WorldWideScience

Sample records for cemented acetabular replacements

  1. 21 CFR 888.3370 - Hip joint (hemi-hip) acetabular metal cemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... prosthesis. 888.3370 Section 888.3370 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... (hemi-hip) acetabular metal cemented prosthesis. (a) Identification. A hip joint (hemi-hip) acetabular metal cemented prosthesis is a device intended to be implanted to replace a portion of the hip...

  2. 21 CFR 888.3320 - Hip joint metal/metal semi-constrained, with a cemented acetabular component, prosthesis.

    Science.gov (United States)

    2010-04-01

    ... cemented acetabular component, prosthesis. 888.3320 Section 888.3320 Food and Drugs FOOD AND DRUG..., prosthesis. (a) Identification. A hip joint metal/metal semi-constrained, with a cemented acetabular component, prosthesis is a two-part device intended to be implanted to replace a hip joint. The...

  3. Is there evidence for accelerated polyethylene wear in uncemented compared to cemented acetabular components? A systematic review of the literature

    NARCIS (Netherlands)

    van der Veen, Hugo; van Jonbergen, H.P.W.; Poolman, R.W.; Bulstra, S.K.; van Raay, J.J.A.M.

    2013-01-01

    Joint arthroplasty registries show an increased rate of aseptic loosening in uncemented acetabular components as compared to cemented acetabular components. Since loosening is associated with particulate wear debris, we postulated that uncemented acetabular components demonstrate a higher polyethyle

  4. The influence of acetabular inclination angle on the penetration of polyethylene and migration of the acetabular component: a prospective, radiostereometric study on cemented acetabular components.

    Science.gov (United States)

    Kadar, T; Furnes, O; Aamodt, A; Indrekvam, K; Havelin, L I; Haugan, K; Espehaug, B; Hallan, G

    2012-03-01

    In this prospective study we studied the effect of the inclination angle of the acetabular component on polyethylene wear and component migration in cemented acetabular sockets using radiostereometric analysis. A total of 120 patients received either a cemented Reflection All-Poly ultra-high-molecular-weight polyethylene or a cemented Reflection All-Poly highly cross-linked polyethylene acetabular component, combined with either cobalt-chrome or Oxinium femoral heads. Femoral head penetration and migration of the acetabular component were assessed with repeated radiostereometric analysis for two years. The inclination angle was measured on a standard post-operative anteroposterior pelvic radiograph. Linear regression analysis was used to determine the relationship between the inclination angle and femoral head penetration and migration of the acetabular component. We found no relationship between the inclination angle and penetration of the femoral head at two years' follow-up (p = 0.9). Similarly, our data failed to reveal any statistically significant correlation between inclination angle and migration of these cemented acetabular components (p = 0.07 to p = 0.9).

  5. The effect of geometry and abduction angle on the stresses in cemented UHMWPE acetabular cups – finite element simulations and experimental tests

    Directory of Open Access Journals (Sweden)

    Santavirta Seppo S

    2005-05-01

    Full Text Available Abstract Background Contact pressure of UHMWPE acetabular cup has been shown to correlate with wear in total hip replacement (THR. The aim of the present study was to test the hypotheses that the cup geometry, abduction angle, thickness and clearance can modify the stresses in cemented polyethylene cups. Methods Acetabular cups with different geometries (Link®: IP and Lubinus eccentric were tested cyclically in a simulator at 45° and 60° abduction angles. Finite element (FE meshes were generated and two additional designs were reconstructed to test the effects of the cup clearance and thickness. Contact pressures at cup-head and cup-cement interfaces were calculated as a function of loading force at 45°, 60° and 80° abduction angles. Results At the cup-head interface, IP experienced lower contact pressures than the Lubinus eccentric at low loading forces. However, at higher loading forces, much higher contact pressures were produced on the surface of IP cup. An increase in the abduction angle increased contact pressure in the IP model, but this did not occur to any major extent with the Lubinus eccentric model. At the cup-cement interface, IP experienced lower contact pressures. Increased clearance between cup and head increased contact pressure both at cup-head and cup-cement interfaces, whereas a decreased thickness of polyethylene layer increased contact pressure only at the cup-cement interface. FE results were consistent with experimental tests and acetabular cup deformations. Conclusion FE analyses showed that geometrical design, thickness and abduction angle of the acetabular cup, as well as the clearance between the cup and head do change significantly the mechanical stresses experienced by a cemented UHMWPE acetabular cup. These factors should be taken into account in future development of THR prostheses. FE technique is a useful tool with which to address these issues.

  6. The concentric all-polyethylene Exeter acetabular component in primary total hip replacement.

    Science.gov (United States)

    Veitch, S W; Whitehouse, S L; Howell, J R; Hubble, M J W; Gie, G A; Timperley, A J

    2010-10-01

    We report the outcome of the flangeless, cemented all-polyethylene Exeter acetabular component at a mean of 14.6 years (10 to 17) after operation. Of the 263 hips in 243 patients, 122 prostheses are still in situ; 112 patients (119 hips) have died, 18 hips have been revised, and three patients (four hips) were lost to follow-up. Radiographs at the final review were available for 110 of the 122 surviving hips. There were acetabular radiolucent lines in 54 hips (49%). Two acetabular components had migrated but neither patient required revision. The Kaplan-Meier survivorship at 15 years with 61 hips at risk with revision for any cause as the endpoint was 89.9% (95% confidence interval (CI) 84.6 to 95.2) and for aseptic loosening of the acetabular component or lysis 91.7% (95% CI 86.6 to 96.8). In 210 hips with a diagnosis of primary osteoarthritis, survivorship with revision for any cause as the endpoint was 93.2% (95% CI 88.1 to 98.3), and for aseptic loosening of the acetabular component 95.0% (95% CI 90.3 to 99.7). The cemented all-polyethylene Exeter acetabular component has an excellent long-term survivorship.

  7. Cemented total hip arthroplasty with impacted morcellized bone-grafts to restore acetabular bone defects in congenital hip dysplasia.

    NARCIS (Netherlands)

    Bolder, S.B.T.; Melenhorst, J.; Gardeniers, J.W.M.; Slooff, T.J.J.H.; Veth, R.P.H.; Schreurs, B.W.

    2001-01-01

    We evaluated the results of 27 acetabular reconstructions in 21 patients with secondary osteoarthritis resulting from congenital dysplasia of the hip in which the acetabular bone defects were restored with impacted morcellized bone-grafts in combination with a cemented cup. At an average follow-up o

  8. Peri-acetabular bone mineral density in total hip replacement

    OpenAIRE

    Gauthier, L.(University of Illinois at Chicago (UIC), Chicago, USA); Dinh, L.; Beaulé, P. E.

    2013-01-01

    Objectives To quantify and compare peri-acetabular bone mineral density (BMD) between a monoblock acetabular component using a metal-on-metal (MoM) bearing and a modular titanium shell with a polyethylene (PE) insert. The secondary outcome was to measure patient-reported clinical function. Methods A total of 50 patients (25 per group) were randomised to MoM or metal-on-polyethlene (MoP). There were 27 women (11 MoM) and 23 men (14 MoM) with a mean age of 61.6 years (47.7 to 73.2). Measurement...

  9. Corrosion on the acetabular liner taper from retrieved modular metal-on-metal total hip replacements.

    Science.gov (United States)

    Gascoyne, Trevor C; Dyrkacz, Richard M; Turgeon, Thomas R; Burnell, Colin D; Wyss, Urs P; Brandt, Jan-M

    2014-10-01

    Eight retrieved metal-on-metal total hip replacements displayed corrosion damage along the cobalt-chromium alloy liner taper junction with the Ti alloy acetabular shell. Scanning electron microscopy indicated the primary mechanism of corrosion to be grain boundary and associated crevice corrosion, which was likely accelerated through mechanical micromotion and galvanic corrosion resulting from dissimilar alloys. Coordinate measurements revealed up to 4.3mm(3) of the cobalt-chromium alloy taper surface was removed due to corrosion, which is comparable to previous reports of corrosion damage on head-neck tapers. The acetabular liner-shell taper appears to be an additional source of metal corrosion products in modular total hip replacements. Patients with these prostheses should be closely monitored for signs of adverse reaction towards corrosion by-products.

  10. Early catastrophic acetabular failure in Furlong total hip replacements

    OpenAIRE

    Knox, David; Hamilton, Steven W.; Wardlaw, Douglas; Gibson, Peter H.

    2009-01-01

    The use of uncemented hip arthroplasty prostheses with ceramic articulations are popular, especially in the young, because of a perceived reduction in wear. We highlight a complication of ceramic on polyethylene articulating couples not previously described in the Furlong replacement. Despite widespread metalosis and particulate debris, osteolysis was not initially seen. The contamination compromised subsequent revision.

  11. Early catastrophic acetabular failure in Furlong total hip replacements.

    Science.gov (United States)

    Knox, David; Hamilton, Steven W; Wardlaw, Douglas; Gibson, Peter H

    2009-03-01

    The use of uncemented hip arthroplasty prostheses with ceramic articulations are popular, especially in the young, because of a perceived reduction in wear. We highlight a complication of ceramic on polyethylene articulating couples not previously described in the Furlong replacement. Despite widespread metalosis and particulate debris, osteolysis was not initially seen. The contamination compromised subsequent revision. PMID:19384635

  12. An Automated Size Recognition Technique for Acetabular Implant in Total Hip Replacement

    CERN Document Server

    Shapi'i, Azrulhizam; Hasan, Mohammad Khatim; Kassim, Abdul Yazid Mohd; 10.5121/ijcsit.2011.3218

    2011-01-01

    Preoperative templating in Total Hip Replacement (THR) is a method to estimate the optimal size and position of the implant. Today, observational (manual) size recognition techniques are still used to find a suitable implant for the patient. Therefore, a digital and automated technique should be developed so that the implant size recognition process can be effectively implemented. For this purpose, we have introduced the new technique for acetabular implant size recognition in THR preoperative planning based on the diameter of acetabulum size. This technique enables the surgeon to recognise a digital acetabular implant size automatically. Ten randomly selected X-rays of unidentified patients were used to test the accuracy and utility of an automated implant size recognition technique. Based on the testing result, the new technique yielded very close results to those obtained by the observational method in nine studies (90%).

  13. Cement replacement materials. Properties, durability, sustainability

    Energy Technology Data Exchange (ETDEWEB)

    Ramezanianpour, Ali Akbar [Amirkabir Univ. of Technology, Tehran (Iran, Islamic Republic of). Concrete Technology Center

    2014-04-01

    The aim of this book is to present the latest findings in the properties and application of Supplementary Cementing Materials and blended cements currently used in the world in concrete. Sustainability is an important issue all over the world. Carbon dioxide emission has been a serious problem in the world due to the greenhouse effect. Today many countries agreed to reduce the emission of CO2. Many phases of cement and concrete technology can affect sustainability. Cement and concrete industry is responsible for the production of 7% carbon dioxide of the total world CO2 emission. The use of supplementary cementing materials (SCM), design of concrete mixtures with optimum content of cement and enhancement of concrete durability are the main issues towards sustainability in concrete industry.

  14. Replacement of asbestos cement fills in natural draft cooling towers

    Energy Technology Data Exchange (ETDEWEB)

    Gay, G.A.; Stackhouse, D.W.

    1986-01-01

    This paper describes some of the deterioration problems which have been encountered with asbestos cement materials, the environmental and regulatory problems associated with asbestos, and some of the concerns to be addressed replacing fill material in a natural draft tower.

  15. Bone impaction grafting and a cemented cup after acetabular fracture at 3-18 years.

    NARCIS (Netherlands)

    Schreurs, B.W.; Zengerink, M.; Welten, M.L.M.; Kampen, A. van; Slooff, T.J.J.H.

    2005-01-01

    The outcome of total hip arthroplasty after acetabular fracture is compromised. We studied if the bone impaction grafting technique could provide long-term prosthesis survival in deformed and irregular acetabula. We studied 20 hips in 20 patients (mean age, 53.3 years; range, 35-75 years) that were

  16. PURIFIED WASTE FCC CATALYST AS A CEMENT REPLACEMENT MATERIAL

    Directory of Open Access Journals (Sweden)

    Danute Vaiciukyniene

    2015-06-01

    Full Text Available Zeolites are commonly used in the fluid catalytic cracking process. Zeolite polluted with oil products and became waste after some time used. The quantity of this waste inevitably rises by expanding rapidly oil industry. The composition of these catalysts depends on the manufacturer and on the process that is going to be used. The main factors retarding hydration process of cement systems and modifying them strength are organic compounds impurities in the waste FCC catalyst. The present paper shows the results of using purified waste FCC catalyst (pFCC from Lithuania oil refinery, as Portland cement replacement material. For this purpose, the purification of waste FCC catalyst (FCC samples was treated with hydrogen peroxide. Hydrogen peroxide (H2O2 is one of the most powerful oxidizers known. By acting of waste with H2O2 it can eliminate the aforementioned waste deficiency, and the obtained product becomes one of the most promising ingredients, in new advanced building materials. Hardened cement paste samples with FCC or pFCC were formed. It was observed that the pFCC blended cements developed higher strength, after 28 days, compared to the samples with FCC or reference samples. Typical content of Portland cement substituting does not exceed 30 % of mass of Portland cement in samples. Reducing the consumption of Portland cement with utilizing waste materials is preferred for reasons of environmental protection.

  17. Utilization of Palm Oil Clinker as Cement Replacement Material

    Directory of Open Access Journals (Sweden)

    Jegathish Kanadasan

    2015-12-01

    Full Text Available The utilization of waste materials from the palm oil industry provides immense benefit to various sectors of the construction industry. Palm oil clinker is a by-product from the processing stages of palm oil goods. Channelling this waste material into the building industry helps to promote sustainability besides overcoming waste disposal problems. Environmental pollution due to inappropriate waste management system can also be drastically reduced. In this study, cement was substituted with palm oil clinker powder as a binder material in self-compacting mortar. The fresh, hardened and microstructure properties were evaluated throughout this study. In addition, sustainability component analysis was also carried out to assess the environmental impact of introducing palm oil clinker powder as a replacement material for cement. It can be inferred that approximately 3.3% of cement production can be saved by substituting palm oil clinker powder with cement. Reducing the utilization of cement through a high substitution level of this waste material will also help to reduce carbon emissions by 52%. A cleaner environment free from pollutants can be created to ensure healthier living. Certain industries may benefit through the inclusion of this waste material as the cost and energy consumption of the product can be minimized.

  18. Effect of Cement Replacement with Carbide Waste on the Strength of Stabilized Clay Subgrade

    Directory of Open Access Journals (Sweden)

    Muntohar A.S.

    2016-03-01

    Full Text Available Cement is commonly used for soil stabilization and many other ground improvement techniques. Cement is believed to be very good to improve the compressive and split-tensile strength of clay subgrades. In some application cement could be partly or fully replaced with carbide waste. This research is to study the effectiveness of the cement replacement and to find the maximum carbide waste content to be allowed for a clay subgrade. The quantities of cement replaced with the carbide waste were 30, 50, 70, 90, and 100% by its mass. The results show that replacing the cement with carbide waste decreased both the compressive and split tensile strength. Replacing cement content with carbide waste reduced its ability for stabilization. The carbide waste content should be less than 70% of the cement to provide a sufficient stabilizing effect on a clay subgrade.

  19. Partial Replacement of Cement with Marble Dust Powder

    Directory of Open Access Journals (Sweden)

    Mr. Ranjan Kumar

    2015-08-01

    Full Text Available The waste generated from the industries cause environmental problems. Hence the reuse of this waste material can be emphasized. MarbleDust Powder (MDP is a developing composite materialthatwillallow the concrèteindustry to optimisemateriel use, generateeconomicbenefits and build structures thatwillstrong, durable and sensitive to environnement. MDP is by-product obtained during the quarrying process from the parent marble rock; which contains high calcium oxide content of more than 50%. The potential use of MDP can be an ideal choice for substituting in a cementitious binder as the reactivity efficiency increases due to the presence of lime. In this research work, the waste MDP passing through 90 microns,has used for investigating of hardened concrete properties. Furthermore, the effect of different percentage replacement of MDP on the compressive strength, splitting tensile strength (indirect tensile strength&flexural strength has been observed. Inthis experimental study, the effect of MDP in concrete on strength ispresented. Five concrete mixtures containing 0%, 5%, 10%, and 20% MDP as cement replacement by weightbasis has been prepared. Water/cement ratio (0.43 was kept constant, in all the concretemixes. Compressive strength, split tensile strength & flexural strength of the concrete mixtures has been obtainedat 7 and 28 days. The results of the laboratory work showed thatreplacement of cement with MDP increase, upto 10% for compressive strength,&upto 15% for split tensilestrength &flexural strength of concrete.

  20. Performance of Non-Cemented, Hemispherical, Rim-Fit, Hydroxyapatite Coated Acetabular Component.

    Science.gov (United States)

    John, Thomas K; Ghosh, Gaurav; Ranawat, Chitranjan S; Ranawat, Amar S; Meftah, Morteza

    2015-12-01

    The purpose of this study was to assess the durability of a non-cemented, hemispherical rim-fit, hydroxyapatite coated cup with a highly cross-linked polyethylene in 223 total hip arthroplasties. At 6-years follow-up (range, 5-9), there were no cup revisions for osteolysis or loosening. Radiologic evidence of osseointegration was based on presence of Stress Induced Reactive Cancellous Bone and radial trabeculae, seen in 47% and 93% of cups, respectively; both were most prevalent in Zone 1. There was no interference demarcation in any zones. Two cups were revised (0.9%): one for dislocation and another for infection. The Kaplan-Meier survivorship for cup revision for any failure (infection, dislocation) was 99% and for mechanical failure (osteolysis, loosening) was 100%. This design has excellent safety, efficacy and durability. PMID:26235521

  1. Mechanical properties of femoral cortical bone following cemented hip replacement.

    Science.gov (United States)

    Ni, G X; Lu, W W; Chiu, P K Y; Wang, Y; Li, Z Y; Zhang, Y G; Xu, B; Deng, L F; Luk, K D K

    2007-11-01

    Femoral bone remodeling following total hip replacement is a big concern and has never been examined mechanically. In this study, six goats underwent unilateral cemented hip hemiarthroplasty with polymethyl methacrylate (PMMA) bone cement. Nine months later animals were sacrificed, and the femoral cortical bone slices at different levels were analysed using microhardness testing and microcomputed tomography (micro-CT) scanning. Implanted femurs were compared to contralateral nonimplanted femurs. Extensive bone remodeling was demonstrated at both the proximal and middle levels, but not at the distal level. Compared with the nonimplanted side, significant decreases were found in the implanted femur in cortical bone area, bone mineral density, and cortical bone hardness at the proximal level, as well as in bone mineral density and bone hardness at the middle level. However, no significant difference was observed in either variable for the distal level. In addition, similar proximal-to-distal gradient changes were revealed both in cortical bone microhardness and bone mineral density. From the mechanical point of view, the results of the present study suggested that stress shielding is an important mechanical factor associated with bone adaptation following total hip replacement. PMID:17506504

  2. Development of Imageless Computer Navigation for Acetabular Component Position in Total Hip Replacement

    OpenAIRE

    Dorr, Lawrence D.; Hishiki, Yuji; Wan, Zhinian; Newton, Deanne; Yun, Andrew

    2005-01-01

    The purpose of this study was to develop an imageless (without preoperative computerized tomography (CT) scans or intraoperative fluoroscopy) computer navigation system for total hip replacement. One-hundred and ninety-five hips were operated with imageless computer navigation. Eighty-five hips were operated prior to obtaining precise results, with precision refined in the subsequent 110 hips. Computer accuracy for cup-adjusted anteversion was achieved in 100% of the final 40 hips, and for ad...

  3. Characterization and utilization of cement kiln dusts (CKDs) as partial replacements of Portland cement

    Science.gov (United States)

    Khanna, Om Shervan

    The characteristics of cement kiln dusts (CKDs) and their effects as partial replacement of Portland Cement (PC) were studied in this research program. The cement industry is currently under pressure to reduce greenhouse gas (GHG) emissions and solid by-products in the form of CKDs. The use of CKDs in concrete has the potential to substantially reduce the environmental impact of their disposal and create significant cost and energy savings to the cement industry. Studies have shown that CKDs can be used as a partial substitute of PC in a range of 5--15%, by mass. Although the use of CKDs is promising, there is very little understanding of their effects in CKD-PC blends. Previous studies provide variable and often conflicting results. The reasons for the inconsistent results are not obvious due to a lack of material characterization data. The characteristics of a CKD must be well-defined in order to understand its potential impact in concrete. The materials used in this study were two different types of PC (normal and moderate sulfate resistant) and seven CKDs. The CKDs used in this study were selected to provide a representation of those available in North America from the three major types of cement manufacturing processes: wet, long-dry, and preheater/precalciner. The CKDs have a wide range of chemical and physical composition based on different raw material sources and technologies. Two fillers (limestone powder and quartz powder) were also used to compare their effects to that of CKDs at an equivalent replacement of PC. The first objective of this study was to conduct a comprehensive composition analysis of CKDs and compare their characteristics to PC. CKDs are unique materials that must be analyzed differently from PC for accurate chemical and physical analysis. The present study identifies the chemical and physical analytical methods that should be used for CKDs. The study also introduced a method to quantify the relative abundance of the different

  4. Osteocondroma acetabular Acetabular osteochondroma

    Directory of Open Access Journals (Sweden)

    Reynaldo Jesus Garcia

    2005-01-01

    Full Text Available Apresentamos o relato de um caso de osteocondroma solitário acetabular, tumor ósseo comum em diversas regiões do esqueleto porém raro nesta localização. O tratamento realizado foi a ressecção do tumor por uma via posterior ao quadril e o paciente evoluiu com resolução do quadro clínico.This is a case report of a patient with a intra-articular hip osteochondroma, an extremely rare location for this kind of lesion. The patient was treated with resection of the lesion and presented a very good evolution with total recovery of the hip movements.

  5. Use of Stone Dust & Granite Powder as a Partial Replacement of Cement

    Directory of Open Access Journals (Sweden)

    Prerit Saxena

    2016-06-01

    Full Text Available The research demonstrate the use of naturally available waste material as a partial replacement of OPC cement resulting in improving the compressive strength of cement. Since cement manufacturing process involves emission of CO2 to a considerable amount in the environment resulting in global warming, thus use of these partial substituents in cement reduces this ill effect making an environment free construction. The objective of this thesis is to find optimum percentage up to which these pozzolanic waste materials can replace OPC-43 grade cement to obtain maximum compressive strength. In this thesis OPC-43 grade cement is replaced partially by stone dust & granite powder simultaneously in the proportion of 5%, 10%, 15% & 20% by weight. Mortar cubes were casted, tested and compared in terms of compressive strength to the standard mortar mixtures. Cubes were subjected to compressive strength test to determine strength at 7 days, 28 days & 56 days. The result obtained clearly represents that on partial replacement of cement by 5% with stone dust, compressive strength obtained is maximum. On the other hand, higher strength is obtained when cement is replaced with 10% granite powder

  6. The effect of fly ash and coconut fibre ash as cement replacement materials on cement paste strength

    Science.gov (United States)

    Bayuaji, R.; Kurniawan, R. W.; Yasin, A. K.; Fatoni, H. AT; Lutfi, F. M. A.

    2016-04-01

    Concrete is the backbone material in the construction field. The main concept of the concrete material is composed of a binder and filler. Cement, concrete main binder highlighted by environmentalists as one of the industry are not environmentally friendly because of the burning of cement raw materials in the kiln requires energy up to a temperature of 1450° C and the output air waste CO2. On the other hand, the compound content of cement that can be utilized in innovation is Calcium Hydroxide (CaOH), this compound will react with pozzolan material and produces additional strength and durability of concrete, Calcium Silicate Hydrates (CSH). The objective of this research is to explore coconut fibers ash and fly ash. This material was used as cement replacement materials on cement paste. Experimental method was used in this study. SNI-03-1974-1990 is standard used to clarify the compressive strength of cement paste at the age of 7 days. The result of this study that the optimum composition of coconut fiber ash and fly ash to substitute 30% of cement with 25% and 5% for coconut fibers ash and fly ash with similar strength if to be compared normal cement paste.

  7. [Favourable long-term results from cemented total hip arthroplasty combined with acetabular bone impaction grafting in patients under the age of 50

    NARCIS (Netherlands)

    Busch, V.J.; Gardeniers, J.W.M.; Slooff, T.J.J.H.; Veth, R.P.H.; Schreurs, B.W.

    2007-01-01

    OBJECTIVE: Determination of long-term results of hip replacements in patients who, at the time of operation, were under the age of 50. Procedures whereby an existing acetabulum defect was filled with bone chips that were impacted into a strong layer, after which a cemented total hip prosthesis was i

  8. Studies on termite hill and lime as partial replacement for cement in plastering

    Energy Technology Data Exchange (ETDEWEB)

    Olusola, K.O.; Olanipekun, E.A.; Ata, O.; Olateju, O.T. [Obafemi Awolowo University, Ile-Ife, Osun State (Nigeria). Department of Building

    2006-03-15

    This study investigated the compressive strength and water absorption capacity of 50x50x50mm mortar cubes made from mixes containing lime, termite hill and cement and sand. Two mix ratios (1:4 and 1:6) and varying binder replacements of cement with lime or termite hill amounting to 0%, 10%, 20%, 30%, 40% and 50% were used. Test results showed that the compressive strength of the mortar cubes increases with age and decreases with increasing percentage replacement of cement with lime and termite hill. However, for mix ratio 1:6, up to 20% replacement of cement with either lime or termite hill, all the mortar cubes had the same strength; subsequently, the termite hill exhibited a higher compressive strength. For mix ratio 1:4, mortar cubes made from lime/cement and termite hill/cement mixtures had the same strength at 50% replacement. Generally, water absorption is higher in mixtures containing lime (18.10% and 14.20% for mix ratios 1:6 and 1:4, respectively, both at 50% replacement level) than those containing termite hill (16.10% and 13.02% for mix ratios 1:6 and 1:4, respectively, both at 50% replacement level). Termite hills seem to be promising as a suitable, locally available housing material for plastering. (author)

  9. Palacos compared to Palamed bone cement in total hip replacement: a randomized controlled trial.

    Science.gov (United States)

    Meinardi, Joris E; Valstar, Edward R; Van Der Voort, Paul; Kaptein, Bart L; Fiocco, Marta; Nelissen, Rob G H H

    2016-10-01

    Background and purpose - Stability and survival of cemented total hip prostheses is dependent on a multitude of factors, including the type of cement that is used. Bone cements vary in viscosity, from low to medium and high. There have been few clinical RSA studies comparing the performance of low- and high-viscosity bone cements. We compared the migration behavior of the Stanmore hip stem cemented using novel low-viscosity Palamed bone cement with that of the same stem cemented with conventional high-viscosity Palacos bone cement. Patients and methods - We performed a randomized controlled study involving 39 patients (40 hips) undergoing primary total hip replacement for primary or secondary osteoarthritis. 22 patients (22 hips) were randomized to Palacos and 17 patients (18 hips) were randomized to Palamed. Migration was determined by RSA. Results - None of these 40 hips had been revised at the 10-year follow-up mark. To our knowledge, the patients who died before they reached the 10-year endpoint still had the implant in situ. No statistically significant or clinically significant differences were found between the 2 groups for mean translations, rotations, and maximum total-point motion (MTPM). Interpretation - We found similar migration of the Stanmore stem in the high-viscosity Palacos cement group and the low-viscosity Palamed cement group. We therefore expect that the risk of aseptic loosening with the new Palamed cement would be comparable to that with the conventional Palacos cement. The choice of which type of bone cement to use is therefore up to the surgeon's preference. PMID:27329869

  10. Use of waste brick as a partial replacement of cement in mortar.

    Science.gov (United States)

    Naceri, Abdelghani; Hamina, Makhloufi Chikouche

    2009-08-01

    The aim of this study is to investigate the use of waste brick as a partial replacement for cement in the production of cement mortar. Clinker was replaced by waste brick in different proportions (0%, 5%, 10%, 15% and 20%) by weight for cement. The physico-chemical properties of cement at anhydrous state and the hydrated state, thus the mechanical strengths (flexural and compressive strengths after 7, 28 and 90 days) for the mortar were studied. The microstructure of the mortar was investigated using scanning electron microscopy (SEM), the mineralogical composition (mineral phases) of the artificial pozzolan was investigated by the X-ray diffraction (XRD) and the particle size distributions was obtained from laser granulometry (LG) of cements powders used in this study. The results obtained show that the addition of artificial pozzolan improves the grinding time and setting times of the cement, thus the mechanical characteristics of mortar. A substitution of cement by 10% of waste brick increased mechanical strengths of mortar. The results of the investigation confirmed the potential use of this waste material to produce pozzolanic cement.

  11. Optimization of fly ash as sand replacement materials (SRM) in cement composites containing coconut fiber

    Science.gov (United States)

    Nadzri, N. I. M.; Jamaludin, S. B.; Mazlee, M. N.; Jamal, Z. A. Z.

    2016-07-01

    The need of utilizing industrial and agricultural wastes is very important to maintain sustainability. These wastes are often incorporated with cement composites to improve performances in term of physical and mechanical properties. This study presents the results of the investigation of the response of cement composites containing coconut fiber as reinforcement and fly ash use as substitution of sand at different hardening days. Hardening periods of time (7, 14 and 28 days) were selected to study the properties of cement composites. Optimization result showed that 20 wt. % of fly ash (FA) is a suitable material for sand replacement (SRM). Meanwhile 14 days of hardening period gave highest compressive strength (70.12 MPa) from the cement composite containing 9 wt. % of coconut fiber and fly ash. This strength was comparable with the cement without coconut fiber (74.19 MPa) after 28 days of curing.

  12. Utilization of Palm Oil Clinker as Cement Replacement Material

    OpenAIRE

    Jegathish Kanadasan; Hashim Abdul Razak

    2015-01-01

    The utilization of waste materials from the palm oil industry provides immense benefit to various sectors of the construction industry. Palm oil clinker is a by-product from the processing stages of palm oil goods. Channelling this waste material into the building industry helps to promote sustainability besides overcoming waste disposal problems. Environmental pollution due to inappropriate waste management system can also be drastically reduced. In this study, cement was substituted with pa...

  13. Wood Ash from Bread Bakery as Partial Replacement for Cement in Concrete

    OpenAIRE

    Akeem Ayinde Raheem; Olumide A Adenuga

    2013-01-01

    This paper reports the results of experiments evaluating the use of wood ash from bread bakery as partial replacement for ordinary Portland cement in concrete. The chemical composition of the wood ash as well as the workability and compressive strength of the concrete were determined. Wood ash was used to replace 5% - 25% by weight of the cement in concrete. Concrete with no wood ash serves as the control. The mix ratio used was 1:2:4 with water to binder ratio maintained at 0.5. The Compress...

  14. The economics of using prophylactic antibiotic-loaded bone cement in total knee replacement.

    Science.gov (United States)

    Gutowski, C J; Zmistowski, B M; Clyde, C T; Parvizi, J

    2014-01-01

    The rate of peri-prosthetic infection following total joint replacement continues to rise, and attempts to curb this trend have included the use of antibiotic-loaded bone cement at the time of primary surgery. We have investigated the clinical- and cost-effectiveness of the use of antibiotic-loaded cement for primary total knee replacement (TKR) by comparing the rate of infection in 3048 TKRs performed without loaded cement over a three-year period versus the incidence of infection after 4830 TKRs performed with tobramycin-loaded cement over a later period of time of a similar duration. In order to adjust for confounding factors, the rate of infection in 3347 and 4702 uncemented total hip replacements (THR) performed during the same time periods, respectively, was also examined. There were no significant differences in the characteristics of the patients in the different cohorts. The absolute rate of infection increased when antibiotic-loaded cement was used in TKR. However, this rate of increase was less than the rate of increase in infection following uncemented THR during the same period. If the rise in the rate of infection observed in THR were extrapolated to the TKR cohort, 18 additional cases of infection would have been expected to occur in the cohort receiving antibiotic-loaded cement, compared with the number observed. Depending on the type of antibiotic-loaded cement that is used, its cost in all primary TKRs ranges between USD $2112.72 and USD $112 606.67 per case of infection that is prevented.

  15. 40 CFR 63.1220 - What are the replacement standards for hazardous waste burning cement kilns?

    Science.gov (United States)

    2010-07-01

    ... hazardous waste burning cement kilns? 63.1220 Section 63.1220 Protection of Environment ENVIRONMENTAL..., and Lightweight Aggregate Kilns § 63.1220 What are the replacement standards for hazardous waste... oxygen; (4) For arsenic, beryllium, and chromium, both: (i) Emissions in excess of 2.1 × 10−5...

  16. STUDY ON PASTES AND MORTARS OF PORTLAND CEMENT WITH REPLACEMENT BY SANITARY WARE

    Directory of Open Access Journals (Sweden)

    Silvina Zito

    2016-06-01

    Full Text Available In this paper the Sanitary Faience, use as a replacement for portland cement is analyzed. Replacements used were 8, 24 and 40% by weight; the assays used contemplated the evolution of hydration from the first minutes (up to 48 hours by calorimetry, and from 2 days (to 28 days by the fixing of calcium hydroxide, water chemically combined, mechanical flexural and compression and porosity. The results showed that with increasing the percentage of replacement, at the earliest ages the effect of dilution overlaps and contrats with the physical stimulation; and at the 28 days all blends showed, as well as physical stimulation, chemistry stimulation, trough of pozzolanic reactivity.

  17. Study of Compressive Strength of Concrete with Coal Power Plant Fly Ash as Partial Replacement of Cement and Fine Aggregate

    Directory of Open Access Journals (Sweden)

    FAREED AHMED MEMON

    2010-10-01

    Full Text Available This research study comprises of concrete cubes made with Ordinary Portland Cement and with different configurations of fly ash by replacing cement and fine aggregate. To achieve the aim of this study, total 81 concrete cubes were cast. Among 81 cubes, 9 cubes were made with normal concrete, 36 cubes were made by replacing 25%, 50%, 75% and 100% of fine aggregate with fly ash and 36 cubes were made by replacing 10%, 25%, 50%, and 75% of cement with fly ash. The cubes were 6\\" x 6\\" in cross-section, and the mix design was aimed for 5000 psi. After proper curing of all 81 cubes, they were tested at 3, 7 and 28 days curing age. The cubes were tested in Forney Universal Testing Machine. By analyzing the test results of all the concrete cubes, the following main findings have been drawn. The compressive strength of concrete cubes made by replacing 100 % fine aggregate by fly ash was higher than the concrete cubes made with Ordinary Portland Cement at all 3, 7 and 28 days curing ages. On the other hand, the compressive strength of concrete cubes made by replacing 10 % and 25 % cement by fly ash was slightly lower than the concrete cubes made with Ordinary Portland Cement at all curing ages, whereas, the compressive strength of concrete cubes made by replacing 50 % and 75 % of cement by fly ash were quite lower than the concrete cubes made with Ordinary Portland Cement at all curing ages.

  18. Revision total hip replacement with a cemented long femoral component: minimum 9-year follow-up results.

    OpenAIRE

    So, Kazutaka; Kuroda, Yutaka; Matsuda, Shuichi; Akiyama, Haruhiko

    2013-01-01

    [Background] Surgical revision after failed total hip replacement is a technically challenging procedure. The aim of this study was to analyze the long-term results of revision total hip replacement using a cemented long femoral component and identify factors that influence the results. [Methods] We retrospectively reviewed 34 hips in 33 patients who had undergone revision total hip replacement using a cemented long femoral component between 1994 and 2001. Hip function was evaluated according...

  19. Porous titanium particles for acetabular reconstruction in total hip replacement show extensive bony armoring after 15 weeks

    NARCIS (Netherlands)

    Walschot, L.H.; Aquarius, R.; Verdonschot, N.J.; Buma, P.; Schreurs, B.W.

    2014-01-01

    Background and purpose - The bone impaction grafting technique restores bone defects in total hip replacement. Porous titanium particles (TiPs) are deformable, like bone particles, and offer better primary stability. We addressed the following questions in this animal study: are impacted TiPs osteoc

  20. Options for acetabular fixation surfaces.

    Science.gov (United States)

    Klika, Alison K; Murray, Trevor G; Darwiche, Hussein; Barsoum, Wael K

    2007-01-01

    Aseptic loosening is the most common cause for revision total hip arthroplasty (THA). Due to poor long-term results with cemented acetabular components, cementless implants that rely on biologic fixation became popular in the United States for both primary and revision procedures in the early 1980s. Cementless acetabular components used in THA have been reported to have superior radiographic performance compared with cemented fixation, although the optimal method of acetabular fixation remains controversial. Cementless acetabular components require initial implant stability to allow for bone ingrowth and remodeling into the acetabular shell, providing long-term durability of the prosthesis. Many improved implant materials are available to facilitate bone growth and remodeling, including the 3 most common surface treatments; fibermesh, sintered beads, and plasma spray coatings. Recently added to these are porous metal surfaces, which have increased porosity and optimal pore sizes when compared with titanium fibermesh. The most studied of these materials is the titanium fibermesh fixation surface, which has demonstrated a mechanical failure rate of 1% at 10 to 15 years. This technology utilizes the diffusion bonding process to attach fiber metal pads to a titanium substrate using heat and pressure. The sintered bead fixation surface offers a porous coating of various sizes of spherical beads, achieved by the sintering process, and has been shown to provide long-term fixation. While there are less long-term published data regarding the titanium plasma spray surface, its early results have provided evidence of its durability, even in the face of significant osteolysis. The most recently added alternative fixation surface is porous tantalum metal, which offers potentially greater bone ingrowth and bone graft incorporation due to its high porosity (80%) and low modulus of elasticity (3 MPa). Porous tantalum implants have shown early favorable clinical results and have

  1. Options for acetabular fixation surfaces.

    Science.gov (United States)

    Klika, Alison K; Murray, Trevor G; Darwiche, Hussein; Barsoum, Wael K

    2007-01-01

    Aseptic loosening is the most common cause for revision total hip arthroplasty (THA). Due to poor long-term results with cemented acetabular components, cementless implants that rely on biologic fixation became popular in the United States for both primary and revision procedures in the early 1980s. Cementless acetabular components used in THA have been reported to have superior radiographic performance compared with cemented fixation, although the optimal method of acetabular fixation remains controversial. Cementless acetabular components require initial implant stability to allow for bone ingrowth and remodeling into the acetabular shell, providing long-term durability of the prosthesis. Many improved implant materials are available to facilitate bone growth and remodeling, including the 3 most common surface treatments; fibermesh, sintered beads, and plasma spray coatings. Recently added to these are porous metal surfaces, which have increased porosity and optimal pore sizes when compared with titanium fibermesh. The most studied of these materials is the titanium fibermesh fixation surface, which has demonstrated a mechanical failure rate of 1% at 10 to 15 years. This technology utilizes the diffusion bonding process to attach fiber metal pads to a titanium substrate using heat and pressure. The sintered bead fixation surface offers a porous coating of various sizes of spherical beads, achieved by the sintering process, and has been shown to provide long-term fixation. While there are less long-term published data regarding the titanium plasma spray surface, its early results have provided evidence of its durability, even in the face of significant osteolysis. The most recently added alternative fixation surface is porous tantalum metal, which offers potentially greater bone ingrowth and bone graft incorporation due to its high porosity (80%) and low modulus of elasticity (3 MPa). Porous tantalum implants have shown early favorable clinical results and have

  2. PERFORMANCE OF CEMENT MORTARS REPLACED BY GROUND WASTE BRICK IN DIFFERENT AGGRESSIVE CONDITIONS

    Directory of Open Access Journals (Sweden)

    ILHAMI DEMIR

    2011-09-01

    Full Text Available This article investigates the sulphate resistance of cement mortars when subjected to different exposure conditions. Cement mortars were prepared using ground waste brick (GWB as a pozzolanic partial replacement for cement at replacement levels of 0%, 2.5%, 5%, 7.5, 10%, 12.5 and 15%. Mortar specimens were stored under three different conditions: continuous curing in lime-saturated tab water (TW, continuous exposure to 5% sodium sulphate solution (SS, and continuous exposure to 5% ammonium nitrate solution (AN, at a temperature of 20 ± 3 ºC, for 7, 28, 90, and 180 days. Prisms with dimensions of 25×25×285 mm, to determine the expansions of the mortar samples; and another set of prisms with dimensions of 40×40×160 mm, were prepared to calculate the compressive strength of the samples. It was determined that the GWB replacement ratios between 2.5% and 10% decreased the 180 days expansion values. The highest compressive strength values were found for the samples with 10% replacement ratio in the TW, SS, and AN conditions for 180 days. The microstructure of the mortars were investigated using scanning electron microscopy (SEM and the Energy dispersive X-ray (EDX.

  3. Utilization of “Marble Slurry” In Cement Concrete Replacing Fine Agreegate

    Directory of Open Access Journals (Sweden)

    Er: Raj.p.singh kushwah

    2015-01-01

    Full Text Available The wastage of marble industry are responsible for many environmental problems because 70% wastes and only 30% recovery of main product contribute to the maximum wastes which are indestructible. Dumping sites give dirty look. Contaminate top fertile soil cover, along with rivers/water bodies affecting irrigation and drinking water resources and air as well as loss to flora and fauna. The most efficient Solution of marble slurry pollution is utilization in Bulk. The only industry which can consume marble slurry at so large level is only the construction industry. Different properties of marble slurry determined in the laboratory. Sp. gravity 2.61, Fineness modulus was found to be 0.91 and Utilization of marble slurry in Cement Concrete replacing Sand is 30% which shows equal strength as of Control i,e. 1:2:4 Cement Concrete 0% Marble slurry. Marble slurry can be easily utilized in construction industry in preparing Cement Concrete.

  4. Study of Compressive Strength of Concrete with Coal Power Plant Fly Ash as Partial Replacement of Cement and Fine Aggregate

    OpenAIRE

    FAREED AHMED MEMON; NAFEES AHMED MEMON; RIZWAN ALI MEMON

    2010-01-01

    This research study comprises of concrete cubes made with Ordinary Portland Cement and with different configurations of fly ash by replacing cement and fine aggregate. To achieve the aim of this study, total 81 concrete cubes were cast. Among 81 cubes, 9 cubes were made with normal concrete, 36 cubes were made by replacing 25%, 50%, 75% and 100% of fine aggregate with fly ash and 36 cubes were made by replacing 10%, 25%, 50%, and 75% of cement with fly ash. The cubes were 6\\" x 6\\" in cross-s...

  5. Effects on cement after partial replacement with burned joss paper ash.

    Science.gov (United States)

    Lin, D F; Huang, L S; Luo, H L; Weng, R S

    2012-12-01

    In the last ten years, as international environmental protection consciousness has increased, the study and applications of green building, green construction materials and energy savings as well as reduction of carbon dioxide have become urgent issues for governments. In Taiwan, joss papers are burned in more than 11,731 registered shrines or temples in traditional Chinese deity or ancestor worship ceremonies during special holidays or occasions. Instead of placing this large amount of burned joss paper ash (BJPA) in landfills, this study proposes recycling BJPA by replacing some cement with calcined BJPA (CBJPA) in mortar specimens. After BJPA samples were calcined at a high kiln temperature, mortar samples were created using CBJPA to replace cement at seven different levels: 0%, 5%, 10%, 15%, 20%, 25% and 30%. Tests like setting time and compressive strength were performed for macro-analyses; scanning electron microscopy-energy dispersive spectroscopy, X-ray diffraction and thermal gravimetric analysis/differential thermal analysis were carried out for the microstructure and chemical composition analyses. The test results showed that the compressive strengths of specimens with different levels of CBJPA replacement were apparently less than those of the control group (0% CBJPA) at all curing times. The compressive strength and setting time both decreased as the fraction of CBJPA in the mortar increased. Furthermore, because the hydration product did not cement and the mortar specimen structure was loose, the expected strength improvement from the pozzolanic reaction provided by the CBJPA was not clearly observed.

  6. Acetabular defect reconstruction with impacted morsellized bone grafts or TCP/HA particles. A study on the mechanical stability of cemented cups in an artificial acetabulum model.

    NARCIS (Netherlands)

    Bolder, S.B.T.; Verdonschot, N.J.J.; Schreurs, B.W.; Buma, P.

    2002-01-01

    In revision surgery of the acetabulum bone defects can be filled with impacted human morsellized bone grafts. Because of a worldwide limited availability of human bone, alternatives are being considered. In this study we compared the initial stability of acetabular cups after reconstructing a cavita

  7. Influence of portland cement replacement in high calcium fly ash geopolymer paste

    Directory of Open Access Journals (Sweden)

    Tanakorn Phoo-ngernkham

    2014-03-01

    Full Text Available This article presents the influence of ordinary Portland cement (OPC replacement in high calcium fly ash (FA geopolymer paste. FA was used to replace OPC at the rate of 5, 10 and 15% by mass of binder. Sodium silicate (Na2SiO3 and 10 molar sodium hydroxide (NaOH solutions were used as the alkaline solution in the reaction. The Na2SiO3/NaOH ratio of 2.0 and the liquid/binder (L/B ratio of 0.60 were used in all mixtures. The results of increase OPC replacement, the setting time and compressive strain capacity decreased while the compressive strength and modulus of elasticity increased. The compressive strength and modulus of elasticity at 28 days of geopolymer pastes with 15% OPC replacement were 36.7 MPa and 13,300 MPa, respectively.

  8. An Experimental Investigation of Partial Replacement of Cement by Various Percentage of Phosphogypsum And Flyash In Cement Concrete

    Directory of Open Access Journals (Sweden)

    Suchita R Saikhede

    2014-07-01

    Full Text Available Over 15 million tons of fly ash (FA and 3 million tons of phospho-gypsum (PG are produced every year. The utilization of these industrial by-product materials is important in terms of environmental and economical issues are concerned. The main purpose of this study is to evaluate the technical possibilities of incorporating FA and PG in production of concrete .In this study Combination of FA and PG is use as a mineral admixture with, phosphogypsum 0%., 5%,10%, 15% and fly ash is constant as 20% , Last proportion was taken PG- 5% and FA- 25%. . The compressive, tensile and flexural strength are studied by casting and testing specimens for 7, 14 and 28 days. It is shown that a part of ordinary Portland cement can be replaced with PG and FA to develop a good and hardened concrete to achieve economy; above 10% replacement of phosphogypsum and 20% replacement of F in concrete lead to drastic reduction not only in the compressive strength but also in Flexural and split tensile strength of concrete.

  9. Statistical Analyses of Optimum Partial Replacement of Cement by Fly Ash Based on Complete Consumption of Calcium Hydroxide

    Directory of Open Access Journals (Sweden)

    Ouypornprasert Winai

    2016-01-01

    Full Text Available The objectives of this technical paper were to propose the optimum partial replacement of cement by fly ash based on the complete consumption of calcium hydroxide from hydration reactions of cement and the long-term strength activity index based on equivalent calcium silicate hydrate as well as the propagation of uncertainty due to randomness inherent in main chemical compositions in cement and fly ash. Firstly the hydration- and pozzolanic reactions as well as stoichiometry were reviewed. Then the optimum partial replacement of cement by fly ash was formulated. After that the propagation of uncertainty due to main chemical compositions in cement and fly ash was discussed and the reliability analyses for applying the suitable replacement were reviewed. Finally an applicability of the concepts mentioned above based on statistical data of materials available was demonstrated. The results from analyses were consistent with the testing results by other researchers. The results of this study provided guidelines of suitable utilization of fly ash for partial replacement of cement. It was interesting to note that these concepts could be extended to optimize partial replacement of cement by other types of pozzolan which were described in the other papers of the authors.

  10. Cement replacement by sugar cane bagasse ash: CO2 emissions reduction and potential for carbon credits.

    Science.gov (United States)

    Fairbairn, Eduardo M R; Americano, Branca B; Cordeiro, Guilherme C; Paula, Thiago P; Toledo Filho, Romildo D; Silvoso, Marcos M

    2010-09-01

    This paper presents a study of cement replacement by sugar cane bagasse ash (SCBA) in industrial scale aiming to reduce the CO(2) emissions into the atmosphere. SCBA is a by-product of the sugar/ethanol agro-industry abundantly available in some regions of the world and has cementitious properties indicating that it can be used together with cement. Recent comprehensive research developed at the Federal University of Rio de Janeiro/Brazil has demonstrated that SCBA maintains, or even improves, the mechanical and durability properties of cement-based materials such as mortars and concretes. Brazil is the world's largest sugar cane producer and being a developing country can claim carbon credits. A simulation was carried out to estimate the potential of CO(2) emission reductions and the viability to issue certified emission reduction (CER) credits. The simulation was developed within the framework of the methodology established by the United Nations Framework Convention on Climate Change (UNFCCC) for the Clean Development Mechanism (CDM). The State of São Paulo (Brazil) was chosen for this case study because it concentrates about 60% of the national sugar cane and ash production together with an important concentration of cement factories. Since one of the key variables to estimate the CO(2) emissions is the average distance between sugar cane/ethanol factories and the cement plants, a genetic algorithm was developed to solve this optimization problem. The results indicated that SCBA blended cement reduces CO(2) emissions, which qualifies this product for CDM projects. PMID:20493626

  11. The behavior of the micro-mechanical cement-bone interface affects the cement failure in total hip replacement

    NARCIS (Netherlands)

    Waanders, D.; Janssen, D.; Mann, K.A.; Verdonschot, N.J.J.

    2011-01-01

    In the current study, the effects of different ways to implement the complex micro-mechanical behavior of the cement-bone interface on the fatigue failure of the cement mantle were investigated. In an FEA-model of a cemented hip reconstruction the cement-bone interface was modeled and numerically im

  12. Evaluation of red mud as pozzolanic material in replacement of cement for production of mortars

    International Nuclear Information System (INIS)

    Red mud is a by-product of the alkaline extraction of aluminum from the bauxite and represents a renewed environmental problem due the significant annual throughput by the plants. In the present work, the pozzolanic properties of Brazilian red mud fired at 600, 700, 800 and 900 deg C were investigated by monitoring lime consumption using DTA analysis and Brazilian standard methodology NBR 5772 (1992). Products and kinetics of hydration were determined in cement pastes produced with 5 and 15% red mud using x-ray diffraction and DTA analysis. Compressive strength and capillary absorption tests were realized on mortars constituted by 5, 10 and 15% red mud in replacement of cement. When calcined at 600 deg C, the red mud develops good pozzolanic properties, and the compressive strength of mortars produced with this waste meet values in accordance with regulatory standard. These results shown than red mud can be used, in partial replacement of cement, as new construction material to produce sustainable mortars with low environmental impact. (author)

  13. A brief on high-volume Class F fly ash as cement replacement – A guide for Civil Engineer

    Directory of Open Access Journals (Sweden)

    Alaa M. Rashad

    2015-12-01

    Full Text Available Disposal of fly ash (FA resulting from the combustion of coal-fired electric power stations is one of the major environmental challenges. This challenge continues to increase with increasing the amount of FA and decreasing the capacity of landfill space. Therefore, studies have been carried out to re-use high-volumes of fly ash (HVFA as cement replacement in building materials. This paper presents an overview of the previous studies carried out on the use of high volume Class F FA as a partial replacement of cement in traditional paste/mortar/concrete mixtures based on Portland cement (PC. Fresh properties, mechanical properties, abrasion resistance, thermal properties, drying shrinkage, porosity, water absorption, sorptivity, chemical resistance, carbonation resistance and electrical resistivity of paste/mortar/concrete mixtures containing HVFA (⩾45% as cement replacement have been reviewed. Furthermore, additives used to improve some properties of HVFA system have been reviewed.

  14. Laboratory Investigation Of Partial Replacement Of Coarse Aggregate By Plastic Chips And Cement By Human Hair

    Directory of Open Access Journals (Sweden)

    A.S.Balaji

    2014-04-01

    Full Text Available The use of plastic is increasing day by day, although steps were taken to reduce its consumption. The suitability of recycled plastics as coarse aggregate in concrete and its advantage are discussed here. Experimental investigation was done using M20 mix and tests were carried out as per recommended procedures by relevant codes. As 100% replacement of natural coarse aggregate (NCA with plastic coarse aggregate (PCA is not feasible, partial replacement were examined. And also Hair is used as a fibred reinforcing material in concrete as partial replacement of cement. It has a high tensile strength which is equal to that of a copper wire with similar diameter. It is also available in abundance and at a very low cost. Tests were conducted to determine the properties of plastic aggregate and human hair such as density, specific gravity and crushing value. Experiments were conducted on concrete cubes with various percentages of human hair i.e. 0%, 0.5%, 1%, 1.5%, 2%, and 3% by weight of cement and with constant percentage of plastic aggregate as 20%.

  15. A Biomimetic Hip Joint Simulator and its Application in in vitro Study of the Integrity of Replacement Cemented Hip

    Institute of Scientific and Technical Information of China (English)

    Liu Chao-zong; S.M.Green; N.D.Watkins; A.W.McCaskie

    2005-01-01

    A biomimetic hip joint simulator that can be used to evaluate the outcome of the cemented total hip replacement has been designed, manufactured and evaluated. The simulator produces motion in the extension/flexion plane, with a socket to rotate internal/externally. At the same time a dynamic loading cycle is applied. A validation test was performed on a cemented femoral stem within a novel composite femur. The bone quality has a strong effect on the stem migration and on the integrity of the interfaces. The migration of the stem is a combination of 3-D translation and rotation of the stem. Under the same loading conditions, weak bone allows more stem migration than strong bone. There is a great decrease in the strength of the stem-cement interface after the dynamic test, and the weak bone composite exhibited a greater reduction in interfacial strength than the strong bone composite. The decrease of the interfacial strength indicates that the primary bonding between the stem and the cement mantle had deteriorated and the integrity of stem-cement interface was damaged.The study demonstrates the value of using a hip joint simulator to investigate stem migration and interface integrity within the cemented hip replacement, suggesting that method can be used for in vitro evaluation of the biomaterials used in the cemented hip replacements.

  16. Recycling municipal incinerator fly- and scrubber-ash into fused slag for the substantial replacement of cement in cement-mortars.

    Science.gov (United States)

    Lee, Tzen-Chin; Rao, Ming-Kang

    2009-06-01

    Fly- and scrubber-ash (weight ratio of approximately 1:3) from municipal solid waste incinerators (MSWI) are a major land-fill disposal problem due to their leaching of heavy metals. We uniformly mixed both types of ash with optimal amounts of waste glass frit, which was then melted into a glassy slag. The glassy slag was then pulverized to a particle size smaller than 38microm for use as a cement substitute (20-40% of total cement) and blended with sand and cement to produce slag-blended cement-mortar (SCM) specimens. The toxicity characteristics of the leaching procedure tests on the pulverized slag samples revealed that the amount of leached heavy metals was far below regulatory thresholds. The compressive strength of the 28-day cured SCM specimens was comparable to that of ordinary Portland cement mortars, while the compressive strength of specimens cured for 60 or 90 days were 3-11% greater. The observed enhanced strength is achieved by Pozzolanic reaction. Preliminary evaluation shows that the combination of MSWI fly- and scrubber-ash with waste glass yields a cost effective and environmentally friendly cement replacement in cement-mortars.

