共查询到20条相似文献,搜索用时 31 毫秒
1.
Kwang-Jun Oh Young-Bong Ko Sagar Jaiswal In-Cheul Whang 《Journal of materials science. Materials in medicine》2016,27(12):179
The purpose of this study was to compare the osteoconductivity, and absorbability of hydroxyapatite or beta-tricalcium phosphate in clinical scenario of opening wedge high tibial osteotomy Total 41 knees of 40 patients with follow up period of more than 1 year were enrolled. These patients were divided into two groups, Group I (22 knees, 21 patients) used hydroxyapatite and Group II (19 knees, 19 patients) used beta-tricalcium phosphate as a substitute in the opening gap. According to proven method, the osteoconductivity was assessed radiographically by the extent of new bone formation at osteotomy space and absorbability was evaluated by measuring the area occupied by substitute at immediate postoperative, postoperative 6 months and 1 year. Regarding preoperative demographic data, no significant differences were found between two groups. No statistically significant differences were found between two groups regarding lower limb alignment (mechanical femorotibial angle, weight-bearing line%) and posterior tibial slope at postoperative and final follow up radiographs. Concerning the osteoconductivity, there were no significant differences between two groups in any zone. However, the absorption rate was significantly greater in the Group II than in Group I at 6 months (Group I: 13.7?±?6.8, group II: 35.3?±?15.8, P?=?0.001) and 1 year (Group I: 24.2?±?6.3, Group II: 49.6?±?14.3, P?<?0.0001). The complications related to bone substitutes were not observed. Both hydroxyapatite and beta-tricalcium phosphate showed satisfactory gap healing without complications and can be successfully used as alternative healing materials in opening wedge high tibial osteotomy. Our study showed that beta-tricalcium phosphate has superior absorbability than hydroxyapatite. But osteoconductivity showed no significant difference. 相似文献
2.
Shashwat Bhakta Paulo E. Faira Luiz A. Salata Patricio Jose de Oliveira Neto Cheryl A. Miller Richard van Noort Ian M. Reaney Ian M. Brook Paul V. Hatton 《Journal of materials science. Materials in medicine》2012,23(10):2521-2529
Potassium fluorrichterite (KNaCaMg5Si8O22F2) glass–ceramics were modified by either increasing the concentration of calcium (GC5) or by the addition of P2O5 (GP2). Rods (2?×?4?mm) of stoichiometric fluorrichterite (GST), modified compositions (GC5 and GP2) and 45S5 bioglass, which was used as the reference material, were prepared using a conventional lost-wax technique. Osteoconductivity was investigated by implantation into healing defects in the midshaft of rabbit femora. Specimens were harvested at 4 and 12?weeks following implantation and tissue response was investigated using computed microtomography (μCT) and histological analyses. The results showed greatest bone to implant contact in the 45S5 bioglass reference material at 4 and 12?weeks following implantation, however, GST, GC5 and GP2 all showed direct bone tissue contact with evidence of new bone formation and cell proliferation along the implant surface into the medullary space. There was no evidence of bone necrosis or fibrous tissue encapsulation around the test specimens. Of the modified potassium fluorrichterite compositions, GP2 showed the greatest promise as a bone substitute material due to its osteoconductive potential and superior mechanical properties. 相似文献
3.
Heikkilä JT Kukkonen J Aho AJ Moisander S Kyyrönen T Mattila K 《Journal of materials science. Materials in medicine》2011,22(4):1073-1080
Purpose of this study was to compare bioactive glass and autogenous bone as a bone substitute material in tibial plateau fractures.
We designed a prospective, randomized study consisting of 25 consecutive operatively treated patients with depressed unilateral
tibial comminuted plateau fracture (AO classification 41 B2 and B3).14 patients (7 females, 7 males, mean age 57 years, range
25–82) were randomized in the bioglass group (BG) and 11 patients (6 females, 5 males, mean age 50 years, range 31–82) served
as autogenous bone control group (AB). Clinical examination of the patients was performed at 3 and 12 months, patients’ subjective
and functional results were evaluated at 12 months. Radiological analysis was performed preoperatively, immediately postoperatively
and at 3 and 12 months. The postoperative redepression for both studied groups was 1 mm until 3 months and remained unchanged
at 12 months. No differences were identified in the subjective evaluation, functional tests and clinical examination between
the two groups during 1 year follow-up. We conclude that bioactive glass granules can be clinically used as filler material
instead of autogenous bone in the lateral tibial plateau compression fractures. 相似文献
4.
