a decrease in ODI indicators and an improvement in the quality of life of patients from 63.8 (57.1; 69.1) to 3.0 (2.0; 7.5) at 12 months. When comparing the parameters (VAS and ODI), the obtained differences before/after the operation were statistically significant, while these changes have a pronounced correlation. Postoperative CT studies (3, 6, 12 months) showed no instability of the screws.Conclusion. Osteoplasty of vertebral bone defects and screw augmentation using orthobiological approaches have demonstrated their primary efficacy and safety. Further studies with a large sample size are needed to confirm the obtained results.

FRI681 OsteoboostTm Is Effective In Preserving Bone Strength And Density Of The Spine In Women With Low Bone Mass

Abstract Disclosure: L.D. Bilek: Grant Recipient; Self; Bone Health Technologies. Stock Owner; Self; Bone Health Technologies. L.E. Flores: Employee; Self; Bone Health Technologies. N. Waltman: None. L.R. Mack: None. K. Smith: None. D. Hillstrom: Employee; Self; Bone Health Technologies. M. Griffin: Consulting Fee; Self; Bone Health Technologies. Stock Owner; Self; Bone Health Technologies. L. Yecies: Employee; Self; Bone Health Technologies. Stock Owner; Self; Bone Health Technologies. M. Jaasma: Consulting Fee; Self; Bone Health Technologies. Stock Owner; Self; Bone Health Technologies. Introduction: Fragility fractures result in significant morbidity and mortality, which is of particular concern in postmenopausal women who are at high risk of fractures due to loss of estrogen. Pharmaceutical interventions are effective but have low uptake and adherence and are generally not indicated for patients with osteopenia. Vibration has the potential to prevent bone loss and holds promise as an effective, yet minimal risk, treatment. The Osteoboost, a novel wearable device delivering targeted vibration to the lumbar spine and hips, is designed to improve bone strength and bone density. Thus, this study aims to evaluate the efficacy of a 12-month intervention with the OsteoboostTM on preserving strength of the first lumbar vertebrae in postmenopausal women with low bone mass. Methods: This double-blinded, randomized controlled trial enrolled postmenopausal women with low bone mass who were not taking bone-active medications. Women had a bone density DXA and assessment of thyroid function to screen for eligibility Those who qualified were randomized to receive Osteoboost treatment 5x/week for 12 months with the belt in either the active or sham setting. The sham device created a sound but did not deliver vibration. Compressive strength (N) and volumetric density of the 1st lumbar vertebra (L1) was analyzed using Finite Element Analysis (FEA) of computed tomography (CT) scans of lumbar spine by ON Diagnostics. Results: 126 women (64 Active, 62 Sham) with low bone mass participated in the study, with an average age of 62.1 years (SD ± 5.8) and 60.6 years (± 5.3) in the Active and Sham groups, respectively. Most participants were of White race (98%) and non-Hispanic (96%). There were no significant differences in baseline demographics between the sham and active groups. Intent to treat analysis revealed no significant difference in percent change in vertebral bone strength between the Active and Sham groups over time (baseline to 12 months). When stratified by age category, significant differences in percent change in vertebral bone strength were present in the 50-60 year old category; the Sham group lost 3.4% of their vertebral bone strength compared to a 0.5% loss in the Active group (p=0.018). While bone was preserved in the active group relative to the sham in the women over 60, it was not significant (p=0.20). With analysis of those who met the compliance criterion of 3x/week, the Sham group lost 2.84% compared to 0.48% in the Active group (p=0.014); representing a 5 times greater loss in the Sham group. Additionally, the Osteoboost treatment preserved volumetric bone density of L1, with the Active treatment group losing 0.29% BMD relative to a 1.97% loss in the Sham group; representing a 6.8 times greater loss in the Sham group (p=0.008). Conclusion: The Osteoboost holds promise as a therapeutic intervention for women with low bone mass to prevent decline to osteoporosis and reduce fracture risk. Presentation: Friday, June 16, 2023

Development of a Diagnostic Model for Differentiating Tuberculous Spondylitis and Pyogenic Spondylitis with MRI: A Multicenter Retrospective Observational Study.

