scholarly journals Biomechanics and Numerical Evaluation of Cervical Porcine Models Considering Compressive Loads Using 2-D Classic Computer Tomography CT, 3-D Scanner and 3 -D Computed Tomography

2010 ◽  
Vol 24-25 ◽  
pp. 287-295 ◽  
Author(s):  
Juan Alfonso Beltrán-Fernández ◽  
Luis Héctor Hernández-Gómez ◽  
G. Urriolagoitia-Calderón ◽  
A. González-Rebatú ◽  
G. Urriolagoitia-Sosa
Keyword(s):  
Titanium Alloy ◽  
Bone Graft ◽  
Vertebral Body ◽  
Computer Tomography ◽  
Numerical Evaluation ◽  
Ct Scanning ◽  
Biomechanical Behavior ◽  
Compressive Loads ◽  
Classic Technique ◽  
Cervical Plate

In this paper the biomechanical behavior and numerical evaluation results of three C3-C5 porcine cervical models created with different modeling techniques are shown. The objective of this evaluation is to know the differences between the biomechanical effects on a bone graft, which replaces a damaged C4 vertebral body, a titanium alloy (Ti-6A1-4V) cervical plate, used to isolate the C4 damaged vertebra, and the influence on the compressive loads on the complete and instrumented C3-C5 cervical model. The biomechanical integrity of the healthy C3 and C5 vertebral body after the fixation of the cervical plate using titanium alloy screws is considered. Besides, 2-D Computer Tomography classic technique, 3-D Scanner Z-Corp 700 and a CT scanning Philips Brilliance system was used to create the three FEM models. In addition, 3-D Software as Pro-E Wildfire 4.0, ScanIP 3.1, UGS NX-4 and Geomagics R 10.0 was used to create specific numerical model. Main displacements and von Misses stresses between the upper and lower surfaces of the vertebral bodies and the bone graft and the influence of the titanium alloy (Ti-6A1-4V) screws on the vertebral body of C3 and C5 were evaluated. The contribution of this study is to optimize the actual surgical technique once the numerical results on the FEM model have been analyzed. In other words, the numerical disparity between classic CT techniques versus 3-D modern techniques is established.

Use of a nano-hydroxyapatite/polyamide composite in anterior cervical subtotal corpectomy and fusion

2021 ◽  
Vol 11 (9) ◽  
pp. 1491-1496
Author(s):  
Xiaojiang Li ◽  
Xudong Zhang ◽  
Shanshan Dong ◽  
Haijun Li ◽  
Chunlan Wang ◽  
...  
Keyword(s):  
Bone Graft ◽  
Vertebral Body ◽  
Cervical Spondylotic Myelopathy ◽  
Interbody Fusion ◽  
Japanese Orthopaedic Association ◽  
Fusion Rate ◽  
Graft Material ◽  
Improvement Rate ◽  
Fusion Surgery ◽  
Cervical Vertebral Body

This study aimed to explore the safety and efficacy of using nano-hydroxyapatite/polyamide (N-HA/PA) composite in anterior cervical vertebral body subtotal corpectomy and interbody fusion. Total 50 patients with cervical spondylotic myelopathy were enrolled to undergo anterior cervical spondylectomy. Bone graft pedicles were compounded with N-HA/PA and intervertebral body fusion was performed. Study outcomes included surgical efficacy and the degree of fusion. Patients in whom vertebral body fusion was performed with N-HA/PA composite pedicles had significantly improved symptoms. The postoperative Japanese Orthopaedic Association scores increased to 18.56±4.37 from 11.37±3.52, reflecting an improvement rate of 87.3%. The composite pedicle fusion rate was 96.4%. Therefore, N-HA/PA composite pedicle as a bone graft material in fusion surgery provides significant therapeutic efficacy. Moreover, the composite pedicle fusion rate is high, making it ideal for anterior cervical vertebral body subtotal corpectomy and fusion.

scholarly journals Mechanical Behavior of a Calcium Phosphate Ceramic Bone Graft Used in the Rehabilitation of a C4 Human Vertebra

2007 ◽  
Vol 7-8 ◽  
pp. 101-106 ◽  
Author(s):  
Juan Alfonso Beltrán-Fernández ◽  
Luis Héctor Hernández-Gómez ◽  
R.G. Rodríguez-Cañizo ◽  
G. Urriolagoitia-Calderón ◽  
G. Urriolagoitia-Sosa ◽  
...  
Keyword(s):  
Bone Graft ◽  
Experimental Tests ◽  
Element Model ◽  
Calcium Phosphate Ceramic ◽  
Compression Load ◽  
Head Weight ◽  
Anterior Side ◽  
Average Patient ◽  
On Line ◽  
Cervical Plate

