scholarly journals Femoral neck fracture prediction by anisotropic yield criteria

Author(s):  
Mohamed Tellache ◽  
Martine Pithioux ◽  
Patrick Chabrand ◽  
Christian Hochard

The fracture risk due to osteoporosis, is undertaken with Dual-Energy X-ray Absorptiometry (DEXA) which is an average of bone mineral density measurement, without taking into account the bone structure. The objective of this study was an experimental test to solicit the human proximal femurs by a physiological configuration (one leg stance phase of walking). For this, transversely isotropic finite element models were developed from CT scan acquisition. The failure load assessment was insured by anisotropic yield behaviour criteria based on distortion energy criterion (Hill’s criterion) and taking into account the difference between tension and compression yield properties (Tsai–Wu’s criterion). The results found in this study showed the significance part of anisotropic yield behaviour of bone on proximal femur.

2020 ◽  
Vol 24 (4) ◽  
pp. 108-118
Author(s):  
A. V. Petraikin ◽  
A. K. Smorchkova ◽  
N. D. Kudryavtsev ◽  
K. A. Sergunova ◽  
Z. R. Artyukova ◽  
...  

Rationale. Quantitative CT (QCT) bone densitometry with asynchronous calibration not require a phantom during the scan procedure. Based on calibration data it converts X-ray density in HU to bone mineral density (BMD). Given the large number of CT studies performed on patients at risk of osteoporosis, there is a need for a hands-on method capable of assessing BMD in a short period of time without tailored software or protocols.Goal. To develop a method for QCT bone densitometry using an PHK (PHantom Kalium), to compare the volume BMD measurements with the QCT data with asynchronous calibration provided by software from a reputable developer.Methods. The studies were performed at 64-slice CT unit with body scanning parameters. The BMD was measured using two techniques: 1) QCT with asynchronous calibration using software from a reputable developer; 2) QCT using a PHK phantom (QCT-PHK). For convert the HU to BMD values, we scanned the PHK phantom and calculate correction factor. Phantom contains “vertebrae” filled with potassium hydrogen phosphate in different concentrations. In both methods, the BMD values measured for LI–II, and sometimes for ThXII, LIII.Results. The study enrolled 65 subjects (11 male and 54 female patients); median age 69.0 years. A comparison of the vertebrae BMD measured by QCT and QCT-PHK revealed a significant linear Pearson correlation r = 0.977 (p < 0.05). The Bland–Altman analysis demonstrated a lack of relationship between the difference in measurements and the average BMD and a systematic BMD; bias of +4.50 mg/ml in QCT vs. QCT-PHK. Differences in the division into groups osteoporosis / osteopenia / norm according to the ACR criteria for the two methods were not significant.Conclusion. The developed asynchronous QCT-PHK method measure BMD comparable to the widely used QCT with asynchronous calibration. This method can be used for opportunistic screening for osteoporosis.


1996 ◽  
Vol 89 (8) ◽  
pp. 457-461 ◽  
Author(s):  
D J Torgerson ◽  
C Donaldson ◽  
D M Reid

Bone mineral density measurements have been criticized on the grounds that they are not a worth-while screening tool. In this paper we argue that bone mineral measurements can be an efficient diagnostic tool even if they are not of proven value for screening. There is complex relationship between the costs of a measurement, the intervention and the predictive value of the test all of which must be accounted for when assessing the value of a bone density measurement. For bone density measurements to be used for screening, a wider evaluation needs to be undertaken compared with that for their use as a diagnostic tool. We address some common objections, for example, that low compliance with screening would undermine efficiency, and show that these are not relevant. Evaluations of screening need to address issues that are likely to affect efficiency.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Hideki Ueyama ◽  
Yoichi Ohta ◽  
Yuuki Imai ◽  
Akinobu Suzuki ◽  
Ryo Sugama ◽  
...  

