Finite Element Investigations of the Proximal Femur After Implantation of the Thrust Plate Prosthesis Compared with Findings in a Post-mortem Histological Specimen and in Radiological Follow-Up Examinations

1997 ◽  
pp. 48-62 ◽  
Author(s):  
H. Bereiter ◽  
M. Bürgi ◽  
R. Schenk
Keyword(s):  
Finite Element ◽  
Proximal Femur ◽  
Post Mortem ◽  
Thrust Plate Prosthesis ◽  
Histological Specimen

Mechanical strength of a femoral reconstruction in paediatric oncology: A finite element study

2003 ◽  
Vol 217 (2) ◽  
pp. 111-119 ◽  
Author(s):  
F Taddei ◽  
M Viceconti ◽  
M Manfrini ◽  
A Toni
Keyword(s):  
Finite Element ◽  
Mechanical Strength ◽  
Bone Tissue ◽  
Proximal Femur ◽  
Morphological Changes ◽  
Equivalent Stress ◽  
Bone Allograft ◽  
Risk Of Fracture ◽  
Vascularized Fibula

In 1997 the proximal femur of a four-year-old child affected by a Ewing sarcoma was reconstructed using a massive bone allograft in conjunction with a vascularized fibula autograft. During the first three years of follow-up the reconstruction underwent important morphological changes. The aim of the present study was to evaluate the risk of fracture of the reconstructed proximal femur, once the physiological loads are restored, associated with a short, slow but unprotected level walk. Subject-specific finite element models of the operated femur, and of the intact contralateral one, were generated from a computed tomography exam, taken for routine clinical monitoring at month 33 of follow-up. The material properties were mapped on to the mesh and a loading condition comprising the hip joint reaction and the abductor muscle force was simulated. The risk of fracture was locally estimated, for the operated and intact femur, using the ratio between the bone tissue strength and the predicted Von Mises equivalent stress, taking into account the different behaviours of the bone tissue in tension or compression. The results showed that although the fibula grew dramatically during follow-up, the reconstructed femur had not recovered the whole mechanical strength of a normal femur. The reconstructed femoral neck seemed to be weaker than the contralateral one and hence at a higher fracture risk. However, no region reached the failure limit, so the model predicted no fracture of the femur if a short, slow but unprotected walk were allowed. The model predictions found an indirect clinical validation when the child was allowed to perform short unprotected walks and did not experience any fracture.

Bone and Bone Marrow Blood Flow in Blastic Crisis of Chronic Granulocytic Leukaemia

1979 ◽  
Vol 18 (06) ◽  
pp. 290-292 ◽  
Author(s):  
R. Lahtinen ◽  
T. Lahtinen
Keyword(s):  
Bone Marrow ◽  
Cell Proliferation ◽  
Blood Flow ◽  
Proximal Femur ◽  
Blastic Crisis ◽  
Normal Bone ◽  
Chronic Granulocytic Leukaemia ◽  
Washout Curves ◽  
Bone Marrow Blood

SummaryA l33Xe washout method has been used for measuring changes of blood flow in the proximal femur of a patient with the blastic crisis of chronic granulocytic leukaemia. In the hyperplastic phase the blood flow was highly increased and over three times greater than in the hypoplastic phase of the disease and over thirteen times greater than the value in normal bone. The bone circulation and especially the first component of the two-exponential bone washout curves appeared to reflect cell proliferation and neoplastic activity of the whole bone marrow. The method may provide clinically important information in the follow-up of selected haematological diseases.

scholarly journals MDCT-Based Finite Element Analyses: Are Measurements at the Lumbar Spine Associated with the Biomechanical Strength of Functional Spinal Units of Incidental Osteoporotic Fractures along the Thoracolumbar Spine?

Diagnostics ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 455
Author(s):  
Nico Sollmann ◽  
Nithin Manohar Rayudu ◽  
Long Yu Yeung ◽  
Anjany Sekuboyina ◽  
Egon Burian ◽  
...  
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Fracture Risk ◽  
Thoracolumbar Spine ◽  
Areal Bone Mineral Density ◽  
Mineral Density ◽  
Osteoporotic Vertebral Fractures ◽  
The Mean ◽  
Biomechanical Strength