Low versus high dialysate calcium concentration in alternate night nocturnal hemodialysis: A randomized controlled trial 下载免费PDF全文
Rosemary Masterson Susan Blair Kevan R. Polkinghorne Kenneth K. Lau Michael Lian Boyd J. Strauss John G. Morgan Peter Kerr Nigel D. Toussaint 《Hemodialysis international. International Symposium on Home Hemodialysis》2017,21(1):19-28
5.
从临床观点探讨人工骨材料研究 总被引:19,自引:0,他引:19
综述近年来长骨缺损修复方法以及人工骨替代材料的发展和临床应用,由于长骨结构,功能,营养,代谢以及生物力学的特殊性,要求人工骨替代材料不仅具有良好的生物力学性能,与受体骨有良好的生物相容性,还要求材料可梯度降解,可快速血管化等。目前的人工骨替代材料不能满足临床要求。 相似文献
6.
Ohsawa K Neo M Okamoto T Tamura J Nakamura T 《Journal of materials science. Materials in medicine》2004,15(8):859-864
The behavior of porous apatite- and wollastonite-containing glass-ceramic (AW) in the bone marrow cavity was investigated. Cylinders of porous AW (4 mm in diameter and 20 mm long, mean porosity of 70% and mean pore diameter of 200 microm) were implanted into the bone marrow cavity of rabbit femurs, and analyzed by chronological radiograms and by scanning electron microscopy one, three, six, and 12 months later. The pores of porous AW are interconnected and homogeneously distributed, and its compressive strength is nearly equal to that of human cancellous bone. Bone formed in the pores at the center of the material by one month and bonded to the material directly. The volume of newly formed bone in the material pores reached a peak at three months, and decreased gradually after six months. The trabecular structures of AW were gradually remodeled by newly formed bone, while AW-bone bonding was maintained during bone remodeling and material absorption. AW was absorbed continuously, and at six and 12 months the residual material corresponded to about 64 and 30% of the starting material, respectively. Porous AW may therefore be useful as an absorbable bone substitute. 相似文献
7.
Handolin L Partio EK Arnala I Pajarinen J Pätiälä H Rokkanen P 《Journal of materials science. Materials in medicine》2007,18(6):1239-1245
The effects of low-intensity pulsed ultrasound (30 mW/cm2) were investigated in experimental cancellous bone fracture healing in bioabsorbable self-reinforced poly-l-lactide (SR-PLLA) rod fixed distal femur osteotomy in rats. A transverse transcondylar osteotomy was fixed with one SR-PLLA
rod in 32 male Wistar rats of the age of 20 weeks. Half of the rats had a daily 20-min ultrasound exposure for three weeks.
The follow-up times were three, six, and 12 weeks. Radiographical, histological, microradiographical, oxytetracycline labeling,
and histomorphometrical analyses were performed. No foreign-body reactions were noted. The biocompatibility of SR-PLLA and
ultrasound was found to be good. In the radiological and histological assessments there was a slight tendency for enhanced
healing in the ultrasound group at three weeks, but at six and 12 weeks no differences were observed. The histomorphometrical
and oxytetracycline labeling analyses showed that ultrasound exposure had no significant effects on bone healing.
The present study shows that there were no obvious findings to support the hypothesis that low-intensity pulsed ultrasound
enhances bone healing in self-reinforced poly-l-lactide (SR-PLLA) rod fixed experimental metaphyseal distal femur osteotomy in rats. The observed good biocompatibility provides
a safe starting-point for clinical trials on bioabsorbable fixation combined with low-intensity ultrasound. 相似文献
8.