Multicenter retrospective observational study. This study aimed to distinguish tuberculous spondylitis (TS) from pyogenic spondylitis (PS), using magnetic resonance imaging (MRI). Further, a novel diagnostic model for differential diagnosis was developed. TS and PS are the two most common spinal infections. Distinguishing between these types clinically is challenging. Delayed diagnosis can lead to deficits or kyphosis. Currently, there is a lack of radiology-based diagnostic models for TS and PS. We obtained radiological images from MRI imaging of patients with TS and PS and applied least absolute shrinkage and selection operator (LASSO) regression to select the optimal features for a predictive model. Predictive models were built using multiple logistic regression analysis. Clinical utility was determined using decision curve analysis (DCA) and internal validation was performed using bootstrap resampling. A total of 201 patients with TS (n=105) or PS (n=96) were enrolled. We identified significant differences in MRI features between both groups. We found that non-contiguous multi- and single-vertebral body involvement were common in TS and PS, respectively. Vertebral bone lesions were more severe in the TS group than in the PS group (Z=-4.553，P<0.001). The patients in the TS group were also more prone to vertebral intraosseous, epidural, and paraspinal abscesses (P<0.001). A total of 8 predictors were included in the diagnostic model. Analysis of the calibration curve and area under the receiver operating characteristic curve suggested that the model was well-calibrated with a high prediction accuracy. This is the largest study comparing MRI features in TS and PS and the first to develop an MRI-based nomogram which may help clinicians distinguish between TS and PS.

Impact of leptin deficiency on male tibia and vertebral body 3D bone architecture independent of changes in body weight.

Leptin an adipokine with potent effects on energy balance and body weight plays an important role in defining bone architecture in growing mammals. However, major changes in body weight can also influence morphology of trabecular and cortical bone. Therefore, we examined the impact of leptin deficiency on tibia and vertebral body 3D bone architecture independent of changes in body weight. Furthermore, advances in computational 3D image analysis suggest that average morphological values may mask regional specific differences in trabecular bone thickness. The study utilized leptin-deficient Ob/Ob mice (n = 8) weight-paired to C57BL/6 (C57) control mice (n = 8) which were split into either lean or obese groups for 24 ± 2 weeks. Whole tibias and L3 vertebrae were fixed before high resolution microcomputed tomography (μCT) scanning was performed. Leptin deficiency independent of body weight reduced tibia cortical bone volume, trabecular bone volume/tissue volume, number, and mineral density. Mean tibia trabecular thickness showed no significant differences between all groups; however, significant changes in trabecular thickness were found when analyzed by region. This study demonstrates that leptin deficiency significantly impacts tibia and vertebral body trabecular and cortical bone 3D architecture independent of changes in body weight.

Comparison of Hounsfield units and vertebral bone quality score for the prediction of time to pathologic fracture in mobile spine metastases treated with radiotherapy.

Spine metastases are commonly treated with radiotherapy for local tumor control; pathologic fracture is a potential complication of spinal radiotherapy. Both Hounsfield units (HUs) on CT and vertebral bone quality (VBQ) on MRI have been argued to predict stability as measured by odds of pathologic fracture, although it is unclear if there is a difference in the predictive power between the two methodologies. The objective of the present study was to examine whether one methodology is a better predictor of pathologic fracture following radiotherapy for mobile spine metastases. Patients who underwent radiotherapy (conventional external-beam radiation therapy, stereotactic body radiation therapy, or intensity-modulated radiation therapy) for mobile spine (C1-L5) metastases at a tertiary care center were retrospectively identified. Details regarding underlying pathology, patient demographics, and tumor morphology were collected. Vertebral involvement was assessed using the Weinstein-Boriani-Biagini (WBB) system. Bone quality of the non-tumor-involved bone was assessed on both pretreatment CT and MRI. Univariable analyses were conducted to identify independent predictors of fracture, and Kaplan-Meier analyses were used to identify significant predictors of time to pathologic fracture. Stepwise Cox regression analysis was used to determine independent predictors of time to fracture. One hundred patients were included (mean age 62.7 ± 11.9 years; 61% male), of whom 35 experienced postradiotherapy pathologic fractures. The most common histologies were lung (22%), prostate (21%), breast (14%), and renal cell (13%). On univariable analysis, the mean HUs of the vertebrae adjacent to the fractured vertebra were significantly lower among those experiencing fracture; VBQ was not significantly associated with fracture odds. Survival analysis showed that average HUs ≤ 132, nonprostate pathology, involvement of ≥ 3 vertebral body segments on the WBB system, Spine Instability Neoplastic Score (SINS) ≥ 7, and the presence of axial pain all predicted increased odds of fracture (all p < 0.001). Cox regression found that HUs ≤ 132 (OR 2.533, 95% CI 1.257-5.103; p = 0.009), ≥ 3 WBB vertebral body segments involved (OR 2.376, 95% CI 1.132-4.987; p = 0.022), and axial pain (OR 2.036, 95% CI 0.916-4.526; p = 0.081) predicted increased fracture odds, while prostate pathology predicted decreased odds (OR 0.076, 95% CI 0.009-0.613; p = 0.016). Sensitivity analysis suggested that an HU threshold of ≤ 132 and a SINS of ≥ 7 identified patients at increased risk of fracture. The present results suggest that bone density surrogates as measured on CT, but not MRI, can be used to predict the risk of pathologic fracture following radiotherapy for mobile spine metastases. More extensive vertebral body involvement and the presence of mechanical axial pain additionally predict increased fracture odds.