  17. Use of disposed waste ash from landfills to replace Portland cement.

    Science.gov (United States)

    Rukzon, Sumrerng; Chindaprasirt, Prinya

    2009-09-01

    In this study, waste ash was utilized as a pozzolanic material in blended Portland cement in order to reduce negative environmental effects and landfill volume required to dispose of waste ash. The influence of waste ash, namely palm oil fuel ash, rice husk ash and fly ash on compressive strength and sulfate resistance in mortar were studied and evaluated by some accelerated short-term techniques in sodium sulfate solutions. Ordinary Portland cement (OPC) was partially replaced with ground palm oil fuel ash (POA), ground rice husk ash (RHA) and classified fly ash (FA). Single pozzolan and a blend of equal weight portions of POA, RHA and FA were also used. The resistance to sulfate attack of mortar improves substantially with partial replacement of OPC with POA, RHA and FA. The use of a blend of equal weight portions of FA and POA or RHA produced mixes with good strength and resistance to sulfate attack. POA, RHA and FA have a high potential to be used as a pozzolanic material.

  18. Wood Ash from Bread Bakery as Partial Replacement for Cement in Concrete

    Directory of Open Access Journals (Sweden)

    Akeem Ayinde Raheem

    2013-04-01

    Full Text Available This paper reports the results of experiments evaluating the use of wood ash from bread bakery as partial replacement for ordinary Portland cement in concrete. The chemical composition of the wood ash as well as the workability and compressive strength of the concrete were determined. Wood ash was used to replace 5% - 25% by weight of the cement in concrete. Concrete with no wood ash serves as the control. The mix ratio used was 1:2:4 with water to binder ratio maintained at 0.5. The Compressive strength was determined at curing ages 3, 7, 28, 56, 90 and 120 days. The results showed that wood ash from bread bakery is a Class F fly ash since the sum of (SiO2 +Al2O3 +Fe2O3 is greater than 70%. The compressive strength of wood ash concrete increases with curing period and decreases with increasing wood ash content. There was a sharp decrease in compressive strength beyond 10% wood ash substitution. It was concluded that a maximum of 10% wood ash substitution is adequate for use in structural concrete

  19. Study on properties of rice husk ash and its use as cement replacement material

    Directory of Open Access Journals (Sweden)

    Ghassan Abood Habeeb

    2010-06-01

    Full Text Available This paper investigates the properties of rice husk ash (RHA produced by using a ferro-cement furnace. The effect of grinding on the particle size and the surface area was first investigated, then the XRD analysis was conducted to verify the presence of amorphous silica in the ash. Furthermore, the effect of RHA average particle size and percentage on concrete workability, fresh density, superplasticizer (SP content and the compressive strength were also investigated. Although grinding RHA would reduce its average particle size (APS, it was not the main factor controlling the surface area and it is thus resulted from RHA's multilayered, angular and microporous surface. Incorporation of RHA in concrete increased water demand. RHA concrete gave excellent improvement in strength for 10% replacement (30.8% increment compared to the control mix, and up to 20% of cement could be valuably replaced with RHA without adversely affecting the strength. Increasing RHA fineness enhanced the strength of blended concrete compared to coarser RHA and control OPC mixtures.

  20. New methodology for assessing the environmental burden of cement mortars with partial replacement of coal bottom ash and fly ash.

    Science.gov (United States)

    Menéndez, E; Álvaro, A M; Hernández, M T; Parra, J L

    2014-01-15

    This paper assess the mechanical an environmental behaviour of cement mortars manufactured with addition of fly ash (FA) and bottom ash (BA), as partial cement replacement (10%, 25% and 35%). The environmental behaviour was studied by leaching tests, which were performed under several temperature (23 °C and 60 °C) and pH (5 and 10) conditions, and ages (1, 2, 4 and 7 days). Then, the accumulated amount of the different constituents leached was analysed. In order to obtain an environmental burden (EB) value of each cement mixture, a new methodology was developed. The EB value obtained is related to the amount leached and the hazardous level of each constituent. Finally, the integral study of compressive strength and EB values of cement mixtures allowed their classification. The results showed that mortars manufactured with ordinary Portland cement (OPC) and with coal BA had similar or even better environmental and mechanical behaviour than mortars with FA. Therefore, the partial replacement of cement by BA might be as suitable or even better as the replacement by FA.

  1. A Comparative Study on Compressive and Flexural Strength of Concrete Containing Different Admixtures as Partial Replacement of Cement

    Directory of Open Access Journals (Sweden)

    Apoorv Singh

    2014-09-01

    Full Text Available Concrete is the most widely used material in the world today. This paper is about the comparative study of the flexural strength and compressive strength of concrete when different admixtures are used as partial replacement of cement in the concrete mix. The mineral admixtures that are used here are Silica Fume, Rice Husk Ash and Iron slag as partial replacement of cement. All these materials are industrial waste products and are abundantly available nowadays. These materials have high silica content and pozzolanic properties and can be effectively used as a replacement of cement during the formation of High Performance Concrete. Compressive and Flexural strength are the two most important characteristic of concrete and are calculated for the hardened concrete to analyze the load bearing capacity for design purposes. Thus for the effective judgment of type of mineral admixtures to be used a comparative study is very useful.

  2. Performance of High-Strength Concrete Using Palm Oil Fuel Ash as Partial Cement Replacement

    Directory of Open Access Journals (Sweden)

    Dr. M. Swaroopa Rani

    2015-04-01

    Full Text Available The advancement in material technology has led to development of concrete with higher strengths. Presence of high cementitious materials contents in high strength concrete mixes increases heat of hydration that causes higher shrinkage and leading it to potential of cracking. However, use of supplementary cementitious materials leads to control in heat of hydration which further avoids higher shrinkage. Materials such as fly ash, silica fume, metakaolin and ground granulated blast furnace slag are largely been used as supplementary cementitious materials in High strength concrete mixes. In the present study use of palm oil fuel ash (POFA as partial cement replacement in high strength concrete mixes is evaluated with an experimental study. High strength concrete mix of M60 grade is taken as a reference and the compressive strength, split tensile strength and flexural strength where performed for 7, 28 and 56 days and analyzed it with results for partial replacement mixes of POFA 5%, 10%, 15%, 20% & 25%. It has been observed that concrete with 15% replacement of POFA gave the highest strength.

  3. Study on the Utilization of Paper Mill Sludge as Partial Cement Replacement in Concrete

    Directory of Open Access Journals (Sweden)

    Nazar A.M. Md

    2014-03-01

    Full Text Available A major problem arising from the widespread use of forestry biomass and processed timber waste as fuel is related to the production of significant quantities of ash as a by-product from the incineration of such biomasses. A major portion (approximately 70% of the wood waste ash produced is land-filled as a common method of disposal. If the current trend continues with waste products, such as paper mill sludge landfills, a large amount of space would be required by 2020. A revenue study was conducted as a result of investigations into the use of paper mill sludge as recycled materials and additives in concrete mixes for use in construction projects. The study had to provide the assurance that the concrete produced had the correct mechanical strength. Concrete mixes containing paper mill sludge were prepared, and their basic strength characteristics such as the compressive strength, flexural strength, ultra pulse velocity and dynamic modulus elasticity were tested. Four concrete mixes, i.e. a control mix, and a 10%, 20%, and 30% mix of paper mill sludge as cement replacement for concrete were prepared with a DoE mix design by calculating the weight of cement, sand and aggregate. The performance of each concrete specimen was compared with the strength of the control mix. As a result, when the percentage of paper mill sludge in the concrete increased, the strength decreased. Overall, a high correlation was observed between density and strength of the concrete containing paper mill sludge.

  4. Primary and revision total hip replacement without cement and with associated femoral osteotomy.

    Science.gov (United States)

    Holtgrewe, J L; Hungerford, D S

    1989-12-01

    Nine porous-coated total hip prostheses were implanted without cement in nine patients who had a major proximal femoral deformity. Six patients had revision and three, primary total hip replacement. In all nine patients, as well placed corrective osteotomy was needed to successfully perform the arthroplasty. The average time until union of the proximal femoral osteotomy was fifteen weeks for the patients who had a primary arthroplasty and twenty-seven weeks for the patients who had a revision arthroplasty. The average Harris hip-rating score was 94 points for the patients who had a primary arthroplasty and 84 points (range, 60 to 93 points) for those who had a revision arthroplasty. The length of follow-up averaged forty-seven months.

  5. Loosening After Acetabular Revision

    DEFF Research Database (Denmark)

    Beckmann, Nicholas A.; Weiss, Stefan; Klotz, Matthias C.M.;

    2014-01-01

    The best method of revision acetabular arthroplasty remains unclear. Consequently, we reviewed the literature on the treatment of revision acetabular arthroplasty using revision rings (1541 cases; mean follow-up (FU) 5.7 years) and Trabecular Metal, or TM, implants (1959 cases; mean FU 3.7 years)...

  6. Exploratory Study of Palm Oil Fuel Ash as Partial Cement Replacement in Oil Palm Shell Lightweight Aggregate Concrete

    OpenAIRE

    K. Muthusamy; Z. Nur Azzimah

    2014-01-01

    In Malaysia, issue of environmental pollution resulting from disposal of Palm Oil Fuel Ash (POFA) which is a by-product from palm oil mill has initiated research to incorporate this waste in Oil Palm Shell (OPS) lightweight aggregate concrete production. The current study investigates the effect of palm oil fuel ash content as partial cement replacement towards compressive strength OPS lightweight aggregate concrete. Several OPS lightweight aggregate concrete mixes were produced by replacing ...

  7. Cemented versus uncemented fixation in total hip replacement: a systematic review and meta-analysis of randomized controlled trials.

    LENUS (Irish Health Repository)

    Abdulkarim, Ali

    2013-02-22

    The optimal method of fixation for primary total hip replacements (THR), particularly fixation with or without the use of cement is still controversial. In a systematic review and metaanalysis of all randomized controlled trials comparing cemented versus uncemented THRS available in the published literature, we found that there is no significant difference between cemented and uncemented THRs in terms of implant survival as measured by the revision rate. Better short-term clinical outcome, particularly an improved pain score can be obtained with cemented fixation. However, the results are unclear for the long-term clinical and functional outcome between the two groups. No difference was evident in the mortality and the post operative complication rate. On the other hand, the radiographic findings were variable and do not seem to correlate with clinical findings as differences in the surgical technique and prosthesis design might be associated with the incidence of osteolysis. We concluded in our review that cemented THR is similar if not superior to uncemented THR, and provides better short term clinical outcomes. Further research, improved methodology and longer follow up are necessary to better define specific subgroups of patients in whom the relative benefits of cemented and uncemented implant fixation can be clearly demonstrated.

  8. Assessment of the Severity of CO2 Emission from Anthill Soils Used as Replacement for Shale in Cement Manufacture

    Directory of Open Access Journals (Sweden)

    Ogunfayo I. K.

    2012-12-01

    Full Text Available This paper assessed the replacement of shale in the production of cement with anthill soil. It also looked into the severity of carbon (IV oxide (CO2 emission of the anthill soil during the production of the cement. This was compared with that emitted when shale alone is used. Various tests were carried out on the anthill soil, shale and limestone. The test results were analysed and it was discovered that the emission of carbon (II oxide gas using anthill soil is benign when compared to that of shale.

  9. Size of metallic and polyethylene debris particles in failed cemented total hip replacements

    Science.gov (United States)

    Lee, J. M.; Salvati, E. A.; Betts, F.; DiCarlo, E. F.; Doty, S. B.; Bullough, P. G.

    1992-01-01

    Reports of differing failure rates of total hip prostheses made of various metals prompted us to measure the size of metallic and polyethylene particulate debris around failed cemented arthroplasties. We used an isolation method, in which metallic debris was extracted from the tissues, and a non-isolation method of routine preparation for light and electron microscopy. Specimens were taken from 30 cases in which the femoral component was of titanium alloy (10), cobalt-chrome alloy (10), or stainless steel (10). The mean size of metallic particles with the isolation method was 0.8 to 1.0 microns by 1.5 to 1.8 microns. The non-isolation method gave a significantly smaller mean size of 0.3 to 0.4 microns by 0.6 to 0.7 microns. For each technique the particle sizes of the three metals were similar. The mean size of polyethylene particles was 2 to 4 microns by 8 to 13 microns. They were larger in tissue retrieved from failed titanium-alloy implants than from cobalt-chrome and stainless-steel implants. Our results suggest that factors other than the size of the metal particles, such as the constituents of the alloy, and the amount and speed of generation of debris, may be more important in the failure of hip replacements.

  10. Studies on Punching Shear Resistance of Two Way Slab Specimens with Partial Replacement of Cement by GGBS with Different Edge Conditions

    Science.gov (United States)

    Nemani, Ravi Dakshina Murthy; Rao, M. V. S.; Grandhe, Veera Venkata Satya Naranyana

    2016-09-01

    The present work is an effort to quantify the punching shear load resistance effect on two way simply supported slab specimens with replacement of cement by Ground Granulated Blast Furnace Slag (GGBS) with different edge conditions at various replacement levels and evaluate its efficiency. GGBS replacement has emerged as a major alternative to conventional concrete and has rapidly drawn the concrete industry attention due to its cement savings, cost savings, environmental and socio-economic benefits. The two way slab specimens were subjected to punching shear load by in house fabricated apparatus. The slab specimens were cast using M30 grade concrete with HYSD bars. The cement was partially replaced with GGBS at different percentages i.e., 0 to 30 % at regular intervals of 10 %. The test results indicate that the two way slab specimens with partial replacement of cement by GGBS exhibit high resistance against punching shear when compared with conventional concretes slab specimens.

  11. Exploratory Study of Palm Oil Fuel Ash as Partial Cement Replacement in Oil Palm Shell Lightweight Aggregate Concrete

    Directory of Open Access Journals (Sweden)

    K. Muthusamy

    2014-07-01

    Full Text Available In Malaysia, issue of environmental pollution resulting from disposal of Palm Oil Fuel Ash (POFA which is a by-product from palm oil mill has initiated research to incorporate this waste in Oil Palm Shell (OPS lightweight aggregate concrete production. The current study investigates the effect of palm oil fuel ash content as partial cement replacement towards compressive strength OPS lightweight aggregate concrete. Several OPS lightweight aggregate concrete mixes were produced by replacing various percentage of POFA ranging from 10, 20, 30, 40 and 50%, respectively by weight of cement. All the mixes were cast in form of cubes and then subjected to water curing until the testing date. The compressive strength test is conducted in accordance to BSEN 12390 (2009 at 7 and 28 days. From the results, it was observed that the combination of appropriate POFA content would enhance the compressive strength of OPS lightweight aggregate concrete. Specimen produced using 20% POFA as partial cement replacement exhibit higher value of compressive strength than that of control OPS lightweight aggregate concrete. However, mixes consisting POFA up to 50% is also suitable for structural application.

  12. Use of Rice Husk Ash as Partial Replacement with Cement In Concrete- A Review

    Directory of Open Access Journals (Sweden)

    Sourav Ghosal,

    2015-09-01

    Full Text Available Rapid increase in construction activities has resulted in shortage of conventional construction materials.In the present scenario, the high cost of conventional building materials is a major factor affecting housing delivery in the world.This has necessitated research into alternative materials of construction.The effective housing techniques deal with reduction in cost of construction as well as providing strength to buildings.Mainly gravel,sand and cement are used in the preparation of conventional concrete.While the use of agricultural by-product i.e. rice husk as a partial replacement with the conventional fine aggregates is expected to serve the purpose of encouraging housing developers in building construction.Rice husk is produced in about 100 million tons per annum in India. Twenty kg of rice husk are obtained from 100 kg of rice.It contains organic substances and 20% inorganic material.Ash from rice is obtained as a result of combustion of rice husk at suitable temperature. Proper utilization of it aims to save the environment,encourages the Government to find solutions regarding disposal to land fills of waste materials,and provides new knowledge to the contractors and developers on how to improve the construction industry by using rice husk, to sustain good product performance and to meet recycling goals.The rice husk ash concrete aims to prepare light weight structural concrete which may reduce considerably the self load of structures and permits large precast units to be handled.The main objective is therefore to encourage the use of these ‘seemingly’ waste products as construction materials in low cost housing.The various basic properties of rice husk concrete are reviewed in this paper.

  13. Potential use of sewage sludge ash (SSA as a cement replacement in precast concrete blocks

    Directory of Open Access Journals (Sweden)

    Pérez-Carrión, M.

    2014-03-01

    Full Text Available The present study explored the technological feasibility of re-using sewage sludge ash (SSA as a Portland cement replacement in commercially manufactured pre cast concrete blocks. The blocks analysed were made to the guidelines laid down in Spain’s National Plan for Waste Water Treatment Plant Sludge, 2001–2006, and European Union specifications (CE marking for such products. Performance was compared in three families of blocks, with 0, 10 and 20% SSA. The findings proved that SSA is apt for pre cast concrete block manufacture and that, in addition to the economic and environmental benefits afforded, its use would improve certain of the properties of conventional block.El objetivo de esta investigación es estudiar el uso potencial de las cenizas de lodos de depuradora (CLD, como sustitución del cemento Portland en bloques de hormigón prefabricados, de forma que se pueda lograr una revalorización de este material de desecho mediante este procedimiento. La metodología utilizada en este trabajo se rige por las directrices del Plan Nacional Español de Lodos de Aguas Residuales de 2001–2006, y por las exigencias del Consejo Europeo (marcado CE, que es obligatorio para este tipo de productos. Se han utilizado dos niveles de sustitución de cemento (10% y 20%, y todos los resultados han sido referidos a las muestras control. Los resultados obtenidos muestran que es posible utilizar una sustitución parcial del cemento por CLD, en la fabricación de bloques de hormigón prefabricados, y por lo tanto, se pueden conseguir beneficios económicos y ambientales, así como la mejora de una serie de propiedades.

  14. Femoral and obturator nerves palsy caused by pelvic cement extrusion after hip arthroplasty.

    Directory of Open Access Journals (Sweden)

    Pawel Zwolak

    2011-05-01

    Full Text Available Cement extrusion into the pelvis with subsequent palsy of the obturator and femoral nerves is a rare entity after hip replacement surgery. Cemented fixation of the acetabular cup has been considered as a safe and reliable standard procedure with very good long term results. We present a case of fifty year old female patient after hip arthroplasty procedure which suffered an obturator and femoral nerve palsy caused by extrusion of bone cement into the pelvis. Postoperative X-rays and CT-scan of the pelvis demonstrated a huge mass consisted of bone cement in close proximity of femoral and obturator nerves. The surgery charts reported shallow and weak bony substance in postero-superior aspect of the acetabulum. This weak bony acetabular substance may have caused extrusion of bone cement during press-fitting of the polyethylene cup into the acetabulum, and the following damage of the both nerves produced by polymerization of bone cement. The bone cement fragment has been surgically removed 3 weeks after arthroplasty. The female patient underwent intensive postoperative physical therapy and electro stimulation which resulted in full recovery of the patient to daily routine and almost normal electromyography results.

  15. Difference in the acetabular cup orientation in standing and supine radiographs.

    Science.gov (United States)

    Khan, Munir; Beckingsale, Tom; Marsh, Martin; Holland, Jim

    2016-09-01

    Acetabular orientation changes with that of the pelvis during lying and standing. This study was designed to measure these changes. We assessed 17 BHR replacements using EBRA software. The mean acetabular anteversion was more (p = 0.02) on erect than supine radiographs. Linear regression analysis showed that anteversion and inclination increased in some while decreased in others, and Bland and Altman analysis showed wide limits of agreement. The changes in acetabular orientation are thus subject to significant variations between the patients. We suggest studying the factors affecting acetabular orientation in standing to help reduce joint reaction forces and improve outcomes. PMID:27408490

  16. Trabecular metal acetabular revision system (cup-cage construct to address the massive acetabular defects in revision arthroplasty

    Directory of Open Access Journals (Sweden)

    Rajesh Malhotra

    2012-01-01

    Full Text Available The increasing number of total hip replacements in the younger clique has added to the demand for revision procedures. Revision situations are often encountered with infection, loss of bone stock and bone defects. There are various methods of reconstruction of acetabular defects. The management options of type 3B Paprosky acetabular defects are limited with allograft and conventional cages. Trabecular metal technology has evolved to address these bone defects. Trabecular metal acetabular revision system (TMARS cup-cage construct is a new technique to address massive acetabular defects. We describe a case of failed hip reconstruction done for a Giant cell tumour of proximal femur managed by a two stage procedure, initial debridement and second stage reconstruction of acetabulum with TMARS cup-cage construct and femur with allograft prosthesis composite.

  17. Effect of copolymer latexes on physicomechanical properties of mortar containing high volume fly ash as a replacement material of cement.

    Science.gov (United States)

    Negim, El-Sayed; Kozhamzharova, Latipa; Gulzhakhan, Yeligbayeva; Khatib, Jamal; Bekbayeva, Lyazzat; Williams, Craig

    2014-01-01

    This paper investigates the physicomechanical properties of mortar containing high volume of fly ash (FA) as partial replacement of cement in presence of copolymer latexes. Portland cement (PC) was partially replaced with 0, 10, 20, 30 50, and 60% FA. Copolymer latexes were used based on 2-hydroxyethyl acrylate (2-HEA) and 2-hydroxymethylacrylate (2-HEMA). Testing included workability, setting time, absorption, chemically combined water content, compressive strength, and scanning electron microscopy (SEM). The addition of FA to mortar as replacement of PC affected the physicomechanical properties of mortar. As the content of FA in the concrete increased, the setting times (initial and final) were elongated. The results obtained at 28 days of curing indicate that the maximum properties of mortar occur at around 30% FA. Beyond 30% FA the properties of mortar reduce and at 60% FA the properties of mortar are lower than those of the reference mortar without FA. However, the addition of polymer latexes into mortar containing FA improved most of the physicomechanical properties of mortar at all curing times. Compressive strength, combined water, and workability of mortar containing FA premixed with latexes are higher than those of mortar containing FA without latexes.

  18. Effect of Copolymer Latexes on Physicomechanical Properties of Mortar Containing High Volume Fly Ash as a Replacement Material of Cement

    Directory of Open Access Journals (Sweden)

    El-Sayed Negim

    2014-01-01

    Full Text Available This paper investigates the physicomechanical properties of mortar containing high volume of fly ash (FA as partial replacement of cement in presence of copolymer latexes. Portland cement (PC was partially replaced with 0, 10, 20, 30 50, and 60% FA. Copolymer latexes were used based on 2-hydroxyethyl acrylate (2-HEA and 2-hydroxymethylacrylate (2-HEMA. Testing included workability, setting time, absorption, chemically combined water content, compressive strength, and scanning electron microscopy (SEM. The addition of FA to mortar as replacement of PC affected the physicomechanical properties of mortar. As the content of FA in the concrete increased, the setting times (initial and final were elongated. The results obtained at 28 days of curing indicate that the maximum properties of mortar occur at around 30% FA. Beyond 30% FA the properties of mortar reduce and at 60% FA the properties of mortar are lower than those of the reference mortar without FA. However, the addition of polymer latexes into mortar containing FA improved most of the physicomechanical properties of mortar at all curing times. Compressive strength, combined water, and workability of mortar containing FA premixed with latexes are higher than those of mortar containing FA without latexes.

  19. Experimental study on compressive strength of concrete by partially replacement of cement with sugar cane bagasse ash

    OpenAIRE

    Jayminkumar A. Patel; Dr. D. B. Raijiwala

    2015-01-01

    Use of waste material in concrete is important for environmental aspect. Sugar cane bagasse ash is a waste by product of sugar mill. Present study is to investigate impact of sugar cane bagasse ash in concrete. In this experimental work sugar cane bagasse ash which is taken from Maroli sugar mill, Navsari, Gujarat, INDIA is partially replace with cement at 0%, 5%, 10%, 15% and 20% by weight in concrete. The grade of concrete is M25 and w/c ratio is 0.49 taken as a reference. 150*1...

  20. Analysis of the Effect of Artificial Hip Replacement in the Treatment of Acetabular Defect%髋臼缺损畸形的人工髋关节置换手术疗效分析

    Institute of Scientific and Technical Information of China (English)

    武豪杰

    2015-01-01

    Objective To study the acetabulum defect deformity treatment methods of artificial total hip replacement. Methods 30 cases of acetabular defects were selected in our hospital, including 13 cases of acetabulum hypoplasia, acetabulum fracture malunion after trauma in 5 cases, 6 patients with rheumatoid arthritis, ankylosing spondylitis hip lesions, 6 cases were performed total hip replacement, take the acetabulum deepening, double cone spiral acetabulum, autologous bone graft and structural methods such as titanium mesh and bone graft line true acetabular reconstruction, all patients preoperative CT three-dimensional reconstruction, with Harris scoring criteria. Results Followed up for 6~36 months, has not occurred during the follow-up period of artificial hip prosthesis loosening and fracture around, etc. Harris scoring (36±6.5) preoperatively, postoperative (93±5.2). Conclusion Deformity of total hip replacement for defects of acetabulum, through the acetabulum, Zweymulle double cone spiral acetabulum, grain pressure distribution, structural bone graft autologous bone graft and titanium mesh and bone graft and so on the many kinds of methods can be a very good reconstruction of acetabulum, restore good stability and the Harris score, can achieve very good effect.%目的探讨髋臼缺损畸形的人工全髋关节置换术的处理方法。方法选取我院收治存在髋臼缺损畸形患者30例,包括髋臼发育不良13例、髋臼创伤骨折后畸形愈合5例、类风湿性关节炎6例,强直性脊柱炎髋关节病变6例,均行全髋关节置换术,采取髋臼加深、双锥  面螺旋型髋臼、自体结构性植骨及钛网加植骨等多种方法行真臼重建,全部病例术前行 CT 三维重建,评分标准采用 Harris 评分。结果随访6~36个月,随访期间未发生人工髋关节假体松动、周围骨折等。Harris 评分术前(36±6.5),术后(93±5.2)。结论对于髋臼缺损畸形的全髋关节置

  1. Cemented total hip prosthesis: Radiographic and scintigraphic evaluation

    International Nuclear Information System (INIS)

    Conventional radiographs, technetium-99m bone scans, and gallium-67 scans were reviewed in 44 patients who had undergone cemented total hip joint replacement and were imaged because of suspicion of prosthesis loosening or infection. A complete radiolucent line of 2 mm or wider along the bone-cement interface or metal-cement lucency on conventional radiographs was used as the criterion for prosthetic loosening with or without infection and proved to be 54% sensitive and 96% specific. Scintigraphic criteria for prosthetic loosening were increased focal uptake of the radiopharmaceutical for the femoral component and increased focal or diffuse uptake for the acetabular component. For bone scintigraphy, sensitivity was 73% and specificity was 96%. Combining the results of conventional radiographs and bone scans increased sensitivity to 84% and decreased specificity to 92% for the diagnosis of loosening, infection, or both. The study also showed that Ga-67 scintigraphy has a low sensitivity for the detection of infection

  2. Operative strategy of acetabular fractures

    Institute of Scientific and Technical Information of China (English)

    WANG Yan; TANG Pei-fu; HUANG Peng

    2006-01-01

    Anatomic structure of acetabular fractures are complex and operative exposure and fixation are extremely difficult.For those obviously displaced acetabular fractures, close reduction is doomed to cause deformative healing. Open reduction with internal fixation (ORIF) not only results in anatomic reduction, but also brings complications. No matter which method will be adopted, traumatic arthritis or avascular necrosis of femoral head might occur. In order to treat acetabular fractures more effectively, orthopedic surgeons should be required to fully master the acetabular anatomy, biomechanics, classification and the necessary knowledge for complication prevention.

  3. An Experimental Investigation of Partial Replacement of Cement by Industrial Waste (Hypo Sludge

    Directory of Open Access Journals (Sweden)

    Mr.R.Balamurugan

    2014-04-01

    Full Text Available Concrete is strength and tough material but it is porous material also which interacts with the surrounding environment. The durability of concrete depends largely on the movement of water and gas enters and moves through it. To produce low cost concrete by blending various ratios of cement with hypo sludge & to reduce disposal and pollution problems due to hypo sludge it is most essential to develop profitable building materials from hypo sludge. To make good quality paper limited number of times recycled Paper fibers can be used which produces a large amount of solid waste. The innovative use of hypo sludge in concrete formulations as a supplementary cementations material was tested as an alternative to traditional concrete.

  4. INFLUENCE OF FLY ASH REPLACEMENT ON STRENGTH PROPERTIES OF CEMENT MORTAR

    OpenAIRE

    AMARNATH YERRAMALA; BHASKAR DESAI V; RAMA CHANDURDU C

    2012-01-01

    Strength properties of fly ash mortars were evaluated through laboratory investigations. OPC of 53 grade replaced with class F fly ash with 5 - 25 % in the increments of 5 %. The results shown that at early age at all fly ash replacements the strength decreased with respect to normal mortar. However, after 28 days and above themortars made with fly ash replacement up to 15% resulted higher strength than normal OPC mortar. Fly ash replacement of 20 and 25% always had lower strength than normal...

  5. Use of Rice Husk Ash as Partial Replacement with Cement In Concrete- A Review

    OpenAIRE

    Sourav Ghosal; S. Moulik

    2015-01-01

    Rapid increase in construction activities has resulted in shortage of conventional construction materials.In the present scenario, the high cost of conventional building materials is a major factor affecting housing delivery in the world.This has necessitated research into alternative materials of construction.The effective housing techniques deal with reduction in cost of construction as well as providing strength to buildings.Mainly gravel,sand and cement are used in th...

  6. Calcium looping spent sorbent as a limestone replacement in the manufacture of portland and calcium sulfoaluminate cements.

    Science.gov (United States)

    Telesca, Antonio; Marroccoli, Milena; Tomasulo, Michele; Valenti, Gian Lorenzo; Dieter, Heiko; Montagnaro, Fabio

    2015-06-01

    The calcium looping (CaL) spent sorbent (i) can be a suitable limestone replacement in the production of both ordinary Portland cement (OPC) and calcium sulfoaluminate (CSA) cement, and (ii) promotes environmental benefits in terms of reduced CO2 emission, increased energy saving and larger utilization of industrial byproducts. A sample of CaL spent sorbent, purged from a 200 kWth pilot facility, was tested as a raw material for the synthesis of two series of OPC and CSA clinkers, obtained from mixes heated in a laboratory electric oven within temperature ranges 1350°-1500 °C and 1200°-1350 °C, respectively. As OPC clinker-generating mixtures, six clay-containing binary blends were investigated, three with limestone (reference mixes) and three with the CaL spent sorbent. All of them showed similar burnability indexes. Moreover, three CSA clinker-generating blends (termed RM, MA and MB) were explored. They included, in the order: (I) limestone, bauxite and gypsum (reference mix); (II) CaL spent sorbent, bauxite and gypsum; (III) CaL spent sorbent plus anodization mud and a mixture of fluidized bed combustion (FBC) fly and bottom ashes. The maximum conversion toward 4CaO·3Al2O3·SO3, the chief CSA clinker component, was the largest for MB and almost the same for RM and MA. PMID:25915150

  7. Relationship between Wiberg's lateral center edge angle, Lequesne's acetabular index, and medial acetabular bone stock

    Energy Technology Data Exchange (ETDEWEB)

    Werner, Clement M.L. [Balgrist University Hospital Zurich, Department of Orthopaedics, Zurich (Switzerland); University of Maryland Medical Systems, R. Adams Cowley Shock Trauma Center, Baltimore, MD (United States); Copeland, Carol E.; Stromberg, Jeff; Turen, Clifford H. [University of Maryland Medical Systems, R. Adams Cowley Shock Trauma Center, Baltimore, MD (United States); Ruckstuhl, Thomas; Bouaicha, Samy [Balgrist University Hospital Zurich, Department of Orthopaedics, Zurich (Switzerland)

    2011-11-15

    Knowledge of acetabular anatomy is crucial for cup positioning in total hip replacement. Medial wall thickness of the acetabulum is known to correlate with the degree of developmental dysplasia of the hip (DDH). No data exist about the relationship of routinely used radiographic parameters such as Wiberg's lateral center edge angle (LCE-angle) or Lequesne's acetabular index (AI) with thickness of the medial acetabular wall in the general population. The aim of our study was to clarify the relationship between LCE, AI, and thickness of the medial acetabular wall. Measurements on plain radiographs (LCE and AI) and axial CT scans (quadrilateral plate acetabular distance QPAD) of 1,201 individuals (2,402 hips) were obtained using a PACS imaging program and statistical analyses were performed. The mean thickness of the medial acetabulum bone stock (QPAD) was 1.08 mm (95% CI: 1.05-1.10) with a range of 0.1 to 8.8 mm. For pathological values of either the LCE (<20 ) or the AI (>12 ) the medial acetabular wall showed to be thicker than in radiological normal hips. The overall correlation between coxometric indices and medial acetabular was weak for LCE (r =-0.21. 95% CI [-0.25, -0.17]) and moderate for AI (r = 0.37, [0.33, 0.41]). We did not find a linear relationship between Wiberg's lateral center edge angle, Lequesne's acetabular index and medial acetabular bone stock in radiological normal hips but medial acetabular wall thickness increases with dysplastic indices. (orig.)

  8. 髋臼前倾角术前测量在全髋关节置换术中的临床意义%The clinical significance of preoperative measurement of acetabular anteversion in total hip replacement

    Institute of Scientific and Technical Information of China (English)

    蒲超; 张珊珊; 李伟; 吴青霞; 候小倩

    2014-01-01

    Objective Discussion the clinical significance of preoperative measurement of acetabular antever-sion in total hip replacement .Methods 121 patients were randomly assigned into normal group and preoperative measurement group .Made the statistical analysis of postoperative differ between anteversion of artificial acetabulum with preoperative measuring value within 1° and 5° ,and contrast the postoperative anteversion of artificial acetabulum in two groups .Results Postoperative error within 1° and 5° was 3 .13% ,29 .69% in preoperative measurement group respectively .There was no statistically significans in the difference of postoperative anteversion of artificial acetabu-lum between two groups .Conclusion acetabulum The preoperative measurement can improve the accuracy in playing artificial acetabulum ,but the accuracy of lay need to improve .%目的:探讨髋臼前倾角术前测量在全髋关节置换术中的临床意义。方法将121例需行全髋关节置换术的患者随机分入常规组和术前测量组。常规组按照前倾15°安放人工髋臼,术前测量组按照术前测量角度安放人工髋臼,并统计分析术前测量组术后人工髋臼前倾角度与术前测量值相差1°和5°的比例以及两组患者术后人工髋臼前倾角度差异。结果术前测量组人工髋臼前倾角度术后误差小于1°和5°的比例分别为3.13%和29.69%,常规组与术前测量组术后人工髋臼前倾角度比较,差异有统计学意义( P<0.05)。结论髋臼前倾角术前测量可提高人工髋臼安放的精确度,但安放的准确性还需进一步提高。

  9. Rice husk derived waste materials as partial cement replacement in lightweight concrete Utilização de resíduos derivados da casca de arroz como substitutos parciais do cimento no concreto leve

    OpenAIRE

    Celso Yoji Kawabata; Holmer Savastano Junior; Joana Sousa-Coutinho

    2012-01-01

    In this study rice husk ash (RHA) and broiler bed ash from rice husk (BBA), two agricultural waste materials, have been assessed for use as partial cement replacement materials for application in lightweight concrete. Physical and chemical characteristics of RHA and BBA were first analyzed. Three similar types of lightweight concrete were produced, a control type in which the binder was just CEMI cement (CTL) and two other types with 10% cement replacement with, respectively, RHA and BBA. All...

  10. 21 CFR 888.3330 - Hip joint metal/metal semi-constrained, with an uncemented acetabular component, prosthesis.

    Science.gov (United States)

    2010-04-01

    ... uncemented acetabular component, prosthesis. 888.3330 Section 888.3330 Food and Drugs FOOD AND DRUG..., prosthesis. (a) Identification. A hip joint metal/metal semi-constrained, with an uncemented acetabular component, prosthesis is a two-part device intended to be implanted to replace a hip joint. The...

  11. Partial replacement of fossil fuel in a cement plant: risk assessment for the population living in the neighborhood.

    Science.gov (United States)

    Rovira, Joaquim; Mari, Montse; Nadal, Martí; Schuhmacher, Marta; Domingo, José L

    2010-10-15

    In cement plants, the substitution of traditional fossil fuels not only allows a reduction of CO(2), but it also means to check-out residual materials, such as sewage sludge or municipal solid wastes (MSW), which should otherwise be disposed somehow/somewhere. In recent months, a cement plant placed in Alcanar (Catalonia, Spain) has been conducting tests to replace fossil fuel by refuse-derived fuel (RDF) from MSW. In July 2009, an operational test was progressively initiated by reaching a maximum of partial substitution of 20% of the required energy. In order to study the influence of the new process, environmental monitoring surveys were performed before and after the RDF implementation. Metals and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were analyzed in soil, herbage, and air samples collected around the facility. In soils, significant decreases of PCDD/F levels, as well as in some metal concentrations were found, while no significant increases in the concentrations of these pollutants were observed. In turn, PM(10) levels remained constant, with a value of 16μgm(-3). In both surveys, the carcinogenic and non-carcinogenic risks derived from exposure to metals and PCDD/Fs for the population living in the vicinity of the facility were within the ranges considered as acceptable according to national and international standards. This means that RDF may be a successful choice in front of classical fossil fuels, being in accordance with the new EU environmental policies, which entail the reduction of CO(2) emissions and the energetic valorization of MSW. However, further long-term environmental studies are necessary to corroborate the harmlessness of RDF, in terms of human health risks. PMID:20709362

  12. Partial replacement of fossil fuel in a cement plant: risk assessment for the population living in the neighborhood.

    Science.gov (United States)

    Rovira, Joaquim; Mari, Montse; Nadal, Martí; Schuhmacher, Marta; Domingo, José L

    2010-10-15

    In cement plants, the substitution of traditional fossil fuels not only allows a reduction of CO(2), but it also means to check-out residual materials, such as sewage sludge or municipal solid wastes (MSW), which should otherwise be disposed somehow/somewhere. In recent months, a cement plant placed in Alcanar (Catalonia, Spain) has been conducting tests to replace fossil fuel by refuse-derived fuel (RDF) from MSW. In July 2009, an operational test was progressively initiated by reaching a maximum of partial substitution of 20% of the required energy. In order to study the influence of the new process, environmental monitoring surveys were performed before and after the RDF implementation. Metals and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were analyzed in soil, herbage, and air samples collected around the facility. In soils, significant decreases of PCDD/F levels, as well as in some metal concentrations were found, while no significant increases in the concentrations of these pollutants were observed. In turn, PM(10) levels remained constant, with a value of 16μgm(-3). In both surveys, the carcinogenic and non-carcinogenic risks derived from exposure to metals and PCDD/Fs for the population living in the vicinity of the facility were within the ranges considered as acceptable according to national and international standards. This means that RDF may be a successful choice in front of classical fossil fuels, being in accordance with the new EU environmental policies, which entail the reduction of CO(2) emissions and the energetic valorization of MSW. However, further long-term environmental studies are necessary to corroborate the harmlessness of RDF, in terms of human health risks.

  13. Porous surface replacement of the hip with chamfered-cylinder component.

    Science.gov (United States)

    Amstutz, H; Kilgus, D; Kabo, M; Dorey, F

    1988-01-01

    One hundred porous surface replacements (PSR) were performed in 92 patients (63 men and 29 women) with a mean age of 53 (range 17-76). Follow-up times range from 1 to 4 years, with 48 patients having a follow-up of at least 2 years. Preoperative diagnoses were osteoarthritis (OA) 63, osteonecrosis (ON) 13, dysplasia 9, rheumatoid-ankylosing spondylitis 6, and other 9. Seventeen hips had metal-backed acrylic-fixed THARIES acetabular sockets, nine hips had a porous cobalt chrome hemispheric beaded acetabular component with adjuvant fixation screws and externally protruding screw hubs, and 74 hips had a porous chamfered cylinder-design acetabulum. Pain relief had been immediate and more complete than with acrylic-fixed or biologic-ingrowth stem-type replacement with comparable walking and function improvements. There have been no major systemic complications, sepsis, or loosening. There have been two transient peroneal nerve palsies and three trochanteric fibrous unions. There have been three reoperations, one for subluxation, one for "metalosis" due to mesh pad loosening, and one femoral neck fracture. Examination of one removed femoral surface component which has been histologically sectioned revealed excellent (90%) bone in-growth. Circumferential progressive radiolucencies developed at the bone-cement interface by 1 year in all of the 17 acrylic-fixed acetabular components. Reaming or seating defects were noted in 25% of the ingrowth components on postoperative radiographs. Radiographic analysis of immediate postoperative films of the chamfered cylinder design acetabular components frequently demonstrated bone-component interface radiolucencies which represented component seating defects. These initial interface radiolucencies became progressively more narrow over the first six months postoperatively suggesting "healing" of the reamed bone-component interface with trabecular bone around the chamfered cylinder acetabular components. Partial healing of initial

  14. Pressurization of bioactive bone cement in vitro.

    Science.gov (United States)

    Fujita, H; Iida, H; Kawanabe, K; Okada, Y; Oka, M; Masuda, T; Kitamura, Y; Nakamura, T

    1999-01-01

    We have developed a bioactive bone cement consisting of MgO-CaO-SiO2-P2O5-CaF2 glass-ceramic powder (AW glass-ceramic powder), silica glass powder as an inorganic filler, and bisphenol-a-glycidyl methacrylate (bis-GMA) based resin as an organic matrix. The efficacy of this bioactive bone cement was investigated by evaluating its pressurization in a 5-mm hole and small pores using a simulated acetabular cavity. Two types of acetabular components were used (flanged and unflanged sockets) and a commercially available polymethylmethacrylate (PMMA) bone cement (CMW 1 Radiopaque Bone Cement) was selected as a comparative control. Bioactive bone cement exerted greater intrusion volume in 5-mm holes than PMMA bone cement in both the flanged and unflanged sockets 10 minutes after pressurization (p anchor holes than PMMA bone cement.

  15. Revision Total Hip Replacement: A Case Report

    Directory of Open Access Journals (Sweden)

    Md Hafizur Rahman

    2013-07-01

    Full Text Available Total hip replacement is a reconstructive procedure that has improved the management of those diseases of the hip joint that have responded poorly to conventional medical therapy. Conventional, primary total hip replacement is a durable operation in the majority of patients. A hip replacement is a mechanical device with parts that are assembled before and during the operation. But the possible complications of total hip arthroplasty, and its clinical performance over time, is a challenging occasion to the surgeons, and such a challenge we faced with our presenting patient. A 68 year old lady with history of cemented bipolar hemiarthroplasty done in a tertiary care hospital, due to fracture neck of the left femur having the history of diabetes, chronic kidney disease, heart disease, anaemia, and mental disorders presented with loosened prosthesis, thinning of medial proximal cortex of the femur which had broken within few months after surgery. She complained of painful walking at left hip joint. There was also evidence of chronic infective and degenerative arthritis of acetabular component of the affected hip joint. Cemented revision total hip replacement surgery was performed with expert multidisciplinary involvement. On 2nd postoperative day the patient was allowed to walk on operated limb with the aid of walker. On 12th postoperative day all the stitches were removed and wound was found healthy.

  16. Efficacy observation of acetabular cups of hip replacement surgery on adult hip crowe II and III dysplasia%大臼杯全髋关节置换术治疗 CroweⅡ~Ⅲ型成人髋关节发育不良疗效观察

    Institute of Scientific and Technical Information of China (English)

    谢贵杰; 何森荣; 甘伟伟

    2014-01-01

    目的:总结大型臼杯生物型人工全髋关节置换术治疗CroweⅡ~Ⅲ型成人髋关节发育的早期疗效。方法12例12髋, CroweⅡ型为7例,CroweⅢ型为5例,全髋关节置换术臼杯外径58~64 mm,假体选用国产爱康宜诚公司生产的假体。结果随访2~3年。髋关节功能Harris标准评分平均92分,其中功能优9例,良3例,目前尚无1例需行翻修。结论对部分CroweⅡ、Ⅲ型成人髋关节发育不良,采用大型臼杯全髋关节置换术治疗早期能够获得满意的临床疗效。%Objective To summize the early efficacy of large-scare acetabular cups of hip replacement surgery on adult hip Crowe II and III dysplasia .Methods There were 12 patients in which 7 cases were Crowe II and 5 cases were Crowe III .The outside diameter of acetabular cup for total hip replacement surgery was 58~64 mm.Ai-Kang prostheses which were made in China were used .Results The patients were followed up for 2 to 3 years.The average Harris hip standard score was 92.The hip functions of 9 cases were excel-lent and those of 3 cases were good .No case needed to restore .Conclusions For some cases of adult hip Crowe II and III dysplasia , early hip replacement surgery with large-scare acetabular cups can obtain satisfactory clinical effect .

  17. Study of Structural Performance and Durability of Concrete by Partial Replacement of Cement with Hypo Sludge (Paper waste

    Directory of Open Access Journals (Sweden)

    K. Hari kishan,

    2015-12-01

    Full Text Available Utilization of industrial waste products as supplementary cementitious materials (SCM in concrete making is very important aspect in view of economical, environmental and technical reasons. As these supplementary cementitious materials have different chemical and mineralogical composition, their effect on micro structural properties and strength performance vary considerably. While producing paper, various wastes come out from the various processes in paper industries. The preliminary waste from paper industry is named as hypo sludge. In this study the material obtained from the paper industry waste (hypo sludge is admixed with Portland cement at different replacement levels. The properties of concrete investigated include compressive strength, split tensile strength, flexural strength, sorptivity and acid effect keeping optimum percentage of hypo sludge supposedly supplementary cementitious material (SCM. In this work, M20 grade was developed using IS method of mix design. Specimens of dimensions of 150 x 300mm cylinders for split tensile strength and dimensions of 100 x 100 x 500mm prisms for flexure strength and 150*150*150mm cubes were cast, with and without hypo sludge and tested under axial compression to justify the compressive strength for 7 and 28 days. Standard cubes were immersed in 5%HCL, 5%H2SO4 for inspecting the durability properties. The Sorptivity test has also been conducted. It is concluded that hypo sludge concrete had better mechanical properties and durability properties compared to normal concrete. Test results indicate that the use of hypo sludge in concrete has improved the performance of concrete from strength as well as durability aspects. The split tensile strength is less in hypo sludge concrete compared to normal concrete.

  18. Laboratory Investigation on Compressive Strength and Micro-structural Features of Foamed Concrete with Addition of Wood Ash and Silica Fume as a Cement Replacement

    Directory of Open Access Journals (Sweden)

    Othuman Mydin M.A.

    2014-01-01

    Full Text Available Wood Ash (WA and Silica Fume (SF exhibit good cementation properties and have great potential as supplementary binder materials for the concrete production industry. This study will focus on enhancing the micro-structural formation and compressive strength of foamed concrete with the addition of WA and SF. A total of 3 mixes were prepared with the addition of WA and SF at various cement replacement levels by total binder weight. For this particular study, the combination of WA (5%, 10%, and 15% by binder weight and SF (5%, 10%, and 15% by binder weight were utilized as supplementary binder materials to produce foamed concrete mixes. As was made evident from micrographs obtained in the study, the improvement observed in the compressive strength of the foamed concrete was due to a significant densification in the microstructure of the cement paste matrix in the presence of WA and SF hybrid supplementary binders. Experimental results indicated that the combination of 15% SF and 5% WA by binder weight had a more substantial influence on the compressive strength of foamed concrete compared to the control mix. Furthermore, the addition of WA and SF significantly prolonged the setting times of the blended cement paste of the foamed concrete.

  19. Durability Studies on Concrete and Comparison with Partial Replacement of Cement with Rice Husk Ash and Sugarcane Bagasse Ash in Concrete

    Directory of Open Access Journals (Sweden)

    B.Someswara Rao

    2015-11-01

    Full Text Available This research work describes the feasibility of using the Rice Husk Ash (RHA and Sugarcane Bagasse Ash (SCBA waste in concrete production as a partial replacement of cement. This present work deals with the effect on strength and mechanical properties of concrete using RHA and SCBA instead of cement. The cement has been replaced by rice husk ash, accordingly in the range of 0%, 5%, 10%, 15%, and 20% by weight. Concrete mixtures with RHA, were produced, tested and compared in terms of compressive strengths with the Conventional concrete. These tests were carried out to evaluate the mechanical properties for the test results of 7, 28, 60, 90 days for compressive strengths in normal water and in MgSO4 solution of 1%, 3% and 5%. Also the durability aspect for rice husk ash concrete for sulphate attack was tested. Similarly the above tests were also performed for SCBA. The result indicates that the RHA and SCBA improve concrete durability. Finally the test results for RHA and SCBA were compared. Key words: Rice Husk Ash, Sugarcane Bagasse Ash, Concrete, M35 grade concrete, cubes, cylinders, MgSO4, durability.

  20. Dislocation of a dual mobility total hip replacement following fracture of the polyethylene liner.

    Science.gov (United States)

    Vedrine, Bertrand; Guillaumot, Pierre; Chancrin, Jean-Luc

    2016-05-18

    An eight-year-old male English Setter was referred for management of a dislocation of a cemented dual mobility canine total hip prosthesis that occurred four months after the initial surgery. Revision surgery showed that the dislocation was associated with fracture of the ultra-high molecular weight polyethylene liner. The dislocation was successfully reduced after replacing the liner. A dual mobility acetabular component is composed of a mobile polyethylene liner inside a metallic cemented cup. Chronic wear of the components of a canine dual mobility total hip replacement has not been described previously. The use of this type of implant is fairly recent and limited long term follow-up of the implanted cases may be the explanation. Acute rupture of a polyethylene liner has never been described in humans, the only case of rupture of a polyethylene liner occurred 10 years after implantation. The case presented here of rupture of the polyethylene liner of a dual mobility total hip replacement is a hitherto unreported failure mode in this model of acetabular cup in the dog. PMID:26991949

  1. Antibiotic bone cement and renovation after artificial joint replacement%抗生素骨水泥与人工关节置换后的翻修

    Institute of Scientific and Technical Information of China (English)

    李文成

    2013-01-01

    BACKGROUND:Antibiotic bone cement is the important method for the prevention and treatment of infection after artificial hip replacement and renovation. OBJECTIVE:To review the research progress of antibiotic bone cement. METHODS:A computer-based online search was performed in PubMed database, CNKI database, Chinese Biomedical Literature database, VIP database and Wanfang database for the literatures from 1978 to 2012. The key words were“bone cement, antibiotic bone cement, infection, joint replacement”in English and Chinese. RESUTLS AND CONCLUSION:A total of 335 literatures were screened out. Final y, 29 literatures were included for in-depth analysis after the primary screen through reading the title, abstract and ful-text. Antibiotic bone cement has been widely used in the treatment of infection after artificial joint replacement and renovation as it can reduce the risk of infection after initial joint replacement and renovation. The material properties and mechanical properties wil not change after bone cement mixed with appropriate amount of antibiotic. Different antibiotics in the bone cement have different release rates, which were closely related with the porosity of bone cement. Adding the additive that used for increasing the porosity of bone cement can increase the antibiotic release.%  背景:抗生素骨水泥是预防和治疗人工关节置换以及翻修后感染的重要方法。目的:综述抗生素骨水泥的研究进展以及人工关节置换后翻修。方法:通过计算机检索Pubmed数据库、中国知网数据库、中国生物医学文献数据库、维普期刊全文数据库、万方数据库,时间范围在1978年至2012年,中文检索词“骨水泥”、“抗生素骨水泥”、“感染”、“关节置换”;英文检索词“bone cement”、“antibiotic bone cement”、“infection”、“joint replacement”。结果与结论:共检索到相关文献335篇。通过阅读标题、摘要以及全

  2. Biological and mechanical properties of an experimental glass-ionomer cement modified by partial replacement of CaO with MgO or ZnO

    Directory of Open Access Journals (Sweden)

    Dong-Ae KIM

    2015-08-01

    Full Text Available AbstractSome weaknesses of conventional glass ionomer cement (GIC as dental materials, for instance the lack of bioactive potential and poor mechanical properties, remain unsolved.Objective The purpose of this study was to investigate the effects of the partial replacement of CaO with MgO or ZnO on the mechanical and biological properties of the experimental glass ionomer cements.Material and Methods Calcium fluoro-alumino-silicate glass was prepared for an experimental glass ionomer cement by melt quenching technique. The glass composition was modified by partial replacement (10 mol% of CaO with MgO or ZnO. Net setting time, compressive and flexural properties, and in vitrorat dental pulp stem cells (rDPSCs viability were examined for the prepared GICs and compared to a commercial GIC.Results The experimental GICs set more slowly than the commercial product, but their extended setting times are still within the maximum limit (8 min specified in ISO 9917-1. Compressive strength of the experimental GIC was not increased by the partial substitution of CaO with either MgO or ZnO, but was comparable to the commercial control. For flexural properties, although there was no significance between the base and the modified glass, all prepared GICs marked a statistically higher flexural strength (p<0.05 and comparable modulus to control. The modified cements showed increased cell viability for rDPSCs.Conclusions The experimental GICs modified with MgO or ZnO can be considered bioactive dental materials.

  3. The mechanical effect of the existing cement mantle on the in-cement femoral revision.

    LENUS (Irish Health Repository)

    Keeling, Parnell

    2012-08-01

    Cement-in-cement revision hip arthroplasty is an increasingly popular technique to replace a loose femoral stem which retains much of the original cement mantle. However, some concern exists regarding the retention of the existing fatigued and aged cement in such cement-in-cement revisions. This study investigates whether leaving an existing fatigued and aged cement mantle degrades the mechanical performance of a cement-in-cement revision construct.

  4. High-volume natural volcanic pozzolan and limestone powder as partial replacements for portland cement in self-compacting and sustainable concrete

    KAUST Repository

    Celik, Kemal

    2014-01-01

    A laboratory study demonstrates that high volume, 45% by mass replacement of portland cement (OPC) with 30% finely-ground basaltic ash from Saudi Arabia (NP) and 15% limestone powder (LS) produces concrete with good workability, high 28-day compressive strength (39 MPa), excellent one year strength (57 MPa), and very high resistance to chloride penetration. Conventional OPC is produced by intergrinding 95% portland clinker and 5% gypsum, and its clinker factor (CF) thus equals 0.95. With 30% NP and 15% LS portland clinker replacement, the CF of the blended ternary PC equals 0.52 so that 48% CO2 emissions could be avoided, while enhancing strength development and durability in the resulting self-compacting concrete (SCC). Petrographic and scanning electron microscopy (SEM) investigations of the crushed NP and finely-ground NP in the concretes provide new insights into the heterogeneous fine-scale cementitious hydration products associated with basaltic ash-portland cement reactions. © 2013 Published by Elsevier Ltd.

  5. Management of acetabular fractures: challenging work

    Institute of Scientific and Technical Information of China (English)

    CHEN Zheng-rong; YANG Yi

    2006-01-01

    @@ Acetabular fractures are complex and special intraarticular fractures. For most orthopaedic surgeons management of acetabular fractures is hard and challenging because the fractures are the results of high-energy trauma, and usually accompany with severe associated injuries. In addition, these fractures are uncommon except in a few trauma centers. The number of cases a surgeon can encounter is scarce.

  6. Revision stapes surgery for lysis of the long process of the incus: comparing hydroxyapatite bone cement versus malleovestibulopexy and total ossicular replacement prosthesis.