The main results of a static analysis with a finite element model of the cervical section between C3 – C5 of a human spine are reported. In this case, it is assumed that the element C4 is completely damaged and has to be replaced. Therefore, a bone graft was installed between the anterior side of C3 and C5. Besides, a cervical plate of 55 mm. was fixed at the same side with 4 expansive screws. The resultant stresses caused by compression loads were analyzed and the displacements between the graft and adjacent vertebrae were calculated. Three loading conditions were applied: 80 N, 637.5 N and 6374.5 N. The first one corresponds to the head weight. In the second case, it is assumed that the average patient weight is supported by those vertebrae, while in the last one; the compression load failure is applied on the vertebrae. Results show that displacements were lower than 3 mm between the graft and the adjacent vertebrae. In accordance with the concept of spine stability after Müller [1], the arrangement is a stable one. Another advantage is that no wires are used in this surgical technique. Two more issues should be noticed. There is no risk that the plate may be broken and the geometry of the bone graft allows bone regeneration. These results are on line with those observed in preliminary experimental tests with porcine vertebrae.

Effects of Vertebral Body Changes on Cervical Spine Load Sharing

2002 ◽  
Author(s):  
Jiangyue Zhang ◽  
Narayan Yoganandan ◽  
Frank A. Pintar
Keyword(s):  
Cervical Spine ◽  
Young’S Modulus ◽  
Vertebral Body ◽  
Modulus Of Elasticity ◽  
Young's Modulus ◽  
Compressive Force ◽  
Axial Compressive Force ◽  
Inferior Surface ◽  
Biomechanical Behavior ◽  
Young’S Modulus Of Elasticity

The objective of the study was to determine the effects of changes in the Young’s modulus of elasticity of the cancellous bone that occur due to the ageing process on the biomechanical behavior of the cervical spine. An anatomically accurate three-dimensional (3-D) nonlinear finite element model of the C4-C5-C6 cervical spinal unit was used. The inferior surface of the C6 vertebrae was fixed in all degrees of freedom, and external loads were applied to the top surface of the C4 vertebra. The model was exercised under an axial compressive force of 754 N. In addition, flexion and extension bending moments of 3.44 Nm were applied individually to the model. The effects of ageing on bone strength were simulated by decreasing the Young’s modulus of elasticity from 100 MPa in the healthy spine to 40 MPa in the degenerated spine. The degenerated spine was found to be more flexible than the healthy spine. In addition, the degenerated spine responded with increased forces in the outer anterior and posterior regions of the vertebral body. Furthermore, forces in the facet joints increased in the degenerated spine. In contrast, the middle region of the disc showed decreased forces. These increases in the forces leading to stress risers may explain the occurrence of osteophytes in the spine with age.

scholarly journals Experimental substantiation of osteotransplant application in traumatic vertebral defects

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.

scholarly journals Biomechanical Effects of Polyetheretherketone and Titanium Rods in Transforaminal Lumbar Interbody Fusion: A Finite Element Analysis

2021 ◽  
Author(s):  
Jie Li ◽  
Shuai Cao ◽  
Jie Wang ◽  
Gaoyang Zong ◽  
Hao Qiao ◽  
...  
Keyword(s):  
Finite Element ◽  
Bone Graft ◽  
Interbody Fusion ◽  
Transforaminal Lumbar Interbody Fusion ◽  
Lumbar Interbody Fusion ◽  
Element Analysis ◽  
Positive Role ◽  
Biomechanical Behavior ◽  
Peek Rods ◽  
Rod System

Abstract Background: Currently, the comprehensive biomechanical evaluation of polyetheretherketone (PEEK) rods in transforaminal lumbar interbody fusion (TLIF) is limited. The purpose of this study was to compare the biomechanical differences between titanium alloy (Ti) rods and PEEK rods in TLIF. Methods: L3-5 lumbar models were developed using the finite element method. Four surgical models of TLIF were constructed by simulating different fusion methods and rods: cage fusion with Ti rods, cage fusion with PEEK rods, bone graft alone with Ti rods, and bone graft alone with PEEK rods. The range of motion (ROM) and stress distribution of the surgical and adjacent segments were then compared. Results: Compared to the Ti rods, the PEEK rods increased the ROM by 0.7–20% at the L4/5 segment and decreased the ROM by 0.8–15.1% at the L3/4 segment. The disc stresses at the L3/4 level were similar among the surgical models (0.79–1.80 MPa). The peak stresses of the screws, rods, and bone-screw interfaces in the PEEK rod models were 0–1.2 times, 1.6–4.4 times, and 0–1.4 times lower than those of the Ti rod models, respectively. PEEK rods increased the average strain of the bone graft by 0.5–61.6% and the stresses of the cage by 0.9–44.1% and endplates by 2.1–52.9%. Conclusion: In TLIF, PEEK rods played a positive role in restoring the ROM. They also increased the strain of the bone graft, stresses of the endplates and cages, and the risk of rod fracture and reduced the stress of the screw-rod system. Bone grafts alone combined with PEEK rods had acceptable biomechanical behavior in TLIF.