Evaluating alternatives to dual-energy x-ray absorptiometry for assessing bone quality in patients undergoing spine surgery.

The purpose of this study was to compare and contrast lumbar bone quality and osteoporosis/osteopenia screening results via dual-energy x-ray absorptiometry (DEXA), CT, and MRI. A consecutive series of 426 candidates screened for lumbar disc replacement over a 5-year period beginning in 2018 was reviewed. Patients with a preoperative lumbar spine DEXA scan and a CT and/or MRI scan were included. The primary outcome measures included the bone mineral density (BMD) and osteoporosis or osteopenia classification from DEXA scans, Hounsfield units (HUs) for CT, and vertebral bone quality (VBQ) assessment for MRI. Patients were included if they had a DEXA scan within 1 year of an MRI or CT scan. DEXA BMD scores from composite or level-by-level reports were recorded. Asynchronous MRI and CT measurements were conducted using PACS. Interrater and intrarater reliability scores were generated for both CT and MRI measurements and ranged from 1.000 for MRI L1-4 scans to 0.683 for MRI VBQ. All 3 types of scans were statistically significantly correlated with one another; however, CT was more strongly correlated with the lumbar DEXA value (r = 0.439, p < 0.001). The correlation between MRI VBQ and DEXA was -0.103, (p < 0.045). The CT level-by-level measurements correlate with the corresponding level-by-level DEXA BMD values (correlation ranging from 0.531 to 0.289, p < 0.001 to p = 0.007). CT HU values were more strongly related to osteoporosis/osteopenia classification based on DEXA T-scores than were MRI VBQ values. Receiver operating characteristic analyses found that the area under the curve was 0.817 for CT and 0.539 for MRI. These results demonstrate that CT HUs more closely correlate to DEXA scores than MRI VBQ in this population of patients undergoing surgery for symptomatic disc degeneration. Thus, CT may be an alternative to DEXA for assessing VBQ in this population.

To Evaluate the Value of Vertebral Body Cortical Thickness in Predicting Osteoporosis by Opportunistic CT

In vertebrae, the amount of cortical bone has been estimated at 30-60%, but 45-75% of axial load on a vertebral body is borne by cortical bone(1). The purpose of this study is to investigate the accuracy, sensitivity, specificity, positive predictive value and negative predictive value of vertebral body cortical thickness in predicting osteoporosis(OP) by analyzing the relationship between vertebral body cortical thickness and bone mineral density(BMD) in different age and gender groups. The optimal diagnostic cut-off value of vertebral body cortical thickness in predicting OP was analyzed. The data of 150 patients (50-89 years old) who underwent chest or abdominal Quantitative computed tomography (QCT) scan(obtained in one scan) in our hospital from July 2021 to July 2022 were retrospectively analyzed. The average volume bone mineral density (vBMD) of L1-L2 vertebral bodies was obtained and grouped according to BMD, age, and gender. According to BMD, the patients were divided into three groups: osteoporosis, osteopenia and normal. According to age, the patients were divided into three groups: 50-59 years, 60-69 years and ≥70 years. The axial images of T11, T12 and L1 were reconstructed with 1.25mm slice thickness by AW4.7 workstation provided by General Electric Co (GE) Company. The images were imported into the computed tomography (CT) Spine Bone Quantification System software for spine analysis, and the vertebral body cortical thickness values were obtained. CT Spine Bone Quantification System is a software for quantitative analysis and separation of cortical bone and cancellous bone. A total of 150 patients were enrolled in this study, including 49 patients in the osteoporosis group, 51 patients in the osteopenia group, and 50 patients in the normal group. The cortical thickness values of T11, T12 and L1 were positively correlated with BMD, and the correlation coefficient was 0.750 at T11. According to the receiver operating characteristic (ROC) curve analysis of T11, T12, L1 cortical thickness value and BMD, OP was diagnosed when T11<2.75mm, T12<3.06mm, and L1<2.67mm. The sensitivity was 83.67%, 87.76%, 75.51%, respectively. The specificity was 79.21%, 71.29% and 90.10%, respectively, and the difference was statistically significant. Vertebral body cortical thickness is correlated with BMD and age. According to the cut-off value of different vertebral bodies, OP can be predicted when T11<2.75mm or T12<3.06mm or L1<2.67mm.