    Science.gov (United States)

    Pitiot, Vincent; Hermann, Ruben; Tringali, Stéphane; Dubreuil, Christian; Truy, Eric

    2016-09-01

    The objective of the study was to report audiological results in revision stapes surgery, comparing hydroxyapatite (HAP) bone cement, malleovestibular (MV) prosthesis, and total ossicular replacement prosthesis (TORP). The study is a retrospective case review conducted in a tertiary referral center. Patients treated for revision stapes surgery from 2010 to 2014, where a lysis of the long process of the incus (LPI) was observed with the use of HAP bone cement, MV prosthesis, or a TORP were included in the study. The main outcomes measured were pre- and postoperative bone conduction (BC) and air conduction (AC) pure-tone averages (PTA) (0.5, 1, 2, 3 kHz), including high frequencies BC (HFBC) (1, 2, 3, 4 kHz) and air-bone gap (ABG). 107 revision stapes surgery were performed in 96 ears. Main cause of failure was LPI lysis in 38 cases (39.6 %). 31 patients were analyzed: HAP bone cement was used in 11 patients (Group I), MV prosthesis in ten patients (Group II), and TORP in ten patients (Group III). The mean post-operative ABG was 10.7 dB (±7.4) (p = 0.003), 10.7 dB (±8.8) (p = 0.001), and 16.9 dB (±9.8) (p = 0.001), respectively. There were no significant differences between groups. In Group I, the mean change in HFBC revealed an improvement of 5.6 dB (±7.9) (p = 0.03), while in Group III there was a significant deterioration of the thresholds of 5.8 dB (±7.6) (p = 0.04). There were no cases of post-operative anacusis. In revision stapes surgery when LPI is eroded, we recommend to perform a cement ossiculoplasty for stabilizing a standard Teflon piston when LPI is still usable, the LPI lengthening with cement being not recommended. When LPI is too eroded, we prefer performing a malleovestibulopexy, and reserve TORP for cases with a bad anatomical presentation. PMID:26690574

  7. Fly and bottom ashes from biomass combustion as cement replacing components in mortars production: rheological behaviour of the pastes and materials compression strength.

    Science.gov (United States)

    Maschio, Stefano; Tonello, Gabriele; Piani, Luciano; Furlani, Erika

    2011-10-01

    In the present research mortar pastes obtained by replacing a commercial cement with the equivalent mass of 5, 10, 20 and 30 wt.% of fly ash or bottom ash from fir chips combustion, were prepared and rheologically characterized. It was observed that the presence of ash modifies their rheological behaviour with respect to the reference blend due to the presence, in the ashes, of KCl and K2SO4 which cause precipitation of gypsum and portlandite during the first hydration stages of the pastes. Hydrated materials containing 5 wt.% of ash display compression strength and absorption at 28 d of same magnitude as the reference composition; conversely, progressive increase of ash cause a continuous decline of materials performances. Conversely, samples tested after 180 d display a marked decline of compression strength, as a consequence of potassium elution and consequent alkali-silica reaction against materials under curing.

  8. An Unusual Combination of Acetabular and Pelvic Fracture: Is This a New Subtype of Acetabular Fracture?

    Directory of Open Access Journals (Sweden)

    Reza Tavakoli Darestani

    2013-01-01

    Full Text Available Introduction: Acetabular fractures are a common problem among young males. An acetabular fracture with disruption of the joint surface, if untreated, will rapidly lead to post-traumatic osteoarthritis. Proper reduction and internal fixation depend on accurate classification and the quality of imaging.Case Presentation: We present an unusual form of acetabular fracture, which is not included in the conventional classification (Judet and Letournel ; this occurred in a middle-aged male who was operatively treated without any complications. In this case due to posterior extension of the fracture into the SI joint and concomitant anterior column fracture in the area above the acetabular dome, no portion of the acetabular anterior surface remained connected to the innominate bone.Conclusions: We recognized this type of fracture and treated it similarly to both column fractures. We recommend that the classification of acetabular fractures be modified to include this type of fracture.

  9. Percutaneous acetabuloplasty for metastatic acetabular lesions

    Directory of Open Access Journals (Sweden)

    Logroscino Giandomenico

    2008-05-01

    Full Text Available Abstract Background Osteolytic metastases around the acetabulum are frequent in tumour patients, and may cause intense and drug-resistant pain of the hip. These lesions also cause structural weakening of the pelvis, limping, and poor quality of life. Percutaneous acetabuloplasty is a mini-invasive procedure for the management of metastatic lesions due to carcinoma of the acetabulum performed in patients who cannot tolerate major surgery, or in patients towards whom radiotherapy had already proved ineffective. Methods We report a retrospective study in 25 such patients (30 acetabuli who were evaluated before and after percutaneous acetabuloplasty, with regard to pain, mobility of the hip joint, use of analgesics, by means of evaluation forms: Visual Analog Scale, Harris Hip Score, Western Ontario and McMaster Universities Index of Osteoarthritis (WOMAC, Eastern Cooperative Oncology Group (ECOG. The results obtained were analysed using the χ2 Test and Fisher's exact test. Significance was sent at P Results Marked clinical improvement was observed in all patients during the first six post-operative months, with gradual a worsening thereafter from deterioration of their general condition. Complete pain relief was achieved in 15 of our 25 (59% of patients, and pain reduction was achieved in the remaining 10 (41% patients. The mean duration of pain relief was 7.3 months. Pain recurred in three patients (12% between 2 weeks to 3 months. No major complications occurred. There was transient local pain in most cases, and 2 cases of venous injection of cement without clinical consequences. Conclusion Percutaneous acetabuloplasty is effective in improving the quality of life of patients with osteolytic bone tumours, even though the improvement is observed during the first 6 months only. It can be an effective aid to chemo- and radiotherapy in the management of acetabular metastases.

  10. Primary total hip arthroplasty for acetabular fracture

    Institute of Scientific and Technical Information of China (English)

    WANG Zi-ming; SUN Hong-zhen; WANG Ai-min; DU Quan-yin; WU Siyu; ZHAO Yu-feng; TANG Ying

    2006-01-01

    Objective: To explore the operative indications and operative methods of primary total hip arthroplasty for acetabular fracture and to observe the clinical curative effect.Methods: We retrospectively summarized and analyzed the traumatic conditions, fracture types, complications,operative time, operative techniques, and short-term curative effect of 11 patients( 10 males and 1 female, with a mean age of 42. 4 years ) with acetabular fracture who underwent primary total hip arthroplasty.Results: The patients were followed up for 6-45 months ( mean = 28 months). Their average Harris score of postoperative hip joint was 78.Conclusion: Under strict mastery of indications,patients with acetabular fracture may undergo primary total hip arthroplasty, but stable acetabular components should be made.

  11. Osteoarthritis of the hip and acetabular dysplasia.

    OpenAIRE

    Croft, P.; Cooper, C.; Wickham, C; Coggon, D

    1991-01-01

    The relation between acetabular dysplasia and osteoarthritis of the hip was examined in a series of 1516 pelvic radiographs taken for non-skeletal indications. Osteoarthritis was assessed by measuring joint space, and dysplasia by the centre-edge angle and acetabular depth. In contrast with previous studies of patients with symptomatic osteoarthritis of the hip, no evidence that dysplasia predisposes to osteoarthritis was found. Possible reasons for the discrepancy are discussed. It was concl...

  12. Reducing cement's CO2 footprint

    Science.gov (United States)

    van Oss, Hendrik G.

    2011-01-01

    The manufacturing process for Portland cement causes high levels of greenhouse gas emissions. However, environmental impacts can be reduced by using more energy-efficient kilns and replacing fossil energy with alternative fuels. Although carbon capture and new cements with less CO2 emission are still in the experimental phase, all these innovations can help develop a cleaner cement industry.

  13. Surgical treatment for complicated acetabular fractures

    Institute of Scientific and Technical Information of China (English)

    Ning An; Yang Yanmin

    2004-01-01

    Objective: To sum up the surgical approaches and clinical outcome of complicated acetabular fractures. Methods: 17 patients with complicated acetabular fractures (including 4 cases of transverse with posterior wall fractures, 7 cases of posterior column and wall fractures, 4 cases of anterior and posterior columns fractures, 1 cases of T-type fracture and 1 cases of anterior column with posterior hemitransverse fractures) underwent open reduction and internal fixation with screws and plates by Kocher-Langenbeck (8 cases), ilio-inguinal (2 cases), extended iliofemoral (4 cases) or ilio-inguinal combined with K-L approaches (3 cases). Results: 12 patients with anatomical reduction, 4 patients with satisfactory reduction and 1 patient with non-satisfactory reduction. 15 out of 17 cases were followed up for 6 months to 5 years, and the excellent and good rate was 70.5%. Conclusion: Surgical treatment for complicated acetabular fractures can get a satisfactory reduction and a good clinical outcome.

  14. Osteopathic diagnosis of an acetabular injury.

    Science.gov (United States)

    Morthland, Tim; Cote, Nicholas S; Humphrey, Jon; Fulk, Doug

    2010-05-01

    Physical findings demarking pathologic somatovisceral reflex activity and fascial strain patterns may lead the osteopathic physician to diagnoses that are masked within the initial presentation of a patient. The authors present a case report that demonstrates the use of osteopathic principles in the diagnosis of a chronic acetabular fracture and acetabular labral tear in a 19-year-old man. The injuries resulted from a posterior hip dislocation sustained during a basketball game more than 1 year before presentation. Osteopathic manipulative treatment and diagnostic techniques also relieved the patient's persistent thoracic pain, nausea, and vomiting. Subsequent orthopedic repair had the potential to avert or delay degenerative hip disease in the patient. PMID:20538751

  15. “钢筋混凝土”在髋臼重建中的应用★%Application of “reinforced concrete” in acetabular reconstruction

    Institute of Scientific and Technical Information of China (English)

    王子富; 尚希福

    2013-01-01

      背景:在全髋关节置换中,髋臼缺损很常见,为重建一个稳定、牢固的髋臼,置换过程中往往需要髋臼的重建。目的:探讨螺钉固定钛网结合骨水泥型髋臼杯在髋臼重建中应用的早期疗效。方法:纳入采用螺钉固定钛网结合骨水泥型臼杯重建髋臼髋关节翻修的患者23例。疼痛病史1-3年,术前 Harris 评分20-48分,平均34分。重建后采用 X 射线平片评价髋臼假体松动标准进行影像学评价及 Harris 评分定期随访。结果与结论:重建后随访1-3年,平均随访24个月,无脱失。重建后3个月 Harris 评分较重建前显著增高,置换后2年髋关节活动度较置换前显著增高,差异均有显著性意义(P <0.05)。2例患者下肢不等长,1例患者下蹲后出现脱位,保守治疗后好转。最后一次随访时无早期感染、脱位,无盆腔不适感。重建后随访影像学上显示无髋臼假体松动与移位,未发生钛网断裂。说明螺钉固定钛网结合骨水泥型髋臼杯治疗65岁以上髋关节翻修患者其近期疗效十分满意,后期疗效还有待于进一步随访观察。%BACKGROUND: In total hip arthroplasty, acetabular defects are common, for the reconstruction of a stable and solid acetabulum, the acetabular reconstruction is often required during the replacement process.OBJECTIVE: To investigate the early effect of the short term results of titanium mesh fixed by screws combined with a cemented acetabular cup in acetabular reconstruction. METHODS: Twenty-three patients treated with acetabular reconstruction by screw fixed titanium mesh combined with a cemented acetabular cup were selected. The pain history was 1 to 3 years. Harris scores before operation were 20-48 with an average score of 34. X-ray plain film was used to evaluate theacetabular prosthesis loosening standards after reconstruction for the radiographic evaluation and Harris score of regular fol ow

  16. Experimental and analytical validation of a modular acetabular prosthesis in total hip arthroplasty

    Directory of Open Access Journals (Sweden)

    Aram Luke

    2007-05-01

    Full Text Available Abstract A finite element model has been developed to predict in vivo micro motion between a modular acetabular cup and liner after cement less total hip arthroplasty. The purpose of this study is to experimentally validate the model. Six LVDT sensors were used to monitor the micromotion of the liner when subjected to loading conditions ranging from 250 N to 5000 N. Deformations at points of interest for both the experiment and FEM were compared. Results of the FEM with different coefficient of friction between the liner and the cup were investigated to correlate with the experimental results.

  17. CT evaluation of acetabular dysplasta in adults.

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective: To evaluate methods of measurement by CT and their clinical significance for acetabular dysplasia(AD) in adults. Methods: CT imaging was examined and measured in 33 adult patients with AD, compared with the normal control group of 210 adults. Results: This study showed the results of AD patients

  18. Acetabular fractures in children and adolescents

    NARCIS (Netherlands)

    Heeg, M; de Ridder, VA; Tornetta, P; de Lange, S; Klasen, HJ

    2000-01-01

    A retrospective study of 29 acetabular fractures in children 2 to 16 years of age with an average followup of 14 years is presented. Nineteen patients had an additional dislocation of the femoral head and 14 patients had an associated neurologic injury. Surgical treatment was performed in 16 patient

  19. Evaluation of red mud as pozzolanic material in replacement of cement for production of mortars; Avaliacao da lama vermelha como material pozolanico em substituicao ao cimento para producao de argamassas

    Energy Technology Data Exchange (ETDEWEB)

    Manfroi, E.P.; Cheriaf, M.; Rocha, J.C., E-mail: elizmanfroi@yahoo.com.b, E-mail: malik@valores.ufsc.b [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. de Engenharia Civil

    2010-07-01

    Red mud is a by-product of the alkaline extraction of aluminum from the bauxite and represents a renewed environmental problem due the significant annual throughput by the plants. In the present work, the pozzolanic properties of Brazilian red mud fired at 600, 700, 800 and 900 deg C were investigated by monitoring lime consumption using DTA analysis and Brazilian standard methodology NBR 5772 (1992). Products and kinetics of hydration were determined in cement pastes produced with 5 and 15% red mud using x-ray diffraction and DTA analysis. Compressive strength and capillary absorption tests were realized on mortars constituted by 5, 10 and 15% red mud in replacement of cement. When calcined at 600 deg C, the red mud develops good pozzolanic properties, and the compressive strength of mortars produced with this waste meet values in accordance with regulatory standard. These results shown than red mud can be used, in partial replacement of cement, as new construction material to produce sustainable mortars with low environmental impact. (author)

  20. Resistência à compressão do solo-cimento com substituição parcial do cimento Portland por resíduo cerâmico moído Compressive strength of soil-cement with partial replacement of the Portland cement by crushed ceramic waste

    Directory of Open Access Journals (Sweden)

    Rivanildo Dallacort

    2002-12-01

    Full Text Available Neste trabalho, apresenta-se o estudo experimental da resistência à compressão do solo-cimento, com substituição parcial do cimento Portland por resíduo cerâmico moído. Para tanto, foram ensaiados 81 espécimenes cilíndricos desse material à compressão, em que parte do cimento foi substituída por material cerâmico moído. Realizou-se uma programação fatorial, na qual três variáveis foram selecionadas para estudo: o teor de material ligante (cimento + resíduo cerâmico, a umidade do solo e o teor de resíduo cerâmico adicionado. É apresentado um estudo estatístico através de análise de variância da massa específica do material e da resistência a compressão. Tal estudo permitiu concluir-se que substituições de 25 e 57% do teor de cimento por material cerâmico podem produzir blocos de solo-cimento com resistências superiores a 2 MPa, com teor de material ligante de 6 e 8%, respectivamente.In this paper, an experimental study of the compressive strength of soil-cement with partial replacement of the Portland cement by crushed ceramic waste is presented and discussed. For this, eighty-one cylindrical specimens of soil-cement were tested, where part of cement percentage was replaced by crushed ceramic waste. The experiment was conducted in factorial design and three variables were selected and studied: the binding material content (cement + ceramic waste, soil moisture content and the ratio of ceramic waste. A statistical study using variance analysis of the specific mass and compressive strength of the material is presented. This study concluded that replacement ratios of 25 and 57% of the Portland cement by crushed ceramic material can be used to fabricate soil-cement bricks with strength higher than 2 MPa, for a binding material content of 6 and 8% respectively.

  1. Comparison of postoperative curative effect and the possible survival rate of prosthesis following cemented and cementless total hip replacement%人工全髋关节置换骨水泥和无骨水泥假体术后疗效及假体可能的生存率比较

    Institute of Scientific and Technical Information of China (English)

    张勇; 杨彤涛; 周勇; 马保安

    2006-01-01

    ,假体都没有达到理想固定的效果.假体类型的选择并不影响假体的寿命,要根据患者的年龄及是否还要行翻修术来决定假体类型;骨溶解与患者年龄、性别、假体类型无关.%BACKGROUND: Patients who suffered total hip replacement are most concerned about the survivorship of prosthesis. OBJECTIVE: To evaluate the postoperative curative effect following ce mented and cementless THR with a retrospective method, so as to provide experience for prolonging the survivoship of prosthesis. DESIGN: Randomized and controlled observation. SETTING: General Center of Orthopaedic Department, General Institute of Bone Oncology, Tangdu Hospital, Fourth Military Medical University of Chinese PLA. PARTICIPANTS: We admitted 356 patients who underwent THR from Department of Orthopaedics, Tangdu Hospital, Fourth Military Medical U niversity of Chinese PLA between March 1993 and March 2004. Among them, 298 were contacted and 105 (108 hips) followed up. The patients participated in the review voluntarily. They were of either gender and had different types of prosthesis. Prosthesis made in China was adopted before 2000 and prosthesis made in American STRIKER company after 2000: Prosthesis made in China was made of home-made bone cement; Prosthesis bone cement (import) was provided by American STRIKER prosthesis company. Home-made bone cement and import have the same components. Barium was added in both bone cement . The whole operation was con ducted by the physicians who worked in the artificial joint department after examination. METHODS: According to informal discussion summary about total hip replacement of Chinese Journal of Surgery in 1982 and Evaluation Scale of Mayo Total Hip Replacement Curative Effect, we designed follow-up table by ourselves. Totally 105 (108 hips) patients were followed up, among them, 62 (63 hips) were in the cemented group, 43 (45 hips) in the ce mentless group. Pain, function and motion range of the patients and

  2. A porous tantalum uncemented acetabular cup in acetabular revision arthroplasty%生物学固定骨小梁金属杯在髋臼翻修中的应用

    Institute of Scientific and Technical Information of China (English)

    徐卫东; 陈刚; 张东华

    2009-01-01

    前后X射线平片显示无假体移位下沉等不稳迹象,骨小梁金属杯周围骨质向内长入.本组患者无置换后并发症发生,截至最后1次随访有14例行走时无疼痛,2例轻度疼痛伴轻度跛行.未出现症状性深静脉血栓或神经损伤.无需要再度翻修病例.结论:初次固定人工髋臼杯失败的病例,若无骨缺损,翻修时使用骨小梁金属杯可以获得良好的早期效果.%BACKGROUND: Biological fixation refers to the treatment of coarse or porous prosthetic surface. It is favorable to "bone ingrowth" prosthesis to achieve long-term stability. Porous tantalum is the latest scientific product that appears suitable to prosthetic surface owing to its porous feature and has been attracting a great deal attention.OBJECTIVE: To investigate the therapeutic efficacy of a porous tantalum uncemented acetabular cup in acetabular revision arthroplasty.DESIGN, TIME AND SETTING: A retrospective case analysis was performed at the Department of Orthopedics, Changhai Hospital, Second Military Medical University of Chinese PLA between April and November 2006.PARTICIPANTS/MATERIALS: Sixteen patients (16 hips), 7 males and 9 females, aged 54-81 years old, who received treatment at the Department of Orthopedics, Changhai Hospital, Second Military Medical University of Chinese PLA were included in this study. Of these patients, 2 suffered from femoral neck fracture, 6 from aseptic femoral head necrosis, and 8 from osteoarthritis. Trabecular metal cup (Zimmer, Warsaw, Indiana) provided a titanium alloy bottom layer and porous tantalum-coated surface, which was realized by technical combination of bone trabecular tantalum and titanium alloy. The prosthesis contained an ultrahigh modulus polyethylene lining.METHODS: All patients underwent acetabular revision with modular porous tantalum uncemented acetabular cup. Prior to replacement, acetabular defects and femoral prosthesis were evaluated. A posterolateral approach of hip joint was made. Following

  3. Computed tomography analysis of acetabular anteversion and abduction

    Energy Technology Data Exchange (ETDEWEB)

    Stem, Eric S. [Mayo Clinic, Department of Orthopedic Surgery, Jacksonville, FL (United States); South Carolina Sports Medicine and Orthopaedic Center, North Charleston, SC (United States); O' Connor, Mary I. [Mayo Clinic, Department of Orthopedic Surgery, Jacksonville, FL (United States); Kransdorf, Mark J. [Mayo Clinic, Department of Radiology, Jacksonville, FL (United States); Crook, Julia [Mayo Clinic, Biostatistic Unit, Jacksonville, FL (United States)

    2006-06-15

    The purpose of this study is to define the normal range of acetabular abduction and anteversion in relation to pelvic anatomy as depicted on conventional CT scan. We retrospectively reviewed 100 pelvic CT scans performed on patients presenting for evaluation of non-orthopaedic pathology. The study group consisted of 58 women and 42 men, aged between 18 and 88 years. Standard imaging protocol included an anteroposterior (AP) topogram with contiguous 5-mm thick axial images from the superior margin of the iliac crest to the lesser trochanter of the femur. The acetabular abduction was measured from the AP topogram by obtaining the angle between a line drawn from the acetabular teardrop to the lateral acetabular margin and a horizontal line between the ischial tuberosities. Acetabular anteversion was measured on axial images at the level of the mid-femoral head. We found the mean acetabular abduction to be 39 degrees (standard deviation 4 degrees, range 27 to 51 degrees) and the mean acetabular anteversion to be 23 degrees (standard deviation 5 degrees, range 12 to 39 degrees). Data suggests that acetabular anteversion may average 2.7 degrees lower in males than females and increase slightly with age, while abduction may tend to decrease with age. Ninety percent of patients had acetabular abduction between 31 and 46 degrees; the 90% central range for acetabular anteversion was estimated to be from 14 to 31 degrees. CT scanning is useful in accurately defining the normal range of acetabular abduction and antiversion. Knowledge of this normal anatomy will allow accurate assessment of acetabular component position as delineated on conventional CT scanning. (orig.)

  4. Failure analysis of retrieved PE-UHMW acetabular liners.

    Science.gov (United States)

    Laska, Anna; Archodoulaki, Vasiliki-Maria; Duscher, Bernadette

    2016-08-01

    Ultra-high molecular weight polyethylene (PE-UHMW) acetabular liners have a limited lifespan in a patient's body. There are many factors affecting the performance of the implant and furthermore the properties of the polymeric material are changing after implantation. In this work material changes according to structure and morphology and their implication on mechanical properties are in focus. The physical and mechanical properties of ten crosslinked (xL) PE-UHMW and nine conventional (conv) gamma-sterilized PE-UHMW hip components, used as sliding surface in total hip joint replacement, with different in-vivo times are compared. The evaluation of the retrieved acetabular liners is performed in view of crosslinking and conventional gamma-sterilization but also in terms of the influence of gender concerning alteration in properties. The oxidative degradation in the PE-UHMW is investigated by means of Fourier Transformed Infrared Spectroscopy (FTIR). The characterization of the morphology is carried out via differential scanning calorimetry (DSC). A depth profile of the micro-hardness and elastic modulus is taken over the cross-section of the components in order to find the influence of chemical constitution and morphology on the micro-mechanical properties. It could be shown that crosslinking and oxidative degradation influence the degree of crystallinity of the polymer. Oxidation occurs for both types of the material due to in-vivo time. Higher degree of crystallinity can be correlated to higher hardness and indentation modulus. No unequivocal superiority of crosslinked over conventional liners can be observed. The influence of sex concerning alteration of the evaluated properties matters but need to be further investigated.

  5. Cement Conundrum

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    China aims to streamline the crowded cement industry Policymakers are looking to build a concrete wall around the cement-making industry as they seek to solidify the fluid cement market and cut excessive production.

  6. Surgical treatment for complex acetabular fractures

    Institute of Scientific and Technical Information of China (English)

    LIU Qiang; WU Dou; LI Ping; HAN Shu-feng

    2006-01-01

    Objective: To explore the effect of surgical treatment on complex acetabular fractures.Methods: The data of 46 patients (38 males and 8 females, aged 16-75 years, mean = 38. 5 years ) with complex acetabular fractures, who were admitted to our hospital from January 1998 to December 2005, were analyzed retrospectively in this study. According to Letournel rules, posterior wall and posterior column fractures were found in 11 patients, transverse and posterior wall fractures in 13, T-type fracture in 4, both columns fracture in 10, and anterior column and posterior transverse fracture in 8. The choice of surgical approach was based on the individual fractures, which included ilioinguinal approach in 5 patients, Kocher-Langenbech approach in 7, combined approach in 26, and extended iliofemoral approach in 8.Results: All the patients were followed up for 3.5 years averagely. The clinical outcomes were analyzed with Harris hip score and radiography. In 36 patients (78.3%), the surgical procedure was successful (Harris hip score > 80 points). The rate of excellent and good was about 86 %.Conclusions: The keys to increase the effectiveness of surgical treatment on acetabular fractures are correct preoperative classification of factures and choices of appropriate surgical approach and time.

  7. Bipolar hip arthroplasty as salvage treatment for loosening of the acetabular cup with significant bone defects

    Directory of Open Access Journals (Sweden)

    Ghanem, Mohamed

    2016-04-01

    Full Text Available Introduction: Revision arthroplasty of the hip is becoming increasingly important in recent years. Early primary arthroplasty and longer life expectancy of the patients increases the number of revision surgery. Revision surgery of hip arthroplasty is major surgery for the patients, especially the elderly, with significant risks concerning the general condition of the patient. The aim of this work is to evaluate the outcome of bipolar hip arthroplasty as a salvage procedure for treatment of loosening of the acetabular cup with significant acetabular bone defects after total hip replacement (THR in multi-morbid patients.Patients and methods: During the period from January 1 2007 to December 31 2011 19 revision hip surgeries were performed in , in which the loosened acetabular cup was replaced by a bipolar head. The examined patient group consisted exclusively of female patients with an average of 75 years. The predominant diagnosis was “aseptic loosening” (84.2%. All patients in our study were multi-morbid. We decided to resort to bipolar hip arthroplasty due to the compromised general condition of patients and the major acetabular bone defects, which were confirmed intraoperatively. The postoperative follow-up ranged from 0.5 to 67 months (average 19.1 months. Results: Evaluation of the modified Harris Hip Score showed an overall improvement of the function of the hip joint after surgery of approximately 45%.Surgery was less time consuming and thus adequate for patients with significantly poor general health condition. We noticed different complications in a significant amount of patients (68.4%. The most common complication encountered was the proximal migration of the bipolar head.The rate of revision following the use of bipolar hip arthroplasty in revision surgery of the hip in our patients was high (21%. Despite the high number of complications reported in our study, we have noticed significant improvement of hip joint function as well

  8. The efficacy of a “double-D-shaped” wire marker for radiographic measurement of acetabular cup orientation and wear

    OpenAIRE

    Derbyshire, Brian; Raut, Videshnandan V.

    2013-01-01

    Historically, wire markers were attached to cemented all-plastic acetabular cups to demarcate the periphery and to measure socket wear. The wire shape was either a semi-circle passing over the pole of the cup, or a circle around the cup equator. More recently, “double-D” shaped markers were introduced with a part-circular aspect passing over the pole and a semi-circular aspect parallel to the equatorial plane. This configuration enabled cup retroversion to be distinguished from anteversion. I...

  9. 非骨水泥型踝关节置换术治疗踝关节骨性关节炎%Non-cement total ankle replacement for osteoarthritis of ankle joint

    Institute of Scientific and Technical Information of China (English)

    李志锐; 董纪元

    2012-01-01

    Objective To study the surgical procedure and therapeutic effect of non-cement total ankle replacement for osteoarthritis of ankle joint. Methods Eighteen patients(19 ankle-joints) with osteoarthritis of ankle joint underwent non-cement total ankle replacement and were followed up for 18.5 months(range 8-45 months). Pain, motion and function of ankle joints were compared before and after operation. The function of ankle-joint was assessed with the Kofoed scoring system. Results The symptoms, signs and function of ankle-joint were improved in all patients after operation, with the extension, flexion and score of ankle-joint increased to 18.6°, 28.3°, and 80.7 after operation from 8.8°, 12.5°, and 42.2 before operation. No looseness and infection were found on X-ray film. Conclusion Non-cement total ankle replacement is an effective procedure for osteoarthritis of ankle joint.%目的 探讨非骨水泥型踝关节置换术治疗踝关节骨性关节炎的手术策略和临床疗效.方法 对18例(19踝)踝关节骨性关节炎患者行非骨水泥型踝关节置换术,平均随访时间为18.5(8-45)个月.对手术前后关节疼痛、活动度、关节功能改善进行对比研究,术后关节功能根据Kofoed评分进行评价.结果 所有患者术后临床症状及踝关节功能都有不同程度的改善.背伸活动度由术前平均8.8°,改善为术后平均18.6°;跖屈活动度由术前平均12.5°,改善为术后平均28.3°; Kofoed评分由术前平均42.2分,改善为术后平均80.7分.X线片分析未见假体松动及感染表现.结论 非骨水泥型踝关节置换术是治疗踝关节骨性关节炎的有效方法.

  10. Epinephrine hydrochloride prevents bone cement implantation syndrome in cemented hip replacement%盐酸肾上腺素在骨水泥型髋关节置换术中预防骨水泥植入综合征发生的作用

    Institute of Scientific and Technical Information of China (English)

    齐向北; 张英泽; 潘进社; 马利杰; 王琳; 王建朝

    2010-01-01

    Objective To investigate the clinical application of epinephrine hydrochloride in the prevention of bone cement implantation syndrome in the cemented hip replacement. Methods The clinical data of 48 patients treated with cemented hip replacement from July 2008 to April 2009 were retrospectively analyzed. All the patients were divided into control group and intervention group. The bone marrow cavities of 24 patients in the control group were not pretreated with saline epinephrine hydrochloride before implantation of bone cement; the bone marrow cavities of 24 patients in the intervention group were pretreated with saline epinephrine hydrochloride before implantation of bone cement. Systolic blood pressure (SBP), diastolic blood pressure (DBP), the mean arterial pressure (MAP), heart rate (HR)and pulse oxygen saturation ( SPO2 ) were compared between the two groups before bone cement implantation and 1,2, 3, 4, 5, 6, 7, 8, 9, 10 minutes after bone cement implantation. The data were analyzed with variance analysis and Q test. Results (1) In the control group: the blood pressure was decreased in control group one minute after bone cement implantation and a significant decrease of the blood pressure was observed at 2-6 minutes after the implantation ( P < 0. 01 ). The blood pressure was increased seven minutes after the implantation, with the most significant increase of DBP ( P < 0.05 ).The blood pressure recovered to normal 10 minutes later. The SPO2 was decreased significantly ( P <0.05 ) but no significant change was observed in HR ( P > 0.05). (2) In the intervention group: the bone marrow cavity was pretreated with saline epinephrine hydrochloride before implantation of bone cement.ity. No significant difference was found in SBP, DBP, MAP, HR and SPO2 at different time points before and after bone cement implantation (P >0.05 ). Significant decrease of blood pressure and SPO2 was observed in control group and a significant hemodynamic change was detected

  11. Polyethylene sterilized without irradiation in a polished uncemented acetabular component-a clinical and radiographic analysis.

    Science.gov (United States)

    Crockarell, John R

    2008-09-01

    Clinical and radiographic analysis of the Reflection uncemented acetabular component was performed. Features of this component include a polished inner shell and ethylene oxide sterilization. Clinical information was available for 158 hips (mean, 4.6 years follow-up). A total of 19 hips have undergone or were recommended revision, 8 for aseptic loosening or wear (5%). Wear analysis was performed for 38 hips with more than 5 years of follow-up (mean, 6.7 years). Osteolysis was present in 20 of these patients. Penetration rate averaged 0.15 mm/y. Patients with uncemented femoral fixation (vs cemented) had a significantly higher penetration rate. Increased volumetric wear was seen with uncemented femoral fixation, thin liners, and ceramic heads. This component demonstrated relatively high penetration and osteolysis rates. Continued surveillance is recommended, particularly for active patients with thin liners. PMID:18534518

  12. Osteochondritis dissecans after rotational acetabular osteotomy for dysplastic hip

    Energy Technology Data Exchange (ETDEWEB)

    Nozawa, Masahiko; Maezawa, Katsuhiko; Yuasa, Takahito; Morimoto, Kouichi; Asakura, Taro; Kurosawa, Hisashi [Juntendo University School of Medicine, Department of Orthopaedic Surgery, Tokyo (Japan)

    2005-12-01

    We encountered a rare case of osteochondritis dissecans of the femoral head after rotational acetabular osteotomy that recovered with conservative treatment 4 years after the detection of characteristic radiological findings. (orig.)

  13. Breathing zone concentrations of methylmethacrylate monomer during joint replacement operations

    DEFF Research Database (Denmark)

    Darre, E; Jørgensen, L G; Vedel, P;

    1992-01-01

    By use of a methylmethacrylate (MMA) Dräger tube and bellow bump, the breathing zone concentrations of MMA monomer were measured for the operating surgeon during cementation of the components of hip and knee joint prostheses. The highest recordings (50-100 p.p.m.) were encountered during cementat......By use of a methylmethacrylate (MMA) Dräger tube and bellow bump, the breathing zone concentrations of MMA monomer were measured for the operating surgeon during cementation of the components of hip and knee joint prostheses. The highest recordings (50-100 p.p.m.) were encountered during...... cementation of the acetabular cups with conventional polymethylmethacrylate cement. Such exposure could be eliminated by the use of personal protection equipment, local punctual field suction or change to a MMA/n-decylmethacrylate/isobornylmethacrylate bone cement....

  14. Delayed cementless total hip arthroplasty for neglected dislocation of hip combined with complex acetabular fracture and deficient bone stock

    Directory of Open Access Journals (Sweden)

    Gavaskar Ashok S

    2012-12-01

    Full Text Available 【Abstract】Total hip arthroplasty (THA for an un-treated acetabular fracture is technically challenging and the long-term result is not so favorable. A 45-year-old fe-male patient with untreated column and comminuted poste-rior wall fracture of the acetabulum was treated in our insti-tution by reconstruction of the posterior wall using iliac strut autograft and plate stabilization of the posterior col-umn with cancellous grafting and cementless THA in a single stage. At 3 years’ follow-up, the patient was independently mobile without limb length discrepancy. Radiological evalu-ation showed well integrated components and bone grafts. No evidence of aseptic loosening or osteolysis was found. This report aims to emphasize that bony acetabular recon-struction allows the use of primary hip components, which improves prosthesis longevity and preserves bone stock for a future revision. Key words: Acetabulum; Fractures, bone; Hip dislocation; Arthroplasty, replacement, hip

  15. Rice husk derived waste materials as partial cement replacement in lightweight concrete Utilização de resíduos derivados da casca de arroz como substitutos parciais do cimento no concreto leve

    Directory of Open Access Journals (Sweden)

    Celso Yoji Kawabata

    2012-10-01

    Full Text Available In this study rice husk ash (RHA and broiler bed ash from rice husk (BBA, two agricultural waste materials, have been assessed for use as partial cement replacement materials for application in lightweight concrete. Physical and chemical characteristics of RHA and BBA were first analyzed. Three similar types of lightweight concrete were produced, a control type in which the binder was just CEMI cement (CTL and two other types with 10% cement replacement with, respectively, RHA and BBA. All types of similar lightweight concrete were prepared to present the same workability by adjusting the amount of superplasticizer. Properties of concrete investigated were compressive and flexural strength at different ages, absorption by capillarity, resistivity and resistance to chloride ion penetration (CTH method and accelerated carbonation. Test results obtained for 10% cement replacement level in lightweight concrete indicate that although the addition of BBA conducted to lower performance in terms of the degradation indicative tests, RHA led to the enhancement of mechanical properties, especially early strength and also fast ageing related results, further contributing to sustainable construction with energy saver lightweight concrete.Neste trabalho, cinzas de casca de arroz (RHA e cinzas de cama de frango (BBA, dois resíduos agrícolas, foram avaliadas para uso como substitutos parciais do cimento para produção de concreto leve. Características físicas e químicas de RHA e BBA foram analisadas. Três tipos semelhantes de concreto leve foram produzidos, um controle em que o ligante era totalmente cimento CEM I (CTL e dois outros tipos de concreto, com substituição de 10% com RHA e BBA, respectivamente. Todos os tipos de concreto leve foram feitos através do ajuste da quantidade de superplastificante para apresentarem a mesma trabalhabilidade. Propriedades de concreto investigados foram resistência à compressão e à flexão em diferentes idades

  16. Initial Results of an Acetabular Center Axis Registration Technique in Navigated Hip Arthroplasty with Deformed Acetabular Rims

    OpenAIRE

    Wada, Hiroshi; Mishima, Hajime; Yoshizawa, Tomohiro; Sugaya, Hisashi; Nishino, Tomofumi; Yamazaki, Masashi

    2016-01-01

    Background In cementless total hip arthroplasty, imageless computer-assisted navigation is usually used to register the anterior pelvic plane (APP). The accuracy of this method is influenced by the subcutaneous tissues overlying the registration landmarks. On the other hand, the acetabular center axis (ACA) is determined from the acetabular rim. Precise registration of the ACA is possible because of direct palpation using a pointer. Imageless navigation using the ACA usually targets patients ...

  17. Performance of Cement Containing Laterite as Supplementary Cementing Material

    Directory of Open Access Journals (Sweden)

    Abbas Bukhari, Z. S.

    2013-03-01

    Full Text Available The utilization of different industrial waste, by-products or other materials such as ground granulated blast furnace slag, silica fume, fly ash, limestone, and kiln dust, etc. as supplemen- tary cementing materials has received considerable attention in recent years. A study has been conducted to look into the performance of laterite as Supplementary Cementing Materials (SCM. The study focuses on compressive strength performance of blended cement containing different percentage of laterite. The cement is replaced accordingly with percentage of 2 %, 5 %, 7 % and 10 % by weight. In addition, the effect of use of three chemically different laterites have been studied on physical performance of cement as in setting time, Le-Chatlier expansion, loss on ignition, insoluble residue, free lime and specifically compressive strength of cement cubes tested at the age of 3, 7, and 28 days. The results show that the strength of cement blended with laterite as SCM is enhanced. Key words: Portland cement, supplementary cementing materials (SCM, laterite, compressive strength KUI – 6/2013 Received January 4, 2012 Accepted February 11, 2013

  18. Three-fin acetabular prosthesis for superior acetabular bone defects: a three-dimensional finite element analysis

    Institute of Scientific and Technical Information of China (English)

    LIU Yu-zeng; HAI Yong; ZHAO Hui

    2012-01-01

    Background Given that three-dimensional finite element models have been successfully used to analyze biomechanics in orthopedics-related research,this study aimed to establish a finite element model of the pelvic bone and three-fin acetabular component and evaluate biomechanical changes in this model after implantation of a three-fin acetabular prosthesis in a superior segmental bone defect of the acetabulum.Methods In this study,three-dimensional finite element models of the pelvic bone and three-fin acetabular component were first established.The prosthesis model was characterized by three different conformational fins to facilitate and optimize the prosthetic design.The spongy and cortical bones were evaluated using a different modulus of elasticity in this established model.Results The maximum and minimum von Mises stresses on the fins of the acetabular component were 15.2 and 0.74,respectively.The maximum and minimum micromotion between the three-fin acetabular component and the acetabulum bone interface were 27 and 13 μm,respectively.A high primary stability and implied better clinical outcome were revealed.Conclusion Finite element analysis may be an optimal strategy for biomechanics-related research of prosthetic design for segmental acetabular bone defects.

  19. Composite cements containing natural pozzolan and granulated blast furnace slag

    OpenAIRE

    Irassar, E. F.; Rahhal, V. F.; Donza, H. A.; Menéndez, G.; Bonavetti, V. L.

    2006-01-01

    For reasons of market demand and Portland cement production,the manufacture of cements with two or more separately ground additions to produce customized cements is becoming common practice.When pozzolan or slag content in this type of cements is high, however, the initial strength of the resulting product may be adversely impacted. This problem can be minimized by activating one or both of the replacement materials. The present study analyzes the effect of Portland cement additions such as p...

  20. Clinical and radiological evaluation of hybrid hip replacement in various disorders of hip

    Directory of Open Access Journals (Sweden)

    Dhaon B

    2005-01-01

    Full Text Available Background: High rates of loosening of cemented implants led to change in technique of fixation of the implant. Methods: Fifty-nine hips were operated in 42 patients with non-cemented acetabular and cemented femoral components between January 1999 and July 2003. The average age of the patient was 45.2 years in our study. Preoperative diagnosis was avascular necrosis (28, ankylosing spondylitis (18, fracture neck femur (9, rheumatoid arthritis (2 and osteoarthritis (2. Results: At an average follow up of 3.6 years (range 1.2-5.8 years excellent to good results were obtained 92% according to Harris hip criteria. No radiological loosening was noted in any femoral or acetabular component on follow up. One poor result was seen in a case of bilateral ankylosing spondylitis operated on one side. Conclusion: Hybrid THA provides a viable and highly acceptable method of treatment of diseases of hip in young patients.

  1. CEMENT SLURRIES FOR GEOTHERMAL WELLS CEMENTING

    OpenAIRE

    Nediljka Gaurina-Međimurec; Davorin Matanović; Gracijan Krklec

    1994-01-01

    During a well cementing special place belongs to the cement slurry design. To ensure the best quality of cementing, a thorough understanding of well parameters is essential, as well as behaviour of cement slurry (especially at high temperatures) and application of proven cementing techniques. Many cement jobs fail because of bad job planning. Well cementing without regarding what should be accomplished, can lead to well problems (channels in the cement, unwanted water, gas or fluid production...

  2. Accuracy of the modified Hardinge approach in acetabular positioning

    Science.gov (United States)

    Goyal, Prateek; Lau, Adrian; McCalden, Richard; Teeter, Matthew G.; Howard, James L.; Lanting, Brent A.

    2016-01-01

    Background The surgical approach chosen for total hip arthroplasty (THA) may affect the positioning of the acetabular component. The purpose of this study was to examine the accuracy in orienting the acetabular component using the modified Hardinge approach. Methods We used our institutional arthroplasty database to identify patients with primary, press-fit, hemispherical acetabular components of a metal-on-polyethylene THA performed between 2003 and 2011. Patients with radiographs obtained 1–3 years after the index procedure were included for measurement of anteversion and inclination angles. Acceptable values of anteversion and abduction angles were defined as 15° ± 10° and 40° ± 10°, respectively. Results We identified 1241 patients from the database, and the modified Hardinge approach was used in 1010 of the patients included in our analysis. The acetabular component was anteverted in the acceptable zone in 54.1% of patients. The abduction angle was within the defined range in 79.2% of patients. Combined anteversion and abduction angles within the defined zone were present in 43.6% of patients. Conclusion Consistent with studies examining accuracy from other approaches, our study reveals that the modified Hardinge approach was only moderately accurate in positioning the acetabular component in the acceptable zone. PMID:27240130

  3. Copper Slag Blended Cement: An Environmental Sustainable Approach for Cement Industry in India

    Directory of Open Access Journals (Sweden)

    Jagmeet Singh

    2016-04-01

    Full Text Available Indian cement industry is facing environmental issue of emission of carbon dioxide (CO2, a greenhouse gas. Blended cements including supplementary cementitious materials are substitute of Portland cement to reduce CO2 emission. The present paper investigates theappropriateness of copper slag (CS as supplementary cementitious material. Strength properties and hydration of mixes were determined at different replacement levels of CS with cement. Compressive, flexural and tensile strength of each mix was found out at different curing periods. The hydration of cement was investigated through X-ray diffraction (XRD. The strength test results showed that substitution of up to 20% of CS can significantly replace Portland cement.XRD test results were corresponding to strength test results. The present study encourages the utilization of CS as supplementary cementitious material to make economical and environmentally sustainable blended cement

  4. Potencialidades de um caulim calcinado como material de substituição parcial do cimento portland em argamassas Potentialities of a calcined kaolin as material of partial replacement of portland cement in mortars

    Directory of Open Access Journals (Sweden)

    Marilia P. de Oliveira

    2006-06-01

    Full Text Available A utilização de argilas calcinadas na forma de metacaulinita, como material pozolânico para argamassas e concretos, tem recebido atenção considerável nos últimos anos. Este trabalho objetivou avaliar o desempenho mecânico de argamassas, nas quais foi utilizado um caulim calcinado proveniente do Estado da Paraíba, como material de substituição parcial do cimento Portland. Utilizaram-se duas finuras do caulim: passando nas peneiras ABNT 200 (0,074 mm e 325 (0,044 mm e calcinados nas temperaturas de 700, 800 e 900 ºC pelo tempo de 2 h. As amostras foram caracterizadas através de análise química, análise térmica diferencial, difração de raios-X e área específica. Obteve-se o índice de atividade pozolânica com a cal e o cimento Portland. O percentual de substituição adotado foi de 0, 10, 20, 30 e 40%. A relação aglomerante: areia foi de 1:1,5 e a relação água/aglomerante fixada igual 0,4. O efeito da substituição parcial do cimento na argamassa foi avaliado através da resistência à compressão simples, nas idades de 7, 28 e 90 dias. As argamassas estudadas apresentaram resistência superior em relação à da referência, até o nível de 30% de substituição.The use of burnt clays, in the metakaolin form, as pozzolanic material for mortars and concretes has received a remarkable attention in the last years. This paper aimed to evaluate the mechanical property of mortars, in which a calcined kaolin originating from the State of Paraiba, was used as partial cement replacement material. Two finess of the kaolin were used: ABNT 200 (0.074 mm and 325 (0.044 mm and burnt at temperatures of 700, 800 and 900 ºC for a period of 2 h. Both materials were characterized by chemical analysis, differential thermal analysis, X-ray diffraction, specific area tests. The pozolanic activity index was obtanied using lime and cement Portland. The amounts of replacement were 10, 20, 30 and 40%, besides the reference mortar. The binder

  5. Characterization of cement composites with mineral additives

    OpenAIRE

    Korat, Lidija

    2015-01-01

    Doctoral dissertation is aimed at characterizing cement composites with mineral additives representing the industrial waste material (fly ash, granulated blast furnace slag and biomass fly ash). Their usage can replace high cement shares in individual cases and is, however, favourable due to the production costs reduction and environment burden decrease, including the decreased emission of greenhouse gases as well as lower energy use. Cement composites (in fresh or hardened state)...

  6. MR imaging findings of acetabular dysplasia in adults

    Energy Technology Data Exchange (ETDEWEB)

    James, Steven; Connell, David [The Royal National Orthopaedic Hospital, Radiology Department, London, Middlesex (United Kingdom); Miocevic, Miranda; Malara, Frank; Pike, Jonathan [Victoria House Hospital, Radiology Department, Melbourne (Australia); Young, David [Melbourne Orthopaedic Group, Orthopaedic Surgery, Melbourne (Australia)

    2006-06-15

    To evaluate the diagnostic accuracy of MR imaging in the identification of labral and articular cartilage lesions in patients with acetabular dysplasia. Pre-operative MR imaging was performed on 27 hips in 25 consecutive patients (16 males, 9 females, age range 19-52 years, mean age 31.2 years) with radiographic evidence of acetabular dysplasia (centre-edge angle of Wiberg <20 degrees). The average duration of symptoms was 16.2 months. Two musculoskeletal radiologists assessed MR images in consensus for the presence of abnormality involving the acetabular labrum and adjacent acetabular articular cartilage. A high resolution, non-arthrographic technique was used to assess the labrum and labral chondral transitional zone. Surgical correlation was obtained in all cases by a single surgeon experienced in hip arthroscopy and ten patients with normal hip MRI were included to provide a control group. The acetabular labra in the dysplastic hips demonstrated abnormal signal intensity, and had an elongated appearance when compared with the control group (mean length 10.9 mm vs 6.4 mm). Morphological appearances in the labra included surface irregularity, fissures and cleft formation. MR imaging correctly identified the severity of chondral abnormality in 24 of 27 hips (89%) when compared with arthroscopic findings. MR imaging demonstrates an elongated labrum, focal intra-substance signal change and irregularity and fissuring of the margins in patients with acetabular dysplasia. Abnormality is also identified at the labral chondral transitional zone, where fissuring, focal clefts, chondral deficiency and subchondral cyst formation may be apparent. A high-resolution, non-arthrographic technique can provide an accurate preoperative assessment and evaluate the presence of premature osteoarthritis. (orig.)

  7. Arthroscopic Technique for Acetabular Labral Reconstruction Using Iliotibial Band Autograft.

    Science.gov (United States)

    Chahla, Jorge; Soares, Eduardo; Bhatia, Sanjeev; Mitchell, Justin J; Philippon, Marc J

    2016-06-01

    The dynamic function of the acetabular labrum makes it an important structure for both hip stability and motion. Because of this, injuries to the labrum can cause significant dysfunction, leading to altered hip kinematics. Labral repair is the gold standard for symptomatic labral tears to keep as much labral tissue as possible; however, in cases where the labrum has been injured to such a degree that it is either deficient or repair is not possible, arthroscopic labral reconstruction is preferred. This article describes our preferred approach for reconstruction of the acetabular labrum using iliotibial band autograft.

  8. Acetabular Dysplasia and Surgical Approaches Other Than Direct Anterior Increases Risk for Malpositioning of the Acetabular Component in Total Hip Arthroplasty

    DEFF Research Database (Denmark)

    Gromov, Kirill; Greene, Meridith E; Huddleston, James I;

    2016-01-01

    BACKGROUND: Persistent acetabular dysplasia (AD) after periacetabular osteotomy has been hypothesized to increase the risk for malpositioning of the acetabular component. In this study, we investigate whether AD is an independent risk factor for cup malpositioning during primary total hip...... arthroplasty (THA). METHODS: Patient demographics, surgical approach, presence of AD assessed using the lateral center-edge angle, and acetabular cup positioning determined using Martell Hip Analysis Suite were investigated in 836 primary THA patients enrolled in a prospective multicenter study. RESULTS: We...

  9. Results of cemented bipolar hemiarthroplasty for fracture of the femoral neck - 10 year study

    Directory of Open Access Journals (Sweden)

    Maini P

    2006-01-01

    Full Text Available Background : One of the most common treatments of displaced fracture of femoral neck in elderly is bipolar hemiarthroplasty. Method : Two hundred and seventy patients of displaced fracture of femoral neck were treated by bipolar hemiarthroplasty. The Mean age of the patients at the time of surgery was 69.80 years. Results : Follow up ranged between 12 months and 120 months. There were 8 cases each of acetabular erosion and protrusion with 10 cases of femoral stem loosening. Eight cases had post operative dislocation requiring open reduction. Eighteen patients got revision surgery to total hip replacement. The overall incidence of DVT/PE was 9.9% which declined after regular use of low molecular weight heparin. Eleven patients had post operative infection. There were 54.2 % excellent results, 21.0 % good results, 10.7 % fair and 3.7% poor results. Conclusion : Elderly patients with displaced fracture of neck femur are able to ambulate early after Cemented bipolar hemi arthroplasty. The complication rate is low, the component survival long and pre injury functional status is restored in majority of patients.

  10. Simultaneous bilateral shoulder and bilateral central acetabular fracture dislocation: What to do?

    Institute of Scientific and Technical Information of China (English)

    Hardik Sheth; Abhijeet Ashok Salunke; Ramesh Panchal; Jimmy Chokshi; G.I.Nambi; Saranjeet Singh; Amit Patel

    2016-01-01

    Musculoskeletal injuries following seizures have a high morbidity and mortality.These injuries are often missed and the diagnosis is delayed due to a lack of clinical suspicion and appropriate investigations.We report a case of 72 years old male with simultaneous bilateral central acetabular fracture dislocation and bilateral posterior shoulder fracture dislocation secondary to an epileptic seizure.Present study highlights the significance of clinical suspicion and clinico-radiological evaluation for diagnosis of a rare injury following episode of seizures.Simultaneous fracture dislocation of all four limbs treated with a holistic approach can lead to a good functional recovery.Surgical management with open reduction and internal fixation is preferred and replacement arthroplasty should be reserved for cases with implant failure and elderly patients.

  11. Potencial da cinza do bagaço da cana-de-açúcar como material de substituição parcial de cimento Portland Potential of sugarcane bagasse ash as a partial replacement material for Portland cement

    Directory of Open Access Journals (Sweden)

    Marcos O. de Paula

    2009-06-01

    Full Text Available Este trabalho, voltado para a avaliação do potencial da cinza do bagaço da cana-de-açúcar (CBC como material de substituição parcial do cimento Portland em argamassa, objetivou apresentar opção viável para a destinação deste resíduo, cuja quantidade gerada aumentará significativamente nos próximos anos, em decorrência da ampliação do setor de produção de álcool combustível; além disso, o emprego da CBC como adição mineral, substituindo parte do cimento em argamassas e concretos, contribui para a redução do impacto ambiental desses materiais, em boa parte decorrente da produção do cimento. O procedimento experimental abordou não só caracterização da CBC mas também a avaliação, através de ensaios físicos e mecânicos, em que os resultados mostraram que o bagaço apresenta rendimento de CBC de 10%, com a cinza sendo composta de 84% de SiO2 e 5% de Carbono. A sílica na CBC apresenta-se na fase amorfa e nas fases cristalinas de cristobalita e quartzo. Os índices de atividade pozolânica comprovam a reatividade da CBC. Do ponto de vista da resistência à compressão, argamassas com teores de CBC entre 0 e 30% indicaram a possibilidade de substituição de até 20% do cimento pela CBC.This study is focused on the evaluation of the effects of the partial replacement of Portland cement by sugarcane bagasse ash (CBC in mortars. The main objective was to find a suitable destination for an agricultural residue generated in an increasing amount in Brazil, as a result of the boom of the use of ethanol as an alternative fuel to gasoline. Also, the use of CBC as a mineral admixture in mortars and concretes contributes to a decrease in the environmental impact of these materials related to cement production. Experimental techniques were applied both for the CBC characterization and for the evaluation of its use as a mineral admixture in mortars, based on mechanical and physical tests. The yield of CBC from sugarcane

  12. Cement Formation

    DEFF Research Database (Denmark)

    Telschow, Samira; Jappe Frandsen, Flemming; Theisen, Kirsten;

    2012-01-01

    Cement production has been subject to several technological changes, each of which requires detailed knowledge about the high multiplicity of processes, especially the high temperature process involved in the rotary kiln. This article gives an introduction to the topic of cement, including......−liquid reactions are discussed, as are the influences of particles sizes on clinker phase formation. Furthermore, a mechanism for clinker phase formation in an industrial rotary kiln reactor is outlined....