Boix D Weiss P Gauthier O Guicheux J Bouler JM Pilet P Daculsi G Grimandi G 《Journal of materials science. Materials in medicine》2006,17(11):1145-1152
The aim of the present study was to assess the efficacy of a ready-to-use injectable bone substitute on the prevention of
alveolar ridge resorption after tooth extraction. Maxillary and mandibular premolars were extracted from 3 Beagle dogs with
preservation of alveolar bone. Thereafter, distal sockets were filled with an injectable bone substitute (IBS), obtained by
combining a polymer solution and granules of a biphasic calcium phosphate (BCP) ceramic. As a control, the mesial sockets
were left unfilled. After a 3 months healing period, specimens were removed and prepared for histomorphometric evaluation
with image analysis. Histomorphometric study allowed to measure the mean and the maximal heights of alveolar crest modifications.
Results always showed an alveolar bone resorption in unfilled sockets. Resorption in filled maxillary sites was significantly
lower than in control sites. Interestingly, an alveolar ridge augmentation was measured in mandibular filled sockets including
30% of newly-formed bone. It was concluded that an injectable bone substitute composed of a polymeric carrier and calcium
phosphate can significantly increase alveolar ridge preservation after tooth extraction. 相似文献
9.
M. Sartori G. Giavaresi M. Tschon L. Martini L. Dolcini M. Fiorini D. Pressato M. Fini 《Journal of materials science. Materials in medicine》2014,25(6):1495-1504
Despite several efforts to find suitable alternatives to autologous bone, no bone substitute currently available provides the same characteristics and properties. Nevertheless, among the wide range of materials proposed as bone substitutes, calcium phosphate materials represent the most promising category and the present study is aimed at improving the knowledge on non-stoichiometric magnesium-doped hydroxyapatite substitutes (Mg-HA), tested in two different formulations: Mg-HA Putty and Mg-HA Granules. These bone substitutes were implanted bilaterally into iliac crest bone defects in healthy sheep and comparative histological, histomorphometric, microhardness and ultrastructural assessments were performed 9, 12, 18 and 24 months after surgery to elucidate bone tissue apposition, mineralization and material degradation in vivo. The results confirmed that the biomimetic bone substitutes provide a histocompatible and osteoconductive structural support, during the bone formation process, and give essential information about the in vivo resorption process and biological behavior of biomimetic bone substitutes. 相似文献
10.
Hitoshi Nakayama Douglas M. Burns Tomoyuki Kawase 《Journal of Nondestructive Evaluation》2011,30(2):71-80
Microfocus X-ray computed tomography (μCT) has now become widely available for the nondestructive evaluation of porous bioceramics
suitable for use as a bone substitute in orthopedic surgery. As part of an official Japanese working committee, we recently
participated in the preparation of a proposed standard protocol for the quantitative μCT analysis of porous bioceramics sent
to the International Organization for Standardization (ISO). In this protocol, the recommended basic conditions for analysis
were [field of view (XY plane): 3.0 mm, spatial resolution: 6 μm/pixel (or the closest minimal values available for both parameters on a particular
μCT system), matrix size: 512 pixels], and we have now further determined the optimal values for more detailed parameters
(e.g., threshold determination). To validate the utility of the complete protocol, three different types of ceramic sample
[a ceramic of β-tricalcium phosphate (β-TCP) and two types of hydroxyapatite (HAp) with different porosities] were evaluated with three different types of cone-beam
μCT scanner (the Shimadzu SMX-100CT, Shimadzu inspeXio-90CT, and Skyscan-1174 scanners). Acquired images were quantified using
3D-reconstruction software, VGStudio MAX (version 1.2). After comparing data obtained from these three μCT scanners, we have
found that determinations of both porosity and pore-interconnectivity were very similar from one system to the other although
the total number of measured pores did vary between scanners. The present data indicate that our protocol for μCT analysis
is reliable enough to quantify the porosity and interconnectivity of porous bioceramics and would therefore facilitate both
large-scale screening and quality control of porous bioceramic samples. 相似文献
11.