Reconstructing Nanohydroxyapatite Prosthesis Based on CT-Scanning Data and Its Application in Spinal Injury

2021 ◽  
Vol 17 (9) ◽  
pp. 1745-1753
Author(s):  
Jian Wang ◽  
Ying Li ◽  
Ting Xu ◽  
Jie Zhao ◽  
Cuihua Yuan ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Spinal Injury ◽  
Ct Scanning ◽  
Fusion Rate ◽  
Titanium Mesh ◽  
Mesh Group ◽  
Vertebral Fusion ◽  
Foreign Body Reactions ◽  
Asia Score

This study investigated the nanohydroxyapatite (nHA) prosthesis application effect based on CT-scanning data in spinal injury. This study chose 26 spinal injury patients treated in our hospital from September 2017 to September 2018, who were randomly divided into two groups. nHA prosthesis based on CT-scanning data was implanted in the nHA group, whereas titanium mesh was implanted in the titanium mesh group. Consequently, osteoblasts were cultured to test the biological activity of nHA and titanium alloy. In cell tests, we found osteoblasts could better adhere to nHA, and proliferation and activity were higher when planted on nHA material. After surgical treatment, all patients’ spinal symptoms (VAS score, JOA score, and Cobb angle) had improved and did not cause obvious inflammatory foreign body reactions. During a two-year follow-up, the fusion time and support settlement in the nHA group was lower, and the vertebral fusion rate and ASIA score were higher than those in the titanium mesh group. Thus, CT-scanning data could further improve the vertebral fusion rate in the nHA group. Consequentially, nHA prosthesis based on CT-scanning data is a better choice for spinal injury therapy.

Krónikus dialízis kapcsán kialakult destruktív cervicalis spondylarthropathia esete

2021 ◽  
Vol 74 (5-6) ◽  
pp. 211-215
Author(s):  
Balázs Berta ◽  
Hedvig Komáromy ◽  
Attila Schwarcz ◽  
Béla Kajtár ◽  
András Büki ◽  
...  
Keyword(s):  
Bone Graft ◽  
Vertebral Body ◽  
Posterior Instrumentation ◽  
Plate Fixation ◽  
Neurological Deficits ◽  
Pulmonary Insufficiency ◽  
Unstable Fracture ◽  
Pathologic Fractures ◽  
Vertebral Bodies

A case of a 61-year-old male patient suffered chronic renal failure and dialysed for 23 years with destructive cervical spondylarthropathy is presented. The patient presented with sudden onset of cervical pain radiating into his shoulders without neurological deficits. CT and MRI of the cervical and thoracic spine revealed severe destructive changes and compressive fractures of C6 and C7 vertebrae which caused the narrowing of the nerve root canals at these levels. A 360-degree fixation was performed to treat the unstable fracture and the patient’s pain (C6 and C7 corpectomy, autolog bone graft replacement of the two vertebral bodies, anterior plate fixation and posterior instrumentation with screws and rods). Postoperatively the patient had no significant pain, no neurological deficit and he was able to manage independent life himself. During the immediate follow-up CT of the neck showed the satisfactory position of the bone graft and the metal implantations. The 6 months follow-up CT revealed the anterior migration of the two screws from the Th1 vertebral body and 2 mm ventral elevation of the caudal end of the plate from the anterior surface of the Th1 vertebral body. The 1-year follow-up could not be performed because the patient died due to cardio-pulmonary insufficiency. This is the second Hungarian report of a chronic dialysis related severe spondylarthropathy which may cause pathologic fractures of the vertebral bodies. The typical radiological and histological findings are discussed. This disease affect patients’ quality of life and the conservative treatment alone seems to be ineffective in most cases. Based on the literature and personal experiences, the authors suggest 360-degree fixation of the spine to provide sufficient stability for the vertebrae of ”bad bone quality”, and early mobilisation of the patient can be achieved.

Sign in / Sign up

Export Citation Format

Share Document