  13. Functional outcome of the surgical management of acute acetabular fractures

    Institute of Scientific and Technical Information of China (English)

    Naseem Munshi; Asad Abbas; Mohamed Amirali Gulamhussein; Ghulam Mehboob; Rija Aitzaz Qureshi

    2015-01-01

    Objective:To assess the functional outcome of early surgical management of displaced acetabular fractures and the complications associated with the procedure. Methods: This is a case series study and data was collected using specialized performance. The study included 75 patients and the sampling technique was a non-probability purposive type. Patients presenting with close displaced acetabular fractures of more than 2 mm within 10 days of injury were included. However, elderly patients presenting after 10 days of injury, with evidence of local infection, severe osteoporotic bone and co-morbid such as chronic obstructive pulmonary disease were not included in the study. New acetabular scoring system was used for assessing outcome of patients. Results:A total of 75 patients were operated on. Union was achieved in anatomical position in 66 (88%) patients and in malposition in 9 (12%) patients. Excellent results were obtained in 18 (24%) patients, good results in 41 (54.6%), fair results in 12 (16%), and poor results in 4 (5.4%) patients. Postoperative complications included infection [5 (6.7%)], heterotropic ossification [3 (4%)], sciatic nerve injury [10 (13.3%)], avascular necrosis [3 (4%)] patients. Conclusions: Patients with displaced acetabular fractures should be referred to specialised centres. Early surgical intervention and experienced management is a prime factor in achieving good results.

  14. Properties of Cement Mortar Produced from Mixed Waste Materials with Pozzolanic Characteristics.

    Science.gov (United States)

    Yen, Chi-Liang; Tseng, Dyi-Hwa; Wu, Yue-Ze

    2012-07-01

    Waste materials with pozzolanic characteristics, such as sewage sludge ash (SSA), coal combustion fly ash (FA), and granulated blast furnace slag (GBS), were reused as partial cement replacements for making cement mortar in this study. Experimental results revealed that with dual replacement of cement by SSA and GBS and triple replacement by SSA, FA, and GBS at 50% of total cement replacement, the compressive strength (Sc) of the blended cement mortars at 56 days was 93.7% and 92.9% of the control cement mortar, respectively. GBS had the highest strength activity index value and could produce large amounts of CaO to enhance the pozzolanic activity of SSA/FA and form calcium silicate hydrate gels to fill the capillary pores of the cement mortar. Consequently, the Sc development of cement mortar with GBS replacement was better than that without GBS, and the total pore volume of blended cement mortars with GBS/SSA replacement was less than that with FA/SSA replacement. In the cement mortar with modified SSA and GBS at 70% of total cement replacement, the Sc at 56 days was 92.4% of the control mortar. Modifying the content of calcium in SSA also increased its pozzolanic reaction. CaCl(2) accelerated the pozzolanic activity of SSA better than lime did. Moreover, blending cement mortars with GBS/SSA replacement could generate more monosulfoaluminate to fill capillary pores.

  15. Properties of Cement Mortar Produced from Mixed Waste Materials with Pozzolanic Characteristics

    Science.gov (United States)

    Yen, Chi-Liang; Tseng, Dyi-Hwa; Wu, Yue-Ze

    2012-01-01

    Abstract Waste materials with pozzolanic characteristics, such as sewage sludge ash (SSA), coal combustion fly ash (FA), and granulated blast furnace slag (GBS), were reused as partial cement replacements for making cement mortar in this study. Experimental results revealed that with dual replacement of cement by SSA and GBS and triple replacement by SSA, FA, and GBS at 50% of total cement replacement, the compressive strength (Sc) of the blended cement mortars at 56 days was 93.7% and 92.9% of the control cement mortar, respectively. GBS had the highest strength activity index value and could produce large amounts of CaO to enhance the pozzolanic activity of SSA/FA and form calcium silicate hydrate gels to fill the capillary pores of the cement mortar. Consequently, the Sc development of cement mortar with GBS replacement was better than that without GBS, and the total pore volume of blended cement mortars with GBS/SSA replacement was less than that with FA/SSA replacement. In the cement mortar with modified SSA and GBS at 70% of total cement replacement, the Sc at 56 days was 92.4% of the control mortar. Modifying the content of calcium in SSA also increased its pozzolanic reaction. CaCl2 accelerated the pozzolanic activity of SSA better than lime did. Moreover, blending cement mortars with GBS/SSA replacement could generate more monosulfoaluminate to fill capillary pores. PMID:22783062

  16. MRI morphometric hip comparison analysis of anterior acetabular labral tears

    Energy Technology Data Exchange (ETDEWEB)

    Aly, Abdel Rahman [University of Saskatchewan, Department of Physical Medicine and Rehabilitation, Saskatoon, SK (Canada); Saskatoon City Hospital, Saskatoon, SK (Canada); Rajasekaran, Sathish [HealthPointe, Pain, Spine and Sport Medicine, Alberta (Canada); Obaid, Haron [Royal University Hospital, University of Saskatchewan, Department of Medical Imaging, Saskatoon, SK (Canada)

    2013-09-15

    Anterior (3 o'clock) acetabular labral tears (AALTs) have been reported to be associated with iliopsoas impingement (IPI). However, no study has examined the association between anatomical bony variables of the hip joint and AALTs. The purpose of this study was to evaluate the association between AALTs, femoroacetabular impingement (FAI) and other bony variables of the hip. Seventy-six out of 274 hip MRI records met the inclusion criteria. Two independent blinded investigators evaluated the location of acetabular labral tears (ALTs), edema at the musculotendinous junction of the iliopsoas insertion, femoral neck anteversion angle, femoral neck shaft angle, acetabular anteversion angle, alpha angle, lateral central edge angle (LCEA), acetabular index, and acetabular depth. Comparison analyses between groups were performed. Twenty-two patients had no ALTs (controls), 19 patients had AALTs, and 35 patients had ALTs not isolated at the 3 o'clock position (25 with cam-bony deformities [FAI-cam] and 10 with pincer-bony deformities [FAI-pincer]). The alpha angle mean was significantly higher (p < 0.001) in the FAI-cam group (62.7 , 95 % confidence interval [CI]: 56.2-69.2 ) compared with the AALTs group (46.9 , 95 % CI: 40.1-53.7 ). The LCEA mean was significantly higher (p < 0.001) in FAI-pincer group (41.9 , 95 % CI: 39.3 -44.5 ) compared to AALTs group (29.4 , 95 % CI: 24.2 -34.6 ). There was no statistically significant difference in any of the bony variables between the controls and the AALTs group. Our study demonstrated that AALTs are pathologically distinct and not associated with FAI or other bony abnormalities. This supports the previous studies, which proposed that AALTs are associated with IPI. (orig.)

  17. MRI morphometric hip comparison analysis of anterior acetabular labral tears

    International Nuclear Information System (INIS)

    Anterior (3 o'clock) acetabular labral tears (AALTs) have been reported to be associated with iliopsoas impingement (IPI). However, no study has examined the association between anatomical bony variables of the hip joint and AALTs. The purpose of this study was to evaluate the association between AALTs, femoroacetabular impingement (FAI) and other bony variables of the hip. Seventy-six out of 274 hip MRI records met the inclusion criteria. Two independent blinded investigators evaluated the location of acetabular labral tears (ALTs), edema at the musculotendinous junction of the iliopsoas insertion, femoral neck anteversion angle, femoral neck shaft angle, acetabular anteversion angle, alpha angle, lateral central edge angle (LCEA), acetabular index, and acetabular depth. Comparison analyses between groups were performed. Twenty-two patients had no ALTs (controls), 19 patients had AALTs, and 35 patients had ALTs not isolated at the 3 o'clock position (25 with cam-bony deformities [FAI-cam] and 10 with pincer-bony deformities [FAI-pincer]). The alpha angle mean was significantly higher (p < 0.001) in the FAI-cam group (62.7 , 95 % confidence interval [CI]: 56.2-69.2 ) compared with the AALTs group (46.9 , 95 % CI: 40.1-53.7 ). The LCEA mean was significantly higher (p < 0.001) in FAI-pincer group (41.9 , 95 % CI: 39.3 -44.5 ) compared to AALTs group (29.4 , 95 % CI: 24.2 -34.6 ). There was no statistically significant difference in any of the bony variables between the controls and the AALTs group. Our study demonstrated that AALTs are pathologically distinct and not associated with FAI or other bony abnormalities. This supports the previous studies, which proposed that AALTs are associated with IPI. (orig.)

  18. Changes in bone mineral density of the acetabulum, femoral neck and femoral shaft, after hip resurfacing and total hip replacement

    DEFF Research Database (Denmark)

    Penny, J O; Brixen, K; Varmarken, J E;

    2012-01-01

    It is accepted that resurfacing hip replacement preserves the bone mineral density (BMD) of the femur better than total hip replacement (THR). However, no studies have investigated any possible difference on the acetabular side. Between April 2007 and March 2009, 39 patients were randomised into ...

  19. Aumento acetabular pela técnica de Stahelli modificada Acetabular increase with modified Stahelli technique

    Directory of Open Access Journals (Sweden)

    Sílvio Pereira Coelho

    2000-09-01

    Full Text Available Os autores apresentam neste trabalho um estudo retrospectivo realizado em 18 pacientes submetidos a tratamento cirúrgico de insuficiência acetabular pela osteotomia da pelve seguindo a técnica descrita por Lynn T. Staheli. Enfatizam a modificação da técnica deste autor, com a introdução do enxerto ósseo, retirado da tábua externa do ilíaco, numa fenda aprofundada até cerca da cortical interna do ilíaco. Os pacientes foram acompanhados através de consultas ambulatoriais previamente a cirurgia e pós-operatoriamente com seguimento que variou de 2 meses a 4 anos no serviço de ortopedia infantil do Hospital Independência - Complexo Hospitalar ULBRA/Porto Alegre-RS. O objetivo do trabalho foi avaliar o quadril acometido pré e pós-operatoriamente, demonstrando a evolução e vantagens da variação da técnica de Staheli desenvolvida neste serviço. Observou-se que a cirurgia, se realizada sob técnica adequada e em mãos experientes, torna-se uma fonte válida de tratamento para aquelas patologias que levam a uma insuficiente cobertura da cabeça femoral.The authors present in this paper a retrospective study of eighteen patients treated surgically for insufficiency of the acetabular coverage with the shelf procedure according to Lynn T. Staheli. This study was done at the Service of Pediatric Orthopedics of Hospital Independência - Complexo Hospitalar ULBRA/Porto Alegre-RS. They call attention to the modification of the surgical technique in that the bone graft taken from outer cortex of the iliac bone, is deepened in the slot in the superior rim of the acetabulum. The follow-up ranged from two months to four years. The aim of this paper was to evaluate the affected hip pre and postoperatively showing the results and the advantages of the modified shelf technique. They observed that if the surgery is performed according to the correct technique and by an experienced surgeon, it is a very good alternative to the treatment of those

  20. Treatment of acetabular dysplasia by triple pelvic osteotomy and its short-term results

    OpenAIRE

    Dogan, Ahmet; Zorer, Gazi; Ozer, Utku Erdem

    2004-01-01

    Objectives: We evaluated the effect of triple pelvic osteotomy on acetabular coverage and its clinical implications by clinical and radiographic parameters in patients with acetabular dysplasia. Methods: Triple pelvic osteotomy was performed in 21 hips of 19 patients (13 females, 6 males; mean age during operation 16.3 years; range 8 to 32 years). Acetabular dysplasia was bilateral in two, and unilateral in 17 patients. Etiology was developmental dysplasia of the hip in 12 patients, Legg-C...

  1. Arthritic Pain Relief through Partial Knee Replacement

    Medline Plus

    Full Text Available ... remove a little bit of excess cement that creeps out. Generally, we remove this to make sure ... come into the office who ask about different types of partial knee replacements? Are there any other ...

  2. Arthritic Pain Relief through Partial Knee Replacement

    Medline Plus

    Full Text Available ... cementation, which, as Dr. McCauley mentioned before, basically acts as a gout to hold the components into ... training is that partial knee replacements don’t work in people with high body mass indexes or ...

  3. Arthritic Pain Relief through Partial Knee Replacement

    Medline Plus

    Full Text Available ... replacing. This is an artist's rendition of the prosthesis secured to the bone showing that only part ... is the bone cement, which helps secure the prosthesis into place. The real prosthesis is being tamped ...

  4. Validation of a new radiographic measurement of acetabular version: the transverse axis distance (TAD)

    International Nuclear Information System (INIS)

    This study has three aims: (1) validate a new radiographic measure of acetabular version, the transverse axis distance (TAD) by showing equivalent TAD accuracy in predicting CT equatorial acetabular version when compared to a previously validated, but more cumbersome, radiographic measure, the p/a ratio; (2) establish predictive equations of CT acetabular version from TAD; (3) calculate a sensitive and specific cut point for predicting excessive CT acetabular anteversion using TAD. A 14-month retrospective review was performed of patients who had undergone a dedicated MSK CT pelvis study and who also had a technically adequate AP pelvis radiograph. Two trained observers measured the radiographic p/a ratio, TAD, and CT acetabular equatorial version for 110 hips on a PACS workstation. Mixed model analysis was used to find prediction equations, and ROC analysis was used to evaluate the diagnostic accuracy of p/a ratio and TAD. CT equatorial acetabular version can accurately be predicted from either p/a ratio (p < 0.001) or TAD (p < 0.001). The diagnostic accuracies of p/a ratio and TAD are comparable (p =0.46). Patients whose TAD is higher than 17 mm may have excessive acetabular anteversion. For that cutpoint, the sensitivity of TAD is 0.73, with specificity of 0.82. TAD is an accurate radiographic predictor of CT acetabular anteversion and provides an easy-to-use and intuitive point-of-care assessment of acetabular version in patients with hip pain. (orig.)

  5. Validation of a new radiographic measurement of acetabular version: the transverse axis distance (TAD)

    Energy Technology Data Exchange (ETDEWEB)

    Nitschke, Ashley [University of Colorado School of Medicine, University of Colorado Denver, Division of Musculoskeletal Radiology, Department of Radiology, Aurora, CO (United States); Lambert, Jeffery R. [University of Colorado, Department of Biostatistics and Informatics, Colorado School of Public Health, Aurora, CO (United States); Glueck, Deborah H. [University of Colorado, Department of Biostatistics and Informatics, Colorado School of Public Health, Aurora, CO (United States); University of Colorado School of Medicine, University of Colorado Denver, Department of Radiology, Aurora, CO (United States); Jesse, Mary Kristen; Strickland, Colin [University of Colorado School of Medicine, University of Colorado Denver, Division of Musculoskeletal Radiology, Department of Radiology and Orthopaedics, Aurora, CO (United States); Mei-Dan, Omer [University of Colorado School of Medicine, University of Colorado Denver, Division of Sports Medicine and Hip Preservation, Department of Orthopaedics, Aurora, CO (United States); Petersen, Brian [University of Colorado School of Medicine, University of Colorado Denver, Division of Musculoskeletal Radiology, Department of Radiology and Orthopaedics, Aurora, CO (United States); Inland Imaging, Division of Musculoskeletal Radiology, Spokane, WA (United States)

    2015-11-15

    This study has three aims: (1) validate a new radiographic measure of acetabular version, the transverse axis distance (TAD) by showing equivalent TAD accuracy in predicting CT equatorial acetabular version when compared to a previously validated, but more cumbersome, radiographic measure, the p/a ratio; (2) establish predictive equations of CT acetabular version from TAD; (3) calculate a sensitive and specific cut point for predicting excessive CT acetabular anteversion using TAD. A 14-month retrospective review was performed of patients who had undergone a dedicated MSK CT pelvis study and who also had a technically adequate AP pelvis radiograph. Two trained observers measured the radiographic p/a ratio, TAD, and CT acetabular equatorial version for 110 hips on a PACS workstation. Mixed model analysis was used to find prediction equations, and ROC analysis was used to evaluate the diagnostic accuracy of p/a ratio and TAD. CT equatorial acetabular version can accurately be predicted from either p/a ratio (p < 0.001) or TAD (p < 0.001). The diagnostic accuracies of p/a ratio and TAD are comparable (p =0.46). Patients whose TAD is higher than 17 mm may have excessive acetabular anteversion. For that cutpoint, the sensitivity of TAD is 0.73, with specificity of 0.82. TAD is an accurate radiographic predictor of CT acetabular anteversion and provides an easy-to-use and intuitive point-of-care assessment of acetabular version in patients with hip pain. (orig.)

  6. Acetabular shell deformation as a function of shell stiffness and bone strength.

    Science.gov (United States)

    Dold, Philipp; Pandorf, Thomas; Flohr, Markus; Preuss, Roman; Bone, Martin C; Joyce, Tom J; Holland, James; Deehan, David

    2016-04-01

    Press-fit acetabular shells used for hip replacement rely upon an interference fit with the bone to provide initial stability. This process may result in deformation of the shell. This study aimed to model shell deformation as a process of shell stiffness and bone strength. A cohort of 32 shells with two different wall thicknesses (3 and 4 mm) and 10 different shell sizes (44- to 62-mm outer diameter) were implanted into eight cadavers. Shell deformation was then measured in the cadavers using a previously validated ATOS Triple Scan III optical system. The shell-bone interface was then considered as a spring system according to Hooke's law and from this the force exerted on the shell by the bone was calculated using a combined stiffness consisting of the measured shell stiffness and a calculated bone stiffness. The median radial stiffness for the 3-mm wall thickness was 4192 N/mm (range, 2920-6257 N/mm), while for the 4-mm wall thickness the median was 9633 N/mm (range, 6875-14,341 N/mm). The median deformation was 48 µm (range, 3-187 µm), while the median force was 256 N (range, 26-916 N). No statistically significant correlation was found between shell stiffness and deformation. Deformation was also found to be not fully symmetric (centres 180° apart), with a median angle discrepancy of 11.5° between the two maximum positive points of deformation. Further work is still required to understand how the bone influences acetabular shell deformation.

  7. Outcome of periacetabular osteotomy for the management of acetabular dysplasia: experience in an academic centre.

    LENUS (Irish Health Repository)

    Burke, Neil G

    2011-02-01

    Periacetabular osteotomy (PAO) is a very effective reconstructive procedure for treatment of acetabular dysplasia. An orthopaedic paediatric surgeon and a reconstructive hip arthroplasty surgeon performed this procedure together in the early phase of their learning curve and then performed it individually. The early clinical and radiographic results of 85 consecutive PAOs performed in this academic orthopaedic unit were reviewed. The mean Merle-d\\'Aubigné score increased from 12.4 preoperatively to 16 at follow-up. Pre-operatively 73 hips were anteverted and 12 were neutral or retroverted. The mean angle of Wiberg improved from 5 degrees to 21 degrees (p < 0.0001) in anteverted hips, and from 9 degrees to 30 degrees in neutral or retroverted hips. The mean angle of Lequesne and de Sèze improved from 6 degrees to 35 degrees (p < 0.0001) in anteverted hips, and in neutral or retroverted hips from 9 degrees to 30 degrees (p < 0.0001). The acetabular index improved from 26 degrees to 8 degrees (p < 0.0001) in anteverted hips, and from 21 degrees to 7 degrees (p < 0.0001) in neutral or retroverted hips. Over the 7 year period the blood loss and operative time improved from 2000 ml to 900 ml and 4 hours to 2 hours respectively. Four hips (four patients) required conversion to total hip replacement. The radiographic correction and improved clinical scores are similar to those in previous studies. This study shows a survival rate of 94% at 58 months following periacetabular osteotomy. The learning curve and the early results of this procedure performed in our academic unit are encouraging.

  8. PATHOLOGICAL AND MORPHOLOGICAL RESEARCH OF EXPERIMENTAL ACETABULAR DYSPLASIA

    Institute of Scientific and Technical Information of China (English)

    张自明; 马瑞雪; 吉士俊; 牛之彬

    2004-01-01

    Objective To investigate the pathological mechanism of hip dysplasia. Methods The left knee joints of eighteen rabbits were fixed in extending position with plaster cylinder for four weeks, but their hip joints were flexed. The right side served as control. Roentgenogram was made in all animals. The changes of the xray films and the pathological findings between left and right hips were compared. Results Appearance of hip dysplasia was obvious at four weeks after plaster fixation. There were pathological changes, including shallow acetabulum and flat femoral head, increased acetabular index and decreased acetabular head index on the x-ray films.Conclusion The hip dysplasia is the result of prolonged extending position of the knee joint. Abnormal knee posture seems to be one of the important factors of hip dysplasia. This kind of deformation may be worsened with time.

  9. Nonunion of acetabular fractures: evaluation with interactive multiplanar CT

    International Nuclear Information System (INIS)

    Nonunions involving fractures of the acetabulum are reportedly rare, with few citings and little discussion in the literature. It is possible that acetabular nonunions go undetected because imaging of the acetabulum is difficult by conventional radiography. We report two cases of fracture nonunion involving the weight-bearing surface of the acetabulum diagnosed with the aid of computed tomography (CT) and a newly developed interactive 2D/3D orthotool that uniquely processes and reformats routine CT data. The interactive 2D/3D orthotool is a sophisticated computer program that allows dynamic viewing of standard multiplanar reconstructions in the axial, coronal, and sagittal planes as well as multiple oblique projections. The 2D/3D orthotool provides on screen correlation of two-dimensional multiplanar images with three-dimensional reconstructions of the pelvis. The authors found this capability ideally suited for studying fractures with off-axis orientation such as those through the acetabular dome, greatly facilitating the diagnosis of nonunion

  10. Early total hip arthroplasty for severe displaced acetabular fractures

    Institute of Scientific and Technical Information of China (English)

    YANG Shu-hua; ZHANG Yu-kun; XU Wei-hua; LI Jin; LIU Guo-hui; YANG Cao; LIU Yong; TIAN Hong-tao

    2006-01-01

    Objective : To investigate the effect of early total hip arthroplasty for severe displaced acetabular fractures.Methods: Total hip arthroplasty was performed on 17 cases of severe fracture of the acetabulum from 1997 to 2003. The mean follow-up was 2.1 years (1-6 years) and the average period from fracture to operation was 8 days (5-21 day). The average age of the patients was 53 years (26-69 years).Results: At the final follow-up the Harris hip score averaged 82(69-100) points and 15 cases have got a good outcome. There was one case of heterotopic bone formation. There were no radiographic evidences of late loosening of the prosthesis. One patient had severe central displacement of the cup.Conclusions: In patients with severe displaced acetabular fractures, particularly in elderly patients, early total hip arthroplasty is probably an alternative efficient way to achieve a painless and stable hip.

  11. Acetabular prosthesis: Proff of migration with ruler and pencil?

    International Nuclear Information System (INIS)

    Conventional X-ray films were made with varying degrees of tilt of a pelvic phantom containing an acetabular prosthesis. The position of the prosthesis was then reconstructed graphically. The measurement errors were calculated and an estimate was made for the tilt. There is a linear correlation between the measurement error and the tilt of the prosthesis. Therefore a tilt dependent maximum error can be calculated. This error is very small for small degrees of tilt, so that acetabular migration can in this instance be evaluated with greater confidence than with other graphical methods. The error also correlates with the determination of the selected region of the acetabulum, but not with the position of the central focus spot or image magnification. (orig.)

  12. Multiplanar and 3D CT of acetabular fractures

    Energy Technology Data Exchange (ETDEWEB)

    Haveri, M.; Suramo, I.; Laehde, S. [Oulu Univ., Dept. of Diagnostic Radiology (Finland); Junila, J. [Oulu Univ., Dept. of Orthopaedic Surgery (Finland)

    1998-05-01

    Purpose: To establish a standard protocol for the multiplanar (MPR) and 3D shaded surface display (SSD) reconstruction of CT data on acetabular fractures, and to assess the usefulness of these reformats. Material and Methods: Acetabular fractures in 15 patients were imaged by means of plain radiographs, transaxial CT, MPR reformats, and SSD reformats. Results: The classification of the acetabular fracture was revised in 7/15 cases when the transaxial CT images were read after the plain radiographs. Although the MPR and SSD reformats did not alter the classification, they did add to the degree of confidence in the diagnosis in 9/15 cases. In 2 patients, the MPR and SSD reformats indicated operative instead of conservative treatment. In the MPR reformats, the following views were considered essential in all cases: (a) along the anterior column; (b) along the posterior column; and (c) along both columns and the inferior ramus. In the SSD reformats, the following views were considered essential in all cases: (d) the latero-caudal en face view into the acetabulum; and 180 opposite to this, (e) the medio-cranial view (facing the quadrilateral plate). In 10/15 cases, these views were all that was needed for classification. It was, however, essential to remove the femur from the images before reconstructing the SSD views. Conclusion: Complex acetabular fractures with displacement should be evaluated by means of transaxial CT and additional MPR and SSD reformats. The use of appropriate standard MPR and SSD views shortens the time required to produce the reformats and thereby maximizes the benefit gained. (orig.).

  13. Transosseous Acetabular Labral Repair as an Alternative to Anchors

    OpenAIRE

    Pérez-Carro, Luis; Cabello, Andres Gonzalez; Rakha, Mohamed Ibrahim; Patnaik, Sarthak; Centeno, Elias; Miranda, Victor; Fernández, Ana Alfonso

    2015-01-01

    Labral tears are the most common pathology in patients undergoing hip arthroscopy and the most common cause of mechanical hip symptoms. Labral repair techniques have been described in the literature using suture anchors placed as close as possible to the acetabular rim without penetrating the articular surface. Optimal surgical technique for labral repair is very important, and an inappropriate entry point and guide angulation may lead to intra-articular penetration of the anchor, chondral da...

  14. Imaging diagnosis of acetabular dysplastic coxarthrosis in adult

    International Nuclear Information System (INIS)

    Objective: To investigate the imaging diagnosis of acetabular dysplastic coxarthrosis. Method: The imaging of the acetabular dysplasia was analyzed in 51 patients (87 hips). All but four patients were women. The age ranged from 22 to 78 years, and the mean age was 42.6 years. Pelvis radiographs were studied in all cases, and CT scan was performed in 18 cases and MRI in 10 cases. Results: The fundamental signs on the plain film included shallow acetabulum, increased obliquity and insufficient coverage of the femoral head by the acetabulum. The CE angles were determined in all the cases, ranging from -10 degree to 30 degree, mean 12.9 degree. The sharp angles ranged from 35 degree to 67 degree, mean 45.3 degree. The secondary osteoarthritis were revealed in 75 hips (84.2%). 54 hips (62.1%) had cyst-like lesions in weight-bear area of the acetabulum or femoral head. 19 hips had subluxation of femoral head. CT and MRI displayed small cyst-like lesions and forward shift of the femoral head, which could not be shown on plain film, respectively in 13 and 10 hips. Conclusion: The cyst-like lesion of subarticular region is a common sign in acetabular dysplastic coxarthrosis. CT or MRI can show the early osteolytic lesion and forward subluxations

  15. The influence of cement mantle thickness and stem geometry on fatigue damage in two different cemented hip femoral prostheses.

    Science.gov (United States)

    Ramos, A; Simões, J A

    2009-11-13

    Experimental models can be used for pre-clinical testing of cemented and other type of hip replacements. Total hip replacement (THR) failure scenarios include, among others, cement damage accumulation and the assessment of accurate stress and strain magnitudes at the cement mantle interfaces (stem-cement and cement-bone) can be used to predict mechanical failure. The aseptic loosening scenario in cemented hip replacements is currently not fully understood, and methods of evaluating medical devices must be developed to improve clinical performance. Different results and conclusions concerning the cement micro-cracking mechanism have been reported. The aim of this study was to verify the in vitro behavior of two cemented femoral stems with respect to fatigue crack formation. Fatigue crack damage was assessed at the medial, lateral, anterior and posterior sides of the Lubinus SPII and Charnley stems. All stems were loaded and tested in stair climbing fatigue loading during one million cycles at 2 Hz. After the experiments each implanted synthetic femur was sectioned and analyzed. We observed more damage (cracks per area) for the Lubinus SPII stem, mainly on the proximal part of the cement mantle. The micro-cracking formation initiated in the stem-cement interface and grew towards the direction of cortical bone of the femur. Overall, the cement-bone interface seems to be crucial for the success of the hip replacement. The Charnley stem provoked more damage on the cement-bone interface. A failure index (maximum length of crack/maximum thickness of cement) considered was higher for the cement-stem interface of the Lubinus SPII stem. For a cement mantle thickness higher than 5 mm, cracking initiated at the cement-bone interface and depended on the opening canal process (reaming procedure and instrumentation). The analysis also showed that fatigue-induced damage on the cement mantle, increasing proximally, and depended on the axial position of the stem. The cement

  16. Ankle replacement

    Science.gov (United States)

    ... to the cut bony surfaces. A special glue/bone cement may be used to hold them in place. A piece of plastic is then inserted between the two metal parts. Screws maybe placed to stabilize your ankle. The surgeon ...

  17. Acrylic Bone Cements Modified with Starch

    OpenAIRE

    Krilova, V; Vītiņš, V

    2010-01-01

    The successful result of restorative and replacement surgical operation depends significantly on properties of used bone cement. Acrylic bone cements are usually based on methylmethacrylate polymer, while monomer polymerization begins after mixing of components in mixing device and terminates in living tissue. Polymerization of methylmethacrylate is exothermic process, and temperature increase might cause tissue necrosis with concomitant implant aseptic loosening. Developed non-ionogenic and ...

  18. Pelvic Discontinuity Caused by Acetabular Overreaming during Primary Total Hip Arthroplasty

    Directory of Open Access Journals (Sweden)

    Iori Takigami

    2011-01-01

    Full Text Available Intraoperative acetabular fracture is a rare complication of primary total hip arthroplasty (THA, typically occurring during impaction of the cementless acetabular component. Here we report an unusual case of pelvic discontinuity caused by overreaming of the acetabulum during primary THA. Restoration of posterior columnar continuity was achieved with an autologous fibular graft and a reconstruction plate. Wall defects and cavitary defects were reconstructed with metal mesh and femoral head allograft, followed by placement and fixation of a Kerboull-type acetabular reinforcement device. Previous reports of acetabular fracture during THA have indicated that it has a relatively good prognosis without extensive treatment. However, to our knowledge, there has been no report of pelvic discontinuity necessitating acetabular reconstruction surgery as an intraoperative complication of primary THA.

  19. The importance of a thick cement mantle depends on stem geometry and stem-cement interfacial bonding.

    Science.gov (United States)

    Caruana, J; Janssen, D; Verdonschot, N; Blunn, G W

    2009-04-01

    The thickness of the cement mantle around the femoral component of total hip replacements is a contributing factor to aseptic loosening and revision. Nevertheless, various designs of stems and surgical tooling lead to cement mantles of different thicknesses. Opinion is divided on whether a thick mantle enhances implant longevity. This study investigates the effect of cement mantle thickness on accumulated damage in the cement, and how this is influenced by the presence or absence of a proximal collar and on whether the stem-cement interface remains bonded. Three-dimensional finite element simulations incorporating creep and non-linear damage accumulation were performed to investigate cracking in the cement mantles around Stanmore Hips under physiologically informed stair-climbing and gait loads. Cement mantle thickness, stem-cement interfacial bonding, and collar design were varied to assess the interactive effects of these parameters. In all cases, damage levels were three to six times higher when the stem-cement interface remained bonded. Cement mantle thickness had little effect on cement damage accumulation around debonded collared stems but was critical in both bonded and collarless cases, where a thicker mantle reduced cement cracking. Damage around a smooth debonded stem with a collar is thus much less sensitive to cement thickness than around bonded or collarless stems. PMID:19405437

  20. INFLUENCE OF GLASS CULLET IN CEMENT PASTES

    Institute of Scientific and Technical Information of China (English)

    A.Karamberi; E.Chaniotakis; D.Papageorgiou; A.Moutsatsou

    2006-01-01

    The present study investigates glass and cement compatibility with a view to use glass as a cement replacement. Amber, flint and green glasses were chosen due to their prevalence in the Greek market as packaging materials. The factors under investigation were the pozzolanicity of the glass cullet, the hydration rate and the mechanical strength development of the cement pastes, as well as the expansion of the specimens due to alkali-silica reaction.Moreover, the potential enhancement of glass pozzolanic activity was examined. The results of the study were encouraging to show the potentiality of utilising glass cullet in cementitious products.

  1. Comparison of acetabular version angle measurements between prone and reformatted supine computed tomography images

    Energy Technology Data Exchange (ETDEWEB)

    Chong, Le Roy [Changi General Hospital, Department of Radiology, Singapore (Singapore); Too, Chow Wei [Singapore General Hospital, Department of Diagnostic Radiology, Singapore (Singapore)

    2014-03-15

    To compare acetabular version angle measurements of CT scans in the prone and reformatted supine positions. CT acetabular version angle measurements have previously been done in the prone position to correct for pelvic tilt. With the advent of multidetector CT, recent studies have evaluated acetabular version angles measured in the supine position. To our knowledge, a comparison between these two approaches has not been performed. Case series in which consecutive CT urography studies of 49 adult patients performed in both prone and supine positions were retrospectively reviewed, and acetabular version angles of both hips measured. Retrospective review of 49 consecutive CT urography studies performed in both prone and supine positions was done, and acetabular version angles of both hips were measured. Two radiologists measured the acetabular version angles independently. Multiplanar reformation of the supine CT images was performed to compensate for pelvic tilt and rotation prior to angle measurements. There was excellent interobserver agreement between the two readers (ICC = 0.90). Acetabular version angle measurements from the prone CT images were larger compared to reformatted supine images (24.0 and 21.3 , respectively, p < 0.0001), with greater angles found in women. There was strong correlation between supine and prone acetabular version angle measurements with a Pearson correlation coefficient of 0.743. Acetabular version angles measured from prone and reformatted supine CT images show strong correlation but are significantly different with larger angles obtained from the former and in women; clinical implications of these findings may require further study in other to determine the best method of version angle measurement. CT acetabular version angle measurement is also reliable with excellent interobserver correlation. (orig.)

  2. Slagment Cement Improve the Cement Resistance Toward Acids Attack During Acidizing Treatment

    Directory of Open Access Journals (Sweden)

    Nik Khairul Irfan Bin Nik Ab. Lah.

    2013-05-01

    Full Text Available Acidizing treatment in past experience shows several zonal isolation problems after the treatment. This study presents the effect of the acid treatment toward class G cement and slagment cement as the improvement method to improve the cement resistance toward the acid. Lab experiments were conducted by immerge the respective cement cubes into 12% HCl/3% HF solution for 40 min before several analysis were conducted. Based on the result, the mass loss and compressive strength loss of the cement cubes decrease as the curing temperature and pressure increase due to more evenly distributed cement chemical composition crystal in high curing condition as shown in Scanning Electron Microscopy (SEM analysis. From X-Ray Diffraction (XRD and X-Ray Fluorescence (XRF analysis, only the first layer of the cement cubes shows chemical component change due to the reaction between the acid. This study found that, replacing class G cement to slagment cement can reduce the mass loss and compressive strength loss up to 72% and 82%, respectively.

  3. The use of cementless acetabular component in revision surgery without pelvic discontinuity.

    Science.gov (United States)

    Cherubino, Paolo; D'Angelo, Fabio; Surace, Michele Francesco; Murena, Luigi; Vulcano, Ettore

    2010-10-01

    Reconstruction of the failed acetabular component in total hip arthroplasty (THA) can be challenging. Although there are multiple reconstructive options available, a cementless acetabular component inserted with screws has been shown to have good intermediate-term results and is the reconstructive method of choice for the majority of acetabular revisions This reconstruction is feasible provided at least 50% of the implant contacts host bone. When such contact is not possible, and there is adequate medial and peripheral bone, techniques using alternative uncemented implants can be used for acetabular reconstruction. An uncemented cup can be placed at a "high hip center." Alternatively, the acetabular cavity can be progressively reamed to accommodate extra-large cups. Oblong cups, which take advantage of the oval-shaped cavity resulting from many failed acetabular components, can also be used. The success of these cementless techniques depends on the degree and location of bone loss. The correct indication to revision and the choice of the correct implant is the keystone for the success of this type of surgery and follows an accurate preoperative planning in order to understand the specific pathologic scenario. The aim of this paper is to review some technical options for the revision of the acetabular component also taking into account our personal experiences and series. PMID:21082580

  4. Magnesium oxychloride cement concrete

    Indian Academy of Sciences (India)

    A K Misra; Renu Mathur

    2007-06-01

    The scope of magnesium oxychloride (MOC) cement in concrete works has been evaluated. MOC cement concrete compositions of varying strengths having good placing and finishing characteristics were prepared and investigated for their compressive and flexural strengths, -values, abrasion resistance etc. The durability of MOC concrete compositions against extreme environmental conditions viz. heating–cooling, freezing–thawing, wetting–drying and penetration and deposition of salts etc were investigated. The results reveal that MOC concrete has high compressive strength associated with high flexural strength and the ratio of compressive to flexural strength varies between 6 and 8. The elastic moduli of the compositions studied are found to be 23–85 GPa and the abrasion losses between 0.11 and 0.20%. While alternate heating–cooling cycles have no adverse effect on MOC concrete, it can be made durable against freezing–thawing and the excessive exposure to water and salt attack by replacing 10% magnesium chloride solution by magnesium sulphate solution of the same concentration.

  5. FUNCTIONAL OUTCOME OF SURGICAL MANAGEMENT OF ACETABULAR FRACTURES BY INTERNAL FIXATION

    Directory of Open Access Journals (Sweden)

    Sagar

    2015-06-01

    Full Text Available BACKGROUND: The treatment of acetabular fractures has seen major advances in the field of orthopaedic traumatology. Conservative treatment of acetabular fractures leads to poor results. Newer diagnostic tools like the Computed Tomography (CT scan help in analyzing the three dimensional disturbance in the normal anatomy and plan the surgical management accordingly. In recent years operative treatment has become the treat ment of choice in the management of acetabular fractures as precise anatomical reduction with adequate internal fixation can be attained. OBJECTIVES : To evaluate the functional outcome of operatively managed acetabular fractures , and assess the efficacy of operative fixation of acetabular fractures , and also study the complications of operative fixation of acetabular fractures. MATERIALS AND METHODS: Fifty five patients (49 male & six female admitted to Sanjay Gandhi Institute of Trauma and Orthopaedics wi th acetabular fractures underwent open reduction and internal fixation. All patients were evaluated with Matta et al score with a minimum of follow up of six months. RESULTS: There were 24 (43.6% patients with bicolumnar fractures , 15(27.3% had posterior column fractures , 10(18.1% had posterior wall fractures , five (9.1% had transverse fractures , and one (1.8% patient had an anterior column fracture. Full weight bearing was attained in thirty five (63.6% patients in 16 weeks and in twenty (36.4% pati ents after 16 weeks. Forty five (81.8% patients were free of complications. According to Matta et al score 27(49.1% had excellent , 15(27.3% had good , nine (16.4% had fair , and four (7.3% had poor results. CONCLUSION: Open reduction and internal fixati on of acetabular fractures is a reliable technique , minimizes healing time and provides congruent joint reduction. Operative treatment of acetabular fractures results in predictable union and good clinical results with a low rate of complications.

  6. Massive acetabular bone loss: Limits of trabecular metal cages

    Directory of Open Access Journals (Sweden)

    Villanueva-Martínez Manuel

    2011-01-01

    Full Text Available Massive acetabular bone loss (more than 50% of the acetabular area can result in insufficient native bone for stable fixation and long-term bone ingrowth of conventional porous cups. The development of trabecular metal cages with osteoconductive properties may allow a more biological and versatile approach that will help restore bone loss, thus reducing the frequency of implant failure in the short-to-medium term. We report a case of massive bone loss affecting the dome of the acetabulum and the ilium, which was treated with a trabecular metal cage and particulate allograft. Although the trabecular metal components had no intrinsic stability, they did enhance osseointegration and incorporation of a non-impacted particulate graft, thus preventing failure of the reconstruction. The minimum 50% contact area between the native bone and the cup required for osseointegration with the use of porous cups may not hold for new trabecular metal cups, thus reducing the need for antiprotrusio cages. The osteoconductive properties of trabecular metal enhanced allograft incorportation and iliac bone rebuilding without the need to fill the defect with multiple wedges nor protect the reconstruction with an antiprotrusio cage.

  7. Acetabular fractures following rugby tackles: a case series

    LENUS (Irish Health Repository)

    Good, Daniel W

    2011-10-05

    Abstract Introduction Rugby is the third most popular team contact sport in the world and is increasing in popularity. In 1995, rugby in Europe turned professional, and with this has come an increased rate of injury. Case presentation In a six-month period from July to December, two open reduction and internal fixations of acetabular fractures were performed in young Caucasian men (16 and 24 years old) who sustained their injuries after rugby tackles. Both of these cases are described as well as the biomechanical factors contributing to the fracture and the recovery. Acetabular fractures of the hip during sport are rare occurrences. Conclusion Our recent experience of two cases over a six-month period creates concern that these high-energy injuries may become more frequent as rugby continues to adopt advanced training regimens. Protective equipment is unlikely to reduce the forces imparted across the hip joint; however, limiting \\'the tackle\\' to only two players may well reduce the likelihood of this life-altering injury.

  8. Para-acetabular peritendinitis calcarea; its radiographic manifestations

    International Nuclear Information System (INIS)

    Peritendinitis calcarea and os acetabuli have long been confused during interpretations of hip-joint radiographs. Such confusion is reflected in the medical literature. The present study differentiated these two entities according to their interval radiographic progression and regression. There were 137 instances of para-acetabular calcifications among 110 subjects (59 men and 51 women), whose mean age was 46.8 years at the time of their initial detection. Twenty-six of the subjects had lumbago, which was probably unrelated. Other abnormalities including narrowed intervertebral spaces, scoliosis, and spondylolysis were observed in 21 of the subjects. These could have been responsible for any symptoms they had had, but none of the subjects complained of local hip-joint pain when the radiographs in question were made. Ninety-three of these instances of calcification were reviewed by means of serial radiographs. Interval changes in the sizes and shapes of the calcifications occurred among 90 of them, indicative of the latent type of peritendinitis calcarea. No interval changes were noted in the remaining three cases, indicating they were secondary ossification centers; namely, os acetabuli. This study showed that in asymptomatic adults, most para-acetabular calcifications were really not os acetabuli, but actually peritendinitis calcarea. (author)

  9. Rapid porcelain veneers: smile design, preparation, and cementation.

    Science.gov (United States)

    Javaheri, D S

    2001-11-01

    A technique for replacing existing porcelain veneers has been presented. Technique for smile design, tooth preparation, and cementation were described. The objective was to meet the patient's aesthetic expectations while also meeting functional requirements.

  10. 21 CFR 888.3800 - Wrist joint metal/polymer semi-constrained cemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... cemented prosthesis. 888.3800 Section 888.3800 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Wrist joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. A wrist joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace a wrist...

  11. 21 CFR 888.3480 - Knee joint femorotibial metallic constrained cemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... cemented prosthesis. 888.3480 Section 888.3480 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Knee joint femorotibial metallic constrained cemented prosthesis. (a) Identification. A knee joint femorotibial metallic constrained cemented prosthesis is a device intended to be implanted to replace part of...

  12. 21 CFR 888.3110 - Ankle joint metal/polymer semi-constrained cemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... cemented prosthesis. 888.3110 Section 888.3110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Ankle joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. An ankle joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace an...

  13. 21 CFR 888.3160 - Elbow joint metal/polymer semi-constrained cemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... cemented prosthesis. 888.3160 Section 888.3160 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Elbow joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. An elbow joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace an...

  14. 21 CFR 888.3340 - Hip joint metal/composite semi-constrained cemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... cemented prosthesis. 888.3340 Section 888.3340 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Hip joint metal/composite semi-constrained cemented prosthesis. (a) Identification. A hip joint metal/composite semi-constrained cemented prosthesis is a two-part device intended to be implanted to replace...

  15. 21 CFR 888.3100 - Ankle joint metal/composite semi-constrained cemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... cemented prosthesis. 888.3100 Section 888.3100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Ankle joint metal/composite semi-constrained cemented prosthesis. (a) Identification. An ankle joint metal/composite semi-constrained cemented prosthesis is a device intended to be implanted to replace...

  16. [Acetabular Osteolysis in Total Hip Replacement - When to Retain the Cup?].

    Science.gov (United States)

    Lutz, B; Faschingbauer, M; Bieger, R; Reichel, H; Kappe, T

    2016-08-01

    Periacetabular osteolysis is a frequent long-term complication of cementless total hip arthroplasty. The decision whether to retain or to revise a cup in the presence of osteolysis remains a challenge. The options are regular clinical and radiological check-ups, isolated liner exchange with and without bone grafting, and complete cup revision. Thorough preoperative diagnostics, including a medical history, examination and imaging, are mandatory for correct decision making. In most patients, computed tomography is useful to assess periacetabular osteolysis. If the cup is well-fixed and positioned in an asymptomatic patient without progressive osteolysis and no implant defect or higher grade polyethylene wear and no signs of infection, continuous clinical and radiological monitoring is preferred. If imaging reveals cup loosening, malposition, osteolysis localised in a weight-bearing area, imminent or present periprosthetic fractures, rapid progressive osteolysis, implant defects or massive inlay wear, surgical treatment may be preferred. Cup revision is usually performed in such patients. If the cup is well-positioned and well-fixed in the X-ray, the procedure has to be discussed with the patient individually. Apart from patient-specific risk factors, the risk of further progression has to be assessed. Isolated liner exchange can be performed if the patient is asymptomatic and the cup proves to be stable intraoperatively. It is still unclear whether filling osteolyses through screw holes or osseous windows is of long-term benefit. PMID:27249047

  17. Calcium phosphate cements properties with polymers addition

    International Nuclear Information System (INIS)

    Calcium phosphate cements (CPC) have attracted great interest to use in orthopedics and dentistry as replacements for damaged parts of the skeletal system, showing good biocompatibility and osseointegration, allowing its use as bone graft. Several studies have shown that the addition of polymer additives have a strong influence on the cement properties. The low mechanical strength is the main obstacle to greater use of CPC as an implant material. The objective of this study was to evaluate properties of a cement based on α-tricalcium phosphate (α-TCP), added polymers. PVA (10%, 8%, 6%), sodium alginate (2%) and polyacrylate ammonia (3%), all in weight, were added to the synthesized α-TCP powder. The samples were molded and evaluated for density, porosity in vitro test (Simulated Body Fluid), crystalline phases and mechanical strength. The results show increased the mechanical properties of the cement when added these polymers

  18. Production of cement requiring low energy expenditure. An industrial test

    Energy Technology Data Exchange (ETDEWEB)

    Gimenez, S.; Blanco, M.T.; Palomo, A.; Puertas, F. (Instituto de Ciencias de la Construccion, Madrid (Spain))

    1991-01-01

    A new method for making cement is proposed. It is based on the use of CaF{sub 2} and CaSO{sub 4} for partial replacement of the usual raw materials in cement manufacturing. This paper shows the feasibility of the proposed method on an industrial scale. A test carried out in a Spanish cement factory (1500 t yield of the new cement) has revealed that the mehtod can not only be adapted to the current technology but also requires a much lower energy expenditure. The final product is shown to have excellent properties in comparison with OPC. (orig.).

  19. Development and clinical trial of a novel bioactive bone cement

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Strontium(Sr)and related compounds have become more attractive in the prevention and treatment of osteoporosis.Previously,we developed a novel bioactive bone cement which is mainly composed of strontium-containing hydroxyapatite(Sr-HA)filler and bisphenol A diglycidylether dimethacrylate(Bis-GMA)resin.This bone cement is superior to conventional polymethylmethacrylate (PMMA)bone cement in bioactivity,biocompatibility,and osseointegration.It also has shown sufficient mechanical strength properties for its use in percutaneous vertebroplasty(PVP)and total hip replacement(THR).In this paper,we review the in vitro,in vivo and clinical evidence for the effectiveness of this bioactive bone cement.

  20. A reduction clamp for an aiming component in associated acetabular fractures

    Directory of Open Access Journals (Sweden)

    Zhang-Fu Wang

    2015-01-01

    Full Text Available Background: The treatment of acetabular fractures is complex and requires specialized equipment. However, all currently available instruments have some disadvantages. A new reduction clamp that can firmly enable reduction and not hinder subsequent fixation procedures for some special fracture types is needed. Materials and Methods: In this study, we introduce a new acetabular clamp and its preliminary clinical application in three T-shaped acetabular fractures. Results: This new clamp can successfully pull the posterior column back to the anterior column and firmly maintain the reduction. This clamp′s aiming plate can facilitate the insertion of long lag screws. The clamp is also easy to assemble and use. Conclusion: This reduction clamp is a useful instrument that can facilitate open reduction and internal fixation of acetabular fractures.

  1. Comparison of acetabular reamings during hip resurfacing versus uncemented total hip arthroplasty.

    LENUS (Irish Health Repository)

    Brennan, S A

    2009-04-01

    PURPOSE: To compare the quantity of bone removed from the acetabulum during resurfacing hip arthroplasty versus uncemented total hip arthroplasty (THA). METHODS: 62 consecutive patients with osteoarthritis of the hip were prospectively studied. 24 men and 7 women aged 40 to 86 (mean, 59) years underwent Birmingham hip resurfacing. 13 men and 18 women aged 34 to 88 (mean, 61) years underwent uncemented THA using the trident acetabular cup. Obese elderly women at risk of femoral neck fracture and patients with large subchondral pseudocysts or a history of avascular necrosis of the femoral head were assigned to uncemented THA. Acetabular reamings were collected; marginal osteophytes were not included. The reamings were dehydrated, defatted, and weighed. RESULTS: The mean weight of acetabular reamings was not significantly different between patients undergoing hip resurfacing and uncemented THA (p=0.57). CONCLUSION: In hip resurfacing, the use of an appropriately small femoral component avoids oversizing the acetabular component and removal of excessive bone stock.

  2. Cement with silica fume and granulated blast-furnace slag: strength behavior and hydration

    OpenAIRE

    Bonavetti, V. L.; Castellano, C.; Donza, H.; Rahhal, V. F.; Irassar, E. F.

    2014-01-01

    This paper analyses the influence of portland cement replacement by silica fume (up to 10%) and/or granulated blast furnace slag (up to 70%) on the hydration cement (XRD, heat of hydration, non evaporable water content and calcium hydroxide content) curing under sealed conditions and their effect on the mechanical strength. The obtained results indicate that binary cements containing silica fume and ternary cements there was a significant increase of hydration rate at early age. At later a...

  3. EFFECT OF NATURAL ZEOLITE ON THE COMPRESSIVE STRENGTH AND FREEZE-THAW RESISTANCE OF PORTLAND CEMENT

    OpenAIRE

    Bayartsetseg, E.; Lkhagvajargal, G.; Batgerel, D.; Sarangerel, D.; Ochirkhuyag, B

    2011-01-01

    Effects of zeolites in various natural deposits as replacement cementing material on mechanical performance of Portland cement were studied. The blended cement pastes with zeolites were cured at room temperature in air for various durations (1, 7 and 28 days). Mechanical performance of the blended cement samples such as setting time, volume of water, compressive strength, normal consistency and freeze-thaw resistance of the mortar are determined. The optimal substitution ratio was 20 wt. % of...

  4. Treatment of severe bone deficiency in acetabular revision surgery using a reinforcement device and bone grafting

    Institute of Scientific and Technical Information of China (English)

    ZHAI Ji-liang; LIN Jin; JIN Jin; QIAN Wen-wei; WENG Xi-sheng

    2011-01-01

    Background Severe acetabular bone deficiency is a major challenge in acetabular revision surgery. Most cases require reconstruction of the acetabulum with bone grafting and a reinforcement device. The purpose of this study was to evaluate the results of this procedure for severe acetabular bone deficiency in acetabular revision surgery.Methods This study involved 12 patients (2 males and 10 females) with severe acetabular bone defects who underwent implantation of a reinforcement device (ring or cage) and bone grafting between February 2003 and October 2008. Using the Paprosky classification, 2 cases were Paprosky ⅡC, 6 were ⅢA, and 4 were ⅢB. The mean age at the time of surgery was 63.0 years (range, 46-78 years). During revision surgery, a reinforcement ring was implanted in 6patients, and a cage in 6 patients. The clinical and radiographic results were evaluated retrospectively. The mean duration of follow-up was 37 months (range, 9-71 months).Results The average Harris Hip Score improved from 35.2 preoperatively to 82.9 at the time of the final follow-up visit.The results were excellent in 8 hips (66.7%), good in 2 (16.7%), and fair in 2 (16.7%). Osteolysis was found in 1 case, but did not worsen. Three patients had yellow wound effusion, with healing after administration of dressing changes,debridement, and antibiotics. Dislocation occurred in a 62-year-old woman. Closed reduction was performed, and dislocation did not recur. There was no evidence of intraoperative acetabular fracture, nerve injury, ectopic ossification,aseptic loosening, or infection.Conclusion Reconstruction with a reinforcement device and bone grafting is an effective approach to the treatment of acetabular bone deficiency in acetabular revision surgery, given proper indications and technique.

  5. SeIectlng the incision In the surgical treatment of acetabular fractures

    OpenAIRE

    Asik, Mehmet; Basturk, Sırrı; Akpinar, Sercan; Taser, Omer; Akalin, Yilmaz

    2004-01-01

    In acetabular fractures which may have totally differing three dimensional appearances selecting the incision directly influences the quality, directly influences the quality of the surgical reduction and, therefore, the postoperative clinical outcome of the patierit. Becauseof this, it is a subject that has to be meticulously done. According to the fracture types, we used 6 distinct incisions on the 35 acetabular fractures which were operated in our clinic between 1988 and 1992. We presente...

  6. A novel classification to guide total hip arthroplasty for adult acetabular dysplasia

    OpenAIRE

    Zhu, Chen; CHENG, MENG-QI; Cheng, Tao; MA, RUI-XIANG; Kong, Rong; GUO, YONG-YUAN; Qin, Hui; SHI, SI FENG; Zhang, Xian-long

    2013-01-01

    In the field of hip arthroplasties, the secondary fixation of the implants depends directly on the quality of the primary stability. A good acetabular fit and metaphyseal filling between the prostheses and implants improve the initial stabilization, and optimize the transmission of forces to the bone. A precise knowledge of the three-dimensional acetabular or femoral shape is essential to the selection of adapted implants. A total of 63 patients diagnosed with developmental dysplasia were ana...

  7. Numerical modelling of the pelvis and acetabular construct following hip arthroplasty

    OpenAIRE

    Phillips, Andrew T. M.

    2005-01-01

    The study presents finite element models of the acetabular construct and the pelvis. Particular attention is given to investigating the behaviour of the acetabular construct following revision hip arthroplasty, carried out using the Slooff-Ling impaction grafting technique. Mechanical tests are carried out on bone graft, and constitutive models are developed to describe its non-linear elasto-plastic behaviour, for inclusion in finite element analyses. Impaction of bone graft was found to have...

  8. Radiologic analysis of femoral acetabular impingement: from radiography to MRI

    Energy Technology Data Exchange (ETDEWEB)

    Dwek, Jerry R. [University of California at San Diego, Department of Radiology, Rady Children' s Hospital and Health Center, San Diego, CA (United States); San Diego Imaging, San Diego, CA (United States); Monazzam, Shafagh [Rady Children' s Hospital and Health Center, Department of Orthopedics, San Diego, CA (United States); Chung, Christine B. [University of California at San Diego, Department of Radiology, San Diego, CA (United States)

    2013-03-15

    Femoral acetabular impingement is a set of morphologic abnormalities that are considered to be a major cause of degenerative disease in the hip joint. Early changes are already present in adolescence when it is the pediatric radiologist who must assess current damage with the aim of averting progression to more severe and debilitating osteoarthritis. A multimodality approach is used for diagnosis, that includes conventional radiography and CT to assess the osseous structures. MR arthrography is the primary advanced imaging modality for assessment of morphologic changes as well as injuries of the labrum and articular cartilage. Details of radiologic imaging are offered to guide the radiologist and provide an avenue for the accurate description of the osseous and articular alterations and injury. (orig.)