M. Feteha Sh. Ebrahim M. Soliman W. Ramdan M. Raoof 《Journal of Materials Science: Materials in Electronics》2012,23(11):1938-1943
In the present work, mercaptopropionic acid (MPA) capped CdTe and CdHgTe quantum dots (QDs) are synthesized using a method based on the bottom up approach in aqueous medium. The CdTe QDs were prepared with a two different ratios of Cd:Te (3:1 and 4:1). It was noticed that there was a minimum concentration of MPA for each Cd:Te ratio. The resulting QDs were characterized using optical absorption spectroscopy, energy dispersion X-ray (EDX) and high resolution transmission electron microscopy (HRTEM). It was found that the EDXs of CdTe and CdHgTe QDs showed that the stiochiometric ratios of CdTe obtained with Cd:Te ratio of 3:1 is 50:50 and for CdHgTe is 40:26:34 for 100?% of Hg. The band gap of CdHgTe QDs varies slightly with composition from 2.21?eV for a pure CdTe to 1.4?eV for a CdHgTe with 100?% of Hg. The HRTEM image showed a good dispersed nano-crystalline structure for the CdTe QDs with average size of 3–4?nm. The existence of the lattice planes on the HRTEM images of the QD indicated that the CdTe QDs are highly crystalline. In addition, the CdHgTe QDs size is 12?nm for 100?% of Hg. 相似文献
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14.
Cardone KE Manley HJ Grabe DW Meola S Hoy CD Bailie GR 《Hemodialysis international. International Symposium on Home Hemodialysis》2011,15(2):234-242
Medication regimen simplification may improve adherence in end-stage kidney disease. The effect of nocturnal home hemodialysis (NHHD) on medication burden is unknown. A retrospective pilot study of NHHD patients was conducted. Medication information was collected at baseline, NHHD start, and at 3, 6, 12, 18, and 24 months. SF-36 scores were collected at baseline, 6, 12, and 24 months. The number of medications, pill burden, and number of administrations per day were determined. Medication Regimen Complexity Index was used at each time point as a comparator. Medications for anemia, mineral and bone disorders (MBD), cardiovascular (CV) disease, infection, and vitamins were analyzed for number of medications and pill burden. Thirty-five patients were included. Patients used 10.5 ± 4.4 medications at baseline and 11.8 ± 4.7 at the end of the study (P=NS). Regarding the number of medications, anemia medications, anti-infectives, and vitamins increased; MBD and CV medications decreased by the end of the study. Total pill burden did not change over 24 months, nor did anemia pill burden. Mineral bone disorder and CV pill burden decreased, and vitamins and anti-infective pill burden increased. Daily medication administration times decreased significantly from 5.0 ± 1.5 to 3.6 ± 1.5 by 24 months. Switching to NHHD was associated with a significant increase in Medication Regimen Complexity Index at 24 months (P<0.05). SF-36 scores increased significantly once patients began on NHHD. No measure of medication regimen complexity was correlated with the SF-36 score. Medication burden changes over time after starting NHHD. It is unknown what effect NHHD has on adherence or medication costs, and warrants further study in a prospective comparative investigation. 相似文献
15.
K. Goto K. Kawanabe R. Kowalski D. Baker T. Nakamura 《Journal of materials science. Materials in medicine》2010,21(1):139-146
A composite bone cement designated G2B1 that contains β tricalcium phosphate particles was developed as a bone substitute for percutaneous transpedicular vertebroplasty. In this study, both G2B1 and commercial PMMA bone cement (CMW1) were implanted into proximal tibiae of rabbits, and their bone-bonding strengths were evaluated at 4, 8, 12 and 16 weeks after implantation. Some of the specimens were evaluated histologically using Giemsa surface staining, contact microradiography (CMR) and scanning electron microscopy (SEM). Histological findings showed that G2B1 contacted bone directly without intervening soft tissue in the specimens at each time point, while there was always a soft tissue layer between CMW1 and bone. The bone-bonding strength of G2B1 was significantly higher than that of CMW1 at each time point, and significantly increased from 4 weeks to 8 and 12 weeks, while it decreased significantly from 12 weeks to 16 weeks. Bone remodeling of the cortex under the cement was observed especially for G2B1 and presumably influenced the bone bonding strength of the cement. The results indicate that G2B1 has bioactivity, and bone bonding strength of bioactive bone cements can be estimated fairly with this experimental model in the short term. 相似文献
16.