Assessment of osteoporosis-associated fracture risk during clinical routine is based on the evaluation of clinical risk factors and T-scores, as derived from measurements of areal bone mineral density (aBMD). However, these parameters are limited in their ability to identify patients at high fracture risk. Finite element models (FEMs) have shown to improve bone strength prediction beyond aBMD. This study aims to investigate whether FEM measurements at the lumbar spine can predict the biomechanical strength of functional spinal units (FSUs) with incidental osteoporotic vertebral fractures (VFs) along the thoracolumbar spine. Multi-detector computed tomography (MDCT) data of 11 patients (5 females and 6 males, median age: 67 years) who underwent MDCT twice (median interval between baseline and follow-up MDCT: 18 months) and sustained an incidental osteoporotic VF between baseline and follow-up scanning were used. Based on baseline MDCT data, two FSUs consisting of vertebral bodies and intervertebral discs (IVDs) were modeled: one standardly capturing L1-IVD–L2-IVD–L3 (FSU_L1–L3) and one modeling the incidentally fractured vertebral body at the center of the FSU (FSU_F). Furthermore, volumetric BMD (vBMD) derived from MDCT, FEM-based displacement, and FEM-based load of the single vertebrae L1 to L3 were determined. Statistically significant correlations (adjusted for a BMD ratio of fracture/L1–L3 segments) were revealed between the FSU_F and mean load of L1 to L3 (r = 0.814, p = 0.004) and the mean vBMD of L1 to L3 (r = 0.745, p = 0.013), whereas there was no statistically significant association between the FSU_F and FSU_L1–L3 or between FSU_F and the mean displacement of L1 to L3 (p > 0.05). In conclusion, FEM measurements of single vertebrae at the lumbar spine may be able to predict the biomechanical strength of incidentally fractured vertebral segments along the thoracolumbar spine, while FSUs seem to predict only segment-specific fracture risk.

scholarly journals Fibrotic progression and radiologic correlation in matched lung samples from COVID-19 post-mortems

2020 ◽  
Author(s):  
Emanuela Barisione ◽  
Federica Grillo ◽  
Lorenzo Ball ◽  
Rita Bianchi ◽  
Marco Grosso ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Diffuse Alveolar Damage ◽  
Ground Glass Opacity ◽  
Post Mortem ◽  
Mechanically Ventilated ◽  
Illness Duration ◽  
Transbronchial Lung Cryobiopsy ◽  
Histopathologic Analysis ◽  
Lung Lobes

Abstract Data on the pathology of COVID-19 are scarce; available studies show diffuse alveolar damage; however, there is scarce information on the chronologic evolution of COVID-19 lung lesions. The primary aim of the study is to describe the chronology of lung pathologic changes in COVID-19 by using a post-mortem transbronchial lung cryobiopsy approach. Our secondary aim is to correlate the histologic findings with computed tomography patterns. SARS-CoV-2-positive patients, who died while intubated and mechanically ventilated, were enrolled. The procedure was performed 30 min after death, and all lung lobes sampled. Histopathologic analysis was performed on thirty-nine adequate samples from eight patients: two patients (illness duration < 14 days) showed early/exudative phase diffuse alveolar damage, while the remaining 6 patients (median illness duration—32 days) showed progressive histologic patterns (3 with mid/proliferative phase; 3 with late/fibrotic phase diffuse alveolar damage, one of which with honeycombing). Immunohistochemistry for SARS-CoV-2 nucleocapsid protein was positive predominantly in early-phase lesions. Histologic patterns and tomography categories were correlated: early/exudative phase was associated with ground-glass opacity, mid/proliferative lesions with crazy paving, while late/fibrous phase correlated with the consolidation pattern, more frequently seen in the lower/middle lobes. This study uses an innovative cryobiopsy approach for the post-mortem sampling of lung tissues from COVID-19 patients demonstrating the progression of fibrosis in time and correlation with computed tomography features. These findings may prove to be useful in the correct staging of disease, and this could have implications for treatment and patient follow-up.

scholarly journals Desmoplastic fibroma in the proximal femur: A case report with long-term follow-up

2015 ◽  
Vol 10 (4) ◽  
pp. 2465-2467 ◽  
Author(s):  
YU-BAO GONG ◽  
LI-MEI QU ◽  
XIN QI ◽  
JIAN-GUO LIU
Keyword(s):  
Case Report ◽  
Proximal Femur ◽  
Desmoplastic Fibroma ◽  
Long Term Follow Up

scholarly journals All-endoscopic management of benign bone lesions; a case series of 26 cases with minimum of 2 years follow-up

SICOT-J ◽  
2018 ◽  
Vol 4 ◽  
pp. 50 ◽  
Author(s):  
Hazem A. Farouk ◽  
Mostafa Saladin ◽  
Wessam Abu Senna ◽  
Walid Ebeid
Keyword(s):  
Proximal Femur ◽  
Aneurysmal Bone Cyst ◽  
Proximal Tibia ◽  
Bone Cyst ◽  
Oncologic Outcome ◽  
Functional Scores ◽  
Bony Lesions ◽  
Anatomic Locations ◽  
Endoscopic Curettage