  9. Computerized tomography in evaluation of decreased acetabular and femoral anteversion

    International Nuclear Information System (INIS)

    Computerized tomography has received a new importance. It has been shown that decreased anteversion of femur and acetabulum, when both have decreased angles, are causing pain and osteoarthritis of the hip joint. Operative treatment should be performed before osteoarthritis develops. Exact measurements therefore are necessary. The investigation should be performed in prone position to have the pelvis lying in a defined and normal position. Femoral torsion is measured between the transverse axis of the knee and the femoral neck. The transverse axis for measurement of the femoral anteversion is defined by a rectangular line to the sagittal plane. For evaluation of the femoral anteversion in total the angle of the condyles has to be added to the femoral neck angle when the knee is found in internal rotation. Acetabular anteversion should be measured at the level where the femoral head is still in full contact and congruence with the anterior margin of the acetabulum. (orig.)

  10. Patient-specific acetabular shape modelling: comparison among sphere, ellipsoid and conchoid parameterisations.

    Science.gov (United States)

    Cerveri, Pietro; Manzotti, Alfonso; Baroni, Guido

    2014-04-01

    The shape of the human acetabular cup was commonly represented as a hemisphere, but different geometries and patient-specific shapes have been recently proposed in the literature. Our aim was to test the limits of the sphericity assumption by comparing three different parameterisations, namely the sphere, the ellipsoid and the rotational conchoid. Models of hip surfaces, reconstructed from CT scans taken from Caucasian race cadavers and patients, were automatically processed to extract the acetabular surface. Two separate analyses were carried out on the overall acetabular shape, including both the acetabular fossa and the lunate surface (case A) and acetabular cup represented by the lunate surface only (case B). Nonlinear gradient-based and evolutionary computation approaches were implemented for the fitting process. Minor differences from the three idealised geometries were detected (median values of the fitting errors different from both the ellipsoid (p difference was detected between the ellipsoid and the conchoid for case A. Significance of the difference between ellipsoid and sphere (p difference was detected between the ellipsoid and the conchoid. In conclusion, we synthesise that the morphology of the overall acetabular cup can be parameterised both with an ellipsoid shape and with a conchoid shape as well with superior quality than the simple sphere. Differently, if one considers just the lunate surface, better fitting results are expected when using the ellipsoid. PMID:22789071

  11. Three-dimensional computed tomography analysis of non-osteoarthritic adult acetabular dysplasia

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Hiroshi; Matsuno, Takeo; Hirayama, Teruhisa; Tanino, Hiromasa; Yamanaka, Yasuhiro [Asahikawa Medical College, Department of Orthopaedic Surgery, Asahikawa (Japan); Minami, Akio [Hokkaido University School of Medicine, Department of Orthopaedic Surgery, Sapporo (Japan)

    2009-02-15

    Little data exists on the original morphology of acetabular dysplasia obtained from patients without radiographic advanced osteoarthritic changes. The aim of this study was to investigate the distribution and degree of acetabular dysplasia in a large number of patients showing no advanced degenerative changes using three-dimensional computed tomography (3DCT). Eighty-four dysplastic hips in 55 consecutive patients were studied. All 84 hips were in pre- or early osteoarthritis without radiographic evidence of joint space narrowing, formation of osteophytes or cysts, or deformity of femoral heads. The mean age at the time of CT scan was 35 years (range 15-64 years). 3D images were reconstructed and analyzed using recent computer imaging software (INTAGE Realia and Volume Player). Deficiency types and degrees of acetabular dysplasia were precisely evaluated using these computer software. The average Harris hip score at CT scans was 82 points. Twenty-two hips (26%) were classified as anterior deficiency, 17 hips (20%) as posterior deficiency, and 45 hips (54%) as lateral deficiency. No significant difference was found in the Harris hip score among these groups. The analysis of various measurements indicated wide variations. There was a significant correlation between the Harris hip score and the acetabular coverage (p < 0.001). Our results indicated wide variety of deficiency type and degree of acetabular dysplasia. Hips with greater acetabular coverage tended to have a higher Harris hip score. (orig.)

  12. Surgical Outcome of Acetabular Fracture Using Trochanteric Flip Osteotomy

    Directory of Open Access Journals (Sweden)

    Espandar R

    2012-01-01

    Full Text Available Background: One of the difficulties in acetabulum surgery is appropriate exposure of the site of surgery. Trochanteric flip osteotomy is one of the surgical methods for superoposterior and posterior acetabulum exposure. However, due to possible complications some surgeons prefer to avoid this procedure. This study was undertaken to determine the outcome of surgical treatment of acetabular fracture using trochanteric flip osteotomy. Methods : In this prospective cohort study, 14 patients with acetabular fracture who had been admitted in Imam Khomeini Hospital in Tehran, Iran, during 2003-2006 underwent trochanteric flip osteotomy. The patients were followed for at least one year post-surgically. Demographics, radiologic findings, intensity of pain using visual analogue scale (VAS, Harris hip score (HHS, force of hip abductors and complications were noted. Data analysis was performed using SPSS ver. 13.Results : The mean HHS was 82.5 (55-95. Heterotopic ossification was observed in three patients. There were no cases of postoperative infection or nonunion. Only two patients showed displacement of osteotomized fragments. Reduction was anatomic in 10 patients. In one patient, the force of hip abductors was three-fifth. The mean hip pain was 3.4 based on VAS. There were no cases of femoral head osteonecrosis. With respect to HHS, the final hip status was excellent and good in four and six patients, respectively. Three patients had fair and only one patient had poor condition.Conclusion: It seems that trochanteric flip osteotomy has much fewer complications in comparison to other methods justifying its use in such cases.

  13. Asphalt cement poisoning

    Science.gov (United States)

    ... petroleum material that hardens when it cools. Asphalt cement poisoning occurs when someone swallows asphalt. If hot ... found in: Road paving materials Roofing materials Tile cements Asphalt may also be used for other purposes.

  14. Quantitative Computerized Assessment of the Degree of Acetabular Bone Deficiency: Total radial Acetabular Bone Loss (TrABL

    Directory of Open Access Journals (Sweden)

    Frederik Gelaude

    2011-01-01

    Full Text Available A novel quantitative, computerized, and, therefore, highly objective method is presented to assess the degree of total radical acetabular bone loss. The method, which is abbreviated to “TrABL”, makes use of advanced 3D CT-based image processing and effective 3D anatomical reconstruction methodology. The output data consist of a ratio and a graph, which can both be used for direct comparison between specimens. A first dataset of twelve highly deficient hemipelves, mainly Paprosky types IIIB, is used as illustration. Although generalization of the findings will require further investigation on a larger population, it can be assumed that the presented method has the potential to facilitate the preoperative use of existing classifications and related decision schemes for treatment selection in complex revision cases.

  15. Directed Replacement

    CERN Document Server

    Karttunen, L

    1996-01-01

    This paper introduces to the finite-state calculus a family of directed replace operators. In contrast to the simple replace expression, UPPER -> LOWER, defined in Karttunen (ACL-95), the new directed version, UPPER @-> LOWER, yields an unambiguous transducer if the lower language consists of a single string. It transduces the input string from left to right, making only the longest possible replacement at each point. A new type of replacement expression, UPPER @-> PREFIX ... SUFFIX, yields a transducer that inserts text around strings that are instances of UPPER. The symbol ... denotes the matching part of the input which itself remains unchanged. PREFIX and SUFFIX are regular expressions describing the insertions. Expressions of the type UPPER @-> PREFIX ... SUFFIX may be used to compose a deterministic parser for a ``local grammar'' in the sense of Gross (1989). Other useful applications of directed replacement include tokenization and filtering of text streams.

  16. The contemporary cement cycle of the United States

    Science.gov (United States)

    Kapur, A.; Van Oss, H. G.; Keoleian, G.; Kesler, S.E.; Kendall, A.

    2009-01-01

    A country-level stock and flow model for cement, an important construction material, was developed based on a material flow analysis framework. Using this model, the contemporary cement cycle of the United States was constructed by analyzing production, import, and export data for different stages of the cement cycle. The United States currently supplies approximately 80% of its cement consumption through domestic production and the rest is imported. The average annual net addition of in-use new cement stock over the period 2000-2004 was approximately 83 million metric tons and amounts to 2.3 tons per capita of concrete. Nonfuel carbon dioxide emissions (42 million metric tons per year) from the calcination phase of cement manufacture account for 62% of the total 68 million tons per year of cement production residues. The end-of-life cement discards are estimated to be 33 million metric tons per year, of which between 30% and 80% is recycled. A significant portion of the infrastructure in the United States is reaching the end of its useful life and will need to be replaced or rehabilitated; this could require far more cement than might be expected from economic forecasts of demand for cement. ?? 2009 Springer Japan.

  17. Increasing thickness and fibrosis of the cartilage in acetabular dysplasia: a rabbit model research

    Institute of Scientific and Technical Information of China (English)

    LI Tian-you; MA Rui-xue

    2010-01-01

    Background The order and mechanism of pathological changes in acetabular dysplasia are still unclear. This study investigated cartilage changes in rabbit acetabular dysplasia models at different ages.Methods Twenty-seven 1-month-old New Zealand rabbits underwent cast immobilization of the left hind limb in knee extension. Serial acetabular dysplasia models were established by assessment of the acetabular index and Sharp's angle on radiographs. The thickness of the acetabular cartilage was measured under a microscope, and fibrosis was observed. Ultrastructural changes were investigated with scanning electron microscopy and transmission electron microscopy. The messenger RNA expression of collagen Ⅰ and Ⅱ, β1 integrin, and caspase-9 were measured by real-time fluorescence quantitative polymerase chain reaction.Results In an immature group of rabbits, the acetabular index of the treated hip increased with animal growth. The cartilage on the brim of the left acetabulum was significantly thicker than that on the right side. The collagen fibrils on the surface of the cartilage became gross, and the chondrocytes in the enlargement layer underwent necrosis. In a mature group of rabbits, the left Sharp's angle increased in the rabbits with 6-week casting. The cartilage on the brim of the left acetabulum underwent fibrosis. The chondrocytes were weakly stained, and the number of lysosomes was much larger than normal. The messenger RNA expression of collagen Ⅰ and Ⅱ, β1 integrin, and caspase-9 in the cartilage differed significantly at different ages.Conclusions Increasing thickness followed by fibrosis may be the order of pathological cartilage changes in acetabular dysplasia, with changes in ultrastructure and collagen expression contributing to the process.

  18. Magnesia-Based Cements: A Journey of 150 Years, and Cements for the Future?

    Science.gov (United States)

    Walling, Sam A; Provis, John L

    2016-04-13

    This review examines the detailed chemical insights that have been generated through 150 years of work worldwide on magnesium-based inorganic cements, with a focus on both scientific and patent literature. Magnesium carbonate, phosphate, silicate-hydrate, and oxysalt (both chloride and sulfate) cements are all assessed. Many such cements are ideally suited to specialist applications in precast construction, road repair, and other fields including nuclear waste immobilization. The majority of MgO-based cements are more costly to produce than Portland cement because of the relatively high cost of reactive sources of MgO and do not have a sufficiently high internal pH to passivate mild steel reinforcing bars. This precludes MgO-based cements from providing a large-scale replacement for Portland cement in the production of steel-reinforced concretes for civil engineering applications, despite the potential for CO2 emissions reductions offered by some such systems. Nonetheless, in uses that do not require steel reinforcement, and in locations where the MgO can be sourced at a competitive price, a detailed understanding of these systems enables their specification, design, and selection as advanced engineering materials with a strongly defined chemical basis. PMID:27002788

  19. ULTRA-LIGHTWEIGHT CEMENT

    International Nuclear Information System (INIS)

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). Work reported herein addresses Task 1: Assess Ultra-Lightweight Cementing Issues, Task 2: Review Russian Ultra-Lightweight Cement Literature, Task 3: Test Ultra-Lightweight Cements, and Task 8: Develop Field ULHS Cement Blending and Mixing Techniques. Results reported this quarter include: preliminary findings from a literature review focusing on problems associated with ultra-lightweight cements; summary of pertinent information from Russian ultra-lightweight cement literature review; laboratory tests comparing ULHS slurries to foamed slurries and sodium silicate slurries for two different applications; and initial laboratory studies with ULHS in preparation for a field job

  20. Failure of dual radius hydroxyapatite-coated acetabular cups

    Directory of Open Access Journals (Sweden)

    Zatti Giovanni

    2008-08-01

    Full Text Available Abstract Introduction Many kind of hydroxyapatite-coated cups were used, with favorable results in short term studies; it was supposed that its use could improve osteointegration of the cup, enhancing thus stability and survivorship. The purpose of this study is to analyze the long term behavior of the hemispheric HA coated, Dual Radius Osteonics cup and to discuss the way of failure through the exam of the revised components and of both periacetabular and osteolysis tissue. Materials and Methods Between 1994 and 1997, at the Department of Orthopedic Sciences of the Insubria University, using the posterolateral approach, were implanted 276 Dual Radius Osteonics® in 256 patients, with mean age of 63 years. Results At a mean follow-up of 10 years (range 8–12 years, 183 cups in 165 patients, were available for clinical and radiographical evaluation. 22 Cups among the 183 were revised (11%. The cause of revision was aseptic loosening in 17 cases, septic loosening in one case, periprosthetic fracture in another case, osteolysis and polyethylene wear in two cases and, finally, recurrent dislocations in the last one. In the remaining patients, mean HHS increased from a preoperative value of 50,15 to a postoperative value of 92,69. The mean polyethylene wear was 1,25 mm (min. 0,08, max. 3,9 mm, with a mean annual wear of 0,17 mm. The mean acetabular migration on the two axis was 1,6 mm and 1,8 mm. Peri-acetabular osteolysis were recorded in 89% of the implants (163 cases. The cumulative survivorship (revision as endpoint at the time was 88,9%. Conclusion Our study confirms the bad behavior of this type of cup probably related to the design, to the method of HA fixation. The observations carried out on the revised cup confirm these hypotheses but did not clarify if the third body wear could be a further problem. Another interesting aspect is the high incidence of osteolysis, which are often asymptomatic becoming a problem for the surgeon as the

  1. Radiographic and clinical analysis of cementless acetabular fixation in total hip arthroplasty

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hui; PEI Fu-xing; YANG Jing; SHEN Bin; SHI Rui

    2005-01-01

    Objective: To investigate the factors affecting the fixation, loosening and therapeutic effect of cementless acetabular prosthesis through following up the patients with total hip arthroplasty clinically and radiographically.Methods: From February 1998 to May 1999, 139 patients (148 hips) underwent total hip arthroplasty with cementless acetabular prosthesis in our department. In this study, the clinical therapeutic effect and the anteroposterior radiographs of the pelvis and anteroposterior and lateral radiographs of the hips of 109 patients (116 hips) made before operation, at 1 week, 3, 6, and 12 months after operation and annually thereafter were analyzed retrospectively. The clinical therapeutic effects were evaluated with Harris hip score. Radiographs were used to observe the position of prostheses and the bone changes around the implant, and to measure the wearing speed and direction of the acetabular cup. All evaluations were made by an independent examiner who did not participate in the operation. The patients were followed up for 5-6 years.Results: The mean Harris score was 44 points (range, 10-70 points) before operation, but it increased to 92.4 points (range, 80-100 points) at the latest review after operation, which was significantly higher than that before operation (P<0.05). No acetabular component was revised because of infection or aseptic loosening. And no acetabular component migrated. There was no revision of fixed acetabular component because of pelvic osteolysis secondary to polyethylene wear. The mean linear wear rate was 0.15 mm per year. All the acetabular prostheses were classified as stable on the radiographs.Conclusions: In terms of fixation, total hip arthroplasty with cementless acetabular components was successful. Although there is no aseptic loosening and a low incidence of osteolysis at the latest follow-up evaluation, polyethylene wear cannot be avoided and can lead to expansile osteolysis near the cups. This kind of osteolysis

  2. Pelvic Incidence: A Predictive Factor for Three-Dimensional Acetabular Orientation—A Preliminary Study

    Directory of Open Access Journals (Sweden)

    Christophe Boulay

    2014-01-01

    Full Text Available Acetabular cup orientation (inclination and anteversion is a fundamental topic in orthopaedics and depends on pelvis tilt (positional parameter emphasising the notion of a safe range of pelvis tilt. The hypothesis was that pelvic incidence (morphologic parameter could yield a more accurate and reliable assessment than pelvis tilt. The aim was to find out a predictive equation of acetabular 3D orientation parameters which were determined by pelvic incidence to include in the model. The second aim was to consider the asymmetry between the right and left acetabulae. Twelve pelvic anatomic specimens were measured with an electromagnetic Fastrak system (Polhemus Society providing 3D position of anatomical landmarks to allow measurement of acetabular and pelvic parameters. Acetabulum and pelvis data were correlated by a Spearman matrix. A robust linear regression analysis provided prediction of acetabulum axes. The orientation of each acetabulum could be predicted by the incidence. The incidence is correlated with the morphology of acetabula. The asymmetry of the acetabular roof was correlated with pelvic incidence. This study allowed analysis of relationships of acetabular orientation and pelvic incidence. Pelvic incidence (morphologic parameter could determine the safe range of pelvis tilt (positional parameter for an individual and not a group.

  3. Acetabular rim and surface segmentation for hip surgery planning and dysplasia evaluation

    Science.gov (United States)

    Tan, Sovira; Yao, Jianhua; Yao, Lawrence; Summers, Ronald M.; Ward, Michael M.

    2008-03-01

    Knowledge of the acetabular rim and surface can be invaluable for hip surgery planning and dysplasia evaluation. The acetabular rim can also be used as a landmark for registration purposes. At the present time acetabular features are mostly extracted manually at great cost of time and human labor. Using a recent level set algorithm that can evolve on the surface of a 3D object represented by a triangular mesh we automatically extracted rims and surfaces of acetabulae. The level set is guided by curvature features on the mesh. It can segment portions of a surface that are bounded by a line of extremal curvature (ridgeline or crestline). The rim of the acetabulum is such an extremal curvature line. Our material consists of eight hemi-pelvis surfaces. The algorithm is initiated by putting a small circle (level set seed) at the center of the acetabular surface. Because this surface distinctively has the form of a cup we were able to use the Shape Index feature to automatically extract an approximate center. The circle then expands and deforms so as to take the shape of the acetabular rim. The results were visually inspected. Only minor errors were detected. The algorithm also proved to be robust. Seed placement was satisfactory for the eight hemi-pelvis surfaces without changing any parameters. For the level set evolution we were able to use a single set of parameters for seven out of eight surfaces.

  4. Minimum ten-year follow-up of acetabular fracture fixation from the Irish tertiary referral centre.

    LENUS (Irish Health Repository)

    Magill, Paul

    2012-04-01

    Successful outcome from acetabular fracture fixation is multi-factorial. Long-term results are not frequently reported. Pooling such data from high output centres will help progress acetabular fixation. This paper presents the first ten-year data from the Irish tertiary referral centre.

  5. Effect of metakaolin on strength and efflorescence quantity of cement-based composites.

    Science.gov (United States)

    Weng, Tsai-Lung; Lin, Wei-Ting; Cheng, An

    2013-01-01

    This study investigated the basic mechanical and microscopic properties of cement produced with metakaolin and quantified the production of residual white efflorescence. Cement mortar was produced at various replacement ratios of metakaolin (0, 5, 10, 15, 20, and 25% by weight of cement) and exposed to various environments. Compressive strength and efflorescence quantify (using Matrix Laboratory image analysis and the curettage method), scanning electron microscopy, and X-ray diffraction analysis were reported in this study. Specimens with metakaolin as a replacement for Portland cement present higher compressive strength and greater resistance to efflorescence; however, the addition of more than 20% metakaolin has a detrimental effect on strength and efflorescence. This may be explained by the microstructure and hydration products. The quantity of efflorescence determined using MATLAB image analysis is close to the result obtained using the curettage method. The results demonstrate the best effectiveness of replacing Portland cement with metakaolin at a 15% replacement ratio by weight.

  6. ULTRA-LIGHTWEIGHT CEMENT

    International Nuclear Information System (INIS)

    The objective of this project is to develop an improved ultra-lightweigh cement using ultralight hollow glass spheres (ULHS). Work reported herein addresses Task 1: Assess Ultra-Lightweight Cementing Problems, Task 2: Review Russian Ultra-Lightweight Cement Literature, and Task 3: Test Ultra-Lightweight Cements. Results reported this quarter include a review and summary surface pipe and intermediate casing cementing conditions historically encountered in the US and establishment of average design conditions for ULHS cements. Russian literature concerning development and use of ultra-lightweight cements employing either nitrogen or ULHS was reviewed, and a summary is presented. Quality control testing of materials used to formulate ULHS cements in the laboratory was conducted to establish baseline material performance standards. A testing protocol was developed employing standard procedures as well as procedures tailored to evaluate ULHS. This protocol is presented and discussed. finally, results of initial testing of ULHS cements is presented along with analysis to establish cement performance design criteria to be used during the remainder of the project

  7. Results of Chiari pelvic osteotomy for acetabular dysplasia in adults

    International Nuclear Information System (INIS)

    In an attempt to determine indications of Chiari pelvic osteotomy in acetabular dysplasia, postoperative outcome of hip joint (64 joints) was examined on the basis of findings of bone scintigraphy. The subjects were 61 patients with osteoarthrosis of hip joint who underwent preoperative bone scintigraphy. The follow-up period ranged from 2 years to 9 years and 7 months with a mean of 4 years and 9 months. According to X-ray findings, 37 osteoarthrosis joints were staged as early and 27 as progressive. Preoperative bone scintigraphic findings fell into three: (I) normal or slight hot type (33 joints), (II) hot type at the weighting part (16 joints), and (III) double hot type in the weighting part and inside part (15 joints). None of the patients had severe surgical complications such as deep-seated infection, neuroparalysis and pseudojoint. According to the clinical staging for hip joint function, 7 (47%) of 64 joints were judged as poor after osteotomy, belonging to type III. Deterioration of osteoarthrosis was seen in 11 joints (41%) on X-ray films. Of these, 9 had type III. In conclusion, Chiari pelvic osteotomy should not be indicated when type III is shown on bone scintigrams. (N.K.)

  8. Ultrasound versus Magnetic Resonance Arthrography in Acetabular Labral Tear Diagnostics: A Prospective Comparison in 20 Dysplastic Hips

    Energy Technology Data Exchange (ETDEWEB)

    Troelsen, A.; Jacobsen, S.; Bolvig, L.; Gelineck, J.; Roemer, L.; Soeballe, K. [Orthopedic Research Unit and Dept. of Radiology, Univ. Hospital of Aarhus, A arhus (Denmark)

    2007-11-15

    Background: Acetabular labral tears are highly associated with hip dysplasia. Magnetic resonance arthrography (MR arthrography) is the expensive and time-consuming contemporary gold-standard method in the radiological assessment of acetabular labral tears. Purpose: To assess the diagnostic ability of noninvasive ultrasound (US) examination compared to MR arthrography in diagnosing acetabular labral tears in dysplastic hip joints. Material and Methods: The study compared US examination and MR arthrography diagnosis of labral tears in 20 consecutively referred dysplastic hip joints. Results: The ability to diagnose acetabular labral tears upon US examination was calculated: sensitivity 44%, specificity 75%, positive predictive value 88%, and negative predictive value 25%. Conclusion: The ability of US examination in diagnosing acetabular labral tears is not yet good enough. The technique is still to be developed, and more experience, especially with the interpretation of US examinations, is needed.

  9. Oxidation and other property changes of retrieved sequentially annealed UHMWPE acetabular and tibial bearings.

    Science.gov (United States)

    Reinitz, Steven D; Currier, Barbara H; Van Citters, Douglas W; Levine, Rayna A; Collier, John P

    2015-04-01

    This investigation analyzed retrieved sequentially crosslinked and annealed (SXL) ultra-high molecular weight polyethylene bearings to determine whether the material is chemically stable in vivo. A series of retrieved tibial and acetabular components were analyzed for changes in ketone oxidation, crosslink density, and free radical concentration. Oxidation was observed to increase with in vivo duration, and the rate of oxidation in tibial inserts was significantly greater than in acetabular liners. SXL acetabular bearings oxidized at a rate comparable to gamma-sterilized liners, while SXL tibial inserts oxidized at a significantly faster rate than their gamma-sterilized counterparts. A significant decrease in crosslink density with increased mean ketone oxidation index was observed, suggesting that in vivo oxidation may be causing material degradation. Furthermore, a subsurface whitened damage region was also found in a subset of the bearings, indicating the possibility of a clinically relevant decrease in mechanical properties of these components.

  10. Central acetabular fracture with dislocation treated by minimally invasive plate osteosynthesis.

    Science.gov (United States)

    2015-06-01

    Central acetabular fractures with dislocation are usually the result of high-energy trauma, resulting in joint incongruity, and are frequently associated with other injuries. Open reduction and internal fixation has been the standard treatment for acetabular fractures, but it is associated with extensive surgical trauma, and complications such as haematoma formation, iatrogenic nerve injury, and heterotopic ossification. We present the case of a 63-year-old female who sustained a central acetabular fracture of the hip with dislocation as a result of an automobile collision. Closed reduction of the dislocation was performed, and the fracture was managed by minimally invasive plate osteosynthesis using a specially prepared plate. At 01 year postoperatively, radiographs showed the fracture to have been well-healed with good congruity of the joint. However, heterotopic ossification of the joint was noted. The technique allowed reduction of the fracture with minimal surgical trauma.

  11. A novel technique for impaction bone grafting in acetabular reconstruction of revision total hip arthroplasty using an ex vivo compaction device

    International Nuclear Information System (INIS)

    Impaction bone grafting allows restoration of the acetabular bone stock in revision hip arthroplasty. The success of this technique depends largely on achieving adequate initial stability of the component. To obtain well-compacted, well-graded allograft aggregates, we developed an ex vivo compaction device to apply it in revision total hip arthroplasty on the acetabular side, and characterized mechanical properties and putative osteoconductivity of allograft aggregates. Morselized allograft bone chips were compacted ex vivo using the creep technique and subsequent impaction technique to form the bone aggregates. Impaction allograft reconstruction of the acetabulum using an ex vivo compaction device was performed on eight hips. The mechanical properties and three-dimensional micro-CT-based structural characteristics of the bone aggregates were investigated. In clinical practice, this technique offered good reproducibility in reconstructing the cavity and the segmental defects of the acetabulum, with no migration and no loosening of the component. In vitro analysis showed that the aggregates generated from 25 g fresh-frozen bone chips gained compression stiffness of 13.5-15.4 MPa under uniaxial consolidation strain. The recoil of the aggregates after compaction was 2.6-3.9%. The compression stiffness and the recoil did not differ significantly from those measured using a variety of proportions of large- and small-sized bone chips. Micro-CT-based structural analysis revealed average pore sizes of 268-299 μm and average throat diameter of pores in the bone aggregates of more than 100 μm. These sizes are desirable for osteoconduction, although large interconnected pores of more than 500 μm were detectable in association with the proportion of large-sized bone chips. Cement penetration into the aggregates was related to the proportion of large-sized bone chips. This study introduces the value of an ex vivo compaction device in bone graft compaction in clinical

  12. EFFECT OF PORTLAND-POZZOLAN CEMENTS ON CONCRETE MATURITY

    Directory of Open Access Journals (Sweden)

    Arın YILMAZ

    2004-03-01

    Full Text Available The maturity concept expressed by the combined effect of time and temperature on the concrete is a useful technique for prediction of the strength gain of concrete. According to maturity concept, samples of the same concrete at same maturity whatever combination of temperature and time, have approximately the same strength. Many maturity functions have been proposed for the last 50 years. The validity of these functions are only for ordinary portland cements. In this study, the suitable of traditional maturity functions for different types of Portland-pozzolan cements were investigated and a new maturity-strength relationship was tried to be established. For this purpose, four different pozzolans and one Portland cement was selected. Portland-pozzolan cements were prepared by using three different replacement amounts of % 5, % 20 and 40 % by weight of cement.

  13. Use of Oscillatory Shear to Study the Effect of Limestone Filler on the Rheology of Early-Age Portland Cement

    OpenAIRE

    Barney, Christopher W; Erk, Kendra

    2013-01-01

    Cement is a material that has been in use since the ancient times and is the most widely manufactured material in industry today. During the production of cement, limestone undergoes a process called calcination which releases CO2. In order to reduce the environmental impact and cost of cement production it has become standard practice to replace a portion of the cement mixture with ground limestone, but this causes a change in the rheological profile of the mixture. This change in rheology a...

  14. Quantifying the contribution of pincer deformity to femoro-acetabular impingement using 3D computerised tomography

    Energy Technology Data Exchange (ETDEWEB)

    Dandachli, Wael; Najefi, Ali; Iranpour, Farhad; Lenihan, Jonathan; Hart, Alister; Cobb, Justin [Imperial College London, Charing Cross Hospital, Department of Orthopaedic Surgery, London (United Kingdom)

    2012-10-15

    To provide a simple, reliable method for the three-dimensional quantification of pincer-type hip deformity. Computerised tomography scans of 16 normal female hips and 15 female hips with clinical femoro-acetabular impingement (FAI) and radiographic signs of pincer secondary to acetabular protrusio were analysed. After orientating the pelvis in the anterior pelvic plane, the acetabular centre was determined, and the ratios of its coordinates to the corresponding pelvic dimensions were calculated. Acetabular coverage of the femoral head and centre-edge angles were also measured for the two groups. In hips with a pincer, the hip was medialised by 37 % (p = 0.03), more proximal by 5 % (p = 0.05) and more posterior by 9 % (p = 0.03) compared with the normal hips. Coverage of the femoral head in protrusio hips was significantly greater than normal (average 71 % vs 82 %, p = 0.0001). Both the lateral centre-edge angle and the combined anterior-posterior centre-edge angle were greater in protrusio hips than in the normal ones (48 vs 37 , p < 0.001; and 216 vs 176 , p < 0.0001 respectively). Displacement in acetabular protrusio occurs in all planes. This CT-based method allows for the accurate and standardised quantification of the extent of displacement, as well as 3D measurement of femoral head coverage. In the adult female population, a combined centre-edge angle of over 190 suggests an acetabulum that is too deep and a potential cause of symptoms of femoro-acetabular impingement. Conversely, an acetabulum that has a combined centre-edge angle of less than 190 may be considered to be of normal depth, and therefore not contributing a pincer to FAI should it occur. (orig.)

  15. Acetabular stress fractures in military endurance athletes and recruits: incidence and MRI and scintigraphic findings

    Energy Technology Data Exchange (ETDEWEB)

    Williams, T.R. [Portsmouth Naval Medical Center, Radiology Department, Charette Health Care Center, Portsmouth, VA (United States); Puckett, M.L.; Shin, A.Y.; Gorman, J.D. [Naval Medical Center San Diego, Radiology Department, San Diego, CA (United States); Denison, G. [US Naval Hospital Guam (United States)

    2002-05-01

    Objective: To evaluate the incidence and the MRI and scintigraphic appearance of acetabular stress (fatigue) fractures in military endurance athletes and recruits. Design and patients: One hundred and seventy-eight active duty military endurance trainees with a history of activity-related hip pain were evaluated by both MRI and bone scan over a 2-year period. Patients in the study ranged in age from 17 to 45 years. They had hip pain related to activity and had plain radiographs of the hip and pelvis that were interpreted as normal or equivocal. The study was originally designed to evaluate the MRI and scintigraphic appearance of femoral neck stress fractures. Patients had scintigraphy and a limited MRI examination (coronal imaging only) within 48 h of the bone scan. Twelve patients demonstrated imaging findings compatible with acetabular stress fractures. Results: Stress fractures are common in endurance athletes and in military populations; however, stress fracture of the acetabulum is uncommon. Twelve of 178 patients (6.7%) in our study had imaging findings consistent with acetabular stress fractures. Two patterns were identified. Seven of the 12 (58%) patients had acetabular roof stress fractures. In this group, two cases of bilateral acetabular roof stress fractures were identified, one with a synchronous tensile sided femoral neck stress fracture. The remaining five of 12 (42%) patients had anterior column stress fractures, rarely occurring in isolation, and almost always occurring with inferior pubic ramus stress fracture (4 of 5, or 80%). One case of bilateral anterior column stress fractures was identified without additional sites of injury. Conclusions: Stress fractures are commonplace in military populations, especially endurance trainees. Acetabular stress fractures are rare and therefore unrecognized, but do occur and may be a cause for activity-related hip pain in a small percentage of military endurance athletes and recruits. (orig.)

  16. Quantifying the contribution of pincer deformity to femoro-acetabular impingement using 3D computerised tomography

    International Nuclear Information System (INIS)

    To provide a simple, reliable method for the three-dimensional quantification of pincer-type hip deformity. Computerised tomography scans of 16 normal female hips and 15 female hips with clinical femoro-acetabular impingement (FAI) and radiographic signs of pincer secondary to acetabular protrusio were analysed. After orientating the pelvis in the anterior pelvic plane, the acetabular centre was determined, and the ratios of its coordinates to the corresponding pelvic dimensions were calculated. Acetabular coverage of the femoral head and centre-edge angles were also measured for the two groups. In hips with a pincer, the hip was medialised by 37 % (p = 0.03), more proximal by 5 % (p = 0.05) and more posterior by 9 % (p = 0.03) compared with the normal hips. Coverage of the femoral head in protrusio hips was significantly greater than normal (average 71 % vs 82 %, p = 0.0001). Both the lateral centre-edge angle and the combined anterior-posterior centre-edge angle were greater in protrusio hips than in the normal ones (48 vs 37 , p < 0.001; and 216 vs 176 , p < 0.0001 respectively). Displacement in acetabular protrusio occurs in all planes. This CT-based method allows for the accurate and standardised quantification of the extent of displacement, as well as 3D measurement of femoral head coverage. In the adult female population, a combined centre-edge angle of over 190 suggests an acetabulum that is too deep and a potential cause of symptoms of femoro-acetabular impingement. Conversely, an acetabulum that has a combined centre-edge angle of less than 190 may be considered to be of normal depth, and therefore not contributing a pincer to FAI should it occur. (orig.)

  17. Application of porous tantalum in acetabular revision after total hip arthroplasty%多孔金属钽髋臼在全髋关节置换术后髋臼翻修中的应用

    Institute of Scientific and Technical Information of China (English)

    李亮; 赵阳; 王志强

    2013-01-01

    To review the application effects of the porous tantalum acetabular cup in acetabular revision for acetabular failure after total hip arthroplasty ( THA ). The related literatures about the characteristics of porous tantalum and its application in acetabular revision in recent 10 years were retrieved from China National Knowledge Internet ( CNKI ) and PubMed databases, and a review was made. The porous tantalum acetabular cup had unique high porosity, low elasticity, high friction coefficient and good function to promote bone ingrowth inwardly. Good clinical results could be obtained using the porous tantalum acetabular cup in acetabular revision for patients with initial fixation failure using the artificial acetabular cup. In acetabular revision, the porous tantalum acetabular cup can provide superior mechanical stability, with good early and medium-term results.

  18. Clay content of argillites: Influence on cement based mortars

    OpenAIRE

    Habert, Guillaume; CHOUPAY, Nathalie; Escadeillas, Gilles; MONTEL, Jean Marc; Guillaume, D

    2009-01-01

    The pozzolanic activity of four heated powders containing different clays has been tested. Mineral transformations during calcination from 20 to 900 °C have been followed by X-ray diffraction (XRD) and Differential Scanning Calorimetry (DSC). Compressive strength tests were performed at 1, 7 and 28 days on cement-clay mortars using 30% of pozzolanic material as a replacement by mass for cement. Calcination temperatures corresponded to the stages of potentially high reactivity identified by XR...

  19. Pore Distribution and Water Uptake in a Cenosphere–Cement

    OpenAIRE

    Baroniņš, J; Sētiņa, J; Šahmenko, G; Lagzdiņa, S; Šiškins, A

    2015-01-01

    Alumina silicate cenospheres (CS) is a significant waste material from power plants that use a coal. Use CS as Portland cement replacement material gives opportunity to control physical and mechanical properties and makes a product lighter and more cost-effective. In the frame of this study, Portland cement paste samples were produced by adding CS in the concentration range from 0 to 40 volume %. Water uptake of hardened samples was checked and pore ...

  20. Design of Digital Control System for Cement Raw Material Preparation

    Institute of Scientific and Technical Information of China (English)

    ZHOU Ying; LI Hongsheng

    2006-01-01

    This paper describes the design of cement raw material prepared digital control system by PROFIBUS. It uses the digital technology to implement the digital control system for raw material prepared of the cement factory. This system improves the communication between the industrial system and locale instrument devices. It applies digital communication to replace the 4-20 mA or 24VDC signal between locale lever device and controller.

  1. Absorption Characteristics of Cement Combination Concrete Containing Portland Cement, fly ash, and Metakaolin

    Directory of Open Access Journals (Sweden)

    Folagbade S.O.

    2016-03-01

    Full Text Available The resistance to water penetration of cement combination concretes containing Portland cement (PC, fly ash (FA, and metakaolin (MK have been investigated at different water/cement (w/c ratios, 28-day strengths, and depths of water penetration using their material costs and embodied carbon-dioxide (eCO2 contents. Results revealed that, at equal w/c ratio, eCO2 content reduced with increasing content of FA and MK. MK contributed to the 28-day strengths more than FA. Compared with PC, FA reduced cost and increased the depth of water penetration, MK increased cost and reduced the depth of water penetration, and their ternary combinations become beneficial. At equal strengths and levels of resistance to water penetration, most of the cement combination concretes are more environmentally compatible and costlier than PC concrete. Only MK binary cement concretes with 10%MK content or more and ternary cement concretes at a total replacement level of 55% with 10%MK content or more have higher resistance to water penetration than PC concrete.

  2. Pore Structure of Cement Pastes Blended with Volcanic Rock

    Institute of Scientific and Technical Information of China (English)

    YU Lehua; ZHOU Shuangxi; LI Liling

    2016-01-01

    The pore parameters of cement pastes blended with volcanic rock at the curing age of 1, 28 and 90 d were de-termined by a mercury intrusion porosimetry. The pore structure of the pastes was characterized through the analysis of porosity, average pore diameter, the most probable pore aperture, pore size distribution, as well as total pore volume. For the improvement of mechanical property and durability of cement-based material, the correlation of the formed pore structure with hydration time and replacement level of volcanic rock for cement was revealed. The results indicate that volcanic rock can diminish porosity and reduce pore size in cement paste when curing time prolongs, which is particu-larly prominent with replacement level of less than 20% in late period. The more harmful pores (i.e., capillary pore) are gradually transformed into harmless pore (i.e., gel pores or micropore), even fully filled and disappeared when hydration products increase. The pore structure of the cement paste is thus refined. The beneficial effect of volcanic rock on the pore structure of cement paste could enhance the mechanical property and durability of cement-based material.

  3. Acetabular anteversion is associated with gluteal tendinopathy at MRI

    Energy Technology Data Exchange (ETDEWEB)

    Moulton, Kyle M. [University of Saskatchewan, Department of Medical Imaging, Saskatoon, SK (Canada); Royal University Hospital, Department of Medical Imaging, Saskatoon, SK (Canada); Aly, Abdel-Rahman [University of Saskatchewan, Department of Physical Medicine and Rehabilitation, Saskatoon, SK (Canada); Rajasekaran, Sathish [Health Pointe - Pain, Spine and Sport Medicine, Edmonton, AB (Canada); Shepel, Michael; Obaid, Haron [University of Saskatchewan, Department of Medical Imaging, Saskatoon, SK (Canada)

    2015-01-15

    Gluteal tendinopathy and greater trochanteric pain syndrome (GTPS) remain incompletely understood despite their pervasiveness in clinical practice. To date, no study has analyzed the morphometric characteristics of the hip on magnetic resonance imaging (MRI) that may predispose to gluteal tendinopathy. This study aimed to evaluate whether acetabular anteversion (AA), femoral neck anteversion (FNA), and femoral neck-shaft angle (FNSA) are associated with MRI features of gluteal tendinopathy. A total of 203 MRI examinations of the hip met our inclusion and exclusion criteria. A single blinded investigator measured AA, FNA, and FNSA according to validated MRI techniques. Two blinded subspecialty-trained musculoskeletal radiologists then independently evaluated the presence of gluteal tendinosis, trochanteric bursitis, and subgluteal bursitis. Statistical analysis was performed using a one-way analysis of variance (ANOVA; post-hoc Tukey's range test). At MRI, 57 patients had gluteal tendinosis with or without bursitis, 26 had isolated trochanteric bursitis, and 11 had isolated subgluteal bursitis. AA was significantly (p = 0.01) increased in patients with MRI evidence of gluteal tendinosis with or without bursitis [mean: 18.4 , 95 % confidence interval (CI): 17.2 -19.6 ] compared with normal controls (mean: 15.7 , 95 % CI: 14.7 -16.8 ). Similarly, AA was significantly (p = 0.04) increased in patients with isolated trochanteric bursitis (mean: 18.8 , 95 % CI: 16.2 -21.6 ). No association was found between FNA or FNSA and the presence of gluteal tendinopathy. Interobserver agreement for the presence and categorization of gluteal tendinopathy was very good (kappa = 0.859, 95 % CI: 0.815-0.903). Our MRI study suggests that there is an association between increased AA and gluteal tendinopathy, which supports a growing body of evidence implicating abnormal biomechanics in the development of this condition. (orig.)

  4. Biomechanical Study of Acetabular Tridimensional Memoryalloy Fixation System

    Science.gov (United States)

    Liu, Xin-Wei; Xu, Shuo-Gui; Zhang, Yun-Tong; Zhang, Chun-Cai

    2011-07-01

    We developed the acetabular tridimensional memoryalloy fixation system (ATMFS), which is made of NiTi shape memory alloy, according to the specific mechanical properties of biological memory material, NiTi shape memory alloy and measured distribution of contact area and pressure between the acetabulum and the femoral head of cadaveric pelvis. Seven formalin-preserved cadaveric pelves were used for this investigation. Pressure-sensitive film was used to measure contact area and pressure within the anterior, superior, and posterior regions of the acetabulum. The pelves were loaded under the following four conditions: (1) intact; (2) following a creation posterior wall fracture defect; (3) following reduction and standard internal fixation with reconstruction plate; and (4) following reduction and internal fixation with a new shape memory alloy device named ATMFS. A posterior wall fracture was created along an arc of 40° to 90° about the acetabulur rim. Creation of a posterior wall defect resulted in increased load in the superior acetabulum (1485 N) as compared to the intact condition (748 N, P = 0.009). Following reduction and internal fixation, the load distributed to the superior acetabulum (1545 N) was not statistically different from the defect condition. Following the fixation with ATMFS, the load seen at the superior region of the actabulum (964 N) was familiar with fixation with reconstruction plate and was not different from intact state ( P = 0.45). These data indicate that the use of ATMFS as a fracture internal fixation device resulted a partial restoration of joint loading parameters toward the intact state. ATMFS fixation may result in a clinical benefit.

  5. Reduction of soil pollution by usingwaste of the limestone in the cement industry

    Science.gov (United States)

    Muñoz, M. Cecilia Soto; Robles Castillo, Marcelo; Blanco Fernandez, David; Diaz Gonzalez, Marcos; Naranjo Lamilla, Pedro; Moore Undurraga, Fernando; Pardo Fabregat, Francisco; Vidal, Manuel Miguel Jordan; Bech, Jaume; Roca, Nuria

    2016-04-01

    In the cement manufacturing process (wet) a residue is generated in the flotation process. This builds up causing contamination of soil, groundwater and agricultural land unusable type. In this study to reduce soil and water pollution 10% of the dose of cement was replaced by waste of origin limestone. Concretes were produced with 3 doses of cement and mechanical strengths of each type of concrete to 7, 28 and 90 days were determined. the results indicate that the characteristics of calcareous residue can replace up to 10% of the dose of cement without significant decreases in strength occurs. It is noted that use of the residue reduces the initial resistance, so that the dose of cement should not be less than 200 kg of cement per m3. The results allow recommends the use of limestone waste since it has been observed decrease in soil and water contamination without prejudice construction material Keywords: Soil contamination; Limestone residue; Adding concrete

  6. Tympanoplasty with ionomeric cement

    DEFF Research Database (Denmark)

    Kjeldsen, A D; Grøntved, A M

    2000-01-01

    of > 10 dB, in 4 there was a slight improvement and in 2 a decline. The difference was not statistically significant. Hearing improvement using ionomeric cement in type II tympanoplasty was satisfactory. Reconstruction of the ossicular chain with ionomeric cement is recommended, as the procedure is easy...

  7. Evaluation of the wear performance of a polycarbonate-urethane acetabular component in a hip joint simulator and comparison with UHMWPE and cross-linked UHMWPE.

    Science.gov (United States)

    St John, Kenneth; Gupta, Minakshi

    2012-07-01

    Acetabular hip joint components manufactured from gamma-sterilized ultra high molecular weight polyethylene (UHMWPE), gamma cross-linked UHMWPE, or polycarbonate-urethane (PCU) polymers were evaluated in a hip joint simulator, using cobalt alloy femoral components, for at least 5 million cycles. The volume of material losses due to wear was calculated for each type of sample, based upon mass loss measurements, every 500,000 cycles. The loss of material for the conventional UHMWPE was much higher than for the cross-linked UHMWPE, showing about a 70% reduction in wear due to cross-linking. The material loss for the PCU samples appears to have been at least 24% lower than for the cross-linked UHMWPE. Based upon these results, the PCU material seems to have potential for use as an alternative bearing material to UHMWPE for total hip replacement surgeries.

  8. Accuracy and Precision of Three-Dimensional Low Dose CT Compared to Standard RSA in Acetabular Cups: An Experimental Study

    Directory of Open Access Journals (Sweden)

    Cyrus Brodén

    2016-01-01

    Full Text Available Background and Purpose. The gold standard for detection of implant wear and migration is currently radiostereometry (RSA. The purpose of this study is to compare a three-dimensional computed tomography technique (3D CT to standard RSA as an alternative technique for measuring migration of acetabular cups in total hip arthroplasty. Materials and Methods. With tantalum beads, we marked one cemented and one uncemented cup and mounted these on a similarly marked pelvic model. A comparison was made between 3D CT and standard RSA for measuring migration. Twelve repeated stereoradiographs and CT scans with double examinations in each position and gradual migration of the implants were made. Precision and accuracy of the 3D CT were calculated. Results. The accuracy of the 3D CT ranged between 0.07 and 0.32 mm for translations and 0.21 and 0.82° for rotation. The precision ranged between 0.01 and 0.09 mm for translations and 0.06 and 0.29° for rotations, respectively. For standard RSA, the precision ranged between 0.04 and 0.09 mm for translations and 0.08 and 0.32° for rotations, respectively. There was no significant difference in precision between 3D CT and standard RSA. The effective radiation dose of the 3D CT method, comparable to RSA, was estimated to be 0.33 mSv. Interpretation. Low dose 3D CT is a comparable method to standard RSA in an experimental setting.

  9. Accuracy and Precision of Three-Dimensional Low Dose CT Compared to Standard RSA in Acetabular Cups: An Experimental Study

    Science.gov (United States)

    Olivecrona, Henrik; Maguire, Gerald Q.; Noz, Marilyn E.; Zeleznik, Michael P.

    2016-01-01

    Background and Purpose. The gold standard for detection of implant wear and migration is currently radiostereometry (RSA). The purpose of this study is to compare a three-dimensional computed tomography technique (3D CT) to standard RSA as an alternative technique for measuring migration of acetabular cups in total hip arthroplasty. Materials and Methods. With tantalum beads, we marked one cemented and one uncemented cup and mounted these on a similarly marked pelvic model. A comparison was made between 3D CT and standard RSA for measuring migration. Twelve repeated stereoradiographs and CT scans with double examinations in each position and gradual migration of the implants were made. Precision and accuracy of the 3D CT were calculated. Results. The accuracy of the 3D CT ranged between 0.07 and 0.32 mm for translations and 0.21 and 0.82° for rotation. The precision ranged between 0.01 and 0.09 mm for translations and 0.06 and 0.29° for rotations, respectively. For standard RSA, the precision ranged between 0.04 and 0.09 mm for translations and 0.08 and 0.32° for rotations, respectively. There was no significant difference in precision between 3D CT and standard RSA. The effective radiation dose of the 3D CT method, comparable to RSA, was estimated to be 0.33 mSv. Interpretation. Low dose 3D CT is a comparable method to standard RSA in an experimental setting. PMID:27478832

  10. The efficacy of a "double-D-shaped" wire marker for radiographic measurement of acetabular cup orientation and wear.

    Science.gov (United States)

    Derbyshire, Brian; Raut, Videshnandan V

    2013-01-01

    Historically, wire markers were attached to cemented all-plastic acetabular cups to demarcate the periphery and to measure socket wear. The wire shape was either a semi-circle passing over the pole of the cup, or a circle around the cup equator. More recently, "double-D" shaped markers were introduced with a part-circular aspect passing over the pole and a semi-circular aspect parallel to the equatorial plane. This configuration enabled cup retroversion to be distinguished from anteversion. In this study, the accuracy of radiographic measurement of cup orientation and wear was assessed for cups with "double-D" and circular markers. Each cup was attached to a measurement jig which could vary the anteversion/retroversion and internal/external rotation of the cup. A metal femoral head was fixed within the socket and radiographic images were created for all combinations of cup orientation settings. The images were measured using software with automatic edge detection, and cup orientation and zero-wear accuracies were determined for each setting. The median error for cup version measurements was similar for both types of wire marker (0.2° double-D marker, -0.24° circular marker), but measurements of the circular marker were more repeatable. The median inclination errors were 2.05° (double-D marker) and 0.23° (circular marker). The median overall "zero wear" errors were 0.19 mm (double-D marker) and 0.03 mm (circular marker). Measurements of the circular wire marker were much more repeatable.

  11. Accuracy and Precision of Three-Dimensional Low Dose CT Compared to Standard RSA in Acetabular Cups: An Experimental Study.

    Science.gov (United States)

    Brodén, Cyrus; Olivecrona, Henrik; Maguire, Gerald Q; Noz, Marilyn E; Zeleznik, Michael P; Sköldenberg, Olof

    2016-01-01

    Background and Purpose. The gold standard for detection of implant wear and migration is currently radiostereometry (RSA). The purpose of this study is to compare a three-dimensional computed tomography technique (3D CT) to standard RSA as an alternative technique for measuring migration of acetabular cups in total hip arthroplasty. Materials and Methods. With tantalum beads, we marked one cemented and one uncemented cup and mounted these on a similarly marked pelvic model. A comparison was made between 3D CT and standard RSA for measuring migration. Twelve repeated stereoradiographs and CT scans with double examinations in each position and gradual migration of the implants were made. Precision and accuracy of the 3D CT were calculated. Results. The accuracy of the 3D CT ranged between 0.07 and 0.32 mm for translations and 0.21 and 0.82° for rotation. The precision ranged between 0.01 and 0.09 mm for translations and 0.06 and 0.29° for rotations, respectively. For standard RSA, the precision ranged between 0.04 and 0.09 mm for translations and 0.08 and 0.32° for rotations, respectively. There was no significant difference in precision between 3D CT and standard RSA. The effective radiation dose of the 3D CT method, comparable to RSA, was estimated to be 0.33 mSv. Interpretation. Low dose 3D CT is a comparable method to standard RSA in an experimental setting. PMID:27478832

  12. ULTRA-LIGHTWEIGHT CEMENT

    Energy Technology Data Exchange (ETDEWEB)

    Fred Sabins

    2002-01-23

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report includes results from laboratory testing of ULHS systems along with other lightweight cement systems: foamed and sodium silicate slurries. Comparison studies of the three cement systems examined several properties: tensile strength, Young's modulus, water permeability, and shear bond. Testing was also done to determine the effect that temperature cycling has on the shear bond properties of the cement systems. In addition, analysis was carried out to examine alkali silica reactivity of slurries containing ULHS. Data is also presented from a study investigating the effects of mixing and pump circulation on breakage of ULHS. Information is also presented about the field application of ULHS in cementing a 7-in. intermediate casing in south Texas.

  13. Determinación del desgaste del componente acetabular en prótesis totales de cadera. // Wear determination of acetabular component in total hip prosthesis.

    Directory of Open Access Journals (Sweden)

    G. García del Pino

    2002-01-01

    Full Text Available En este trabajo se realiza un estudio a través del Método de los Elementos Finitos “MEF” sobre el desgaste del componenteacetabular durante el ciclo de marcha y considerando algunos casos extremos de cargas como subir y bajar escaleras,levantarse de una silla, etc. Utilizando el MEF fueron modelados independientemente los componentes acetabular yfemoral de la prótesis total de cadera y puestos en contacto posteriormente. Fueron estudiadas varias posiciones delacetábulo así como diferentes casos de carga simulando pacientes con diferente peso corporal y actividades físicas. Paraevaluar los resultados se crearon rutinas en lenguaje C que organizaron los mismos para un tratamiento estadísticoposterior.Palabras claves: biomecánica, ortopedia, elementos finitos, modelación, desgaste, prótesis de cadera.___________________________________________________________________________Abstract.A wear study of acetabular component during the marching cycle, considering some extreme loads cases as: ascend anddescend stairways, get up from a seat, etc , by means of Finite Elements Method ( FEM , is carried out. The acetabular andfemoral component of the total hip prosthesis were independently modeled and placed in contact lastly. Several acetabulpositions were studied as well as different load cases, simulating patients with different body weight and different physicalactivities. To evaluate the results routines in C language were created in order to organized the same ones for a laterstatistical treatment.Key words. biomechanics, ortophedy, finite elements, modelation, wear, hip bone prosthesis.

  14. 3.0 T conventional hip MR and hip MR arthrography for the acetabular labral tears confirmed by arthroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Chun-Yan [Department of Radiology, Peking University Third Hospital, 49 North Garden Road, Haidian District, Beijing 100191 (China); Wang, Jian-Quan [Department of Sports Medicine, Peking University Third Hospital, 49 North Garden Road, Haidian District, Beijing 100191,PR China (China); Zheng, Zhuo-Zhao, E-mail: zzhuozhao@aliyun.com [Department of Radiology, Peking University Third Hospital, 49 North Garden Road, Haidian District, Beijing 100191 (China); Ren, A.-Hong [Department of Radiology, Beijing Daxing Hospital, 26 West Huangcun Road, Daxing District, Beijing 102600 (China)

    2014-10-15

    Highlights: • MR is the preferred imaging modality for diagnosing acetabular labral tears. • The diagnostic performance of MR arthrography are superior than conventional hip MR. • The hip MR arthrography is recommended for diagnosing acetabular labral lesions. - Abstract: Objective: To evaluate the value of hip MR for diagnosing acetabular labrum tears, and to further compare the diagnostic performances of conventional MR with MR arthrography in acetabular labrum tears. Methods: 90 patients undergoing both hip MR examination and subsequent hip arthroscopy were retrospectively evaluated. Of these patients, 34 accepted both conventional MR and MR arthrography; while the other 56 only underwent conventional MR examination. All hip MR images were independently reviewed by two radiologists, and further compared with the results of hip arthroscopy. Results: 59 of 90 patients were confirmed with acetabular labral tears by hip arthroscopy and 31 without tears. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of conventional MR for evaluating the acetabular labral tears were 61.0%, 77.4%, 83.7% and 51.1% (radiologist A), and 66.1%, 74.2%, 82.9% and 53.4% (radiologist B), respectively, with good consistency between the two observers (K = 0.645). The sensitivity, specificity, PPV and NPV of MR arthrography for assessing the acetabular labral tears were 90.5%, 84.6%, 90.5% and 84.6% (radiologist A), and 95.2%, 84.6%, 90.9% and 91.7% (radiologist B), respectively, with excellent good consistency between the two observers (K = 0.810). The sensitivity and NPV of MR arthrography for diagnosing the acetabular labral tears were significantly higher than those of conventional MR (both P < 0.05). Conclusion: Hip MR arthrography is a reliable evaluation modality for diagnosing the acetabular labral tears, and its diagnostic performance is superior to that of conventional MR at 3.0 T.