Effects of frequent hemodialysis on blood pressure: Results from the randomized frequent hemodialysis network trials 下载免费PDF全文
Peter Kotanko Amit X. Garg Tom Depner Andreas Pierratos Christopher T. Chan Nathan W. Levin Tom Greene Brett Larive Gerald J. Beck Jennifer Gassman Alan S. Kliger John B. Stokes FHN Trial Group 《Hemodialysis international. International Symposium on Home Hemodialysis》2015,19(3):386-401
Hypertension is a common complication of chronic kidney disease and persists among most patients with end‐stage renal disease despite the provision of conventional thrice weekly hemodialysis (HD). We analyzed the effects of frequent HD on blood pressure in the randomized controlled Frequent Hemodialysis Network trials. The daily trial randomized 245 patients to 12 months of 6× (“frequent”) vs. 3× (“conventional”) weekly in‐center hemodialysis; the nocturnal trial randomized 87 patients to 12 months of 6× weekly nocturnal HD vs. 3× weekly predominantly home‐based hemodialysis. In the daily trial, compared with 3× weekly HD, 2 months of frequent HD lowered predialysis systolic blood pressure by ?7.7 mmHg [95% confidence interval (CI): ?11.9 to ?3.5] and diastolic blood pressure by ?3.9 mmHg [95% CI: ?6.5 to ?1.3]. In the nocturnal trial, compared with 3× weekly HD, 2 months of frequent HD lowered systolic blood pressure by ?7.3 mmHg [95% CI: ?14.2 to ?0.3] and diastolic blood pressure by ?4.2 mmHg [95% CI: ?8.3 to ?0.1]. In both trials, blood pressure treatment effects were sustained until month 12. Frequent HD resulted in significantly fewer antihypertensive medications (daily: ?0.36 medications [95% CI: ?0.65 to ?0.08]; nocturnal: ?0.44 mediations [95% CI: ?0.89 to ?0.03]). In the daily trial, the relative risk per dialysis session for intradialytic hypotension was lower with 6×/week HD but given the higher number of sessions per week, there was a higher relative risk for intradialytic hypotensive requiring saline administration. In summary, frequent HD reduces blood pressure and the number of prescribed antihypertensive medications. 相似文献
17.
Chitosan particles agglomerated scaffolds for cartilage and osteochondral tissue engineering approaches with adipose tissue derived stem cells 总被引:4,自引:0,他引:4
B Malafaya PP Pedro AJ Peterbauer A Gabriel C Redl H Reis RL 《Journal of materials science. Materials in medicine》2005,16(12):1077-1085
It is well accepted that natural tissue regeneration is unlikely to occur if the cells are not supplied with an extracellular
matrix (ECM) substitute. With this goal, several different methodologies have been used to produce a variety of 3D scaffolds
as artificial ECM substitutes suitable for bone and cartilage tissue engineering. Furthermore, osteochondral tissue engineering
presents new challenges since the combination of scaffolding and co-culture requirements from both bone and cartilage applications
is required in order to achieve a successful osteochondral construct.
In this paper, an innovative processing route based on a chitosan particles aggregation methodology for the production of
cartilage and osteochondral tissue engineering scaffolds is reported. An extensive characterization is presented including
a morphological evaluation using Micro-Computed Tomography (μCT) and 3D virtual models built with an image processing software.
Mechanical and water uptake characterizations were also carried out, evidencing the potential of the developed scaffolds for
the proposed applications. Cytotoxicity tests show that the developed chitosan particles agglomerated scaffolds do not exert
toxic effects on cells. Furthermore, osteochondral bilayered scaffolds could also be developed. Preliminary seeding of mesenchymal
stem cells isolated from human adipose tissue was performed aiming at developing solutions for chondrogenic and osteogenic
differentiation for osteochondral tissue engineering applications.
An erratum to this article is available at . 相似文献
18.