Abstract Background Bone morphogenetic proteins (BMPs) induce osteogenesis in various environments. However, when BMPs are used alone in the bone marrow environment, the maintenance of new bone formation is difficult owing to vigorous bone resorption. This is because BMPs stimulate the differentiation of not only osteoblast precursor cells but also osteoclast precursor cells. The present study aimed to induce and maintain new bone formation using the topical co-administration of recombinant human BMP-2 (rh-BMP-2) and zoledronate (ZOL) on beta-tricalcium phosphate (β-TCP) composite. Methods β-TCP columns were impregnated with both rh-BMP-2 (30 µg) and ZOL (5 µg), rh-BMP-2 alone, or ZOL alone, and implanted into the left femur canal of New Zealand white rabbits (n = 56). The implanted β-TCP columns were harvested and evaluated at 3 and 6 weeks after implantation. These harvested β-TCP columns were evaluated radiologically using plane radiograph, and histologically using haematoxylin/eosin (H&E) and Masson’s trichrome (MT) staining. In addition, micro-computed tomography (CT) was performed for qualitative analysis of bone formation in each group (n = 7). Results Tissue sections stained with H&E and MT dyes revealed that new bone formation inside the β-TCP composite was significantly greater in those impregnated with both rh-BMP-2 and ZOL than in those from the other experimental groups at 3 and 6 weeks after implantations (p < 0.05). Micro-CT data also demonstrated that the bone volume and the bone mineral density inside the β-TCP columns were significantly greater in those impregnated with both rh-BMP-2 and ZOL than in those from the other experimental groups at 3 and 6 weeks after implantations (p < 0.05). Conclusions The topical co-administration of both rh-BMP-2 and ZOL on β-TCP composite promoted and maintained newly formed bone structure in the bone marrow environment.


Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 570
Author(s):  
Masayoshi Yamada ◽  
Chongxiao Chen ◽  
Toshie Sugiyama ◽  
Woo Kyun Kim

Changes in medullary and cortical bone structure with age remain unclear. Twenty Hy-Line W36 hens, 25 or 52 weeks of age, were euthanized, and both tibiae were collected when an egg was present in the magnum. Serial cross sections of the tibiae were stained with Alcian blue. The bones were scanned using micro-computed tomography. Trabecular width (Tb.Wi) was significantly higher (p < 0.05) in 25-week-old hens, whereas medullary bone tissue volume (TV) was significantly higher (p < 0.01) in 52-week-old hens. 25-week-old hens had significantly higher (p < 0.01) bone volume fraction (BVF = calcified tissue / TV). Moreover, the cortical bone parameters were significantly higher (TV and bone mineral content (BMC) at p < 0.05, and bone volume (BV) and BVF at p < 0.01) in younger hens. Open porosity and total porosity, which indicate less density, were significantly higher (p < 0.01) in older hens. Older hens showed significantly higher (p < 0.01) tibial diaphysis TV than younger hens. Younger hens had significantly higher (p < 0.01) BV, BVF and bone mineral density (BMD) of the tibial diaphysis. These findings reveal that reductions in medullary bone quality might be associated with age-related low estrogen levels and stimulation of osteoclastic bone resorption by parathyroid hormone. Cortical bone quality decreased with enlargement of the Haversian canals and loss of volume, with a longer egg-laying period leading to osteoporosis.


2021 ◽  
Vol 49 (1) ◽  
pp. 030006052198946
Author(s):  
Xiaoguang Fan ◽  
Sha Li ◽  
Xianshang Zeng ◽  
Weiguang Yu ◽  
Xiangzhen Liu

Objective To explore possible risk factors for poor outcomes following percutaneous vertebroplasty (PV) for painful osteoporotic compression fractures of thoracolumbar vertebra. Methods This was a retrospective review of data from patients who underwent PV at our institution over a ten-year period to evaluate the association between possible risk factors and thoracolumbar pain (T11-L2). According to the difference between pre- and post-operative visual analogue scale (VAS) scores for pain, patients were separated into poor relief (PR; <4) and good relief (GR; ≥4) of pain. Results Of the 750 patients identified, 630 (PR group, n =310; GR group, n = 320) fulfilled the eligibility criteria. Multivariate binary logistic analysis showed that bone mineral density (BMD), >2 fractured vertebral bodies, maldistribution of bone cement, <5 ml bone cement injected into a single vertebral body and thoracolumbar fascia injury prior to surgery were independent risk factors associated with thoracolumbar pain following PV. Conclusion Although prospective controlled studies are required to confirm our results, this review suggests that the above factors should be taken into account when selecting patients for PV.


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