  15. Utilization of Iron Ore Tailings as Raw Material for Portland Cement Clinker Production

    OpenAIRE

    Li Luo; Yimin Zhang; Shenxu Bao; Tiejun Chen

    2016-01-01

    The cement industry has for some time been seeking alternative raw material for the Portland cement clinker production. The aim of this research was to investigate the possibility of utilizing iron ore tailings (IOT) to replace clay as alumina-silicate raw material for the production of Portland cement clinker. For this purpose, two kinds of clinkers were prepared: one was prepared by IOT; the other was prepared by clay as a reference. The reactivity and burnability of raw meal, mineralogical...

  16. Effect of Metakaolin on Strength and Efflorescence Quantity of Cement-Based Composites

    OpenAIRE

    Tsai-Lung Weng; Wei-Ting Lin; An Cheng

    2013-01-01

    This study investigated the basic mechanical and microscopic properties of cement produced with metakaolin and quantified the production of residual white efflorescence. Cement mortar was produced at various replacement ratios of metakaolin (0, 5, 10, 15, 20, and 25% by weight of cement) and exposed to various environments. Compressive strength and efflorescence quantify (using Matrix Laboratory image analysis and the curettage method), scanning electron microscopy, and X-ray diffraction anal...

  17. Various durability aspects of calcined Kaolin-blended Portland cement pastes and concretes

    OpenAIRE

    SAILLIO, Mickael; BAROGHEL BOUNY, Véronique; PRADELLE, Sylvain

    2015-01-01

    The use of calcined clay, in the form of metakaolin (MK), as a pozzolanic constituent for concrete has received considerable attention in recent years, due to the lower CO2 emission of this supplementary cementitious material compared to the production of a classic portland cement. Furthermore, concretes incorporating MK show some improve durability properties. In this paper, the durability of concretes and cement pastes with MK as partial replacement of cement (10 and 25%) has been investiga...

  18. High-precision measurements of cementless acetabular components using model-based RSA: an experimental study

    DEFF Research Database (Denmark)

    Baad-Hansen, Thomas; Kold, Søren; Kaptein, Bart L;

    2007-01-01

    BACKGROUND: In RSA, tantalum markers attached to metal-backed acetabular cups are often difficult to detect on stereo radiographs due to the high density of the metal shell. This results in occlusion of the prosthesis markers and may lead to inconclusive migration results. Within the last few yea...

  19. What is the role of clinical tests and ultrasound in acetabular labral tear diagnostics?

    DEFF Research Database (Denmark)

    Troelsen, Anders; Mechlenburg, Inger; Gelineck, John;

    2009-01-01

    BACKGROUND AND PURPOSE: An acetabular labral tear is a diagnostic challenge. Various clinical tests have been described, but little is known about their diagnostic sensitivity and specificity. We investigated the diagnostic validity of clinical tests and ultrasound as compared with MR arthrograph...

  20. An unusual mode of failure of a tripolar constrained acetabular liner: a case report.

    LENUS (Irish Health Repository)

    Banks, Louisa N

    2012-02-01

    Dislocation after primary total hip arthroplasty (THA) is the most commonly encountered complication and is unpleasant for both the patient and the surgeon. Constrained acetabular components can be used to treat or prevent instability after primary total hip arthroplasty. We present the case of a 42-year-old female with a BMI of 41. At 18 months post-primary THA the patient underwent further revision hip surgery after numerous (more than 20) dislocations. She had a tripolar Trident acetabular cup (Stryker-Howmedica-Osteonics, Rutherford, New Jersey) inserted. Shortly afterwards the unusual mode of failure of the constrained acetabular liner was noted from radiographs in that the inner liner had dissociated from the outer. The reinforcing ring remained intact and in place. We believe that the patient\\'s weight, combined with poor abductor musculature caused excessive demand on the device leading to failure at this interface when the patient flexed forward. Constrained acetabular components are useful implants to treat instability but have been shown to have up to 42% long-term failure rates with problems such as dissociated inserts, dissociated constraining rings and dissociated femoral rings being sited. Sometimes they may be the only option left in difficult cases such as illustrated here, but still unfortunately have the capacity to fail in unusual ways.

  1. Free iliac crest grafts with periosteum for treatment of old acetabular defects

    Institute of Scientific and Technical Information of China (English)

    ZHAO De-wei; SUN Qiang; WANG Ben-jie; CUI Da-ping

    2006-01-01

    Objective: To inquire into the therapeutic effectiveness of free iliac crest grafts with periosteum on old acetabular defects.Methods: From February 1996 to June 2005, 9 patients were treated with free iliac crest grafts with periosteum to reconstruct old acetabular defects. There were 7 males and 2 females and the average age was 41.3 years. The acetabular defects were caused by traffic accidents in 6 cases and fall injury in 3 cases. The time from injury to treatment was 4-13 months and averaged 8 months. Intraoperatively we firstly removed the acetabular fracture fragments of the posterior wall. The femoral head was then reducted. Bone graft was harvested from the iliac crest with periosteum, which was sculpted with a rongeur to conform to the defect. The concave (iliac fossa) side of the graft was placed toward the femoral head. The graft was securedly fixed by two to three leg screws.Results: Postoperative syndrome was not found in any of the cases. Harris' score system showed that the score raised from 32. 3 points preoperatively to 81 points postoperatively. The hip function was evaluated as excellent in 3 cases, good in 4 cases and fair in 2 cases.Conclusions: Although this procedure could not exactly reproduce the anatomy of the hip joint, it enables to restore the posterior stability, provide bone-stock for the hip joints and prevent dislocation of the femoral head.

  2. Relationship between developmental dislocation of the hip in infant and acetabular dysplasia at skeletal maturity.

    Science.gov (United States)

    Okano, Kunihiko; Yamaguchi, Kazumasa; Ninomiya, Yoshikazu; Matsubayashi, Shohei; Aoyagi, Kiyoshi; Osaki, Makoto; Enomoto, Hiroshi; Takahashi, Katsuro

    2015-01-01

    Previous reports demonstrated 8-60% patients treated for developmental dislocation of hip (DDH) in infancy have residual acetabular dysplasia (AD) at skeletal maturity. AD patients reportedly exhibit abnormal morphology of the pelvis, high rates of comorbid spinal congenital anomalies and high bone mineral density. These physical findings suggest that AD patients have genetic background. We examined the percentage of AD patients with hip pain at skeletal maturity having a history of DDH in infancy and the correlation between the severity of AD at skeletal maturity and history of DDH treatment to investigate the relationship between AD and DDH.A total of 245 patients were radiographically examined for any history of DDH treatment in infancy. The study included 226 women and 19 men with a mean age at examination of 40.7 years (range 17-59 years).Eighty-eight patients (36%) had a history of DDH treatment (DDH group) and the remaining 157 patients (64%) had no history of DDH treatment (non-DDH group). The average age was lower and acetabular angle was larger in the DDH group. There was a significant increasing trend of the percentage of DDH patients associated with the severity of AD classified with CE, acetabular angle, and acetabular roof angle.Our data suggest that there are several AD patients without a history of DDH in Japan, and AD in patients without a history of DDH has different characteristics from AD in patients with a history of DDH. PMID:25569642

  3. Alternative Fuel for Portland Cement Processing

    Energy Technology Data Exchange (ETDEWEB)

    Schindler, Anton K; Duke, Steve R; Burch, Thomas E; Davis, Edward W; Zee, Ralph H; Bransby, David I; Hopkins, Carla; Thompson, Rutherford L; Duan, Jingran; ; Venkatasubramanian, Vignesh; Stephen, Giles

    2012-06-30

    at a full-scale cement plant with alternative fuels to examine their compatibility with the cement production process. Construction and demolition waste, woodchips, and soybean seeds were used as alternative fuels at a full-scale cement production facility. These fuels were co-fired with coal and waste plastics. The alternative fuels used in this trial accounted for 5 to 16 % of the total energy consumed during these burns. The overall performance of the portland cement produced during the various trial burns performed for practical purposes very similar to the cement produced during the control burn. The cement plant was successful in implementing alternative fuels to produce a consistent, high-quality product that increased cement performance while reducing the environmental footprint of the plant. The utilization of construction and demolition waste, woodchips and soybean seeds proved to be viable replacements for traditional fuels. The future use of these fuels depends on local availability, associated costs, and compatibility with a facility's production process.

  4. Alternative Fuel for Portland Cement Processing

    Energy Technology Data Exchange (ETDEWEB)

    Anton K. Schindler; Steve R. Duke; Thomas E. Burch; Edward W. Davis; Ralph H. Zee; David I. Bransby; Carla Hopkins; Rutherford L. Thompson; Jingran Duan; Vignesh Venkatasubramanian; Stephen Giles.

    2012-06-30

    at a full-scale cement plant with alternative fuels to examine their compatibility with the cement production process. Construction and demolition waste, woodchips, and soybean seeds were used as alternative fuels at a full-scale cement production facility. These fuels were co-fired with coal and waste plastics. The alternative fuels used in this trial accounted for 5 to 16 % of the total energy consumed during these burns. The overall performance of the portland cement produced during the various trial burns performed for practical purposes very similar to the cement produced during the control burn. The cement plant was successful in implementing alternative fuels to produce a consistent, high-quality product that increased cement performance while reducing the environmental footprint of the plant. The utilization of construction and demolition waste, woodchips and soybean seeds proved to be viable replacements for traditional fuels. The future use of these fuels depends on local availability, associated costs, and compatibility with a facility’s production process.

  5. Strength of Ternary Blended Cement Sandcrete Containing Afikpo Rice Husk Ash and Saw Dust Ash

    Directory of Open Access Journals (Sweden)

    L. O. Ettu

    2013-01-01

    Full Text Available This work investigated the compressive strength of ternary blended cement sandcrete containing Afikpo rice husk ash (RHA and sawdust ash (SDA. 105 sandcrete cubes of 150mm x 150mm x 150mm were produced with OPC-RHA binary blended cement, 105 with OPC-SDA binary blended cement, and 105 with OPC-RHA-SDA ternary blended cement, each at percentage OPC replacement with pozzolan of 5%, 10%, 15%, 20%, and 25%. Three cubes for each percentage replacement of OPC with pozzolan and the control were tested for saturated surface dry bulk density and crushed to obtain their compressive strengths at 3, 7, 14, 21, 28, 50, and 90 days of curing. The 90-day strengths obtained from ternary blending of OPC with equal proportions of RHA and SDA were 11.80N/mm2for 5% replacement, 11.20N/mm2for 10% replacement, 10.60N/mm2for 15% replacement, 10.00N/mm2for 20% replacement, and 9.10N/mm2for 25% replacement, while that of the control was 10.90N/mm2. This suggests that very high sandcrete strength values could be obtained with OPCRHA-SDA ternary blended cement with richer mixes, high quality control, and longer days of hydration. Thus, OPC-RHA-SDA ternary blended cement sandcrete could be used for various civil engineering and building works, especially where early strength is not a major requirement.

  6. 21 CFR 888.3210 - Finger joint metal/metal constrained cemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... prosthesis. 888.3210 Section 888.3210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... metal/metal constrained cemented prosthesis. (a) Identification. A finger joint metal/metal constrained cemented prosthesis is a device intended to be implanted to replace a metacarpophalangeal (finger)...

  7. 21 CFR 888.3220 - Finger joint metal/polymer constrained cemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... prosthesis. 888.3220 Section 888.3220 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... metal/polymer constrained cemented prosthesis. (a) Identification. A finger joint metal/polymer constrained cemented prosthesis is a device intended to be implanted to replace a metacarpophalangeal...

  8. 21 CFR 888.3120 - Ankle joint metal/polymer non-constrained cemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... prosthesis. 888.3120 Section 888.3120 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... metal/polymer non-constrained cemented prosthesis. (a) Identification. An ankle joint metal/polymer non-constrained cemented prosthesis is a device intended to be implanted to replace an ankle joint. The...

  9. 21 CFR 888.3350 - Hip joint metal/polymer semi-constrained cemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... prosthesis. 888.3350 Section 888.3350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... metal/polymer semi-constrained cemented prosthesis. (a) Identification. A hip joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace a hip joint. The device...

  10. 21 CFR 888.3300 - Hip joint metal constrained cemented or uncemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... prosthesis. 888.3300 Section 888.3300 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... metal constrained cemented or uncemented prosthesis. (a) Identification. A hip joint metal constrained cemented or uncemented prosthesis is a device intended to be implanted to replace a hip joint. The...

  11. The effect of modified hydrotalcites on mechanical properties and chloride penetration resistance in cement mortar

    NARCIS (Netherlands)

    Yang, Z.; Fischer, H.; Polder, R.B.

    2015-01-01

    In this paper, two types of modified hydrotalcites (MHT) were incorporated into cement mortars with two dosage levels (replacing 5% and 10% cement by mass). Designated testing programme including strength test, porosity test, and rapid chloride migration and diffusion test were employed to investiga

  12. The contradictory effects of pores on fatigue cracking of bone cement.

    NARCIS (Netherlands)

    Janssen, D.; Aquarius, R.J.M.; Stolk, J.; Verdonschot, N.J.J.

    2005-01-01

    The beneficial effect of porosity reduction on the fatigue life of bone cement has been demonstrated in numerous experimental studies. Clinically, however, it seems that the beneficial effect of porosity reduction of cement around total hip replacement components can only be found in large follow-up

  13. Acetabular lateral reconstruction after total hip arthroplasty:understanding and application of core technology%人工髋关节翻修髋臼侧重建:对技术核心的认识及应用

    Institute of Scientific and Technical Information of China (English)

    张文贤; 范有福; 王小燕; 吕江宏

    2014-01-01

    BACKGROUND:After the initial hip replacement, aseptic or infective loosening and subsidence of the prosthesis, acetabular wear, pain, osteolysis and other factors may lead to the loss of prosthesis stability and loss of joint function, which are the common cause of hip arthroplasty. Among the hip arthroplasty, acetabular lateral reconstruction is essential and largely determines the success or failure of revision surgery. OBJECTIVE:To explore the present situation of reconstructing acetabulum after total hip arthroplasty. METHODS:A computer-based online search of PubMed database (http://www.ncbi.nlm.nih.gov/PubMed) between January 1998 and March 2014, and CNKI database (http://www.cnki.net/) from January 2003 to March 2014 was undertaken for the articles about reconstructing acetabulum after total hip arthroplasty. The key words were“artificial joint, reconstruction, acetabular lateral reconstruction, current situation”in Chinese and“reconstructed acetabulum, total hip arthroplasty”in English. Article about hip reconstruction, acetabyular reconstruction, bone defect reconstruction, prosthesis choice and reconstruction, and soft tissue balance were also selected. Repetitive researches were excluded. RESULTS AND CONCLUSION:According to inclusion criteria, 26 articles were involved in this study. A perfect acetabular revision should achieve the fol owing goals:stabilize acetabular prosthesis after acetabular revision;recover hip rotation center and biomechanical properties;repair acetabular bone defects and increase hip bone. Adequate preparation before surgery is an important prerequisite for the success of surgery and good results, aseptic and septic loosening or subsidence of the prosthesis, as wel as acetabular wear and tear are common causes of hip revision. Intraoperative reconstruction of acetabular anteversion and camber angles, acetabular rotation center reconstruction, reconstruction of acetabular bone defects, selection of reconstruction of

  14. ULTRA-LIGHTWEIGHT CEMENT

    Energy Technology Data Exchange (ETDEWEB)

    Fred Sabins

    2003-01-31

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report discusses testing that was performed for analyzing the alkali-silica reactivity of ULHS in cement slurries. DOE joined the Materials Management Service (MMS)-sponsored joint industry project ''Long-Term Integrity of Deepwater Cement under Stress/Compaction Conditions.'' Results of the project contained in two progress reports are also presented in this report.

  15. POZZOLAN AND CEMENTS WITH POZZOLAN

    OpenAIRE

    Kaplan, Hasan; Hanifi BİNİCİ

    1995-01-01

    Cement, one of the basic material of construction engineering, has an important place in view of strength and cost of structures. Cement consumption is increasing parallel to development of building construction sector. For cement producers, minimal cost is desired by using new and economical material sources. On the other hand, the controllers and contractors need cheaper, safer and higher strength materials. From this respect cement industry tends to use cement with pozzolan. In Türkiye, ce...

  16. Porous surface modified bioactive bone cement for enhanced bone bonding.

    Directory of Open Access Journals (Sweden)

    Qiang He

    defect. CONCLUSIONS: Our findings suggested a new bioactive bone cement for prosthetic fixation in total joint replacement.

  17. Cranial acetabular retroversion is common in developmental dysplasia of the hip as assessed by the weight bearing position

    DEFF Research Database (Denmark)

    Troelsen, Anders; Mikkelsen, Lone Rømer; Jacobsen, Steffen;

    2010-01-01

    The appearance of acetabular version differs between the supine and weight bearing positions in developmental dysplasia of the hip. Weight bearing radiographic evaluation has been recommended to ensure the best coherence between symptoms, functional appearance, and hip deformities. Previous preva...

  18. Open reduction and internal fixation aided by intraoperative 3-dimensional imaging improved the articular reduction in 72 displaced acetabular fractures

    DEFF Research Database (Denmark)

    Eckardt, Henrik; Lind, Dennis; Toendevold, Erik

    2015-01-01

    Background and purpose - During acetabular fracture surgery, the acetabular roof is difficult to visualize with 2-dimensional fluoroscopic views. We assessed whether intraoperative 3-dimensional (3D) imaging can aid the surgeon to achieve better articular reduction and improve implant fixation....... Patients and methods - We operated on 72 acetabular fractures using intraoperative 3D imaging and compared the operative results, duration of surgery, and complications with those for 42 consecutive acetabular fracture operations conducted using conventional fluoroscopic imaging. Postoperative reduction...... was evaluated on reconstructed coronal and sagittal images of the acetabulum. Results - The fracture severity and patient characteristics were similar in the 2 groups. In the 3D group, 46 of 72 patients (0.6) had a perfect result after open reduction and internal fixation, and in the control group, 17 of 42 (0...

  19. Tantalum acetabular augments in one-stage exchange of infected total hip arthroplasty: a case-control study.

    Science.gov (United States)

    Klatte, Till Orla; Kendoff, Daniel; Sabihi, Reza; Kamath, Atul F; Rueger, Johannes M; Gehrke, Thorsten

    2014-07-01

    During the one-stage exchange procedure for periprosthetic joint infection (PJI) after total hip arthroplasty (THA), acetabular defects challenge reconstructive options. Porous tantalum augments are an established tool for addressing acetabular destruction in aseptic cases, but their utility in septic exchange is unknown. This retrospective case-control study presents the initial results of tantalum augmentation during one-stage exchange for PJI. Primary endpoints were rates of re-infection and short-term complications associated with this technique. Study patients had no higher risk of re-infection with equivalent durability at early follow-up with a re-infection rate in both groups of 4%. In conclusion, tantalum augments are a viable option for addressing acetabular defects in one-stage exchange for septic THA. Further study is necessary to assess long-term durability when compared to traditional techniques for acetabular reconstruction. PMID:24559522

  20. Massive heterotopic ossification associated with late deficits in posterior wall of acetabulum after failed acetabular fracture operation

    OpenAIRE

    Zhang, Yuntong; Xie, Yang; Xu, Shuogui; Zhang, Chuncai

    2013-01-01

    Background Heterotopic ossification is a common postoperative complication of acetabular fracture. However, functionally significant heterotopic ossification with associated late bone defects in the posterior wall of the acetabulum is rare and challenging to treat. When heterotopic ossification is a late complication of failed acetabular fracture operation, it is disabling and may only be treated by THA. THA is highly susceptible to premature failure in young and active patients and may requi...

  1. Characteristics of Bamboo Leaf Ash Blended Cement Paste and Mortar

    Directory of Open Access Journals (Sweden)

    Umoh A.A.

    2015-01-01

    Full Text Available The use of bamboo leaf ash as cement supplement can contribute to reduction in cost and environmental hazard associated with cement production as well as waste pollution caused by the littered bamboo leaves. Therefore, the characteristics of cement paste and mortar incorporating bamboo leaf ash were investigated. The results of the physical properties of the pastes were within the requirements stipulated by relevant standards while that of the mortar cubes indicated that the compressive strength generally increased with curing age, and that the mix containing 15% Bamboo Leaf Ash (BLA by mass competes favorably with that of the reference mix at 28days and above. The water absorption and apparent porosity were observed to increase with increase in BLA content, while the bulk density decreases as the percentage of BLA increases from 5% to 25% by mass. The study concluded that 15% BLA replacing cement is adequate for the production of masonry mortar.

  2. A review on emission analysis in cement industries

    Energy Technology Data Exchange (ETDEWEB)

    Ali, M.B.; Saidur, R.; Hossain, M.S. [University of Malaya, Kuala Lumpur (Malaysia). Faculty of Engineering

    2011-06-15

    The cement subsector consumes approximately 12-15% of the total industrial energy use. Therefore, this subsector releases CO{sub 2} emissions to the atmosphere as a result of burning fossil fuels to produce energy needed for the cement manufacturing process. The cement industry contributes about 7% of the total worldwide CO{sub 2} emissions. This study complied a comprehensive literature in terms of Thesis (MS and PhD), peer reviewed journals papers, conference proceedings, books, reports, websites for emission generation and mitigation technique. Emission released associated with the burning of fuels have been presented in this paper. Different sources of emissions in a cement industry has been identified and presented in this study. Different techniques to reduce CO{sub 2} emissions from the cement manufacturing industries are reviewed and presented in this paper. The major techniques are: capture and storage CO{sub 2} emissions, reducing clinker/cement ratio by replacing clinker with different of additives and using alternative fuels instead of fossil fuels. Apart from these techniques, various energy savings measures in cement industries expected to reduce indirect emissions released to the atmosphere. Based on review results it was found that sizeable amount of emission can be mitigated using different techniques and energy savings measures.

  3. [Estrogen replacement].

    Science.gov (United States)

    Søgaard, A J; Berntsen, G K; Magnus, J H; Tollan, A

    1998-02-10

    Recent research on long-term postmenopausal hormone replacement therapy (HRT) indicates a positive effect on both total mortality and morbidity. This has raised the question of widespread preventive long-term use of HRT. Possible side-effects and ideological issues related to preventive HRT have led to debate and uncertainty among health professionals, in the media, and in the population at large. In order to evaluate the level of knowledge about and attitudes towards HRT, a randomly selected group of 737 Norwegian women aged 16-79 was interviewed by the Central Bureau of Statistics. One in three women had received information about HRT in the last two years, mainly through weekly magazines and physicians. The proportion who answered the questions on knowledge correctly varied from 36% to 47%. Those who had been given information by a physician possessed accurate knowledge, had more positive attitudes towards HRT and were more willing to use HRT than women who had reviewed information through other channels. Women with a higher level of education were better informed and more knowledgeable than others, but were nevertheless more reluctant to use HRT than those who were less educated. The limited number of women who actually receive information on HRT, the low level of knowledge and the ambivalent attitudes toward HRT are a major challenge to the public health service.

  4. The curative effect evaluations of 46 Bone cement type artificial bipolar femoral head replacement for femoral neck fracture in the elderly patients%骨水泥型人工双极股骨头置换治疗老年人股骨颈骨折46例疗效分析

    Institute of Scientific and Technical Information of China (English)

    张庆凯; 李忠义; 马也

    2014-01-01

    目的:探讨骨水泥型人工双极股骨头置换治疗老年人股骨颈骨折的疗效。方法:我院2009-12至2012-12共收治并采用骨水泥型人工双极股骨头置换治疗老年人股骨颈骨折患者46例,其中,男性15例,女性31例,年龄在65—91岁之间,平均78.8岁;左侧19例,右侧27例,均为单侧股骨颈骨折;致伤原因:摔伤所致35例,交通事故所致11例。骨折按Garden分型:Ⅲ型33例,Ⅳ13例。通过手术时间,出血量及术后肢体功能Harris评分等,评价手术效果。结果:46例患者全部获得随访,随访时间为6-36个月,平均20.5个月。假体松动2例,肺内感染2例,股骨头脱位1例,并发症发生率为:11%;经处理后,患者痊愈。所有患者肢体功能恢复良好。术前Harris评分:43.2±8.3分,术后6个月及12个月分别为91.4±3.2分93.2±4.6分,较置换前明显提高,P<0.01,差异有统计学意义。结论:骨水泥型人工双极股骨头置换治疗老年人股骨颈骨折具有固定牢固,返修率小,术后并发症少,肢体功能恢复良好等优点,是治疗该类疾病一种较为良好的选择。%Objective:To report and discuss The curative effect of surgical treatment with Bone cement type artificial bipolar femoral head replacement for Femoral neck fracture in the elderly patients.Method:From December 2009 to December 2012,46 cases with Femoral neck fractures in the elderly patients were treated with Bone cement type artificial bipolar femoral head replacement in our hospital, Including 15 males and 31 females ,with an average of 78.8 years old .(range,65 to 91 years old).19 cases in the left,27 cases in the right. And al the cases were unilateral fractures. The causes of injury:35 cases were related to fal ing ,11 cases were related to traffic accident. According to Garden classification ,33 cases were of typeⅢ, 14 cases were of typeⅣ. Evaluate the curative effect by the

  5. Alternative fuels in cement industry; Alternativa braenslen i cementindustrin

    Energy Technology Data Exchange (ETDEWEB)

    Nyman, K.E.; Ek, R. [Finnsementti Oy, Parainen (Finland); Maekelae, K. [Finreci Oy (Finland)

    1997-10-01

    In this project the cement industry`s possibilities to replace half of the fossil fuels with waste derived fuels are investigated. Bench-scale experiments, pilot plant tests and full scale tests have been done with used tires and plastics wastes

  6. Determinación del desgaste del componente acetabular en prótesis totales de cadera. // Wear determination of acetabular component in total hip prosthesis.

    OpenAIRE

    G. García del Pino; Gonçalves, E; R. Gonzáles Lima; R. Dantas Queiroz; J. L. Valín Rivera

    2002-01-01

    En este trabajo se realiza un estudio a través del Método de los Elementos Finitos “MEF” sobre el desgaste del componenteacetabular durante el ciclo de marcha y considerando algunos casos extremos de cargas como subir y bajar escaleras,levantarse de una silla, etc. Utilizando el MEF fueron modelados independientemente los componentes acetabular yfemoral de la prótesis total de cadera y puestos en contacto posteriormente. Fueron estudiadas varias posiciones delacetábulo así como diferentes cas...

  7. Scrap tire ashes in portland cement production

    Directory of Open Access Journals (Sweden)

    Mónica Adriana Trezza

    2009-01-01

    Full Text Available Scrap tires are not considered harmful waste, but their stocking and disposal are a potential health and environmental risk. Properly controlled calcinations at high temperatures make tire combustion an interesting alternative due to its high calorific power, comparable to that of fuel-oil. Consequently, using them as an alternative combustible material in cement kilns makes it possible to give it a valuable use. However, it remains to be assured whether the impurities added to the clinker through these fuels do not affect its structure or properties.This paper shows the studies carried out on different clinkers under laboratory conditions with different levels of addition of scrap tire ashes, added by partially replacing traditional fuel in cement kilns.

  8. Utilization of ground waste seashells in cement mortars for masonry and plastering.

    Science.gov (United States)

    Lertwattanaruk, Pusit; Makul, Natt; Siripattarapravat, Chalothorn

    2012-11-30

    In this research, four types of waste seashells, including short-necked clam, green mussel, oyster, and cockle, were investigated experimentally to develop a cement product for masonry and plastering. The parameters studied included water demand, setting time, compressive strength, drying shrinkage and thermal conductivity of the mortars. These properties were compared with those of a control mortar that was made of a conventional Portland cement. The main parameter of this study was the proportion of ground seashells used as cement replacement (5%, 10%, 15%, or 20% by weight). Incorporation of ground seashells resulted in reduced water demand and extended setting times of the mortars, which are advantages for rendering and plastering in hot climates. All mortars containing ground seashells yielded adequate strength, less shrinkage with drying and lower thermal conductivity compared to the conventional cement. The results indicate that ground seashells can be applied as a cement replacement in mortar mixes and may improve the workability of rendering and plastering mortar.

  9. Reuse of grits waste for the production of soil--cement bricks.

    Science.gov (United States)

    Siqueira, F B; Holanda, J N F

    2013-12-15

    This investigation focuses on the reuse of grits waste as a raw material for replacing Portland cement by up to 30 wt.% in soil-cement bricks. The grits waste was obtained from a cellulose factory located in south-eastern Brazil. We initially characterized the waste sample with respect to its chemical composition, X-ray diffraction, fineness index, morphology, pozzolanic activity, and pollution potential. Soil-cement bricks were then prepared using the waste material and were tested to determine their technological properties (e.g., water absorption, apparent density, volumetric shrinkage, and compressive strength). Microstructural evolution was accompanied by confocal microscopy. It was found that the grits waste is mainly composed of calcite (CaCO3) particles. Our results indicate that grits waste can be used economically, safely, and sustainably at weight percentages of up to 20% to partially replace Portland cement in soil-cement bricks. PMID:24140481

  10. Sustainable Nanopozzolan Modified Cement: Characterizations and Morphology of Calcium Silicate Hydrate during Hydration

    Directory of Open Access Journals (Sweden)

    N. Mohamed Sutan

    2015-01-01

    Full Text Available There are environmental and sustainable benefits of partially replacing cement with industrial by-products or synthetic materials in cement based products. Since microstructural behaviours of cement based products are the crucial parameters that govern their sustainability and durability, this study investigates the microstructural comparison between two different types of cement replacements as nanopozzolan modified cement (NPMC in cement based product by focusing on the evidence of pozzolanic reactivity in corroboration with physical and mechanical properties. Characterization and morphology techniques using X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR, energy-dispersive X-ray spectroscopy (EDS, and scanning electron microscopy (SEM were carried out to assess the pozzolanic reactivity of cement paste modified with the combination of nano- and micro silica as NPMC in comparison to unmodified cement paste (UCP of 0.5 water to cement ratio (w/c. Results were then substantiated with compressive strength (CS results as mechanical property. Results of this study showed clear evidence of pozzolanicity for all samples with varying reactivity with NPMC being the most reactive.

  11. Femoro-acetabular impingement and hip pain with conventionally normal x-rays.

    LENUS (Irish Health Repository)

    Baker, J F

    2010-06-01

    There has in recent years been a fundamental change in the understanding of hip pain in the young adult and hip pain without plain radiographic findings of arthritis. Pain in these groups has long represented a diagnostic and therapeutic challenge. With new appreciation of hip biomechanics, pathological processes and the arrival of modern imaging modalities we now have a greater understanding of non-arthritic hip pathology. One of the commonest yet least well recognized \\'new\\' diagnoses around the hip is femoro-acetabular impingement (FAI). FAI is a developmental condition of the hip joint that is associated with abnormal anatomical configuration and thus joint mechanics on either the femoral or acetabular sides or both. It is hypothesized to have a variety of precipitants and may ultimately lead to labral and chondral injury and what has previously been referred to as \\'primary\\' or \\'idiopathic\\' hip osteoarthritis.

  12. INVESTIGATING EFFECTS OF INTRODUCTION OF CORNCOB ASH INTO PORTLAND CEMENTS CONCRETE: MECHANICAL AND THERMAL PROPERTIES

    Directory of Open Access Journals (Sweden)

    Antonio Price

    2014-01-01

    Full Text Available The purpose of this study was to evaluate the benefits of replacing Ordinary Portland Cement (OPC with Corncob Ash (CCA blended cements. The cement industry contributes considerable amount of Carbon Dioxide (CO2 emissions into the atmosphere. The main contribution of CO2 emissions from cement production results from the process of creating Calcium Oxide (CaO from limestone (CaCO3 commonly known as the calcination process. Blending OPC with a pozzolanic material will assist in the reduction of CO2 emissions due to calcination as well as enhance the quality of OPC. There are various pozzolanic materials such as fly ash, rice husk, silica fume and CCA that could be promising partial replacement for OPC. In this study, CCA will serve as the primary blending agent with OPC. An experiment was performed to designate an appropriate percentage replacement of CCA that would comply with specific standards of cement production. The experimental plan was designed to analyze compressive strength, workability and thermal performance of various CCA blended cements. The data from the experiment indicates that up to 10% CCA replacement could be used in cement production without compromising the structural integrity of OPC. In addition, it was found that the compressive strength and workability of the resulting concrete could be improved when CCA is added to the mixtures. Furthermore, it was shown that the introduction of 10% CCA can lead to significant reduction in thermal conductivity of the mixture.

  13. Magnetic resonance imaging of para-acetabular insufficiency fractures in patients with malignancy

    Energy Technology Data Exchange (ETDEWEB)

    Theodorou, S.J. [Department of Radiology, School of Medicine, University of California, San Diego Medical Center, San Diego, CA (United States)]|[Department of Radiology, Veterans Administration Medical Center, San Diego, CA (United States)]|[Department of Clinical Radiology, University of Manchester, Manchester (United Kingdom); Theodorou, D.J. [Department of Radiology, School of Medicine, University of California, San Diego Medical Center, San Diego, CA (United States)]|[Department of Radiology, Veterans Administration Medical Center, San Diego, CA (United States)]. E-mail: daphne_theodorou@hotmail.com; Schweitzer, M.E. [Department of Radiology, New York University Hospital for Joint Diseases, NY (United States); Kakitsubata, Y. [Department of Radiology, School of Medicine, University of California, San Diego Medical Center, San Diego, CA (United States)]|[Department of Radiology, Veterans Administration Medical Center, San Diego, CA (United States); Resnick, D. [Department of Radiology, School of Medicine, University of California, San Diego Medical Center, San Diego, CA (United States)]|[Department of Radiology, Veterans Administration Medical Center, San Diego, CA (United States)

    2006-02-15

    AIM: To describe the characteristic magnetic resonance imaging (MRI) findings of para-acetabular insufficiency fractures in patients with malignancy, and compare the MRI appearance of these fractures with that of metastatic bone disease. MATERIALS AND METHODS: MRI examinations were reviewed in 16 patients with a known malignant tumour and severe hip pain that raised the possibility of local recurrence or metastatic disease. Six patients had received pelvic irradiation, and three patients were receiving steroid medication. RESULTS: The total number of fractures detected was 21: a solitary fracture was present in 11 patients and five patients had bilateral para-acetabular fractures. Two patients had associated sacral insufficiency fractures, and one of them had stress fractures involving both acetabular columns. Conventional radiography allowed the diagnosis of 14 (67%) fractures; six (28%) radiographic examinations were negative; and one (5%) examination was equivocal for fracture. Available scintigraphic and computed tomography (CT) studies revealed typical findings of fracture. Using MRI, insufficiency fractures appeared as linear regions of low signal intensity on T1- and T2-weighted images. Marked marrow oedema was evident in all cases. Fractures characteristically were parallel to the superior acetabulum in a curvilinear fashion in 18 (86%) instances, and were oblique in three (14%) instances. The fractures demonstrated considerable enhancement after intravenous gadolinium administration. No associated soft tissue masses were documented. CONCLUSION: Para-acetabular insufficiency fractures are a cause of hip pain, which may mimic skeletal metastasis in the patient with malignancy and pelvic irradiation. Recognition of the characteristic MRI findings of these fractures can preclude misdiagnosis and unnecessary bone biopsy.

  14. The place of computerized axial tomography in the evaluation of acetabular fractures

    OpenAIRE

    Asik, Mehmet; Akman, Senol; Taser, Omer; Aritamur, Ayhan

    2004-01-01

    Besides the importance of standard AP and Judet s 45° iliac and obturator pelvic views, CAT has proved to be very useful in the evaluation of the fractures of the acetabulum. Of 96 patients with acetabular fractures, who applied to the Orthopaedics and Traumatology Department, Istanbul Medical Faculty, Istanbul University between 1987 and 1991 in addition to conventional radiography, CAT investigation was done in 32 patients for whom it was considered necessary. The results of both convention...

  15. Long-term outcome of operative management of delayed acetabular fractures

    Institute of Scientific and Technical Information of China (English)

    ZHU Shi-wen; SUN Xu; YANG Ming-hui; LI Yu-neng; ZHAO Chun-peng; WU Hong-hua; CAO Qi-yong

    2013-01-01

    Background Surgical treatment of acetabular fracture has long been a challenging area in the field of orthopedic trauma.The aim of this research was to investigate the operative methods for delayed acetabular fractures and to assess the operation results.Methods The operative approaches,procedures,results,and complications of the delayed acetabular fractures between 1995 and 2005 were retrospectively evaluated at Beijing Jishuitan Hospital.Quality of life was assessed for each patient with the Merle d'Aubingne and Postel fracture function rating scale and the radiological result was assessed using the Matta radiological score.Results Sixty-eight cases (70 hips) were followed up with a minimal duration of five years (average of 5.8 years).Excellent functional results were observed in 10 hip joints,good results in 40,fair results in 11,and poor results in nine.The risks of poor prognosis include impact fracture or osteochondral fracture of femoral head,a time beyond 42 days from injury to operative management,and dislocation of femoral head during the injury.Some of the problems,which were observed included postoperative infection in two hips,iatrogenic sciatic nerve injury in eight hips,traumatic arthritis in 15 hips,heterotopic ossification in 17 hips,and necrosis of the femoral head in six hips.Conclusion A careful selection of operative indications for delayed acetabular fractures in combination with a proper ooerative aPProach and appropriate reduction and fixation could guarantee relatively good results.

  16. The effect of femoro-acetabular impingement on the kinematics and kinetics of the hip joint

    OpenAIRE

    Alshameeri, Zeiad; Khanduja, Vikas

    2014-01-01

    Gait analysis is an objective tool that has been used to assess and monitor treatment for many musculoskeletal conditions. Recently, it has been used to assess the impact of femoro-acetabular impingement (FAI) on the hip and lower limb movements. There have been a fairly limited number of studies published so far reporting unexpected and inconsistent results, which calls for more research to be conducted in this arena. In the light of the limited data available, it has been challenging to rec...

  17. Osteonecrosis and femoro-acetabular impingement: sequelae of developmental dysplasia of the hip

    OpenAIRE

    Cheung, Jason Pui Yin; Chow, Wang; To, Michael

    2012-01-01

    A 2-year-old girl with developmental dysplasia of the right hip underwent open reduction and capsulorrhaphy via the anterior approach with hip spica casting in an internally rotated position. During her 26 years of follow-up, she was found to have osteonecrosis and subsequently cam-type femoro-acetabular impingement at 28 years of age. She was treated with surgical dislocation of the hip and osteochondroplasty to recreate the normal contour of the head and neck offset.

  18. Surgical treatment of acetabular fractures: clinical and radiological results and its complications

    International Nuclear Information System (INIS)

    The objective of this work is to analyse a serie of consecutive cases of surigically treated acetabular fractures, evaluating middle-term clinical and radiological results. A retrospective analysis of clinical histories, surgical forms and X-rays was performed for 42 patients who underwent surgery in two centers (Instituto Nacional de Ortopedia y Traumatologia [INOT] and Banco de Protesis), from July 2001 through August 2007

  19. ULTRA-LIGHTWEIGHT CEMENT

    Energy Technology Data Exchange (ETDEWEB)

    Fred Sabins

    2001-10-23

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). Work reported herein addresses tasks performed in the fourth quarter as well as the other three quarters of the past year. The subjects that were covered in previous reports and that are also discussed in this report include: Analysis of field laboratory data of active cement applications from three oil-well service companies; Preliminary findings from a literature review focusing on problems associated with ultra-lightweight cements; Summary of pertinent information from Russian ultra-lightweight cement literature review; and Comparison of compressive strengths of ULHS systems using ultrasonic and crush methods Results reported from the fourth quarter include laboratory testing of ULHS systems along with other lightweight cement systems--foamed and sodium silicate slurries. These comparison studies were completed for two different densities (10.0 and 11.5 lb/gal) and three different field application scenarios. Additional testing included the mechanical properties of ULHS systems and other lightweight systems. Studies were also performed to examine the effect that circulation by centrifugal pump during mixing has on breakage of ULHS.

  20. Rapid Hip Osteoarthritis Development in a Patient with Anterior Acetabular Cyst with Sagittal Alignment Change

    Directory of Open Access Journals (Sweden)

    Yasuhiro Homma

    2014-01-01

    Full Text Available Rapidly destructive coxarthrosis (RDC is rare and develops unusual clinical course. Recent studies suggest multiple possible mechanisms of the development of RDC. However the exact mechanism of RDC is still not clear. The difficulty of the study on RDC is attributed to its rareness and the fact that the data before the onset of RDC is normally unavailable. In this report, we presented the patient having the radiographic data before the onset who had rapid osteoarthritis (OA development after contralateral THA, which meets the current criteria of RDC. We thought that the increased posterior tilt of the pelvis after THA reinforced the stress concentration at pre-existed anterior acetabular cyst, thereby the destruction of the cyst was occurred. As a result the rapid OA was developed. We think that there is the case of rapid osteoarthritis developing due to alternating load concentration by posterior pelvic tilt on preexisting anterior acetabular cyst such as our patient among the cases diagnosed as RDC without any identifiable etiology. The recognition of sagittal alignment changes and anterior acetabular cyst may play important role in prediction and prevention of the rapid hip osteoarthritis development similar to RDC.

  1. Clean Development Mechanism: Laterite as Supplementary Cementing Material (SCM

    Directory of Open Access Journals (Sweden)

    Syed Zaighum Abbass

    2013-02-01

    Full Text Available Carbon dioxide (CO2 a major Green House Gas (GHG in the atmosphere, is believed to be largely responsible for global climate change through industrial emissions. The level of CO2 concentration has exponentially increased from about 280 ppm at the start of the industrial revolution to about 380 ppm to date. Although Kyoto protocol has bound industrialized nations to reduce green house gas emissions by 5.2% below 1990 levels around year 2008-2012, but violation continues. The cement industry is one of the major emitter of green house gases, particularly CO2 due to its energy intensive production process. It is estimated that approximately 1 tone of CO2 is released during the manufacturing of each tone of Portland cement. Most of CO2 emissions originate from burning fossil fuels and de-carbonization of limestone in a cement plant. During past several decades, the use of by-product materials in concrete, either as components of blended cements or as admixtures, has increased significantly. In this study, another alternate Supplementary Cementing Material (SCM, Laterite has been used with the objectives: to evaluate the performance of cement containing different percentages of laterite (5, 10, 15, 20, 25, and 30 %; to identify the optimum replacement percentage; and to investigate the effects of different concentrations of laterite on various properties of cement. For that purpose, laterite was tested: before blending (for elemental and mineralogical composition by using XRF, SEM and XRD: after blending (Elemental analysis using XRF, fineness test by using Blaine’s air permeability test and for particle size % on 45, 90 and 200 µ sieve, respectively; and after hydration (for mineralogical analysis using SEM. Furthermore, physical tests of manufactured cement, i.e., water consistency, setting time, Le-Chatlier-expansion and compressive strength were also evaluated and compared with limestone and fly-ash cement blends. The results show that with the

  2. PART II. HYDRATED CEMENTS

    Directory of Open Access Journals (Sweden)

    Milan Drabik

    2014-09-01

    Full Text Available Essential focus of the study has been to acquire thermoanalytical events, incl. enthalpies of decompositions - ΔH, of technological materials based on two types of Portland cements. The values of thermoanalytical events and also ΔH of probes of technological compositions, if related with the data of a choice of minerals of calcium-silicate-sulfate-aluminate hydrates, served as a valued input for the assessment of phases present and phase changes due to the topical hydraulic processes. The results indicate mainly the effects of "standard humidity" or "wet storage" of the entire hydration/hydraulic treatment, but also the presence of cement residues alongside calcium-silicate-sulfate-aluminate hydrates (during the tested period of treatment. "A diluting" effect of unhydrated cement residues upon the values of decomposition enthalpies in the studied multiphase system is postulated and discussed

  3. Magnetic resonance imaging and magnetic resonance arthography of the acetabular labrum: Comparison with surgical findings; Magnetresonanztomographie und Magnetresonanzarthrographie des Labrum acetabulare: Vergleich mit operativen Ergebnissen

    Energy Technology Data Exchange (ETDEWEB)

    Czerny, C. [Universitaetsklinik fuer Radiodiagnostik, Vienna (Austria). Abt. fuer Osteologie; Kramer, J. [Universitaetsklinik fuer Radiodiagnostik, Vienna (Austria). Abt. fuer Osteologie; Institut fuer bildgebende Diagnostik am Schillerpark, Linz (Austria); Neuhold, A. [Krankenhaus Rudolfinerhaus, Vienna (Austria). Inst. fuer bildgebende Diagnostik; Urban, M. [Krankenhaus Sozialmedizinisches Zentrum Ost, Vienna (Austria). Abt. fuer Radiodiagnostik; Tschauner, C. [Orthopaedisches Landeskrankenhaus Stolzalpe (Austria); Hofmann, S. [Krankenhaus Sozialmedizinisches Zentrum Ost, Vienna (Austria). Abt. fuer Radiodiagnostik; Orthopaedisches Landeskrankenhaus Stolzalpe (Austria)

    2001-08-01

    Aim of the study: To evaluate the accuracy of magnetic resonance imaging (MRI) and magnetic resonance (MR) arthrography in detecting acetabular labral lesions in correlation to surgical findings. Patients and methods: Forty patients (40 hips) with chronic hip pain and a strong clinical suspicion of labral lesions were examined with MRI in the coronal and axial plane by obtaining T{sub 1} weighted and proton density-weighted spin echo sequences. Additionally, MR arthrography of the high joint in the coronal oblique and sagittal oblique plane was performed by obtaining T{sub 1}-weighted three-dimensional gradient echo sequences after the intraarticular injection of gadopentate dimeglumine. The labra were prospectively evaluated on the basis of morphology, signal intensity, the presence or absence of a tear, and their attachment to the acetabulum. All patients underwent surgery, and the MRI findings and MR arthrography findings were compared with the surgical results. Results: Surgically, 34 labral lesions, and 6 normal labra were detected. MRI correctly depicted labral lesions in 24 patients and two normal labra, and MR arthrography correctly depicted labral lesions in 30 patients and 5 normal labra compared with the surgical results. The sensitivity of MRI was 80%, the accuracy of MRI was 65%, the sensitivity of MR arthrography was 95%, and the accuracy of MR arthgrography was 88%. Conclusions: MR arthrography enables considerably more accurate detection of acetabular labral lesions than MRI. MR arthrography should be the method of choice for the diagnosis of the presence or absence of acetabular labral lesions in patients with chronic hip pain and a strong clinical suspicion of labral lesions. (orig.) [German] Ziel: Die Bestimmung der Wertigkeit der konventionellen Magnetresonanztomographie (MRT) und der Magnetresonanzarthrographie (MR-Arthrographie) in der Abklaerung von Laesionen des Labrum acetabulare im Vergleich mit Operationsbefunden (Goldstandard). Methode

  4. Cement Mason's Curriculum. Instructional Units.

    Science.gov (United States)

    Hendirx, Laborn J.; Patton, Bob

    To assist cement mason instructors in providing comprehensive instruction to their students, this curriculum guide treats both the skills and information necessary for cement masons in commercial and industrial construction. Ten sections are included, as follow: related information, covering orientation, safety, the history of cement, and applying…

  5. Cement og politik

    DEFF Research Database (Denmark)

    Lund, Joachim

    2012-01-01

    as well as in the public sphere. Most of the extensive job creating measures he carried out as a minister for public works necessarily involved the use of great amounts of cement – the primary produce of F.L. Smidth & Co. Gunnar Larsen thus became an easy target for Communist propaganda, picturing him...... of the Soviet Union (including an F.L. Smidth & Co. cement plant in former Estonia). He spent the last 15 months of the occupation in Sweden and was arrested after having returned to Copenhagen in May, 1945. Although a Copenhagen city court prison sentence for economic collaboration was reversed, he had...

  6. Technology Roadmaps: Cement

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    To support its roadmap work focusing on key technologies for emissions reductions, the International Energy Agency (IEA) also investigated one particular industry: cement. Cement production includes technologies that are both specific to this industry and those that are shared with other industries (e.g., grinding, fuel preparation, combustion, crushing, transport). An industry specific roadmap provides an effective mechanism to bring together several technology options. It outlines the potential for technological advancement for emissions reductions in one industry, as well as potential cross-industry collaboration.

  7. Cementing a wellbore using cementing material encapsulated in a shell

    Science.gov (United States)

    Aines, Roger D.; Bourcier, William L.; Duoss, Eric B.; Spadaccini, Christopher M.; Cowan, Kenneth Michael

    2016-08-16

    A system for cementing a wellbore penetrating an earth formation into which a pipe extends. A cement material is positioned in the space between the wellbore and the pipe by circulated capsules containing the cement material through the pipe into the space between the wellbore and the pipe. The capsules contain the cementing material encapsulated in a shell. The capsules are added to a fluid and the fluid with capsules is circulated through the pipe into the space between the wellbore and the pipe. The shell is breached once the capsules contain the cementing material are in position in the space between the wellbore and the pipe.

  8. Strength of Blended Cement Sandcrete & Soilcrete Blocks Containing Cassava Waste Ash and Plantain Leaf Ash

    Directory of Open Access Journals (Sweden)

    L. O. Ettu

    2013-01-01

    Full Text Available This work investigated the compressive strength of binary and ternary blended cement sandcrete and soilcrete blocks containing cassava waste ash (CWA and plantain leaf ash (PLA. 135 solid sandcrete blocks and 135 solid soilcrete blocks of 450mm x 225mm x 125mm were produced with OPC-CWA binary blended cement, 135 with OPC-PLA binary blended cement, and 135 with OPC-CWA-PLA ternary blended cement, each at percentage OPC replacement with pozzolan of 5%, 10%, 15%, 20%, and 25%.Three sandcrete blocks and three soilcrete blocks for each OPC-pozzolan mix and the control were crushed to obtain their compressive strengths at 3, 7, 14, 21, 28, 50, 90, 120, and 150 days of curing. Sandcrete and soilcrete block strengths from binary and ternary blended cements were found to be higher than the control values beyond 90 days of hydration. The 150-day strength values for OPC-CWA-PLA ternary blended cement sandcrete and soilcrete blocks were respectively 5.90N/mm2and 5.10N/mm2for 5% replacement, 5.80N/mm2and 4.95N/mm2for 10% replacement, 5.65N/mm2and 4.85N/mm2for 15% replacement, 5.60N/mm2and 4.75N/mm2for 20% replacement, and 5.25N/mm2and 4.65N/mm2for 25% replacement; while the control values were 5.20N/mm2and 4.65N/mm2. Thus, OPC-CWA and OPC-PLA binary blended cements as well as OPC-CWA-PLA ternary blended cement could be used in producing sandcrete and soilcrete blocks with sufficient strength for use in building and minor civil engineering works where the need for high early strength is not a critical factor.

  9. Magnetic resonance imaging evaluation of acetabular orientation in normal Chinese children.

    Science.gov (United States)

    Li, YiQiang; Liu, YuanZhong; Zhou, QingHe; Chen, WeiDong; Li, JingChun; Yu, LingJia; Xu, HongWen; Xie, DengHui

    2016-09-01

    There are no data regarding the acetabular orientation on magnetic resonance imaging (MRI); this study investigates the changes of acetabular orientation with age in normal Chinese children.We retrospectively analyzed the medical records of children who underwent hip MRI examination at our hospital from January 2009 to December 2015. A total of 180 patients with normal MRI reading of the hip joints were included and were divided into 14 groups according to age: from 6 months of age and then for each year from 1 to 16 years. The bony and cartilage acetabular anteversion angle (AAA), acetabular inclination angle (AIA), and acetabular index (AI) were measured. Total bony and cartilage femoral head coverage angles were measured on axial section total femoral head coverage angle (a-TCA) and coronal section total femoral head coverage angle (c-TCA).The mean bony AAA and AIA were 12.2 ± 2.5° and 50.9 ± 2.5°, respectively; both of them stayed constant from the age of 6 months to 16 years. Similar results were found in cartilage AAA (12.1 ± 2.5°) and AIA (41.2 ± 3.0°). There was no difference between bony and cartilage AAA, but bony AIA was significantly larger than cartilage AIA. Bony AI was 24.1 ± 2.4° at the age of 6 months, decreasing to 12.5 ± 2.3° by 12 to 13 years of age; cartilage AI (5.9 ± 1.7°) maintained a steady value with age. The mean bony a-TCA and c-TCA at 6 months were 117.0 ± 5.8° and 127.5 ± 5.1°, increasing to 144.5 ± 4.6° and 140.7 ± 2.5° at the age of 16 years. However, the cartilage a-TCA (145.2 ± 7.2°) and c-TCA (154.1 ± 5.7°) did not change significantly with age.Both bony and cartilage AAA and AIA remain constant up to the age of 16 years in normal Chinese pediatric population. Although the cartilage coverage of femoral head by the acetabulum remains unchanged with age, the bony coverage of femoral head increases. PMID:27631258

  10. Sodium Sulphate Effect on Cement Produced with Building Stone Waste

    Directory of Open Access Journals (Sweden)

    Emre Sancak

    2015-01-01

    Full Text Available In this study, the blended cements produced by using the building stone waste were exposed to sulphate solution and the cement properties were examined. Prepared mortar specimens were cured under water for 28 days and then they were exposed to three different proportions of sodium sulphate solution for 125 days. Performances of cements were determined by means of compressive strength and tensile strength tests. The broken parts of some mortar bars were examined with scanning electron microscope (SEM. Besides, they were left under moist atmosphere and their length change was measured and continuously monitored for period of 125 days. In blended cements, solely cements obtained by replacing 10–20% of diatomites gave similar strength values with ordinary Portland cement (CEM I 42.5R at the ages of 7, 28, and 56 days. In all mortar specimens that included either waste andesite (AP or marble powder (MP showed best performance against very severe effective sodium sulphate solutions (13500 mg/L.