Characterization of rat vertebrae cortical bone microstructures using confocal Raman microscopy combined to tomography and electron microscopy

BackgroundThe rat vertebrae is a good model to study bone regeneration after implantation of biomaterials used to treat bone loss, a major problem in oral and dental surgery. However, the precise characterization of bone microstructures in the rat vertebrae has not been reported. Therefore, the aim of this study was to achieve the complete analysis of such bone, at different scales, in order to have a clear model of healthy bone for comparison with regenerated bone. MethodsIn order to image the cortical bone of rat caudal vertebra, confocal Raman microscopy was combined with high resolution X-ray micro computed tomography (micro-CT), with scanning electron microscopy (SEM) using backscatter electron imaging and with more conventional histology coloration techniques. SEM and Raman microscopy were done in various regions of the cortical bone corresponding to external, middle and internal areas. The spongy bone was imaged in parallel. Micro-CT was performed on the whole vertebra to monitor the network of haversian canals in the cortical bone. Osteonic canals characteristics, and relative chemical composition were analysed in several regions of interest, in cortical and spongy bone. Five rats were included in this study. ResultsOn micro-CT images, differences in intensity were observed in the cortical bone, substantiated by SEM. Chemical analysis with Raman spectra confirmed the difference in composition between the different regions of the cortical and spongy bone. PCA and k-mean cluster analysis separated these groups, except for the external and middle cortical bone. Peak intensity ratio confirmed these results with a CO3 to ν2 PO4 ratio significantly different for the internal cortical bone. Grayscale images stack extracted from micro-CT showed that global architecture of cortical bone was characterized by a dense and complex network of haversian osteonic canals, starting from the surface towards the vertebrae center. The mean diameter of the canals was 18.4 µm (SD 8.6 µm) and the mean length was 450 µm (SD 152 µm). Finally, Raman reconstructed images of the lamellar bone showed an enlargement of the lamellar layer width, both in circumferential lamellar bone and around haversian canals. ConclusionsMicro-CT and confocal Raman microscopy are good tools to complete classical analysis using optical and electron microscopy. The results and measurements presented in a rat model known for its small inter-individual differences provide the main characteristics of a mature bone. This study will allow the community working on this rat vertebrate model to have a set of characteristics, in particular on the structure of the haversian canals.

Alloferon-1 ameliorates estrogen deficiency-induced osteoporosis through dampening the NLRP3/caspase-1/IL-1β/IL-18 signaling pathway

Alloferon-1 is an insect polypeptide that has anti-inflammatory, antitumor and antiviral activity. This study aimed to determine the effects of alloferon-1 on estrogen deficiency-induced osteoporosis and explore the associated mechanism using a murine model of ovariectomy (OVX)-induced osteoporosis. Results showed that alloferon-1 prevented ovariectomy‑induced body weight gain, bone loss and bone mineral content reduction, affected biochemical markers of bone turnover, and restored the microstructure of bone trabeculae. Moreover, alloferon-1 suppressed the expression of the ovariectomy‑mediated inflammatory cytokines in the vertebrae bone tissues, including nucleotide-binding oligomerization domain-like-receptor family pyrin domain-containing 3 (NLRP3), cysteinyl aspartate specific proteinase-1 (Caspase-1), interleukin 1β (IL-1β) and interleukin 18 (IL-18) which were determined by immunofluorescence staining and western blot. Overall, the present study provides evidence for the effectiveness of alloferon-1 against estrogen deficiency-induced osteoporosis, suggesting an alternative drug or an auxiliary modulator for the treatment of postmenopausal osteoporosis (PMOP).