Yuki Sugiura Melvin L. Munar Kunio Ishikawa 《Journal of materials science. Materials in medicine》2018,29(10):151
Although octacalcium phosphate (OCP) powder and a collagen/gelatin composite demonstrate good potential as bone substitutes, an OCP block has not been fabricated to date. In this study, the feasibility of fabricating an OCP block was evaluated through a dissolution-precipitation reaction using a calcium sulfate hemihydrate (CSH) block as a precursor. When the block was immersed in a phosphate salt solution, its composition changed to that of OCP, while its structure was maintained. The diametral tensile strength (DTS) of the OCP block was 1.0?±?0.2?MPa. The macroporosity and microporosity of the OCP block were 33.4?±?4.5% and, 69.0?±?1.6%, respectively. New bone attached well to the OCP block, and this block was partially replaced by bone 2 weeks after implantation. Four weeks after implantation, the surface of the OCP block was nearly covered with new bone and ~30% of the block was replaced by new bone, while no replacement by bone was observed in the case of a hydroxyapatite (HAp) block used as a control. It is concluded that OCP blocks are potentially suitable for their use as artificial bone substitutes. 相似文献
19.
Nan Zhang Dewei Zhao Na Liu Yunfeng Wu Jiahui Yang Yuefei Wang Huanxin Xie Ye Ji Changlong Zhou Jinpeng Zhuang Yaming Wang Jinglong Yan 《Journal of materials science. Materials in medicine》2018,29(9):138
Surgical repair of bone defects remains challenging, and the search for alternative procedures is ongoing. Devices made of Mg for bone repair have received much attention owing to their good biocompatibility and mechanical properties. We developed a new type of scaffold made of a Mg-Zn-Ca alloy with a shape that mimics cortical bone and can be filled with morselized bone. We evaluated its durability and efficacy in a rabbit ulna-defect model. Three types of scaffold-surface coating were evaluated: group A, no coating; group B, a 10-μm microarc oxidation coating; group C, a hydrothermal duplex composite coating; and group D, an empty-defect control. X-ray and micro-computed tomography(micro-CT) images were acquired over 12 weeks to assess ulnar repair. A mechanical stress test indicated that bone repair within each group improved significantly over time (P?<?0.01). The degradation behavior of the different scaffolds was assessed by micro-CT and quantified according to the amount of hydrogen gas generated; these measurements indicated that the group C scaffold better resisted corrosion than did the other scaffold types (P?<?0.05). Calcein fluorescence and histology revealed that greater mineral densities and better bone responses were achieved for groups B and C than for group A, with group C providing the best response. In conclusion, our Mg-Zn-Ca-alloy scaffold effectively aided bone repair. The group C scaffold exhibited the best corrosion resistance and osteogenesis properties, making it a candidate scaffold for repair of bone defects. 相似文献
20.
Histological evaluation of natural coral skeleton as a grafting material in miniature swine mandible
J. P. Ouhayoun A. H. M. Shabana S. Issahakian J. L. Patat G. Guillemin M. H. Sawaf N. Forest 《Journal of materials science. Materials in medicine》1992,3(3):222-228
Natural coral skeleton (NCS) has recently been proposed as a bone graft substitute that enhances bone formation. The present paper describes the effects of implanting NCS in bone cavities prepared in the mandibles of miniature pig, and compares these with the effects of two alloplastic materials; a tricalcium phosphate (TCP) and a porous hydroxyapatite (PHA). On 11 pigs, 5 × 5 mm windows were created through alveolar bone of the four mandibular incisors. Three cavities were filled with the various materials and the fourth was left unfilled. The animals were slaughtered at 0, 1, 2, 4, 12, 26 and 52 weeks post-operatively and the tissues were examined histologically. Healing completed at 26 weeks for NCS and TCP, and at 52 weeks for PHA. NCS granules provided surface for cell attachment and deposition of a distinguishable organic matrix two weeks post-operatively. This matrix developed to bone after four weeks. The granules gradually resorbed and were replaced by bone at 52 weeks. The excellent properties of NCS, biocompatibility, porosity and osteogenic effect make us suggest that it might be a suitable replacement for bone grafting. 相似文献