  11. Influence of CG With High Content of Metallic Particles as a Cement Admixture on Cement Strength

    Institute of Scientific and Technical Information of China (English)

    WAN Hui-wen; LIN Zong-shou; ZHAO Qian; HUANG Yun

    2003-01-01

    Copper gangue (CG), containing a large amount of water with grain sizes of 0.037 to 0.10mm,is an inactive industrial waste generated from copper refineries. When it is dried and used as a cement admixture, the influence of the presence of finely dispersed metallic particles in CG on the microstructure and compressive strength of cement paste has been studied.The results show that the higher the replacement of CG is,the lower the compressive strength of cement mortar is.However,the long-term strength of the specimens with 10% CG,especially after being cured for 3 months,approached to that of the plain mortar.Its mechanism was studied by an electron probe X-ray microanalyzer (EPXMA).The results indicate that a small quantity of Fe(OH)3·nH2O slowly formed from Fe2O3 in the presence of Ca(OH)2, free CaO and MgO of the clinker also slowly hydrated and formed Ca(OH)2 and Mg(OH)2 respectively,so the hardened cement paste became more compact.

  12. 陀螺仪在全髋置换髋臼杯定位中的应用%Application of gyroscope to acetabular cup positioning in total hip arthroplasty

    Institute of Scientific and Technical Information of China (English)

    葛兴涛; 葛兴华; 尚春暖; 王增涛

    2014-01-01

    BACKGROUND:Good position of acetabular prosthesis during total hip replacement plays a key role in success of the operation. Traditional location tool has poor accuracy, is too complicated, and limits its application. OBJECTIVE:To compare the advantages and disadvantages of gyroscope with the traditional technique in acetabular component orientation in total hip arthroplasty. METHODS:Using lateral approach, physicians with different experiences used traditional technique to locate acetabular cup 100 times (20 times in each person; 40° abduction and 15° anteversion), and then used gyroscope to locate 60 times at the same angle in the same plastic hip model. The error between the planed and measured values was recorded. RESULTS AND CONCLUSION: Compared to the traditional technique, the error of the abduction and anteversion decreased obviously. These indicated that the gyroscope can make the orientation of acetabular component more precise in total hip arthroplasty.%背景:全髋置换中良好的髋臼假体方位对于手术的成功起到了至关重要的作用。传统定位工具或精确度欠佳、或太过繁琐,限制了其应用。  目的:对比陀螺定位仪与传统定位技术在全髋置换髋臼杯定位中的优劣。  方法:应用外侧入路,在同一个塑料髋部模型上由不同经验年限的医生利用传统方法进行了100次髋臼杯定位(每人20次40°外展和15°前倾);再利用陀螺定位仪分别进行了60次相同角度的定位,记录实测角度与事先设定角度的误差。  结果与结论:与传统技术相比,使用螺仪定位仪测量的外展角和前倾角误差明显下降。提示陀螺定位仪能使全髋置换中髋臼杯的定位更加精确。

  13. Produktie van cement

    NARCIS (Netherlands)

    Smit JRK; Coenen PWHG; Matthijsen AJCM; LAE; TAUW

    1995-01-01

    This document on cement production has been published within the SPIN project. In this project information has been collected on industrial plants or industrial processes to afford support to governmental policy on emission reduction. This document contains information on the processes, emission sou

  14. Osteotransductive bone cements.

    Science.gov (United States)

    Driessens, F C; Planell, J A; Boltong, M G; Khairoun, I; Ginebra, M P

    1998-01-01

    Calcium phosphate bone cements (CPBCs) are osteotransductive, i.e. after implantation in bone they are transformed into new bone tissue. Furthermore, due to the fact that they are mouldable, their osteointegration is immediate. Their chemistry has been established previously. Some CPBCs contain amorphous calcium phosphate (ACP) and set by a sol-gel transition. The others are crystalline and can give as the reaction product dicalcium phosphate dihydrate (DCPD), calcium-deficient hydroxyapatite (CDHA), carbonated apatite (CA) or hydroxyapatite (HA). Mixed-type gypsum-DCPD cements are also described. In vivo rates of osteotransduction vary as follows: gypsum-DCPD > DCPD > CDHA approximately CA > HA. The osteotransduction of CDHA-type cements may be increased by adding dicalcium phosphate anhydrous (DCP) and/or CaCO3 to the cement powder. CPBCs can be used for healing of bone defects, bone augmentation and bone reconstruction. Incorporation of drugs like antibiotics and bone morphogenetic protein is envisaged. Load-bearing applications are allowed for CHDA-type, CA-type and HA-type CPBCs as they have a higher compressive strength than human trabecular bone (10 MPa).

  15. Acetabular bone density and metal ions after metal-on-metal versus metal-on-polyethylene total hip arthroplasty; short-term results

    NARCIS (Netherlands)

    Zijlstra, Wierd P.; van der Veen, Hugo C.; van den Akker-Scheek, Inge; Zee, Mark J. M.; Bulstra, Sjoerd K.; van Raay, Jos J. A. M.

    2014-01-01

    Information on periprosthetic acetabular bone density is lacking for metal-on-metal total hip arthroplasties. These bearings use cobalt-chromium instead of titanium acetabular components, which could lead to stress shielding and hence periprosthetic bone loss. Cobalt and chromium ions have detriment

  16. Reuse of cement-solidified municipal incinerator fly ash in cement mortars: physico-mechanical and leaching characteristics.

    Science.gov (United States)

    Cinquepalmi, Maria Anna; Mangialardi, Teresa; Panei, Liliana; Paolini, Antonio Evangelista; Piga, Luigi

    2008-03-01

    The reuse of cement-solidified Municipal Solid Waste Incinerator (MSWI) fly ash (solidified/stabilised (S/S) product) as an artificial aggregate in Portland cement mortars was investigated. The S/S product consisted of a mixture of 48 wt.% washed MSWI fly ash, 20 wt.% Portland cement and 32 wt.% water, aged for 365 days at 20 degrees C and 100% RH. Cement mortars (water/cement weight ratio=0.62) were made with Portland cement, S/S product and natural sand at three replacement levels of sand with S/S product (0%, 10% and 50% by mass). After 28 days of curing at 20 degrees C and 100% RH, the mortar specimens were characterised for their physico-mechanical (porosity, compressive strength) and leaching behaviour. No retardation in strength development, relatively high compressive strengths (up to 36 N/mm2) and low leaching rates of heavy metals (Cr, Cu, Pb and Zn) were always recorded. The leaching data from sequential leach tests on monolithic specimens were successfully elaborated with a pseudo-diffusional model including a chemical retardation factor related to the partial dissolution of contaminant.

  17. Navigated non-image-based positioning of the acetabulum during total hip replacement

    OpenAIRE

    Jenny, Jean-Yves; Boeri, Cyril; Dosch, Jean-Claude; Uscatu, Marius; Ciobanu, Eugen

    2007-01-01

    We tested the hypothesis that the non-image-based navigation system used in our department was able to measure accurately the 3D positioning of the acetabular cup of a total hip replacement (THR) and to increase the accuracy of its implantation during THR. We studied 50 consecutive navigated implantations of a THR and compared the intra-operative measurement of the cup by the navigation system to the post-operative measurement by computed tomography (CT) scan. The mean difference between the ...

  18. 21 CFR 888.3410 - Hip joint metal/polymer or ceramic/polymer semiconstrained resurfacing cemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... semiconstrained resurfacing cemented prosthesis. 888.3410 Section 888.3410 Food and Drugs FOOD AND DRUG... prosthesis. (a) Identification. A hip joint metal/polymer or ceramic/polymer semi-constrained resurfacing cemented prosthesis is a two-part device intended to be implanted to replace the articulating surfaces...

  19. 21 CFR 888.3560 - Knee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis.

    Science.gov (United States)

    2010-04-01

    .../polymer semi-constrained cemented prosthesis. 888.3560 Section 888.3560 Food and Drugs FOOD AND DRUG... prosthesis. (a) Identification. A knee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace a knee joint. The device...

  20. 21 CFR 888.3353 - Hip joint metal/ceramic/polymer semi-constrained cemented or nonporous uncemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... cemented or nonporous uncemented prosthesis. 888.3353 Section 888.3353 Food and Drugs FOOD AND DRUG... prosthesis. (a) Identification. A hip joint metal/ceramic/polymer semi-constrained cemented or nonporous uncemented prosthesis is a device intended to be implanted to replace a hip joint. This device...

  1. Utilization of Iron Ore Tailings as Raw Material for Portland Cement Clinker Production

    Directory of Open Access Journals (Sweden)

    Li Luo

    2016-01-01

    Full Text Available The cement industry has for some time been seeking alternative raw material for the Portland cement clinker production. The aim of this research was to investigate the possibility of utilizing iron ore tailings (IOT to replace clay as alumina-silicate raw material for the production of Portland cement clinker. For this purpose, two kinds of clinkers were prepared: one was prepared by IOT; the other was prepared by clay as a reference. The reactivity and burnability of raw meal, mineralogical composition and physical properties of clinker, and hydration characteristic of cement were studied by burnability analysis, differential thermal analysis, X-ray diffraction, and hydration analysis. The results showed that the raw meal containing IOT had higher reactivity and burnability than the raw meal containing clay, and the use of IOT did not affect the formation of characteristic mineralogical phases of Portland cement clinker. Furthermore, the physical and mechanical performance of two cement clinkers were similar. In addition, the use of IOT was found to improve the grindability of clinker and lower the hydration heat of Portland cement. These findings suggest that IOT can replace the clay as alumina-silicate raw material for the preparation of Portland cement clinker.

  2. Performance Comparison between EAFD and Conventional Supplementary Cementing Materials

    Directory of Open Access Journals (Sweden)

    Amir Fauzi Hasbi

    2016-02-01

    Full Text Available Sustainability of concrete construction necessitates exploring potential renewable resource, especially from industrial waste products.  Electric arc furnace dust (EAFD, a by-product of the modern electric arc furnace (EAF process from the steel manufacturing industry has an adverse impact on the environment. Utilizing EAFD in concrete production as a cement replacement material together with silica fume (SF and fly ash (FA has raised the interest of many researchers.  This study investigates the use optimum 5% EAFD content refers to both 15% SF and 20% FA in water binder ratio of 0.5 and sand to cement ratio of 2. The aim of this study is to obtain the percentage replacement levels of EAFD that are equivalent to the SF and FA regarding workability, setting time, compressive strength and resistance to rapid chloride permeability. The compressive strength results showed that replacement of 5% SF and 15% FA are the equivalent replacement levels to 3% EAFD. Similarly, results from resistance to rapid chloride permeability showed that the optimum EAFD content performed better than the replacement levels of FA.  However, SF replacement levels showed the best resistance to rapid chloride permeability. Therefore, 3% replacement of EAFD provided an intermediate performance between the optimum SF and FA contents and exceeded that of the control.

  3. Current topics in the radiology of joint replacement surgery

    Energy Technology Data Exchange (ETDEWEB)

    Weissman, B.N. (Harvard Medical School, Boston, MA (USA))

    1990-09-01

    Several methods of total hip joint replacement are currently used. Radiographic appearances after cemented, bone ingrowth, press-fit, and bipolar hip prostheses are reviewed. The roles of nuclear medicine and arthrographic procedures for identifying complications are discussed. Total knee prostheses and, in particular, complications related to the patellar component are described.115 references.

  4. Late fiber metal shedding of the first and second-generation Harris Galante acetabular component. A report of 5 cases.

    Science.gov (United States)

    Mayman, David J; González Della Valle, Alejandro; Lambert, Edward; Anderson, John; Wright, Timothy; Nestor, Bryan; Sculco, Thomas P; Salvati, Eduardo A

    2007-06-01

    Five patients presented with fiber metal mesh shedding of a Harris Galante II acetabular cup detected between 11 and 15 years after implantation. All patients presented with hip pain and 4 demonstrated gross acetabular loosening and fiber metal separation on preoperative radiographs. The remaining patient underwent revision surgery because of a liner dislodgment and had a radiographically well fixed shell. Loosening and fiber metal separation were detected intraoperatively. Scanning electron microscopy of the retrieved shells demonstrated isolated diffusion bonding marks in the areas where the mesh separated from the substrate and no evidence of corrosion. Progressive osteolysis in the iliac bone was evident in 4 of our cases. Progressive iliac osteolysis may lead to loss of bone support in well-fixed cups and excessive stresses transferred to the interface between the fiber metal mesh and the titanium substrate leading to the separation of the 2 layers. Fiber metal separation may contribute to long-term loosening in the Harris Galante acetabular component.

  5. The effect of cement creep and cement fatigue damage on the micromechanics of the cement-bone interface.

    NARCIS (Netherlands)

    Waanders, D.; Janssen, D.; Mann, K.A.; Verdonschot, N.J.J.

    2010-01-01

    The cement-bone interface provides fixation for the cement mantle within the bone. The cement-bone interface is affected by fatigue loading in terms of fatigue damage or microcracks and creep, both mostly in the cement. This study investigates how fatigue damage and cement creep separately affect th

  6. Femoral anteversion is correlated with acetabular version and coverage in Asian women with anterior and global deficient subgroups of hip dysplasia: a CT study

    Energy Technology Data Exchange (ETDEWEB)

    Akiyama, Mio; Nakashima, Yasuharu; Fujii, Masanori; Sato, Taishi; Yamamoto, Takuaki; Mawatari, Taro; Motomura, Goro; Matsuda, Shuichi; Iwamoto, Yukihide [Kyushu University, Department of Orthopaedic Surgery, Graduate School of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka (Japan)

    2012-11-15

    Morphological correlation between the acetabulum and femur at the hip joint is still controversial. We tested the hypothesis that femoral anteversion correlates with acetabular version and coverage in patients with developmental dysplasia of the hip (DDH). Using pelvic computed tomography (CT) images of 79 hips in 49 Asian women with DDH and 49 normal hips, we measured femoral anteversion, the axial and vertical acetabular version and the acetabular sector angle (ASA) to demarcate femoral head coverage. Depending on the location of the acetabular bone defect, dysplastic hips were divided into three subgroups: the anterior, global and posterior deficiency groups. We performed a comparative analysis between dysplastic and normal hips using the Wilcoxon rank sum test, and a relative analysis between femoral anteversion and acetabular measurements in dysplastic hips using Pearson's correlation coefficient. The amount of femoral anteversion in dysplastic hips was greater and more variable than in normal hips (p < 0.0001, p = 0.0277 respectively). Femoral anteversion in dysplastic hips correlated significantly with acetabular anteversion in the groups with anterior and global deficiency subgroups (p < 0.05, r = 0.2990, p < 0.05, r = 0.451 respectively), but not with the posterior deficiency subgroup. Femoral anteversion also correlated with vertical acetabular version. When acetabular coverage was examined, significant correlations were noted between femoral anteversion and anterior and superior coverage, but not with posterior coverage. These correlations were not observed in normal hips. Our results showed significantly greater and more variable femoral anteversion in DDH, and a significant correlation between femoral anteversion and acetabular version and coverage in DDH with anterior and global acetabular bone deficiency. (orig.)

  7. Femoral anteversion is correlated with acetabular version and coverage in Asian women with anterior and global deficient subgroups of hip dysplasia: a CT study

    International Nuclear Information System (INIS)

    Morphological correlation between the acetabulum and femur at the hip joint is still controversial. We tested the hypothesis that femoral anteversion correlates with acetabular version and coverage in patients with developmental dysplasia of the hip (DDH). Using pelvic computed tomography (CT) images of 79 hips in 49 Asian women with DDH and 49 normal hips, we measured femoral anteversion, the axial and vertical acetabular version and the acetabular sector angle (ASA) to demarcate femoral head coverage. Depending on the location of the acetabular bone defect, dysplastic hips were divided into three subgroups: the anterior, global and posterior deficiency groups. We performed a comparative analysis between dysplastic and normal hips using the Wilcoxon rank sum test, and a relative analysis between femoral anteversion and acetabular measurements in dysplastic hips using Pearson's correlation coefficient. The amount of femoral anteversion in dysplastic hips was greater and more variable than in normal hips (p < 0.0001, p = 0.0277 respectively). Femoral anteversion in dysplastic hips correlated significantly with acetabular anteversion in the groups with anterior and global deficiency subgroups (p < 0.05, r = 0.2990, p < 0.05, r = 0.451 respectively), but not with the posterior deficiency subgroup. Femoral anteversion also correlated with vertical acetabular version. When acetabular coverage was examined, significant correlations were noted between femoral anteversion and anterior and superior coverage, but not with posterior coverage. These correlations were not observed in normal hips. Our results showed significantly greater and more variable femoral anteversion in DDH, and a significant correlation between femoral anteversion and acetabular version and coverage in DDH with anterior and global acetabular bone deficiency. (orig.)

  8. Clinical observation of particulate cancellous bone impaction grafting in combination with total hip arthroplasty for acetabular reconstruction

    Institute of Scientific and Technical Information of China (English)

    LIU Xian-zhe; YANG Shu-hua; XU Wei-hua; LIU Guo-hui; YANG Cao; LI Jin; YE Zhe-wei; LIU Yong; ZHANG Yu-kun

    2008-01-01

    Objective: To investigate the effect of particulate cancellous bone impaction grafting in combination with total hip arthroplasty (THA) for acetabular reconstruction in patients with posttraumatic arthritis and bone loss afteracetabular fractures.Methods: Totally 15 consecutive cases with unilateral acetabular fracture were treated with bone impaction grafting in combination with THA in our department.There were 10 males and 5 females with mean age of 48.2 years (ranging from 36 to 73 years).Eight cases had the fracture at left hips,7 at right hips.The average age at injury was 28 years (ranging from 18 to 68 years).The mean follow-up period was 4.3 years (ranging from 2 to 7 years).Results: Compared with mean 42 points (ranging from 10 to 62) of the preoperative Harris score,the survival cases at the final follow-up had mean 84 points (ranging from 58 to 98).One patient had mild pain in the hip.No revision of the acetabular or femoral component was undertaken during the follow-up.Normal rotational centre of most hips was recovered except 2 cases in which it was 0.8 mm higher than that in opposite side.All of them had a stable radiographic appearance.Progressive radiolucent fines were observed in I,III zones in 2 cases.One patient had a nonprogressive radiolucent fine in zone III.The cup prosthesis was obviously displaced (6 mm) in one patient,but had not been revised.Conclusion: Particulate cancellous bone impaction grafting in combination with THA as a biological solution is an attractive procedure for acetabular reconstruction in patients with posttraumatic arthritis and bone loss after acetabular fracture,which can not only restore acetabular bone stock but also repair normal hip anatomy and its function.

  9. POZZOLAN AND CEMENTS WITH POZZOLAN

    Directory of Open Access Journals (Sweden)

    Hasan KAPLAN

    1995-02-01

    Full Text Available Cement, one of the basic material of construction engineering, has an important place in view of strength and cost of structures. Cement consumption is increasing parallel to development of building construction sector. For cement producers, minimal cost is desired by using new and economical material sources. On the other hand, the controllers and contractors need cheaper, safer and higher strength materials. From this respect cement industry tends to use cement with pozzolan. In Türkiye, cement with pozzolan is produced by adding the pozzolan, which has a large reservoir in the country, in cement in sertain amount. However this type of cement is consumed in the construction sector, sortage of scientific investigation and speculative news on the subject.are worried the users and producers. In this paper, prior to an experimental study on the cements having pozzolan additive, historical development of pozzolan, reservoir of Turkiye, and comparison with portland cement is carried out. Advantages and disadvantages of pozzolan are also discussed in some points.

  10. Mineral resource of the month: hydraulic cement

    Science.gov (United States)

    van Oss, Hendrik G.

    2012-01-01

    Hydraulic cements are the binders in concrete and most mortars and stuccos. Concrete, particularly the reinforced variety, is the most versatile of all construction materials, and most of the hydraulic cement produced worldwide is portland cement or similar cements that have portland cement as a basis, such as blended cements and masonry cements. Cement typically makes up less than 15 percent of the concrete mix; most of the rest is aggregates. Not counting the weight of reinforcing media, 1 ton of cement will typically yield about 8 tons of concrete.

  11. Development of the Use of Alternative Cements for the Treatment of Intermediate Level Waste

    International Nuclear Information System (INIS)

    This paper describes initial development studies undertaken to investigate the potential use of alternative, non ordinary Portland cement (OPC) based encapsulation matrices to treat historic legacy wastes within the UK's Intermediate Level Waste (ILW) inventory. Currently these wastes are encapsulated in composite OPC cement systems based on high replacement with blast furnace slag of pulverised fuel ash. However, the high alkalinity of these cements can lead to high corrosion rates with reactive metals found in some wastes releasing hydrogen and forming expansive corrosion products. This paper therefore details preliminary results from studies on two commercial products, calcium sulfo-aluminate (CSA) and magnesium phosphate (MP) cement which react with a different hydration chemistry, and which may allow wastes containing these metals to be encapsulated with lower reactivity. The results indicate that grouts can be formulated from both cements over a range of water contents and reactant ratios that have significantly improved fluidity in comparison to typical OPC cements. All designed mixes set in 24 hours with zero bleed and the pH values in the plastic state were in the range 10-11 for CSA and 5-7 for MP cements. In addition, a marked reduction in aluminium corrosion rate has been observed in both types of cements compared to a composite OPC system. These results therefore provide encouragement that both cement types can provide a possible alternative to OPC in the immobilisation of reactive wastes, however further investigation is needed. (authors)

  12. Examination and treatment of a professional ballet dancer with a suspected acetabular labral tear: A case report.

    Science.gov (United States)

    Khoo-Summers, Lynnette; Bloom, Nancy J

    2015-08-01

    Dancers are at risk for developing groin pain that is due to acetabular labral tears. Although surgical management of labral tears has been reported extensively, conservative management has been poorly described. This case report describes the examination, diagnosis, and treatment of groin pain in a professional ballet dancer with a suspected acetabular labral tear. Treatment focused on decreasing anterior hip joint stresses and improving the precision of hip motion through correction of alignment and movement impairments noted during functional activities and dance. Successful outcomes included a reduction in pain and return to professional ballet dancing. PMID:25725589

  13. Acetabular morphometry and prevalence of hip dysplasia in the South Asian population

    Directory of Open Access Journals (Sweden)

    Masood Umer

    2009-07-01

    Full Text Available We carried out a cross-sectional study to measure the association of the seven acetabular parameters with pelvic morphometry and prevalence of hip dysplasia in our population. Convenience sampling was carried out and 250 consecutive patients who came to AKUH for intravenous pyelogram and had no complaints in the region of the hip joint were enrolled in the study. Post-micturition standardized plain antero-posterior pelvic radiographs of 250 asymptomatic adults (500 hip joints was studied. There were 136 males (54.4% and 114 females (45.6%. Mean age of our study population was 38 years (15-78 years. The average center edge angle was 35.5±6.6° standard deviation (SD, acetabular angle was 37.76±4.37°, depth to width ratio was 0.31±4.6°, roof obliquity was 10.6±6.2°, extrusion index was 0.1±5.8, lateral subluxation 8.9±2.7 mm, and peak to edge distance 17±3.98 mm. There was significant influence (p lower than  0.05 of age in all angles except depth to width ratio. A total of seven hip joints (1.4% were dysplastic with CE angle lower than 25° while four of the seven hips were severely dysplastic with CE angle  lower than 20°. In the dysplastic group there was significant correlation (p lower than 0.05 of CE angle with acetabular angle, depth to width ratio, extrusion index and peak to edge distance. Prevalence of hip dysplasia was found to be very low in our population. These results are consistent with the findings of studies carried out in other Asian countries.

  14. Inguinal Abnormalities in Male Patients with Acetabular Fractures Treated Using an Ilioinguinal Exposure

    Directory of Open Access Journals (Sweden)

    Reza Firoozabadi

    2015-09-01

    Full Text Available Purpose: Surgeons performing an ilioinguinal exposure for acetabular fracture surgery need to be aware of aberrant findings such as inguinal hernias and spermatic cord lesions. The purpose of this study is to report these occurrences in a clinical series of adult males undergoing acetabular fracture fixation and a series of adult male cadavers. The secondary aim is to characterize these abnormalities to aid surgeons in detecting these abnormalities preoperatively and coordinating a surgical plan with a general surgeon.Methods: Clinical study- Retrospective review of treated acetabular fractures through an ilioinguinal approach. Incidence of inguinal canal and spermatic cord abnormalities requiring general surgery consultation were identified. Corresponding CT scans were reviewed and radiographic characteristics of the spermatic cord abnormalities and/or hernias were noted.Cadaveric study- 18 male cadavers dissected bilaterally using an ilioinguinal exposure. The inguinal canal and the contents of the spermatic cord were identified and characterized.Results: Clinical Study- 5.7% (5/87 of patients had spermatic cord lesion and/or inguinal hernia requiring general surgical intervention. Preoperative pelvic CT scan review identified abnormalities noted intraoperatively in four of the five patients. Cord lipomas visualized as enlargements of the spermatic cord with homogeneous density. Hernias visualized as enlarged spermatic cords with heterogeneous density. Cadaver Study- 31% (11/36 of cadavers studied had spermatic cord and/or inguinal canal abnormalities. Average cord diameter in those with abnormalities was 24.9 mm (15-28 compared to 16 mm (11-22 in normal cords, which was statistically significant.Conclusion: The clinical and cadaveric findings emphasize the importance of understanding inguinal abnormalities and the value of detecting them preoperatively. The preoperative pelvic CT scans were highly sensitive in detecting inguinal abnormalities.

  15. Modified ilioinguinal approach in combined surgical exposures for displaced acetabular fractures involving two columns.

    Science.gov (United States)

    Wang, Peng; Zhu, Xiaodong; Xu, Peng; Zhang, Yan; Wang, Lubo; Liu, Xiangyan; Mu, Weidong

    2016-01-01

    The purpose of this study is to assess the advantages of modified ilioinguinal approach in combined surgical exposures for displaced acetabular fractures involving two columns management. 73 patients with displaced acetabular fractures involving two columns underwent open reduction and internal fixation through combined surgical approaches between 2006 and 2014 in our hospital. The modified ilioinguinal approach combined with Kocher-Langenbeck approach group (group A) included 46 patients. The standard ilioinguinal approach combined with Kocher-Langenbeck approach group (group B) included 27 patients. Outcome was assessed in operative time, blood loss, function outcomes and complications. In group A, the average operative time was 123.2 min, and the average blood loss was 586.2 ml. Anatomic reduction was achieved in 39 patients (84.8 %). The functional recovery was good in 37 patients (80.4 %). Complications related to the approach were observed in 10 patients (21.7 %). In group B, the average operative time was 161.5 min, and the average blood loss was 830 ml. Anatomic reduction was achieved in 24 patients (88.9 %). The functional recovery was good in 22 patients (81.5 %). Complications related to the approach were observed in 9 patients (33.3 %). This study demonstrates that both combined approaches permits good postoperative function results for treatment of acetabular fractures involving two columns. However, the modified ilioinguinal approach combined with Kocher-Langenbeck approach provides less operative time, blood loss and complications. PMID:27652175

  16. SETTING AND HARDENING OF AGRO/CEMENT COMPOSITES

    Directory of Open Access Journals (Sweden)

    Amal Hanafy Abdel-Kader

    2010-02-01

    Full Text Available In this study, the use of bagasse fiber (BF and unbleached bagasse pulp (BP in a cement matrix, as a raw material, to produce lightweight construction materials is reported. The bagasse was used as partial replacement of cement at different levels: 0% (control cement, 1%, 2% 3%, and 4% by weight. The average size of bagasse fibers was less than 2 mm. Although a reduction in the physical and mechanical strength was observed, the incorporation of either fiber or pulp increased the water of consistency and setting time. A composite containing 4% of bagasse fibers can be used for lightweight concrete. FT-IR spectra showed that the BF or BP adversely affect the rate of calcium silicate hydrate (CSH formation by decreasing its promotion.

  17. US cement industry

    Energy Technology Data Exchange (ETDEWEB)

    Nisbet, M.A.

    1997-12-31

    This paper describes the cement and concrete industry, and provides data on energy use and carbon dioxide emissions. The potential impact of an energy tax on the industry is briefly assessed. Opportunities identified for reducing carbon dioxide emissions include improved energy efficiency, alternative fuels, and alternative materials. The key factor in determining CO{sub 2} emissions is the level of domestic production. The projected improvement in energy efficiency and the relatively slow growth in domestic shipments indicate that CO{sub 2} emissions in 2000 should be about 5% above the 1990 target. However, due to the cyclical nature of cement demand, emissions will probably be above target levels during peak demand and below target levels during demand troughs. 7 figs., 2 tabs.

  18. Migration measurement of acetabular components in cementless total hip arthroplasty; Messung der Pfannenwanderung bei zementfreien Hueftimplantaten

    Energy Technology Data Exchange (ETDEWEB)

    Eckardt, A.; Karbowski, A.; Schwitalle, M.; Vogel, J.; Boden, F.; Seeleitner, C. [Mainz Univ. (Germany). Orthopaedische Klinik und Poliklinik; Schunk, K. [Mainz Univ. (Germany). Klinik und Poliklinik fuer Radiologie; Mayrhofer, P. [Innsbruck Univ. (Austria). Inst. fuer Mathematik und Geometrie

    1998-08-01

    Migration measurements of acetabular components using a special computer aided method (EBRA = abbrevation for the German term ``Ein-Bild-Roentgenanalyse``) were performed to evaluate early results of the implants and predict aseptic loosening. Methods: Standard ap-radiographs of the pelvis were marked, specific points were digitised. Simulating the spatial situation the programme computes lengitudinal and vertical migration of the cup. 74 acetabular components in 71 patients could be studied by migration measurements. Results: 14 patients showed migration of more than 1 mm, which is the confidence limit of this method. Each of these patients showed diverse reasons for the migration, i.e. osteoporosis of the acetabular bone stock or problems concerning the surgical technique which means malposition of the cup or insufficient reaming of the bone. There were some patients with severe congenital dysplasia of the hip and in some cases the inclination angle of the cup was too great. Conclusion: The technique applied for measuring migration of acetabular components can be useful for evaluating early instability of the implant and can be helpful in detecting problems concerning the surgical technique. (orig.) [Deutsch] Mittels der Ein-Bild-Roentgenanalyse wurden Pfannenwanderungen nach Implantation von zementfreien, sphaerischen Hueftgelenkspfannen erfasst, um Praediktoren fuer die langfristige Prognose der Implantate zu evaluieren. Methoden: Nach Markierung von Referenzpunkten in den Beckenuebersichtsaufnahmen wurden diese digitalisiert, vom Programm verrechnet und die Wanderung des Implantats im Verlauf angegeben. Bei 71 Patienten wurden von 74 Pfannen ueber einen Mindestnachuntersuchungszeitraum von 12 Monaten Migrationsmessungen durchgefuehrt. Das Konfidenzintervall der Methode liegt bei <1 mm. Bei jedem dieser Patienten fanden sich Hinweise entweder auf ein schlechtes Knochenlager, auf operationsbedingte Probleme, wenn keine ausreichende Primaerstabilitaet der Pfanne

  19. Computer aided technology assesses adult acetabular dysplasia after total hip arthroplasty:biological performance%计算机辅助技术评价成人髋臼发育不良全髋关节置换生物性能分析

    Institute of Scientific and Technical Information of China (English)

    邵正海; 徐卫东

    2016-01-01

    Bone and Joint Surgery, Changhai Hospital, Second Military Medical University of Chinese PLA from January 2015 to August 2015 were selected and analyzed. Al the enrol ed patients underwent total hip arthroplasty. Al the patients were randomly divided into control and computer-aided technology groups. CT scanning was conducted in these two groups before replacement. Three-dimensional reconstruction measuring and surgical rehearsal on the acetabular site were conducted using M3D visualization software in the computer-aided technology group. The effects and biological properties of total hip arthroplasty were compared between these two groups. RESULTS AND CONCLUSION: Patients in these two groups primarily healed after replacement. The excel ent and good rate, Harris score after treatment, acetabular component, valgus angle and anteversion in the computer-aided technology group were significantly higher than those in the control group (P < 0.05). The acetabular cup abduction angle offset degrees, acetabular cup anteversion offset degrees, and the incidences of complications after replacement were significantly decreased compared with those in the control group (P < 0.05). These results suggest that the effect of computer-aided evaluation in adult acetabular dysplasia after total hip arthroplasty is ideal, and can accurately grasp the true acetabular anatomical characteristics and the corresponding relationship with the prosthesis, so as to help patients to choose the proper acetabulum and acetabular prosthesis and reconstruction ways and improve the biological performance of acetabulum after replacement, with a high clinical value.

  20. Experimental research and its clinical significance of precise postural adjustment and mean measurement by multi-slice spiral CT reconstruction of acetabular abduction angle%测量髋臼外展角度的实验研究及其临床意义MSCT三维重建精确体位调整均值法

    Institute of Scientific and Technical Information of China (English)

    范新成; 马振波; 于春丽; 朱海涛; 赵伟; 彭国庆; 张伟; 魏开斌; 刘峰

    2016-01-01

    Objective:To investigate the application of multi-slice spiral CT reconstruction accurate measurement of ace-tabular abduction angle,and to provide a scientific basis for guidance of total hip replacement acetabular prosthesis individu-alized accurate placement and postoperative evaluation. Methods:The research objects were 60 acetabulars of 30 pelvic spec-imens,and with anterior plane of pelvis as a reference plane,acetabular abduction angles were measured respectively by digital goniometer and multi-slice CT reconstruction with precise postural adjustment. Results:The acetabular abduction an-gle means of 30 pelvic specimens by digital goniometer and multi-slice CT reconstruction with precise postural adjustment were(48. 73 ± 3. 19)°and(48. 65 ± 2. 47)° respectively,and they had no significant difference(P > 0. 05). These data showed that the measurement of acetabular abduction angle by multi-slice CT reconstruction with precise postural ad-justment was accurate,which had no significant difference from the actual measurement. Conclusion:Multi-slice CT recon-struction with precise postural adjustment,with the anterior plane of the pelvis as a reference plane,is a new method of a preoperative acetabular abduction angle measurement for total hip arthroplasty,which can reduce human error in operation and achieve standardized measurement and evaluation of hip acetabular abduction angle.%目的:探讨应用 MSCT 三维重建精确测量髋臼外展角度的新方法,为指导全髋关节置换髋臼假体个体化准确置入及术后评估提供科学依据。方法选取30具骨盆标本共60个髋臼为研究对象,以骨盆前平面为参照平面,分别应用数显角度仪及 MSCT 三维重建精确体位调整均值法对髋臼外展角度数值进行测量,对两种方法的测量结果进行比较。结果应用数显角度仪及 MSCT 三维重建精确体位调整均值法测量髋臼外展角度分别为(48.73±3.19)°和(48.65±2.47)°

  1. Tympanoplasty with ionomeric cement.

    Science.gov (United States)

    Kjeldsen, A D; Grøntved, A M

    2000-01-01

    Patients with isolated erosion of the long incus process suffer from severe hearing loss caused by lack of continuity of the ossicular chain. This study is a retrospective evaluation of the hearing results using two different surgical procedures. Since January 1993, 12 consecutive patients with isolated erosion of the long incus process have been treated with a new surgical technique in which the ossicular chain was rebuilt with ionomeric cement. The results in hearing performance (mean pure-tone average (PTA) 0.5, 1 and 2 kHz) were evaluated pre- and post-surgery, and compared to those in a group of 20 historical controls who underwent surgery in 1991 and 1992 using incus autograft interposition. Among the 12 index patients, 7 (58%) achieved improvement in PTA of > 10 dB, in 3 there was no difference and in 2 a slight decline. Among the 20 controls, 14 (70%) achieved improvement in PTA of > 10 dB, in 4 there was a slight improvement and in 2 a decline. The difference was not statistically significant. Hearing improvement using ionomeric cement in type II tympanoplasty was satisfactory. Reconstruction of the ossicular chain with ionomeric cement is recommended, as the procedure is easy to perform, presents less risk of damage to the stapes and cochlea, requires less extensive surgery and does not exclude other surgical methods in cases of reoperation. PMID:10909000

  2. Performance of Periwinkle Shell Ash Blended Cement Concrete Exposed to Magnesium Sulphate

    Directory of Open Access Journals (Sweden)

    Umoh A.A.

    2013-01-01

    Full Text Available The study examined the compressive strength of periwinkle shell ash (PSA blended cement concrete in magnesium sulphate medium. Specimens were prepared from designed characteristics strength of 25 MPa. The cement replacement with PSA ranged between 0 and 40% by volume. A total of 180 cube specimens were cast and cured in water. At 28 days curing, 45 specimens each were transferred into magnesium sulphate of 1%, 3%, and 5% solution, while others were continuously cured in water and tested at 62, 92, and 152 days. The results revealed a higher loss in compressive strength with the control mix, and that it increases with increased in MgSO4 concentration and exposure period, whereas, the attack on the PSA blended cement concrete was less and the least value recorded by 10% PSA content. Therefore, the study concluded that the optimum percentage replacement of cement with 10% PSA could mitigate magnesium sulphate attack.

  3. Effect of Lime on Mechanical and Durability Properties of Blended Cement Based Concrete

    Science.gov (United States)

    Acharya, Prasanna Kumar; Patro, Sanjaya Kumar; Moharana, Narayana C.

    2016-06-01

    This work presents the results of experimental investigations performed to evaluate the effect of lime on mechanical and durability properties of concrete mixtures made with blended cement like Portland Slag Cement (PSC) and Portland Pozzolana Cement (PPC) with lime content of 0, 5, 7 and 10 %. Test result indicated that inclusion of hydraulic lime on replacement of cement up to 7 % increases compressive strength of concrete made with both PSC and PPC. Flexural strength increased with lime content. Highest flexural strength is reported at 7 % lime content for both PSC and PPC. Workability is observed to decrease with lime addition which could be compensated with introduction of super plasticizer. Acid and sulphate resistance increase slightly up to 7 % of lime addition and is found to decrease with further addition of lime. Lime addition up to 10 % does not affect the soundness of blended cements like PSC and PPC.

  4. The encapsulation of Mg(OH){sub 2} sludge in composite cement

    Energy Technology Data Exchange (ETDEWEB)

    Collier, N.C.; Milestone, N.B. [University of Sheffield, Sheffield (United Kingdom). Dept. of Material Engineering

    2010-03-15

    A range of magnesium hydroxide waste sludges arising from the re-processing of nuclear fuel exist in the UK and require safe long-term disposal. Similar wastes undergo a cementation process in order to immobilise radioactive material prior to disposal. Simulant magnesium hydroxide sludges have been prepared and their subsequent interactions with composite cement systems based on the partial replacement of ordinary Portland cement with blast furnace slag and pulverised fuel ash have been studied. This work has concluded that there was little reaction between the sludge and any of the composite cements during hydration. Apart from a small quantity of a hydrotalcite-type phase containing magnesium from the sludge, the main phases detected were C-S-H and unreacted brucite. This indicates that the magnesium in the sludges is encapsulated by the cement, rather than being immobilised or chemically bound within the hardened matrix.

  5. [Haemotoxicity of dental luting cements].

    Science.gov (United States)

    Anders, A; Welker, D

    1989-06-01

    A glass ionomer luting cement (AquaCem) shows a relatively low haemolytic activity in comparison with two zinc phosphate cements. Especially the initial irritation by this cement is smaller. Although it is possible that AquaCem particularly, in unfavourable cases, may damage the pulpa dentin system; this is due to the slowly decrease of the haemolytic activity with increasing of the probes. We found that Adhesor showed in dependence of the batches a varying quality. PMID:2626769

  6. Cement penetration after patella venting.

    Science.gov (United States)

    Jones, Christopher W; Lam, Li-On; Butler, Adam; Wood, David J; Walsh, William R

    2009-01-01

    There is a high rate of patellofemoral complications following total knee arthroplasty. Optimization of the cement-bone interface by venting and suction of the tibial plateau has been shown to improve cement penetration. Our study was designed to investigate if venting the patella prior to cementing improved cement penetration. Ten paired cadaver patellae were allocated prior to resurfacing to be vented or non-vented. Bone mineral density (BMD) was measured by DEXA scanning. In vented specimens, a 1.6 mm Kirschner wire was used to breach the anterior cortex at the center. Specimens were resurfaced with standard Profix instrumentation and Versabond bone cement (Smith and Nephew PLC, UK). Cement penetration was assessed from Faxitron and sectioned images by a digital image software package (ImageJ V1.38, NIH, USA). Wilcoxon rank sum test was used to assess the difference in cement penetration between groups. The relationship between BMD and cement penetration was analyzed by Pearson correlation coefficient. There was a strong negative correlation between peak BMD and cement penetration when analyzed independent of experimental grouping (r(2)=-0.812, p=0.004). Wilcoxon rank sum testing demonstrated no significant difference (rank sum statistic W=27, p=0.579) in cement penetration between vented (10.53%+/-4.66; mean+/-std dev) and non-vented patellae (11.51%+/-6.23; mean+/-std dev). Venting the patella using a Kirschner wire does not have a significant effect on the amount of cement penetration achieved in vitro using Profix instrumentation and Versabond cement. PMID:19010682

  7. Sulfate attack and reinforcement corrosion in concrete with recycled concrete aggregates and supplementary cementing materials

    OpenAIRE

    Corral Higuera, Ramón; Arredondo Rea, Susana Paola; Neri Flores, M.A.; Gómez Soberón, José Manuel Vicente; Almeraya Calderón, F.; Castorena González, J.H.; Almaral Sánchez, Jorge Luis

    2011-01-01

    As strategies to contribute to the concrete industry sustainability, reinforced concrete was fabricated using recycled concrete coarse aggregate and replacing partially portland cement with supplementary cementing materials as fly ash and silica fume. On test specimens, partially immersed in 3.5% Na2SO4 aqueous solution, the effect of the recycled and supplementary materials against sulfate attack and reinforcement corrosion was evaluated. For such aim, weight loss of concrete and corrosion p...

  8. Considerations about the use of lime-cement mortars for render conservation purposes

    OpenAIRE

    Torgal, Fernando Pacheco; Faria, Joana; Shasavandi, Arman; Jalali, Said

    2011-01-01

    Some investigations about conservation renders points out that Portland cement based mortars should be avoided and should be replaced by lime-pozzolan mortars. However, this type of mortar is still under investigation and the majority of Portuguese construction enterprises operating in the field of building conservation do not possess enough know-how about them. Besides the absolute rejection of the use of Portland cement based mortars even with just a minimum amount appears to be a dogmat...

  9. Utilization of Alternative Fuels in Cement Pyroprocessing : the Messebo Factory case study in Ethiopia

    OpenAIRE

    Ebuy Teka, Axumawi

    2015-01-01

    Energy costs and environmental standards encouraged cement manufacturers worldwide to evaluate to what extent conventional fuels (Furnace oil, Coal and Petcock) can be replaced by alternative fuels in cement production, i.e. biomass or processed waste materials like sewage sludge, MSW (municipal solid waste), Refuse Derived Fuels (RDF), Tire Derived Fuel (TDF), Plastic Derived Fuel (PDF), Biomass Derived Fuels (BDF), meat and bone meal (MBM), etc.  High temperature of >1500 C, long residen...

  10. Effect of Coal Gangue with Different Kaolin Contents on Compressive Strength and Pore Size of Blended Cement Paste

    Institute of Scientific and Technical Information of China (English)

    CHEN Yimin; ZHOU Shuangxi; ZHANG Wensheng

    2008-01-01

    The effects of activated coal gangue on compressive strength,porosity and pore size distribution of hardened cement pastes were investigated.Activated coal gangue with two different kaolin contents,one higher and one lower,were used to partially replace Portland cement at 0%,10%,and 30% by weight.The water to binder ratio(w/b)of 0.5 was used for all the blended cement paste mixes.Experimental results indicate that the blended cement of activated coal gangue mortar with higher kaolin mineral content has a higher compressive strength than that with lower kaolin mineral content.The porosity and pore size of blended cement mortar were significantly affected by the replacement of activated coal gangue.

  11. Random ionic mobility on blended cements exposed to aggressive environments

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Rosario, E-mail: rosario.garcia@uam.es [Departamento de Geologia y Geoquimica, Facultad de Ciencias, Universidad Autonoma, 28049 Madrid (Spain); Rubio, Virginia [Departamento de Geografia, Facultad de Filosofia y Letras, Universidad Autonoma, 28049 Madrid (Spain); Vegas, Inigo [Labein-Tecnalia, 48160 Derio, Vizcaya (Spain); Frias, Moises [Instituto Eduardo Torroja, CSIC, c/ Serrano Galvache, 4, 28033 Madrid (Spain)

    2009-09-15

    It is known that the partial replacement of cement by pozzolanic admixtures generally leads to modifications in the diffusion rates of harmful ions. Recent research has centred on obtaining new pozzolanic materials from industrial waste and industrial by-products and on the way that such products can influence the performance of blended cements. This paper reports the behaviour of cements blended with calcined paper sludge (CPS) admixtures under exposure to two different field conditions: sea water and cyclic changes in temperature and humidity. Cement mortars were prepared with 0% and 10% paper sludge calcined at 700 deg. C. The penetration of ions within the microstructure of cement matrices was studied using X-ray diffraction (XRD) and scanning electron microscopy equipped with an energy dispersive X-ray analyser (SEM/EDX) analytical techniques. The results show that ionic mobility varies substantially according to the type of exposure and the presence of the calcined paper sludge. The incorporation of 10% CPS is shown to assist the retention and diffusion of the ions.

  12. Acrylic bone cement in total joint arthroplasty: A review.

    Science.gov (United States)

    Saleh, Khaled J; El Othmani, Mouhanad M; Tzeng, Tony H; Mihalko, William M; Chambers, Monique C; Grupp, Thomas M

    2016-05-01

    Acrylic bone cement has a variety of applications in orthopedic surgery. Primary uses in total arthroplasties are limited to prostheses fixation and antibiotic delivery. With the large number of total joint arthroplasties expected to continue to rise, understanding the role bone cement plays in the success of total joint arthroplasty can have a significant impact on daily practice. The literature is inconclusive on whether cemented or cementless fixation technique is superior, and choice of fixation type is mainly determined by surgeon preference and experience. Surgeons should understand that if poor techniques exist, short-term outcomes of the replaced joint may be at risk. Statement of clinical significance: This article attempts to clarify some points of bone cement use through a review of the mechanical properties related to bone cement, a comparison to alternative materials, influence of additives, and the effects on surgical outcomes. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:737-744, 2016. PMID:26852143

  13. Coagulated silica - a-SiO2 admixture in cement paste

    Science.gov (United States)

    Pokorný, Jaroslav; Pavlíková, Milena; Záleská, Martina; Rovnaníková, Pavla; Pavlík, Zbyšek

    2016-07-01

    Amorphous silica (a-SiO2) in fine-grained form possesses a high pozzolanic activity which makes it a valuable component of blended binders in concrete production. The origin of a-SiO2 applied in cement-based composites is very diverse. SiO2 in amorphous form is present in various amounts in quite a few supplementary cementing materials (SCMs) being used as partial replacement of Portland cement. In this work, the applicability of a commercially produced coagulated silica powder as a partial replacement of Portland cement in cement paste mix design is investigated. Portland cement CEM I 42.5R produced according to the EU standard EN 197-1 is used as a reference binder. Coagulated silica is applied in dosages of 5 and 10 % by mass of cement. The water/binder ratio is kept constant in all the studied pastes. For the applied silica, specific surface area, density, loss on ignition, pozzolanic activity, chemical composition, and SiO2 amorphous phase content are determined. For the developed pastes on the basis of cement-silica blended binder, basic physical properties as bulk density, matrix density, and total open porosity are accessed. Pore size distribution is determined using MIP analysis. Initial and final setting times of fresh mixtures are measured by automatic Vicat apparatus. Effect of silica admixture on mechanical resistivity is evaluated using compressive strength, bending strength, and dynamic Young's modulus measurement. The obtained data gives evidence of a decreased workability of paste mixtures with silica, whereas the setting process is accelerated. On the other hand, reaction activity of silica with Portland cement minerals results in a slight decrease of porosity and improvement of mechanical resistivity of cement pastes containing a-SiO2.

  14. Respiratory Health among Cement Workers in Ethiopia

    OpenAIRE

    Zeleke, Zeyede K.

    2011-01-01

    Background: Little is known on dust exposure and respiratory health among cement cleaners. There are only a few follow-up studies on respiratory health among cement factory workers and also studies on acute effects of cement dust exposure are limited in numbers. Objective: This study aimed at assessing cement dust exposure and adverse respiratory health effects among Ethiopian cement production workers, with particular focus on cement cleaners. Method: The first paper was...

  15. Evaluation of Medial Acetabular Wall Bone Stock in Patients with Developmental Dysplasia of the Hip Using a Helical Computed Tomography Multiplanar Reconstruction Technique

    Energy Technology Data Exchange (ETDEWEB)

    Rui Yu Liu; Kun Zheng Wang; Chun Sheng Wang; Xiao Qian Dang; Zhi Qin Tong (Second Hospital Affiliated to the Medical College of Xi' an Jiaotong Univ., Xi' an Shaanxi (China))

    2009-08-15

    Background: The technique of medialization has been used to reconstruct acetabula at the level of true acetabula in total hip arthroplasty (THA) in patients with developmental dysplasia of the hip (DDH). Appreciation of the bone stock in the medial acetabular wall is significant for making an optimal acetabular reconstruction plan and avoiding complications. Purpose: To evaluate the bone stock of the medial acetabular wall and its relation to the degree of subluxation in patients with DDH using computed tomography (CT). Material and Methods: Helical CT scans of 27 hips were obtained from 21 patients with osteoarthritis secondary to DDH who were scheduled for total hip arthroplasty. Eleven hips belonged to Crowe class I, while 16 hips belonged to Crowe class II/III. The raw CT data were reprocessed in various planes by scrolling multiplanar reformation (MPR). Acetabular opening, depth, and medial bone stock, as indicated by the minimum thickness of the medial acetabular wall, were measured in the transverse reformed MPR plane. Results: The minimum thicknesses of the medial acetabular wall in Crowe-I and Crowe-II/III hips were 3.8+-2.1 mm and 7.1+-3.1 mm, respectively, with statistically significant differences between the groups (P<0.05). Furthermore, the bone stock in the medial acetabular wall correlated with the degree of subluxation (R=0.69) and the acetabular depth (R= ;- ;0.71). Conclusion: There was significantly more bone stock in the medial acetabular wall in patients with higher-degree subluxation than there was in the less-severe class. This difference should be taken into consideration when reconstructing acetabula in THA in patients with DDH using the technique of medialization

  16. Adsorption of Superplasticizers in Fly Ash Blended Cement Pastes and Its Rheological Effects

    Institute of Scientific and Technical Information of China (English)

    CHEN Wei; SHEN Peiliang; SHUI Zhonghe; FAN Jianfeng

    2012-01-01

    The adsorption of superplasticizers in fly ash blended cement paste and its rheological effects were investigated.It is shown that the absorption of superplasticizer on portland cement particles is very different from that on fly ash particles.The fly ash particles have smooth surfaces and are negatively charged,so its adsorption capacity is weaker than the portland cement particles.The amount of adsorbed SP in the fly ash blended cement paste depends highly on the replacement proportion of portland cement with fly ash,and to a much less extent on the nature of the fly ash.However,the amount of adsorbed superplasticizer does not correspond well the ζ-potential of the solid particles,due the strong adsorbing capacities of the Portland cement particles.When fly ash replaces portland cement in the paste,the rheological behavior is radically changed,which is closely related to the fineness and density of the ash.The packing and agglomeration of the solid particles are the controlling factors on the rheological parameters of the fresh paste,instead of the amount and type of adsorbed superplasticizer.

  17. Percutaneous Fixation of Anterior Column Acetabular Fracture in a Renal Transplant Recipient

    Directory of Open Access Journals (Sweden)

    Halil Ceylan

    2013-01-01

    Full Text Available Renal transplantation, performed per million population, ranges from 30 to 60 in developed countries. The transplanted kidney is generally placed in iliac fossa; therefore the treatment procedure of the pelvic trauma in these patients should be selected carefully. The gold standard technique for the treatment of displaced acetabulum fractures is open reduction and internal fixation. Our patient had received a living-related-donor renal transplant due to chronic renal failure. In the second year of transplantation, she had been injured in a motor-vehicle accident, and radiographs showed a right acetabular anterior column fracture and left pubic rami fractures. The patient was treated with percutaneous fixation techniques and at one year of postoperative period there was no evidence of degenerative signs and the clinical outcome was good. Beside having the advantage of avoiding dissection through the iliac fossa by the standard ilioinguinal approach, percutaneous techniques, with shorter surgical time, decreasing soft tissue disruption, and the potential for early discharge from hospital might be ideal for a renal transplant recipient carrying a higher risk of infection. Percutaneous fixation of selected acetabular fractures in a renal transplant recipient would presumably have the potential to decrease the morbidity associated with traditional open surgical procedures.

  18. Acetabular labral tears: contrast-enhanced MR imaging under continuous leg traction

    Energy Technology Data Exchange (ETDEWEB)

    Nishii, T. [Div. of Functional Diagnostic Imaging, Biomedical Research Center, Osaka Univ. Medical School, Suita (Japan); Nakanishi, K. [Dept. of Radiology, Osaka Univ. Medical School, Suita (Japan); Sugano, N. [Dept. of Orthopaedic Surgery, Osaka Univ. Medical School, Suita (Japan); Naito, H. [Div. of Functional Diagnostic Imaging, Biomedical Research Center, Osaka Univ. Medical School, Suita (Japan); Tamura, S. [Div. of Functional Diagnostic Imaging, Biomedical Research Center, Osaka Univ. Medical School, Suita (Japan); Ochi, T. [Dept. of Orthopaedic Surgery, Osaka Univ. Medical School, Suita (Japan)

    1996-05-01

    The objective of this study was to evaluate the effects of continuous leg traction on contrast-enhanced MR imaging of the hip joint and to determine whether MR imaging under these conditions is useful for demonstrating acetabular labral tears. Nineteen hips underwent MR imaging with a T1-weighted spin-echo sequence, followed by MR imaging under continuous leg traction after intravenous injection of gadolinium-DTPA. Joint fluid enhancement and labral contour detection were evaluated. Eleven hips had labral tears shown by conventional arthrography, arthroscopy and macroscopic surgical findings. Assessment of labral tears by MR imaging was correlated with the diagnosis based on these standard techniques. Joint fluid enhancement was obtained in all hips at 30 min after injection. Superior and inferior labral surfaces were completely delineated in 1 hip on the unenhanced MR images, and in 7 and 13 hips, respectively, on the enhanced images under traction. The enhanced images under traction depicted 9 of the 11 labral tears. Comparison between the unenhanced image and the enhanced image under traction avoided mistaking undercutting of the labrum for a tear in 4 hips. Contrast-enhanced MR imaging under traction was valuable for detecting labral tears non-invasively and without radiation. Follow-up examinations using this method in patients with acetabular dysplasia can help to clarify the natural course of labral disorders and enable better treatment planning. (orig./MG)

  19. Thermal Shock-resistant Cement

    Energy Technology Data Exchange (ETDEWEB)

    Sugama T.; Pyatina, T.; Gill, S.

