Locations of bone tissue at high risk of initial failure during compressive loading of the human vertebral body

In generalized osteoporosis, instrumentation with cement-augmented pedicle screws is an amplification of the therapeutic spectrum. Early clinical results are promising for both solid and cannulated screws; however, there are concerns regarding the revision characteristics of these screws, especially for the cannulated-fenestrated type with its continuous cement interconnection from the core of the screw to surrounding bone tissue. In a human cadaver model, bone mineral density (BMD) was assessed radiographically. Spinal levels T9–L4 were instrumented left unilaterally, transpedicularly by using cannulated-fenestrated pedicle screws with the dimensions 6.5 × 45 mm. Polymethylmethacrylate cement (1.5 ml) was injected through the screws into each vertebra. After polymerization of the cement, the extraction torque was recorded. For both implantation and explantation of the screws, a fluoroscope was used to guarantee correct screw and cement positioning and to observe possible co-movements—that is, any movement of the cement mass within the vertebral body upon removal of the screw. For comparison, the extraction torque of same-dimension pedicle screws was recorded in a nonosteoporotic, non–cement-augmented instrumentation. The BMD was 0.60 g/cm2, a level that corresponds to a severe grade of osteoporosis. For removal of the screws, the median and mean extraction torques were 34 and 49 ± 44 Ncm, respectively. No co-movements of the cement mass occurred within the vertebral body. In the nonosteoporotic control, BMD was 1.38 g/cm2. The median and mean extraction torques were 123 and 124 ± 12 Ncm, respectively. Thus, the revision characteristics of cement-augmented, cannulated-fenestrated pedicle screws are not problematic, even in cases of severe osteoporosis. The winglike cement interconnection between the screw core and surrounding bone tissue is fragile enough to break off in the event of an extraction torque and to release the screw. There is no proof to support the theoretical fear that while trying to remove a screw, the composite of screw and cement would not break but instead would rotate as a whole in the osteoporotic vertebral body.

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Risk of Fracture After Single Fraction Image-Guided Intensity-Modulated Radiation Therapy to Spinal Metastases

Journal of Clinical Oncology ◽

10.1200/jco.2008.19.3508 ◽

2009 ◽

Vol 27 (30) ◽

pp. 5075-5079 ◽

Cited By ~ 218

Author(s):

Peter S. Rose ◽

Ilya Laufer ◽

Patrick J. Boland ◽

Andrew Hanover ◽

Mark H. Bilsky ◽

...

Keyword(s):

Radiation Therapy ◽

Vertebral Fracture ◽

High Risk ◽

Vertebral Body ◽

Spinal Metastases ◽

Intensity Modulated Radiation Therapy ◽

Risk Of Fracture ◽

Single Fraction ◽

Image Guided ◽

Intensity Modulated

Purpose Single-fraction image-guided intensity-modulated radiation therapy (IG-IMRT) allows for tumoricidal treatment of traditionally radioresistant cancers while sparing critical adjacent structures. Risk of vertebral fracture after IG-IMRT for spinal metastases has not been defined. Patients and Methods We evaluated 62 consecutive patients undergoing single fraction IG-IMRT at 71 sites for solid organ metastases. A neuroradiologist and three spine surgeons evaluated prospectively obtained magnetic resonance/computed tomography (CT) imaging studies for post-treatment fracture development and tumor recurrence. Results Fracture progression was noted in 27 vertebrae (39%). Multivariate logistic regression analysis showed that CT appearance, lesion location, and percent vertebral body involvement independently predicted fracture progression. Lesions located between T10 and the sacrum were 4.6 times more likely to fracture than were lesions above T10 (95% CI, 1.1 to 19.7). Lytic lesions were 6.8 times more likely to fracture than were sclerotic and mixed lesions (95% CI, 1.4 to 33.3). As percent vertebral body involvement increased, odds of fracture also increased. Patients with fracture progression had significantly higher narcotic use, change in Karnofsky performance score, and a strong trend toward higher pain scores. Local tumor progression occurred in seven patients and contributed to one fracture. Obesity, posterior element involvement, bisphosphonate use, and local kyphosis did not confer increased risk. Conclusion Vertebral fracture is common after single fraction IG-IMRT for metastatic spine lesions. Lytic disease involving more than 40% of the vertebral body and location at or below T10 confer a high risk of fracture, the presence of which yields significantly poorer clinical outcomes. These results may help clinicians identify high-risk patients who would benefit from prophylactic vertebro- or kyphoplasty.