Purpose: Assessment of the functional and oncologic outcomes regarding endoscopic curettage of different benign bone tumor types within variable anatomic locations. Patients and methods: During the period between February 2012 and December 2016, 26 patients with symptomatic intra-osseous benign bony lesions were included. The age ranged from 3 up to 49 years (mean 20), of 14 females and 12 males. The follow-up duration ranged from 26 up to 58 months (mean 41). Functional scoring was done according to the Revised Musculoskeletal Tumour Society Rating Scale. Anatomic locations of the lesions included: 6 cases in the proximal tibia, 6 cases in the distal femur, 4 cases in the calcaneus, 3 cases in the proximal humerus, 3 cases in the distal tibia, 2 cases in the talus, 1 case in the proximal femur, and 1 case in the distal fibula. The procedure used 4 mm 30° scope for endoscopy, and high speed burrs 3.5–5 mm for extended curettage. Autogenous bone grafting was done in 5 cases, and adjuvant material (polymethylmethacrylate) was needed in 7 cases. Results: After exclusion of one case that was lost in the follow-up, the remaining 25 cases showed full functional recovery at a period of 8–12 weeks, and improved mean functional scores from 20.2 to 28.6/30 post-operatively, with p value <0.001 which was considered as a statistically significant result. The oncologic outcome showed 24 cases with adequate healing, while 1 case developed recurrence (aneurysmal bone cyst in the proximal tibia) for which, an open revision surgery was performed. Intra-operative fracture occurred in another case with aneurysmal bone cyst of the proximal femur, which was fixed by flexible nails with complete healing. Conclusion: Endoscopic curettage of different types of intra-osseous benign bony lesions proved to be an effective treatment modality with promising oncologic outcome, improved functional scores, and fast functional recovery.

scholarly journals INTEGRATION OF COMPLEMENTARY BIOMARKERS IN PATIENTS WITH FIRST EPISODE PSYCHOSIS: RESEARCH PROTOCOL OF A PROSPECTIVE FOLLOW UP STUDY

2019 ◽  
Author(s):  
Petra ◽  
Martina Rojnic Kuzman ◽  
Porin Makaric ◽  
Dina Bosnjak Kuharic ◽  
Ivana Kekin ◽  
...  
Keyword(s):  
Genome Wide Association Study ◽  
Single Photon ◽  
Single Gene ◽  
Photon Emission ◽  
Blood Perfusion ◽  
First Episode ◽  
Emission Computed Tomography ◽  
Healthy Controls ◽  
Post Mortem

In this project, we recruited a sample of 150 patients with first episode of psychosis with schizophrenia features (FEP) and 100 healthy controls. We assessed the differences between these two groups, as well as the changes between the acute phase of illness and subsequent remission among patients over 18-month longitudinal follow-up. The assessments were divided into four work packages (WP): WP1- psychopathological status, neurocognitive functioning and emotional recognition; WP2- stress response measured by saliva cortisol during a stress paradigm; cerebral blood perfusion in the resting state (with single photon emission computed tomography (SPECT) and during activation paradigm (with Transcranial Ultrasonography Doppler (TCD); WP3-post mortem analysis in histologically prepared human cortical tissue of post mortem samples of subjects with schizophrenia in the region that synaptic alteration was suggested by WP1 and WP2; WP4- pharmacogenetic analysis (single gene polymorphisms and genome wide association study (GWAS). We expect that the analysis of these data will identify a set of markers that differentiate healthy controls from patients with FEP, and serve as an additional diagnostic tool in the first episode of psychosis, and prediction tool which can be then used to help tailoring individualized treatment options. In this paper, we describe the project protocol including aims and methods and provide a brief description of planned post mortem studies and pharmacogenetic analysis.

scholarly journals Mortality and morbidity of proximal femur fractures in elderly population – A three year follow-up study

2020 ◽  
Vol 6 (2) ◽  
pp. 69-72
Author(s):  
Sandeep Krishna Avulapati ◽  
◽  
Avinash Bajjuri ◽  
Sunil Boddu ◽  
Anudeep Peddineni ◽  
...  
Keyword(s):  
Proximal Femur ◽  
Elderly Population ◽  
Mortality And Morbidity ◽  
Proximal Femur Fractures ◽  
Follow Up Study ◽  
Femur Fractures

Finite-Element-Based Transfer Equations: Post-Mortem Human Subjects versus Hybrid III Test Dummy in Blunt Impact

2014 ◽  
Vol 2 (1) ◽  
pp. 117-129 ◽  
Author(s):  
Raed E. El-jawahri ◽  
Tony R. Laituri ◽  
Agnes S. Kim ◽  
Stephen W. Rouhana ◽  
Para V. Weerappuli
Keyword(s):  
Finite Element ◽  
Human Subjects ◽  
Post Mortem ◽  
Blunt Impact ◽  
Transfer Equations ◽  
Hybrid Iii
Sign in / Sign up

Export Citation Format

Share Document