Combinations of two imaging parameters to improve bone mineral density (BMD) assessment in patients with lumbar degenerative diseases

PurposeTo explore whether combining the Hounsfield unit (HU) values and vertebral bone quality (VBQ) scores can improve the BMD assessment in patients with lumbar degenerative diseases.MethodsThe HU values were measured by CT image, and VBQ scores were calculated by lumbar MRI image. The correlations of the opportunistic imaging parameters to the lowest T-scores were analyzed. Receiver-operating characteristic curve (ROC) analysis was used to evaluate the accuracy in detecting osteoporosis. Finally, the specificity and sensitivity of different combined methods of the HU values and VBQ scores in the diagnosis of osteoporosis were compared.ResultsPatients with osteoporosis had the lowest HU values and the highest VBQ scores. The correlation coefficients between the VBQ scores and the T-scores were smaller than HU values (L1 HU value: 0.702; average HU value:0.700; L1 VBQ score: -0.413; VBQ score: -0.386). The areas under the curve (AUCs) of the HU values were greater than those of the VBQ scores, and the AUCs of the L1 VBQ score were similar to the VBQ score (L1 HU value: 0.850; average HU value:0.857; L1 VBQ score: 0.704; VBQ score: 0.673). When combining the two imaging parameters in series, the specificity of the detection of osteoporosis was improved (L1 HU value and L1 VBQ score: 87.3%; Average HU value and VBQ score: 85.9%). When combining the two imaging parameters in parallel, the sensitivity of the detection of osteoporosis was improved (L1 HU value or L1 VBQ score: 88.1%; Average HU value or VBQ score: 91.5%).ConclusionsCombinations of the HU values and VBQ scores could improve the diagnostic performance of osteoporosis. In addition, considering the same diagnostic performance but easier measurement, parameters at the single-segment level were recommended to assist in the diagnosis of osteoporosis.

Efficacy of two opportunistic methods for screening osteoporosis in lumbar spine surgery patients.

Hounsfield unit (HU) measurements and vertebral bone quality (VBQ) scores are opportunistic screening methods for evaluating bone quality. Since studies comparing the efficacies of the two methods are rare, this retrospective study aimed to examine the efficacy of VBQ scores compared with that of HU measurements for diagnosing osteoporosis in lumbar spine surgery patients. We selected patients who had undergone spinal surgery between January 2020 and May 2022 from our database. The VBQ scores based on magnetic resonance imaging (MRI) and HU measurements based on computed tomography (CT) were calculated. Correlation analysis of the dual-energy X-ray absorptiometry (DEXA) T score and study parameters was performed. The Delong test and decision curve analysis (DCA) were used to compare the efficacies of the two methods. We included 118 consecutive patients who underwent selective spinal surgery. The VBQ score and HU measurement were significantly correlated with the DEXA T score. Based on the Delong test, HU measurement predicted osteoporosis more effectively than the VBQ score did. The DCA revealed that the VBQ score performed better than the HU measurement did. The calculation of VBQ scores is a novel opportunistic screening method for diagnosing osteoporosis; however, CT-based HU measurements outperform MRI-based VBQ scores. HU measurements can be used as a screening method when pre-operative CT scans are available.

The Effect of Halo-Pelvic Traction on Bone Mineral Density of Vertebrae and Corresponding Risk Factors.

Decreased bone mineral density (BMD) is associated with complications in implantation surgery for severe spinal deformity. In this quantitative study, we aimed to investigate the impact of halo-pelvic traction on vertebral bone mineral density (BMD) and identify the risk factors for a decrease in BMD. Patients who underwent halo-pelvic traction at our hospital between 2019 and 2022 were included in the study. Patients' data, including height, weight, and BMD pre- and post-traction, were collected and analyzed. Quantitative computed tomography (QCT) was used to determine the BMD. The paired rank sum test was used to evaluate the changes in each measurement parameter. Linear regression was used to identify risk factors for a decrease in BMD. Fifteen patients were included in the study, nine women and six men, with an average age of 21.2 ± 7.3 years. Eleven patients had severe rigid scoliosis, while four had tuberculotic kyphosis. One expert measured the BMD values of 345 vertebrae using QCT. The average traction time was 143.3 ± 44.4 days. The average pre-traction BMD was 183.1 ± 73.8 mg/cm3 , and the average post-traction BMD was 140.5 ± 61.3 mg/cm3 (p < 0.01) Patients' height increased from an average of 151.3 ± 12.8 cm pre-traction to 165.5 ± 13.7 cm post-traction (p < 0.01), with traction length averaging 14.3 ± 6.2 cm (p < 0.01). The Cobb angle of the main curve declined from an average of 112.5° ± 24.4° pre-traction to 67.7° ± 19.8° post-traction (p < 0.01). Linear regression revealed a positive correlation between BMD loss and traction length and a negative correlation between BMD loss and correction rate. Halo-pelvic traction can lead to a decrease in the BMD of the spinal vertebrae, with traction length positively correlated with BMD loss and correction rate negatively correlated with BMD loss. To prevent osteoporosis, physicians should ensure a limited traction length while utilizing better management techniques.