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SIMULATION ON TISSUE DIFFERENTIATIONS FOR DIFFERENT ARCHITECTURE DESIGNS IN BONE TISSUE ENGINEERING SCAFFOLD BASED ON CELLULAR STRUCTURE MODEL

Journal of Mechanics in Medicine and Biology ◽

10.1142/s0219519415500281 ◽

2015 ◽

Vol 15 (03) ◽

pp. 1550028 ◽

Cited By ~ 4

Author(s):

XIANBIN ZHANG ◽

HE GONG

Keyword(s):

Tissue Engineering ◽

Fluid Flow ◽

Bone Tissue Engineering ◽

Bone Tissue ◽

Compressive Loading ◽

Three Dimensional ◽

Mechanical Stimuli ◽

Interstitial Fluid Flow ◽

Unconfined Compression Test ◽

Defect Sites

In bone tissue engineering, mechanical stimuli are among the key factors affecting cell proliferation and differentiation. This study aimed to investigate the effects of different inlet fluid velocities and axial strains on the differentiation of bone marrow mesenchymal stem cells (BMSCs) on the surface of scaffolds with different morphologies. Five three-dimensional bone scaffold architectures with 65% porosity were designed using typical cellular structural models of trabecular bone. Apparent compressive strains between 0% and 5% were applied to simulate an unconfined compression test. Strain distributions were analyzed on the wall surface of the solid model. The interstitial fluid flow at inlet velocities ranging between 0.01 mm/s and 1 mm/s was applied to interconnected pores, simulating a steady state flow in the scaffold. The shear stress distributions on the surface of the scaffolds were calculated. The differentiation of BMSCs on the surface of the scaffolds with different morphologies was predicted according to mechanoregulation theory. This study shows that different levels of mechanical stimuli can be generated as a result of different scaffold morphologies under compressive loading and fluid flow to satisfy the mechanical requirements for different bone defect sites.

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Peculiarities of Reparative Osteogenesis of Injured Thoracic and Lumbar Vertebral Bodies at Different Terms after Trauma

N.N. Priorov Journal of Traumatology and Orthopedics ◽

10.17816/vto201623444-49 ◽

2016 ◽

Vol 23 (4) ◽

pp. 44-49

Author(s):

N. V Bogomolova ◽

A. E Shul’ga ◽

V. V Zaretskov ◽

A. A Smol’kin ◽

I. A Norkin

Keyword(s):

Bone Tissue ◽

Vertebral Body ◽

Mineral Density ◽

Active Growth ◽

Normal Cycle ◽

Lumbar Vertebral Body ◽

Vertebral Bodies ◽

Males And Females ◽

Serial Samples ◽

Body Bone

The analysis of the results of morphologic examination of vertebral body bone tissue obtained intraoperatively from 43 patients (20 - 67 years) with thoracic and lumbar spine injuries at different terms after trauma was performed. All patients were operated on via anterior approach to create ventral fusion. In the examined serial samples of vertebral body structures the quality and regeneration potential of bone tissue were assessed. It was shown that cell differentiation during the osteogenesis process was closely associated with angiogenesis. In the zones with active growth of microcirculatory bed vessels the normal cycle of osteoblast and osteocytes took place while hypoxia and acidosis resulted in pathologic osteogenesis. In patients under 50 years, both males and females) the full value consolidation time averaged 5 months. In patients over 50 years, independently of the gender, the decrease of spongy structures volume and bone mineral density was observed. The recommendations on surgical treatment tactics of patients with thoracic and lumbar vertebral body injuries were given.

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Experimental substantiation of osteotransplant application in traumatic vertebral defects

Hirurgiâ pozvonočnika ◽

10.14531/2018.4.41-51 ◽

2018 ◽

Vol 15 (4) ◽

pp. 41-51

Author(s):

V. V. Rerikh ◽

Yu. A. Predein ◽

A. M. Zaidman ◽

A. D. Lastevsky ◽

V.A. Bataev V.A. Bataev V.A. Bataev ◽

...

Keyword(s):

Bone Graft ◽

Bone Tissue ◽

Vertebral Body ◽

Morphological Structure ◽

Allogeneic Bone ◽

X Ray ◽

Organ Specific ◽

Ray Density ◽

Vertebral Defects

Objective. To analyze the features of bone tissue formation during plasty of vertebral body defect or fracture with an allogeneic bone graft in an experiment in vitro. Material and Methods. Models of the vertebral body defect (fracture of the cranioventral part with penetration into the nucleus pulposus) were created in an experiment on 20 mini-pigs of the same age. Plasty of traumatic defects was performed with allogeneic bone graft or autologous bone. CT, histological, and spectrometric studies of microscopic specimens were carried out at 14, 30, 90, and 180 day. Reparative osteogenesis, X-ray density, Ca and P content, and microhardness were studied. Results. After implantation of allogeneic bone graft, an organ-specific bone similar to the recipient’s bone in morphological structure, X-ray density, mineral composition and microhardness, was formed on the 90th day (P = 0.01). After transplantation of autobone, the regenerate formed by this day in the central part was in a phase of resorption and restructuring with lower indices of X-ray density, content of Ca and P, and microhardness (P = 0.01). Conclusion. Аfter plasty of vertebral body traumatic defects with allogeneic bone graft, the organ-specific bone tissue is formed at an earlier time and reliably exhibits greater mineralization and strength.

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The peculiarities of osteal system maturation in patients w ith primary estrogenic deficit

Journal of obstetrics and women s diseases ◽

10.17816/jowd89284 ◽

2021 ◽

Vol 50 (1) ◽

pp. 64-68

Author(s):

E. V. Uvarova ◽

A. I. Volobuev ◽

T. V. Rudneva ◽

S. V. Rudnev

Keyword(s):

High Risk ◽

Bone Tissue ◽

Gonadal Dysgenesis ◽

Skeletal System ◽

Ovarian Insufficiency ◽

Peak Density

In patients with congenital ovarian insufficiency, particularly with gonadal dysgenesis, the retarded bone remodelingprevents the bone tissue from achieving its final, peak density and leads to the lagging of skeletal system maturation. This may result in high risk of limb and backbone fractures.The article analyzes the results of the examination of 142 patients with different forms of gonadal dysgenesis. The treatment included the preparations containing estrogens, which were identical with natural ones (Divina, Divitren, Divigel). The data received substantiate the necessity of eliminating the estrogenic deficit in patients with gonadal dysgenesis earlier than it is usually done.

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MORPHOLOGY OF THE INTERVERTEBRAL DISK AND BONE TISSUE OF APOPHIZES OF VERTEBRAL BODY AT MODELING OSTEOPOROSIS

Bulletin of Problems Biology and Medicine ◽

10.29254/2077-4214-2018-1-1-142-285-291 ◽

2018 ◽

Vol 1.1 (142) ◽

pp. 285

Author(s):

S. B. Kosterin ◽

N. V. Dedukh ◽

V. E. Maltseva

Keyword(s):

Bone Tissue ◽

Vertebral Body ◽

Intervertebral Disk

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Convergence analysis and validation of a discrete element model of the human lumbar spine

Reports in Mechanical Engineering ◽

10.31181/rme200103062e ◽

2022 ◽

Vol 3 (1) ◽

pp. 62-70

Author(s):

Galina Eremina ◽

◽

Alexey Smolin ◽

Irina Martyshina ◽

◽

...

Keyword(s):

Lumbar Spine ◽

Intervertebral Disc ◽

Bone Tissue ◽

Vertebral Body ◽

Loading Rate ◽

Numerical Models ◽

Fold Increase ◽

Intervertebral Discs ◽

Effective Stiffness ◽

Structural Element

Degenerative diseases of the spine can lead to or hasten the onset of additional spinal problems that significantly reduce human mobility. The spine consists of vertebral bodies and intervertebral discs. The most degraded are intervertebral discs. The vertebral body consists of a shell (cortical bone tissue) and an internal content (cancellous bone tissue). The intervertebral disc is a complex structural element of the spine, consisting of the nucleus pulposus, annulus fibrosus, and cartilaginous plates. To develop numerical models for the vertebral body and intervertebral disc, first, it is necessary to verify and validate the models for the constituent elements of the lumbar spine. This paper, for the first time, presents discrete elements-based numerical models for the constituent parts of the lumbar spine, and their verification and validation. The models are validated using uniaxial compression experiments available in the literature. The model predictions are in good qualitative and quantitative agreement with the data of those experiments. The loading rate sensitivity analysis revealed that fluid-saturated porous materials are highly sensitive to loading rate: a 1000-fold increase in rate leads to the increase in effective stiffness of 130 % for the intervertebral disc, and a 250-fold increase in rate leads to the increase in effective stiffness of 50 % for the vertebral body. The developed model components can be used to create an L4-L5 segment model, which, in the future, will allow investigating the mechanical behavior of the spine under different types of loading.

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Vertebral hemangiosarcoma as a cause of spinal cord compression in a horse

Ciência Rural ◽

10.1590/s0103-84781997000300024 ◽

1997 ◽

Vol 27 (3) ◽

pp. 503-504 ◽

Cited By ~ 4

Author(s):

Claudio Severo Lombardo de Barros

Keyword(s):

Spinal Cord ◽

Bone Tissue ◽

Vertebral Body ◽

Spinal Cord Compression ◽

Hind Limb ◽

Wallerian Degeneration ◽

Cord Compression ◽

Vertebral Canal

A case compression of the spinal cord in a horse by a tumor located in the vertebra is described. A 10-year-old gelding was euthanized after being found recumbent with hind limb paresis of unknown duration. At necropsy an hemangiosarcoma was detected in the vertebral body of T3. The tumoral mass invaded upwards through the bone tissue of the vertebral body into the vertebral canal, compressing the spinal cord and causing Wallerian degeneration at T1-3 levels of the cord.

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