    2012-02-01

    We studied the effectiveness of sodium silicate-activated Class F fly ash in improving the thermal shock resistance and in extending the onset of hydration of Secar #80 refractory cement. When the dry mix cement, consisting of Secar #80, Class F fly ash, and sodium silicate, came in contact with water, NaOH derived from the dissolution of sodium silicate preferentially reacted with Class F fly ash, rather than the #80, to dissociate silicate anions from Class F fly ash. Then, these dissociated silicate ions delayed significantly the hydration of #80 possessing a rapid setting behavior. We undertook a multiple heating -water cooling quenching-cycle test to evaluate the cement’s resistance to thermal shock. In one cycle, we heated the 200 and #61616;C-autoclaved cement at 500 and #61616;C for 24 hours, and then the heated cement was rapidly immersed in water at 25 and #61616;C. This cycle was repeated five times. The phase composition of the autoclaved #80/Class F fly ash blend cements comprised four crystalline hydration products, boehmite, katoite, hydrogrossular, and hydroxysodalite, responsible for strengthening cement. After a test of 5-cycle heat-water quenching, we observed three crystalline phase-transformations in this autoclaved cement: boehmite and #61614; and #61543;-Al2O3, katoite and #61614; calcite, and hydroxysodalite and #61614; carbonated sodalite. Among those, the hydroxysodalite and #61614; carbonated sodalite transformation not only played a pivotal role in densifying the cementitious structure and in sustaining the original compressive strength developed after autoclaving, but also offered an improved resistance of the #80 cement to thermal shock. In contrast, autoclaved Class G well cement with and without Class F fly ash and quartz flour failed this cycle test, generating multiple cracks in the cement. The major reason for such impairment was the hydration of lime derived from the dehydroxylation of portlandite formed in the autoclaved

  20. Effects of mechanical properties of adhesive resin cements on stress distribution in fiber-reinforced composite adhesive fixed partial dentures.

    Science.gov (United States)

    Yokoyama, Daiichiro; Shinya, Akikazu; Gomi, Harunori; Vallittu, Pekka K; Shinya, Akiyoshi

    2012-01-01

    Using finite element analysis (FEA), this study investigated the effects of the mechanical properties of adhesive resin cements on stress distributions in fiber-reinforced resin composite (FRC) adhesive fixed partial dentures (AFPDs). Two adhesive resin cements were compared: Super-Bond C&B and Panavia Fluoro Cement. The AFPD consisted of a pontic to replace a maxillary right lateral incisor and retainers on a maxillary central incisor and canine. FRC framework was made of isotropic, continuous, unidirectional E-glass fibers. Maximum principal stresses were calculated using finite element method (FEM). Test results revealed that differences in the mechanical properties of adhesive resin cements led to different stress distributions at the cement interfaces between AFPD and abutment teeth. Clinical implication of these findings suggested that the safety and longevity of an AFPD depended on choosing an adhesive resin cement with the appropriate mechanical properties. PMID:22447051

  1. The Association of Femoral Neck Stress Fractures with Femoral Acetabular Impingement

    Science.gov (United States)

    Safran, Marc R.; Goldin, Michael; Anderson, Christian; Fredericson, Michael; Stevens, Kathryn J.

    2013-01-01

    Objectives: To determine if there is an increased incidence of femoral acetabular impingement (FAI) in patients presenting with stress fractures of the femoral neck. Methods: After IRB approval, the imaging studies of 25 athletes (22 females, 3 males, mean age 26, range 19 - 39 years) with femoral neck stress injuries were assessed for the presence of features suggesting FAI, including acetabular retroversion, coxa profunda, abnormal femoral head-neck junction, fibrocystic change, os acetabulae, labral tear and chondral injury. All subjects had to have an adequate AP Pelvis radiograph, a lateral radiograph of the affected hip, and an MRI of the affected hip. The alpha angle, anterior offset ratio, and center to edge (CE) angle were measured on radiographs. The grade of stress injury was determined on MR images. All images and measurements were made by a musculoskeletal fellowship trained radiologist, a fellowship trained orthopaedic surgeon, an orthopaedic sports medicine fellow and a physical medicine and rehabilitation resident. Charts were reviewed to determine treatment of the stress fracture, outcome and final follow up, as well as to determine if the patient had any further treatment for their hip. Results: Of the 25 hips (18 right, 7 left) with femoral neck stress reactions, 9 were grade 2 (bone marrow edema), 5 were grade 3 (high T2 and low T1 marrow signal), and 11 were grade 4 (stress fracture). Twenty patients (80%) had coxa profunda - where the floor of the cotyloid fossa touches or extends beyond the ilioischial line (incidence in general population is 15.2% of males, and 19.4% of females). Coxa profunda, defined by the floor of the cotyloid fossa touching or extending beyond the ilioischial line and a center edge angle of more than 35o, was present in 28% of subjects. Acetabular retroversion as assessed by the crossover sign was present in 42% (normal incidence is 5% of population). Center edge angle was greater than 35o in 20% and greater than 40 o

  2. Precision of radiostereometric analysis (RSA) of acetabular cup stability and polyethylene wear improved by adding tantalum beads to the liner

    DEFF Research Database (Denmark)

    Nebergall, Audrey K; Rader, Kevin; Palm, Henrik;

    2015-01-01

    Background and purpose - In traditional radiostereometric analysis (RSA), 1 segment defines both the acetabular shell and the polyethylene liner. However, inserting beads into the polyethylene liner permits employment of the shell and liner as 2 separate segments, enabling distinct analysis of th...

  3. Reliability of ultrasonographic measurements in suspected patients of developmental dysplasia of the hip and correlation with the acetabular index

    Directory of Open Access Journals (Sweden)

    Cem Copuroglu

    2011-01-01

    Full Text Available Background: Ultrasonography is accepted as a useful imaging modality in the early detection of developmental dysplasia of the hip (DDH. Early detection and early treatment of DDH prevents hip dislocation and related physical, social, economic, and psychological problems. The purpose of this study was to evaluate the reliability of ultrasonographic and roentgenographic measurements measured by seven different observers. Materials and Methods: The alpha angles of 66 hips in 33 patients were measured using the Graf method by seven different observers. Acetabular index degrees on plane roentgenograms were measured in order to assess the correlation between the ultrasonographic alpha angle and the radiographic acetabular index, which both show the bony acetabular depth, retrospectively. Results: The interclass correlation coefficient, measuring the interobserver reliability, was high and statistically significant for the ultrasonographic measurements. There was a negative correlation between the alpha angle and the acetabular index. Conclusions: Ultrasonography, when applied properly, is a reliable technique between different observers, in the diagnosis and follow up of DDH. When assessed concomitantly with the roentgenographic measurements, the results are reliable and statistically meaningful.

  4. Phosphocalcium ceramics are efficient in the management of severe acetabular loss in revision hip arthroplasties. A 22 cases long-term follow-up study.

    Science.gov (United States)

    Schwartz, C; Vautrin, M

    2015-02-01

    Management of bone loss in revision total hip replacement remains a challenge. To eliminate any immunological or infectious problem and so to try to improve the long-term results obtained with allografts, the authors used synthetic ceramics as bone substitutes since 1995. We reviewed 13 of the patients of our study, we previously reported in 2005 (Schwartz and Bordei in Eur J Orthop Surg Traumatol 15: 191 2005), which was a prospective cohort of thirty-two cases of acetabular revision reconstruction, with a mean follow-up of 14.4 years yet (from 9 to 16 years). Clinical results were assessed according to Oxford scale and Postel and Merle d'Aubigne (PMA) scale. Since 2005, no specific complications were noted. The average PMA functional hip score was 14.9 (vs. 9.2 before revision) at follow-up over 9 years. Nine patients still alive in 2013 were seen again by a surgeon, which was not the operator, with a mean follow-up of 15.3 years: Their Oxford average score was 40.3. Radiological assessment affirmed a good integration of the substitutes in bone without any edging in all cases. A progressive invasion of the ceramics by bone can be seen on the X-ray. We conclude that about 15 years of average delay, which is a significant follow-up in orthopedic surgery, the outcomes without specific complications are satisfactory and allow one to go with these materials in total hip revision surgery.

  5. The Use of Micro and Nano Particulate Fillers to Modify the Mechanical and Material Properties of Acrylic Bone Cement

    Science.gov (United States)

    Slane, Joshua A.

    Acrylic bone cement (polymethyl methacrylate) is widely used in total joint replacements to provide long-term fixation of implants. In essence, bone cement acts as a grout by filling in the voids left between the implant and the patient's bone, forming a mechanical interlock. While bone cement is considered the `gold standard' for implant fixation, issues such as mechanical failure of the cement mantle (aseptic loosening) and the development of prosthetic joint infection (PJI) still plague joint replacement procedures and often necessitate revision arthroplasty. In an effort to address these failures, various modifications are commonly made to bone cement such as mechanical reinforcement with particles/fibers and the addition of antibiotics to mitigate PJI. Despite these attempts, issues such as poor particle interfacial adhesion, inadequate drug release, and the development of multidrug resistant bacteria limit the effectiveness of bone cement modifications. Therefore, the overall goal of this work was to use micro and nanoparticles to enhance the properties of acrylic bone cement, with particular emphasis placed on improving the mechanical properties, cumulative antibiotic release, and antimicrobial properties. An acrylic bone cement (Palacos R) was modified with three types of particles in various loading ratios: mesoporous silica nanoparticles (for mechanical reinforcement), xylitol microparticles (for increased antibiotic release), and silver nanoparticles (as an antimicrobial agent). These particles were used as sole modifications, not in tandem with one another. The resulting cement composites were characterized using a variety of mechanical (macro to nano, fatigue, fracture, and dynamic), imaging, chemical, thermal, biological, and antimicrobial testing techniques. The primary outcomes of this dissertation demonstrate that: (1) mesoporous silica, as used in this work, is a poor reinforcement phase for acrylic bone cement, (2) xylitol can significantly

  6. Investigation of cement based composites made with recycled rubber aggregate

    Directory of Open Access Journals (Sweden)

    Jevtić Dragica Lj.

    2012-01-01

    Full Text Available The results of experimental investigations performed on cement based composites made with addition of recycled rubber as a partial replacement of natural river aggregate are presented in this paper. Different properties of cement based mortar were analyzed, both in fresh and in hardened state. Tested properties in the fresh state included: density, consistency and volume of entrained air. In the hardened state, the following properties were tested: density, mechanical properties (compressive and flexural strength, modulus of elasticity, adhesion to concrete substrate, water absorption, freeze-thaw resistance and ultrasonic pulse velocity. The obtained results indicate that recycled rubber can be successfully applied as a partial replacement of natural river aggregate in cement based composites, in accordance with the sustainable development concept. The investigation showed that physical-mechanical properties of cementituous composites depend to a great extent on the percentage of replacement of natural river aggregate with recycled rubber, especially when the density, strength, adhesion and freeze-thaw resistance are concerned. The best results were obtained in the freeze-thaw resistance of such composites.

  7. Self-cleaning and mechanical properties of modified white cement with nanostructured TiO2.

    Science.gov (United States)

    Khataee, R; Heydari, V; Moradkhannejhad, L; Safarpour, M; Joo, S W

    2013-07-01

    In the present study, self-cleaning and mechanical properties of white Portland cement by addition of commercial available TiO2 nanoparticles with the average particle size of 80 nm were investigated. X-ray diffraction (XRD), transmission electron microscopy (TEM) and BET were used to characterize TiO2 nanoparticles. For determination of self-cleaning properties of TiO2-modified white cement, colorimetric tests in decolorization of C.I. Basic Red 46 (BR46) in comparison to unmodified cement samples was applied. The results indicated that with increasing the amount of TiO2 nanoparticles in modified cement, self-cleaning property of the samples increased. The mechanical properties of TiO2-modified and unmodified cement samples, such as time of setting of hydraulic cement, compressive strength of hydraulic cement mortar and flexural strength of hydraulic cement mortar were examined. The results indicated that addition of TiO2 nanoparticles up to maximum replacement level of 1.0% improved compressive and flexural strength and decreased its setting time.

  8. Calcium carbonate-calcium phosphate mixed cement compositions for bone reconstruction.

    Science.gov (United States)

    Combes, C; Bareille, R; Rey, C

    2006-11-01

    The feasibility of making calcium carbonate-calcium phosphate (CaCO(3)-CaP) mixed cements, comprising at least 40% (w/w) CaCO(3) in the dry powder ingredients, has been demonstrated. Several original cement compositions were obtained by mixing metastable crystalline CaCO(3) phases with metastable amorphous or crystalline CaP powders in aqueous medium. The cements set within at most 1 h at 37 degrees C in atmosphere saturated with water. The hardened cement is microporous and exhibits weak compressive strength. The setting reaction appeared to be essentially related to the formation of a highly carbonated nanocrystalline apatite phase by reaction of the metastable CaP phase with part or almost all of the metastable CaCO(3) phase. The recrystallization of metastable CaP varieties led to a final cement consisting of a highly carbonated poorly crystalline apatite analogous to bone mineral associated with various amounts of vaterite and/or aragonite. The presence of controlled amounts of CaCO(3) with a higher solubility than that of the apatite formed in the well-developed CaP cements might be of interest to increase resorption rates in biomedical cement and favors its replacement by bone tissue. Cytotoxicity testing revealed excellent cytocompatibility of CaCO(3)-CaP mixed cement compositions.

  9. Investigation of an effervescent additive as porogenic agent for bone cement macroporosity.

    Science.gov (United States)

    Hesaraki, Saeed; Sharifi, Davood

    2007-01-01

    Calcium phosphate cements (CPCs) are biocompatible and osteoconductive materials used in dental, craniofacial and orthopaedic applications. One of the most important advantages of these materials is their replacement with bone followed by resorption. Already several attempts have been made to improve the resorption behaviour of calcium phosphate cements by increasing the porosity of the material. In this investigation a mixture of NaHCO(3) and citric acid monohydrate was added to the apatite cement component as an effervescent additive for producing interconnected macropores into the cement matrix. Mercury intrusion porosimetry was employed to determine pore volume and pore size distribution in the calcium phosphate cement (CPC) samples. Results showed that addition of only 10 wt % of the effervescent additive (based on the cement powder) to the CPC components lead to producing about 20 V % macropores (with the size of 10 to 1000 mum) into the cement structure. The setting time was measured in an incubator at 37 degrees C and decreased from 40 min for additive-free CPC to about 14 min for CPC containing effervescent additive. Other properties of the CPCs such as compressive strength, phase composition, microstructure morphology and dissolution behavior were evaluated after immersing them in a simulated body fluid solution. The results showed that the rate of formation of poor crystalline apatite phase have been improved by production of macroporosity into the cement matrix. PMID:17264385

  10. Hydration of blended cement pastes containing waste ceramic powder as a function of age

    Science.gov (United States)

    Scheinherrová, Lenka; Trník, Anton; Kulovaná, Tereza; Pavlík, Zbyšek; Rahhal, Viviana; Irassar, Edgardo F.; Černý, Robert

    2016-07-01

    The production of a cement binder generates a high amount of CO2 and has high energy consumption, resulting in a very adverse impact on the environment. Therefore, use of pozzolana active materials in the concrete production leads to a decrease of the consumption of cement binder and costs, especially when some type of industrial waste is used. In this paper, the hydration of blended cement pastes containing waste ceramic powder from the Czech Republic and Portland cement produced in Argentina is studied. A cement binder is partially replaced by 8 and 40 mass% of a ceramic powder. These materials are compared with an ordinary cement paste. All mixtures are prepared with a water/cement ratio of 0.5. Thermal characterization of the hydrated blended pastes is carried out in the time period from 2 to 360 days. Simultaneous DSC/TG analysis is performed in the temperature range from 25 °C to 1000 °C in an argon atmosphere. Using this thermal analysis, we identify the temperature, enthalpy and mass changes related to the liberation of physically bound water, calcium-silicate-hydrates gels dehydration, portlandite, vaterite and calcite decomposition and their changes during the curing time. Based on thermogravimetry results, we found out that the portlandite content slightly decreases with time for all blended cement pastes.

  11. Partial knee replacement - slideshow

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/presentations/100225.htm Partial knee replacement - series To use the sharing features on ... A.M. Editorial team. Related MedlinePlus Health Topics Knee Replacement A.D.A.M., Inc. is accredited ...

  12. Shoulder Joint Replacement

    Science.gov (United States)

    ... en because of implant loosening, wear, infection, and dislocation. When this occurs, a second joint replacement surgery — called a revision surgery — may be necessary. Is Shoulder Joint Replacement for You? The decision to have ...

  13. Acetabulum malignancies: technique and impact on pain of percutaneous injection of acrylic surgical cement

    Energy Technology Data Exchange (ETDEWEB)

    Weill, A.; Kobaiter, H.; Chiras, J. [Neuroradiologie Charcot, Hopital de la Salpetriere, Paris (France)

    1998-02-01

    The aim of our study was to describe the technique of percutaneous injection of acrylic surgical cement into acetabulum malignancies [percutaneous acetabuloplasty (PCA)] and determine its efficiency in relieving pain. Eighteen patients (8 men, 10 women; aged 40-81 years) with painful acetabular malignancies (18 lesions; 17 metastases, 1 multifocal bone sarcoma) were treated with PCA. Procedures were done using lateral approach with fluoroscopic guidance. The 18 procedures were evaluated and resulted in 4 (22 %) total improvement, 7 (39 %) clear improvement, 4 (22 %) moderate improvement, 1 (6 %) no improvement, and 2 (11 %) worsening in keeping with a cement leak in contact with the sciatic nerve and a leak towards the joint. Follow-up ranged from 2 to 48 months (average 9.4 months). We observed 2 cases of recurrence of pain at 6 and 39 months, both in keeping with local tumoral progression. PCA of malignancies is a minimally invasive and low-cost procedure that provides immediate and long-term pain relief. (orig.) With 6 figs., 2 tabs., 20 refs.

  14. Durability of Cement Composites Reinforced with Sisal Fiber

    Science.gov (United States)

    Wei, Jianqiang

    This dissertation focuses mainly on investigating the aging mechanisms and degradation kinetics of sisal fiber, as well as the approaches to mitigate its degradation in the matrix of cement composites. In contrast to previous works reported in the literature, a novel approach is proposed in this study to directly determine the fiber's degradation rate by separately studying the composition changes, mechanical and physical properties of the embedded sisal fibers. Cement hydration is presented to be a crucial factor in understanding fiber degradation behavior. The degradation mechanisms of natural fiber consist of mineralization of cell walls, alkali hydrolysis of lignin and hemicellulose, as well as the cellulose decomposition which includes stripping of cellulose microfibrils and alkaline hydrolysis of amorphous regions in cellulose chains. Two mineralization mechanisms, CH-mineralization and self-mineralization, are proposed. The degradation kinetics of sisal fiber in the cement matrix are also analyzed and a model to predict the degradation rate of cellulose for natural fiber embedded in cement is outlined. The results indicate that the time needed to completely degrade the cellulose in the matrix with cement replacement by 30wt.% metakaolin is 13 times longer than that in pure cement. A novel and scientific method is presented to determine accelerated aging conditions, and to evaluating sisal fiber's degradation rate and durability of natural fiber-reinforced cement composites. Among the static aggressive environments, the most effective approach for accelerating the degradation of natural fiber in cement composites is to soak the samples or change the humidity at 70 °C and higher temperature. However, the dynamic wetting and drying cycling treatment has a more accelerating effect on the alkali hydrolysis of fiber's amorphous components evidenced by the highest crystallinity indices, minimum content of holocellulose, and lowest tensile strength. Based on the

  15. Investigation of a Gas-Solid Separation Process for Cement Raw Meal

    DEFF Research Database (Denmark)

    Maarup, Claus; Hjuler, Klaus; Clement, Karsten;

    2015-01-01

    The gas/solid heat exchanger (2D-HX), developed to replace the cyclone preheaters in cement plants is presented. This design aims at reducing construction height and operation costs. The separation process in the 2D-HX is experimentally investigated, and the results show that separation efficienc......The gas/solid heat exchanger (2D-HX), developed to replace the cyclone preheaters in cement plants is presented. This design aims at reducing construction height and operation costs. The separation process in the 2D-HX is experimentally investigated, and the results show that separation...

  16. Characterization of vapor phase mercury released from concrete processing with baghouse filter dust added cement.

    Science.gov (United States)

    Wang, Jun; Hayes, Josh; Wu, Chang-Yu; Townsend, Timothy; Schert, John; Vinson, Tim; Deliz, Katherine; Bonzongo, Jean-Claude

    2014-02-18

    The fate of mercury (Hg) in cement processing and products has drawn intense attention due to its contribution to the ambient emission inventory. Feeding Hg-loaded coal fly ash to the cement kiln introduces additional Hg into the kiln's baghouse filter dust (BFD), and the practice of replacing 5% of cement with the Hg-loaded BFD by cement plants has recently raised environmental and occupational health concerns. The objective of this study was to determine Hg concentration and speciation in BFD as well as to investigate the release of vapor phase Hg from storing and processing BFD-added cement. The results showed that Hg content in the BFD from different seasons ranged from 0.91-1.44 mg/kg (ppm), with 62-73% as soluble inorganic Hg, while Hg in the other concrete constituents were 1-3 orders of magnitude lower than the BFD. Up to 21% of Hg loss was observed in the time-series study while storing the BFD in the open environment by the end of the seventh day. Real-time monitoring in the bench system indicated that high temperature and moisture can facilitate Hg release at the early stage. Ontario Hydro (OH) traps showed that total Hg emission from BFD is dictated by the air exchange surface area. In the bench simulation of concrete processing, only 0.4-0.5% of Hg escaped from mixing and curing BFD-added cement. A follow-up headspace study did not detect Hg release in the following 7 days. In summary, replacing 5% of cement with the BFD investigated in this study has minimal occupational health concerns for concrete workers, and proper storing and mixing of BFD with cement can minimize Hg emission burden for the cement plant. PMID:24444016

  17. 21 CFR 888.4200 - Cement dispenser.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cement dispenser. 888.4200 Section 888.4200 Food... DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.4200 Cement dispenser. (a) Identification. A cement dispenser is a nonpowered syringe-like device intended for use in placing bone cement (§ 888.3027)...

  18. Factor ten emission reductions : the key to sustainable development and economic prosperity for the cement and concrete industry

    Energy Technology Data Exchange (ETDEWEB)

    Horton, R. [Alchemix Corp., Pittsburgh, PA (United States)

    2001-07-01

    This paper proposes that the negative environmental effects of current cement/concrete production can be reduced by a factor of 10 by using cement blends with minimum portland cement and maximum pozzolanic loading. In addition to extending the longevity of concrete, such cement blends also avoid the huge cost of repairs and replacement cycles. Market forces will drive this transition toward sustainable development in the concrete and cement industry. The economic advantages of improving the quality of the concrete are great. Even if improving the concrete doubles the price of the highest quality cement, this would only add 2 per cent to the cost of the overall construction project, but the service life of the structure would give a many-fold return on this added investment. Also, regulations on carbon dioxide emissions in the near future will assume economic importance in the manufacturing of cement and concrete. While portland cements have dominated the construction industry for more than 150 years, new blended cements priced on a performance basis will become the standard in the twenty first century. Currently, the typical cement formulation in the United States, if it contains fly ash, contains 15 to 20 per cent fly ash by weight of the total cementitious material. This paper states that soon the number will be 50 to 60 per cent ash. Fly ash will be widely acknowledged for improving critical performance characteristics of concrete such as workability, impermeability and durability. Carbon dioxide credits will also be a major economic factor that will drive the cement industry toward a factor ten environmental improvement. The Kyoto Protocol calls for the trading of greenhouse gas credits which includes carbon dioxide credits. Under the new system, cement producers will be taxed on excess emissions, while those using pozzolans in their cements will earn credits to offset these penalties. 10 refs.

  19. Acetabular deepening in the treatment of severe canine hip dysplasia Aprofundamento do acetábulo no tratamento de displasia coxofemoral grave em cães

    OpenAIRE

    Paulo Iamaguti; Luciana S. Iamaguti; Raquel Sartor

    2009-01-01

    A technique to restore acetabular anatomy by deepening the acetabular cavity and reconstructing the femoral head ligament and the joint capsule was tested on nine large breed dogs with severe hip dysplasia and acute subdislocation or dislocation. The technique consisted of two phases. First, all dogs were submitted to bilateral pectinotomy. In a second surgical intervention on the same dogs the acetabulum was approached and deepened, and the femoral head ligament and the joint capsule were re...

  20. A Feasibility Study into the Use of Three-Dimensional Printer Modelling in Acetabular Fracture Surgery

    Directory of Open Access Journals (Sweden)

    A. W. Yu

    2015-01-01

    Full Text Available There are a number of challenges associated with the operative treatment of acetabular fractures. The approach used is often extensive, while operative time and perioperative blood loss can also be significant. With the proliferation of 3D printer technology, we present a fast and economical way to aid the operative planning of complex fractures. We used augmented stereoscopic 3D CT reconstructions to allow for an appreciation of the normal 3D anatomy of the pelvis on the fractured side and to use the models for subsequent intraoperative contouring of pelvic reconstruction plates. This leads to a reduction in the associated soft tissue trauma, reduced intraoperative time and blood loss, minimal handling of the plate, and reduced fluoroscopic screening times. We feel that the use of this technology to customize implants, plates, and the operative procedure to a patient’s unique anatomy can only lead to improved outcomes.

  1. Precooling an acetabular liner makes its insertion into a metal shell easier.

    Science.gov (United States)

    Kyle, Richard F; Bourgeault, Craig A; Lew, William D; Bechtold, Joan E

    2006-02-01

    Temporary shrinkage of an acetabular polyethylene liner due to precooling could reduce the force required to snap the liner into its metal shell. This study documented cooling and heating rates of liners with a particular locking mechanism design, determined forces required to seat liners in their shells as a function of temperature, and quantified the force surgeons can exert with their thumbs when seating a liner. It took up to 8 minutes to cool 58- and 70-mm liners in an ice-water bath from room temperature to near 0 degrees C, and up to 24 minutes to subsequently warm these liners to near body temperature. Forces required to seat liners were greater at room and body temperatures than at 0 degrees C. Liners precooled to 0 degrees C required insertion forces that could be generated manually by surgeons. PMID:16520215

  2. Tranexamic acid reduces the blood loss and blood transfusion requirements following peri-acetabular osteotomy.

    Science.gov (United States)

    Wassilew, G I; Perka, C; Janz, V; Krämer, M; Renner, L

    2015-12-01

    We have investigated the effect of using tranexamic acid (TXA) during peri-acetabular osteotomy (PAO) on peri-operative blood loss and blood transfusion requirements. In addition we analysed whether the use of TXA was associated with an increased risk of venous thromboembolism (VTE) following this procedure. A consecutive series of 96 PAOs, performed by a single surgeon, were reviewed. A total of 48 patients received TXA and 48 did not. The TXA group received a continuous infusion of TXA at a rate of 10 mg/kg/h. The primary outcome measure was the requirement for blood transfusion. Secondary outcomes included total blood loss, the decrease in the level of haemoglobin in the blood, the length of hospital stay, and the complications of this treatment. The mean rate of transfusion was significantly lower in the TXA group (62.5% vs 12.5%, p transfusion after PAO significantly, without adverse effects such as an increased rate of VTE.

  3. Research on Transverse Acetabular Fracture Fixation Using Different Plate Attachment Methods

    Directory of Open Access Journals (Sweden)

    Gediminas Gaidulis

    2015-03-01

    Full Text Available The article deals with the problem of transverse acetabular fracture fixation using different plate attachment methods. A 3D model of pelvis and hip joint structure was created and the design of three different fixation plates using SolidWorks was made. The plates were fixed at distances of 10, 20 and 30 mm from the acetabulum. The model was meshed into finite elements, a static external load of 2500 N was added and the analysis of stress distribution in plates and fracture displacement was performed. The obtained results showed that fracture displacement was quite similar in all fixation methods. However, the maximal stress in the nearest from the acetabulum plate was higher than yield strength. Thus, this placement is not eligible. The plate fixed at a distance of 30 mm from the acetabulum appeared the most suitable because of the smallest and symmetrical stress distribution in the plate.

  4. Cements in Radioactive Waste Disposal

    International Nuclear Information System (INIS)

    The use of cement and concrete to immobilise radioactive waste is complicated by the wide- ranging nature of inorganic cementing agents available as well as the range of service environments in which cement is used and the different functions expected of cement. For example, Portland cement based concretes are widely used as structural materials for construction of vaults and tunnels. These constructions may experience a long pre-closure performance lifetime during which they are required to protect against collapse and ingress of water: strength and impermeability are key desirable characteristics. On the other hand, cement and concrete may be used to form backfills, ranging in permeability. Permeable formulations allow gas readily to escape, while impermeable barriers retard radionuclide transport and reduce access of ground water to the waste. A key feature of cements is that, while fresh, they pass through a fluid phase and can be formed into any shape desired or used to infiltrate other materials thereby enclosing them into a sealed matrix. Thereafter, setting and hardening is automatic and irreversible. Where concrete is used to form structural elements, it is also natural to use cement in other applications as it minimises potential for materials incompatibility. Thus cement- mainly Portland cement- has been widely used as an encapsulant for storage, transport and as a radiation shield for active wastes. Also, to form and stabilise structures such as vaults and silos. Relative to other potential matrices, cement also has a chemical immobilisation potential, reacting with and binding with many radionuclides. The chemical potential of cements is essentially sacrificial, thus limiting their performance lifetime. However performance may also be required in the civil engineering sense, where strength is important, so many factors, including a geochemical description of service conditions, may require to be assessed in order to predict performance lifetime. The

  5. Cement/slag chemistry studies

    International Nuclear Information System (INIS)

    The performance of cement-based matrices intended for radwaste immobilization is assessed. The long-term performance of the matrix is characterized by thermodynamic evaluation of experimental data. The results are presented in a general form, amenable to a range of specific formulations. The interaction of specific radwaste components with cements has been studied, using Iodine as an example. It occurs as both I- and IO3- species, but these differ sharply in sorption characteristics. The effect of ionizing radiation of the pH and Eh of cement matrices is reported. (author)

  6. 髋臼发育不良髋关节置换前髋臼侧的三维测量%Three-dimensional measurement of acetabular side before arthroplasty for acetabular dysplasia

    Institute of Scientific and Technical Information of China (English)

    许杰; 马若凡; 李登; 蔡志清; 李亮平

    2013-01-01

    BACKGROUND:The anatomical strucure of acetabulum is smal and shal ow in adult acetabular dysplasia patients. The large amount of cal us and scar tissues in the acetabulum make it difficult to identify and instal the acetabular cup during arthroplasty. The comprehensive understanding of the acetabulum before arthroplasty is the premise for selecting the appropriate acetabular prosthesis and making the acetabular reconstruction program. OBJECTIVE:To evaluate the application value of three-dimensional reconstruction technique in choosing the size of acetabular cup before total hip arthroplasty for acetabular dysplasia. METHODS:Spiral CT was carried out in the 11 acetabular dysplasia patients who waiting for total hip arthroplasty. The acetabulum was multi-planar reconstructed, and the size of the acetabular cup was determined through digitized acetabular cup template implantation, and then the mathching degree assessment was performed to compare with the actual size. RESULTS AND CONCLUSION:Spiral CT could clearly show the acetabular morphology, and the 71.4%of the acetabular size chosen in the three-dimensional preoperative plan was the same as actual one, the intraclass correlation coefficient was 0.888. The agreement was much higher than that of two-dimensional preoperative plan based on X-ray plain film. For the patients with acetabular dysplasia, the acetabulum became saml er and shal ower, and there were various extents of bone defects in the superior-lateral acetabulum. Three-dimensional multi-planar reconstruction can effectively evaluate the acetabular morphology, and three-dimensional preoperative plan can provide useful information for the choice of implant.%背景:成人髋臼发育不良髋臼小而浅,臼内有大量骨痂和瘢痕组织等都为人工髋关节置换术中真臼的辨认、臼杯的准确安装带来极大困难,关节置换前对髋臼的全面认识是选择合适的髋臼假体和制定个性化髋臼重建方案的前提。目

  7. Performance of RHA Cement Concrete under Marine Environment via Wetting and Drying Cyclic by Rapid Migration Test

    Directory of Open Access Journals (Sweden)

    Ramadhansyah Putra Jaya

    2013-12-01

    Full Text Available In this research, the performance of concrete containing rice husk ash (RHA under marine environment through wetting and drying cycles was investigated. Five levels of cement replacement (0%, 10%, 20%, 30% and 40% by weight were used. The total cementitious content used was 420 kg/m3. A water/binder ratio of 0.49 was used to produce concrete having a target compressive strength of 40MPa at the age of 28 days. The performance of blended cement concrete under marine environment was evaluated using rapid migration test (RMT.  The results clearly showed that RHA can be satisfactorily used as a cement replacement material in order to reduce the chloride penetration depth and hence increases the durability of concrete. Generally, the chloride penetration depth of concrete containing higher RHA replacement is decreased as the RHA replacement increases, resulting in concrete with higher resistance to seawater attack.

  8. Supra-Acetabular Brown Tumor due to Primary Hyperparathyroidism Associated with Chronic Renal Failure

    Directory of Open Access Journals (Sweden)

    Rosaria M. Ruggeri

    2010-01-01

    Full Text Available A 63-year-old woman presented to the Orthopedic Unit of our hospital complaining of right hip pain of 6 months'duration associated with a worsening limp. Her past medical history included chronic renal insufficiency. Physical examination revealed deep pain in the iliac region and severe restriction of the right hip's articular function in the maximum degrees of range of motion. X-rays and CT scan detected an osteolytic and expansive lesion of the right supra-acetabular region with structural reabsorption of the right iliac wing. 99mTc-MDP whole-body bone scan showed an abnormal uptake in the right iliac region. Bone biopsy revealed an osteolytic lesion with multinucleated giant cells, indicating a brown tumor. Serum intact PTH was elevated (1020 pg/ml; normal values, 12 62 pg/ml, but her serum calcium was normal (total = 9.4 mg/dl, nv 8.5–10.5; ionized = 5.0 mg/dl, nv 4.2–5.4 due to the coexistence of chronic renal failure. 99mTc-MIBI scintigraphy revealed a single focus of sestamibi accumulation in the left retrosternal location, which turned out to be an intrathoracic parathyroid adenoma at surgical exploration. After surgical removal of the parathyroid adenoma, PTH levels decreased to 212 pg/ml. Three months after parathyroidectomy, the imaging studies showed complete recovery of the osteolytic lesion, thus avoiding any orthopedic surgery. This case is noteworthy because (1 primary hyperparathyroidism was not suspected due to the normocalcemia, likely attributable to the coexistence of chronic renal failure; and (2 it was associated with a brown tumor of unusual location (right supra-acetabular region.

  9. Properties of Non-Structural Concrete Made with Mixed Recycled Aggregates and Low Cement Content

    Directory of Open Access Journals (Sweden)

    Antonio López-Uceda

    2016-01-01

    Full Text Available In spite of not being legally accepted in most countries, mixed recycled aggregates (MRA could be a suitable raw material for concrete manufacturing. The aims of this research were as follows: (i to analyze the effect of the replacement ratio of natural coarse aggregates with MRA, the amount of ceramic particles in MRA, and the amount of cement, on the mechanical and physical properties of a non-structural concrete made with a low cement content; and (ii to verify if it is possible to achieve a low-strength concrete that replaces a greater amount of natural aggregate with MRA and that has a low cement content. Two series of concrete mixes were manufactured using 180 and 200 kg/m3 of CEM II/A-V 42.5 R type Portland cement. Each series included seven concrete mixes: one with natural aggregates; two MRA with different ceramic particle contents; and one for each coarse aggregate replacement ratio (20%, 40%, and 100%. To study their properties, compressive and splitting tensile strength, modulus of elasticity, density, porosity, water penetration, and sorptivity, tests were performed. The results confirmed that the main factors affecting the properties analyzed in this research are the amount of cement and the replacement ratio; the two MRAs used in this work presented a similar influence on the properties. A non-structural, low-strength concrete (15 MPa with an MRA replacement ratio of up to 100% for 200 kg/m3 of cement was obtained. This type of concrete could be applied in the construction of ditches, sidewalks, and other similar civil works.

  10. Strength Development and Physical Properties of Cement Paste with Incorporated Ceramic Powder

    Directory of Open Access Journals (Sweden)

    Tereza KULOVANÁ

    2016-05-01

    Full Text Available A possible usage of fine waste ceramic powder coming from precise brick cutting in production of blended cement is analyzed in the paper. For the studied ceramic powder, chemical and mineralogical composition is measured by X-Ray Fluorescence and X-Ray Diffraction. The particle size distribution of ceramic powder is accessed on laser diffraction principle. The ceramic powder is used in cement based pastes composition in cement mass replacements of 8, 16, 24, 32, and 40%. For the tested pastes, monitoring of strength development is done using measurement of time dependent mechanical parameters. Bulk density, matrix density, and total open porosity are measured for 28 days cured samples. In order to obtain information on the rate of hydration process, the formation of pastes’ solid structure is monitored using measurement of pore size distribution at chosen times of hydration. Application of waste ceramics is found to give the most promising mechanical properties of the cement-based paste for 8 and 16% cement replacement levels what makes good prerequisites for future research that will be focused on design and development of new types of cement-based composites with incorporated ceramic waste powder. However, also other tested mixtures provide acceptable results. This knowledge can be used for instance in the production of lower strength composites.

  11. Cementing porcelain-fused-to-metal crowns.

    Science.gov (United States)

    Vadachkoria, D

    2009-12-01

    The clinical success of fixed prosthodontic restorations can be complex and involve multifaceted procedures. Preparation design, oral hygiene/micro flora, mechanical forces, and restorative materials are only a few of the factors which contribute to overall success. One key factor to success is choosing the proper cement. Popular use of cements for PFM crowns has shifted from zinc phosphate and glass ionomer cements to resin-reinforced glass ionomer, or RRGI, cements. This change has been rapid and profound. Dental cements have always been less than ideal materials, but this is shift to the relatively new RRGI category justified. Resin-reinforced glass ionomer (RRGI) cements appear to be better than zinc phosphate and glass ionomer cements when placing porcelain-to-metal crowns. RRGI cements, such as RelyX Luting, Fuji Plus and Vitremer Luting Cement, satisfy more of the ideal characteristics of PFM cementation than any other previous cement. Expansion of all three cements has not caused any apparent problems with the cements when used with PFM or metal crowns, but these cements, however, should be avoided when cementing all-ceramic crowns. PMID:20090144

  12. Using of borosilicate glass waste as a cement additive

    Science.gov (United States)

    Han, Weiwei; Sun, Tao; Li, Xinping; Sun, Mian; Lu, Yani

    2016-08-01

    Borosilicate glass waste is investigated as a cement additive in this paper to improve the properties of cement and concrete, such as setting time, compressive strength and radiation shielding. The results demonstrate that borosilicate glass is an effective additive, which not only improves the radiation shielding properties of cement paste, but also shows the irradiation effect on the mechanical and optical properties: borosilicate glass can increase the compressive strength and at the same time it makes a minor impact on the setting time and main mineralogical compositions of hydrated cement mixtures; and when the natural river sand in the mortar is replaced by borosilicate glass sand (in amounts from 0% to 22.2%), the compressive strength and the linear attenuation coefficient firstly increase and then decrease. When the glass waste content is 14.8%, the compressive strength is 43.2 MPa after 28 d and the linear attenuation coefficient is 0.2457 cm-1 after 28 d, which is beneficial for the preparation of radiation shielding concrete with high performances.

  13. A new design of cemented stem using functionally graded materials (FGM).

    Science.gov (United States)

    Hedia, H S; Aldousari, S M; Abdellatif, A K; Fouda, N

    2014-01-01

    One of the most frequent complications of total hip replacement (THR) is aseptic loosening of femoral component which is primarily due to changes of post-operative stress distribution pattern with respect to intact femur. Stress shielding of the femur is known to be a principal factor in aseptic loosening of hip replacements. Many designers show that a stiff stem shields the surrounding bone from mechanical loading causing stress shielding. Others show that reducing stem stiffness promotes higher proximal interface shear stress which increases the risk of proximal interface failure. Therefore, the task of this investigation is to solve these conflicting problems appeared in the cemented total hip replacement. The finite element method and optimization technique are used in order to find the optimal stem material which gives the optimal available stress distribution between the proximal medial femoral bone and the cement mantle interfaces. The stem is designed using the concept of functionally graded material (FGM) instead of using the conventional most common used stem material. The results showed that there are four feasible solutions from the optimization runs. The best of these designs is to use a cemented stem graded from titanium at the upper stem layer to collagen at the lower stem layer. This new cemented stem design completely eliminates the stress shielding problem at the proximal medial femoral region. The stress shielding using the cemented functionally graded stem is reduced by 98% compared to titanium stem. PMID:24840196

  14. Physico-mechanical properties of solid cement bricks containing recycled aggregates

    Directory of Open Access Journals (Sweden)

    Dina M. Sadek

    2012-07-01

    Full Text Available Recycling and reuse of solid wastes as alternative building materials present interesting possibilities for economy on waste disposal sites and conservation of natural resources. This paper investigates the physical and mechanical properties of solid cement bricks manufactured with crushed clay bricks as recycled aggregates. Four series of mixtures with cement content 100, 150, 200 and 300 kg/m3 were prepared. In each series, either natural fine aggregate, coarse aggregate or both were replaced with crushed brick aggregates (CBA at 0%, 50% and 100% by volume. Compressive strength, unit weight and water absorption were determined and compared with the relevant national and international standards for load bearing and non-load bearing units, respectively. The experimental results showed that as the replacement level of natural aggregates increased, the unit weight and compressive strength of solid cement bricks decreased and the water absorption increased regardless of cement content. Furthermore, it is possible to manufacture different grades of solid cement bricks with CBA to be used as load bearing and non-load bearing units depending on the size of the crushed bricks and the replacement percentage of natural aggregates.

  15. Assessment of Natural Radioactivity Levels of Cements and Cement Composites in the Slovak Republic

    OpenAIRE

    Adriana Eštoková; Lenka Palaščáková

    2013-01-01

    The radionuclide activities of 226Ra, 232Th and 40K and radiological parameters (radium equivalent activity, gamma and alpha indices, the absorbed gamma dose rate and external and internal hazard indices) of cements and cement composites commonly used in the Slovak Republic have been studied in this paper. The cement samples of 8 types of cements from Slovak cement plants and five types of composites made from cement type CEM I were analyzed in the experiment. The radionuclide activities in t...

  16. Assessment of the compatibility of wood and plastic with cement for their recycling in cement composites

    OpenAIRE

    Andrade, André De; Caldeira, Fernando

    2010-01-01

    The compatibility between maritime pine wood and cement, and between plastic (LDPE) and cement, was assessed for the recycling of wood and plastic in cement composites. Temperature vs. time profiles of cement setting were registered and compatibility indices were calculated. Results indicate that recycling of plastics in plastic-cement composites does not pose any questions regarding chemical compatibility. However, maritime pine hinders cement setting in some extent. So, in or...

  17. One stage treatment of acetabular fractures combined with ipsilateral femoral head or neck fractures with total hip arthroplasty%Ⅰ期全髋置换术治疗合并股骨头或股骨颈骨折的髋臼骨折

    Institute of Scientific and Technical Information of China (English)

    唐孝明; 张耀明; 袁加斌; 庞健; 王跃

    2008-01-01

    目的 探讨全髋关节置换术(total hip arthroplasty,THA)治疗合并股骨头或股骨颈骨折的髋臼骨折方法、手术特点和疗效.方法 对7例合并股骨头或股骨颈骨折的髋臼骨折行Ⅰ期THA.髋臼骨折按AO分型:A型1例,B型3例,C型3例.股骨头骨折1例,股骨颈骨折6例.伤后7~21 d接受THA,5例行髋臼复位内固定后采用生物型髋臼,2例金属加强环配合骨水泥固定髋臼,股骨侧均采用生物型固定.结果 6例得到随访,平均随访时间3年9个月(2年3个月~6年5个月),出现脱位1例,经手法复位后未再脱位,1例出现异位骨化.所有随访患者髋关节功能均有明显改善,Harris评分术前平均48分,术后提高到91分.随访期内未发现假体松动.结论 THA是治疗合并同侧股骨头或股骨颈骨折髋臼骨折的有效方法,能显著改善关节功能,避免多次手术.%Objective To discuss method,operative characters and curative effect of total hip arthroplasty(THA)in treatment of acetabular fractures combined with ipsilateral femoral head or neck fractures.Methods One stage THA was done in seven patients with acetabular fractures combined with ipsilateral femoral head fracture(one patient)or femoral neck fractures(six patients)7-21 days after fractures.There were five males and two females,at age range of 41-65 years(average 50 years).According to AO classification,there were one patient with type A fracture,three with type B and three with type C.Of all,five patients received biological acetabular replacement after reduction and internal fixation of acetabular fracture and two received PMMA acetabular replacement with metal enforcement ring.All patients received biological femoral stem.Results Of all,six patients were followed up for from 2 years and 3 months to 6 years and 5 months(mean 3 years and 9 months),which showed heterotopic ossitlcation in one patient and dislocation in one who recovered after manipulative reduction.The Harris score was

  18. Processing of Sugarcane Bagasse ash and Reactivity of Ash-blended Cement Mortar

    Science.gov (United States)

    Ajay, Goyal; Hattori, Kunio; Ogata, Hidehiko; Ashraf, Muhammad

    Sugarcane bagasse ash (SCBA), a sugar-mill waste, has the potential of a partial cement replacement material if processed and obtained under controlled conditions. This paper discusses the reactivity of SCBA obtained by control burning of sugarcane bagasse procured from Punjab province of India. X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques were employed to ascertain the amorphousness and morphology of the minerals ash particles. Destructive and non-destructive tests were conducted on SCBA-blended mortar specimens. Ash-blended cement paste specimens were analyzed by XRD, thermal analysis, and SEM methods to evaluate the hydration reaction of SCBA with cement. Results showed that the SCBA processed at 600°C for 5 hours was reactive as ash-blended mortar specimens with up to 15% substitution of cement gave better strength than control specimens.

  19. Utilization of washed MSWI fly ash as partial cement substitute with the addition of dithiocarbamic chelate.

    Science.gov (United States)

    Gao, Xingbao; Wang, Wei; Ye, Tunmin; Wang, Feng; Lan, Yuxin

    2008-07-01

    The management of the big amount of fly ash as hazardous waste from the municipal solid waste incinerator (MSWI) has encountered many problems in China. In this study, a feasibility research on MSWI fly ash utilization as partial cement substitute in cement mortars was therefore carried out. MSWI fly ash was subjected to washing process to reduce its chlorine content (from 10.16% to 1.28%). Consequently, it was used in cement mortars. Ten percent and 20% replacement of cement by washed ash showed acceptable strength properties. In TCLP and 180-day monolithic tests, the mortars with washed ash presented a little stronger heavy metal leachability, but this fell to the blank level (mortar without washed ash) with the addition of 0.25% chelate. Therefore, this method is proposed as an environment-friendly technology to achieve a satisfactory solution for MSWI fly ash management.

  20. INFLUENCE OF POZZOLANA ON THE HYDRATION OF C4AF RICH CEMENT IN CHLORIDE ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    IRMANTAS BARAUSKAS

    2013-03-01

    Full Text Available This study investigated the influence of natural pozzolana - opoka additive on the hydration of C4AF rich cement and the effects of chloride ions on the hydrates formed. In the samples, 25 % (by weight of the sintered C4AF rich cement and OPC was replaced with pozzolana. The mixtures were hardened for 28 days in water, soaked in a saturated NaCl solution for 3 months at 20°C. It was estimated that under normal conditions, pozzolana additive accelerates the hydration of calcium silicates and initiates the formation of CO32- - AFm in the Brownmillerite rich cement. However, the hydration of Brownmillerite cement with opoka additive is still slower to compare with hydration of Portland cement. Also, opoka decreases total porosity and threshold pore diameter of Brownmillerite cement paste after two days of hydration. After 28 days of hydration threshold pore diameter became smaller even to compare with threshold pore diameter of Portland cement. Opoka additive promotes the formation of Friedel’s salt in Brownmillerite samples treated in saturated NaCl solution, because CO32-–AFm affected by saturated NaCl solution become unstable and takes part in reactions producing Friedel’s salt.

  1. Blended Cements Produced With Synthetic Zeolite Made from Industrial By-Product

    Directory of Open Access Journals (Sweden)

    Vitoldas Vaitkevičius

    2015-03-01

    Full Text Available Zeolites are appropriate supplementary cementitious materials in cement and concrete industry. In the present work synthetic zeolites was used like supplementary material in hardened cement paste and some properties as well as its influence on Portland cement hydration was determinate. X-ray powder diffraction, scanning electronic microscopy and energy-dispersive X-ray spectroscopy, FTIR spectroscopy were used as investigation methods. The compressive strength of hardened cement paste was measured at day 3, 28 and 60. The instrumental analysis showed that zeolite A(Na dominates and unreacted Al(OH3 remains in investigated synthetics zeolites, made from thermal and mechanical treated AlF3 production waste. The Chapelle test showed that both zeolites have good pozzolanic properties. The samples compressive strength remained close to the control samples compressive strength, reducing the amount of Portland cement, i.e., changing it by zeolite. After 60 days, the compressive strength was the best in the samples where 5% of Portland cement was replaced by the 2-zeolite. The compressive strength of the samples increased by 9 % compared with control samples. This research provides a real opportunity to save cement thus disposing the waste.DOI: http://dx.doi.org/10.5755/j01.ms.21.1.5635

  2. Slag cement matrix for immobilisation of spent organic ion exchange resins from nuclear power plants

    International Nuclear Information System (INIS)

    The spent IX resins from nuclear power reactors are highly active solid wastes generated during operations of water cooled nuclear power plants. Direct immobilisation of spent IX resins in slag cement matrix was investigated. Slag cement matrix formulations were optimised for mixed, K+ and borate resins by evaluating leaching characteristics, porosity, hydraulic conductivity etc. The 137cesium leaching characteristics of slag cement matrices developed in this study gave the average leach rates of the order of 10-4 g/cm2/d and leachability indices of 8.4 to 9.6. The 137cesium behaviour was in accordance with the porosity and hydraulic conductivity of matrix. The laboratory study revealed that these tests can be effectively used to shortlist cement matrix formulations for long term 137cesium leach tests. The results showed that slag cement matrix can be satisfactorily used to immobilise spent resins arising from PHWR and PWR/VVER type reactors. The selected formulations were successfully deployed to prepare full size (200 litre) slag cement matrix block incorporating 100 litres of mixed IX resins. The compressive strengths of core drilled samples were 64 to 118 kg/cm2 which satisfactorily meet the safety requirements. The study has shown that the slag cement matrix has potential to replace the polymer matrix making treatment of spent IX resins cost effective. (author)

  3. Delayed cementless total hip arthroplasty for neglected dislocation of hip combined with complex acetabular fracture and deficient bone stock

    Institute of Scientific and Technical Information of China (English)

    Ashok S Gavaskar; Naveen Chowdary Tummala

    2012-01-01

    Total hip arthroplasty (THA) for an untreated acetabular fracture is technically challenging and the long-term result is not so favorable.A 45-year-old female patient with untreated column and comminuted posterior wall fracture of the acetabulum was treated in our institution by reconstruction of the posterior wall using iliac strut autograft and plate stabilization of the posterior column with cancellous grafting and cementless THA in a single stage.At 3 years' follow-up,the patient was independently mobile without limb length discrepancy.Radiological evaluation showed well integrated components and bone grafts.No evidence of aseptic loosening or osteolysis was found.This report aims to emphasize that bony acetabular reconstruction allows the use of primary hip components,which improves prosthesis longevity and preserves bone stock for a future revision.

  4. Influence of various amount of diatomaceous earth used as cement substitute on mechanical properties of cement paste

    Science.gov (United States)

    Pokorný, Jaroslav; Pavlíková, Milena; Medved, Igor; Pavlík, Zbyšek; Zahálková, Jana; Rovnaníková, Pavla; Černý, Robert

    2016-06-01

    Active silica containing materials in the sub-micrometer size range are commonly used for modification of strength parameters and durability of cement based composites. In addition, these materials also assist to accelerate cement hydration. In this paper, two types of diatomaceous earths are used as partial cement replacement in composition of cement paste mixtures. For raw binders, basic physical and chemical properties are studied. The chemical composition of tested materials is determined using classical chemical analysis combined with XRD method that allowed assessment of SiO2 amorphous phase content. For all tested mixtures, initial and final setting times are measured. Basic physical and mechanical properties are measured on hardened paste samples cured 28 days in water. Here, bulk density, matrix density, total open porosity, compressive and flexural strength, are measured. Relationship between compressive strength and total open porosity is studied using several empirical models. The obtained results give evidence of high pozzolanic activity of tested diatomite earths. Their application leads to the increase of both initial and final setting times, decrease of compressive strength, and increase of flexural strength.

  5. Manufacture and properties of fluoride cement

    Science.gov (United States)

    Malata-Chirwa, Charles David

    This research work aimed at characterising composition, hydration and physical properties of fluoride cement, by studying samples of the cement obtained from Malawi, and comparing them to ordinary Portland cement. By confirming the suitable characteristics of fluoride cement through this work, the results of the research work provide a good basis for the wider adoption of fluoride cement as an alternative to ordinary Portland cement, especially in developing economies. Numerous accounts have been cited regarding the production and use of fluoride cement. Since there have not been conclusive agreement as to its properties, this study was limited to the theories of successful incorporation of fluoride compounds in the manufacture of fluoride cement. Hence, the properties and characteristics reported in this study relate to the cement currently manufactured in Malawi, and, on a comparative basis only, to that manufactured in other parts of the world. Samples of the fluoride cement used in the study were obtained by synthetic manufacture of the cement using common raw materials for the manufacture of fluoride cement that is limestone, silica sand, and fluorspar. These samples were subjected to several comparative tests used to characterise cements including examination under x-ray diffractometer, scanning electron microscopy and tests for setting time and compressive strength. Under similar laboratory conditions, it was possible to prove that fluoride cement hardens more rapidly than ordinary Portland cement. Also observed during the experimental work is that fluoride cement develops higher compressive strengths than ordinary Portland cement. The hardening and setting times are significantly different between the two cements. Also the nature of the hydration products, that is the microstructural development is significantly different in the two cements. The differences brought about between the two cements are because of the presence of fluorine during the clinkering

  6. Low pH Cements

    Energy Technology Data Exchange (ETDEWEB)

    Savage, David; Benbow, Steven [Quintessa Ltd., Henley-on-Thames (United Kingdom)

    2007-05-15

    The development of low-pH cements for use in geological repositories for radioactive waste stems from concerns over the potential for deleterious effects upon the host rock and other EBS materials (notably bentonite) under the hyperalkaline conditions (pH > 12) of cement pore fluids. Low pH cement (also known as low heat cement) was developed by the cement industry for use where large masses of cement (e.g. dams) could cause problems regarding heat generated during curing. In low pH cements, the amount of cement is reduced by substitution of materials such as fly ash, blast furnace slag, silica fume, and/or non-pozzolanic silica flour. SKB and Posiva have ruled out the use of blast furnace slag and fly-ash and are focusing on silica fume as a blending agent. Currently, no preferred composition has been identified by these agencies. SKB and Posiva have defined a pH limit {<=} 11 for cement grout leachates. To attain this pH, blending agents must comprise at least 50 wt % of dry materials. Because low pH cement has little, or no free portlandite, the cement consists predominantly of calcium silicate hydrate (CSH) gel with a Ca/Si ratio {<=} 0.8. Although there are potential implications for the performance of the spent fuel and cladding due to the presence of hyperalkaline fluids from cement, the principal focus for safety assessment lies with the behaviour of bentonite. There are a number of potential constraints on the interaction of hyperalkaline cement pore fluids with bentonite, including mass balance, thermodynamic issues, mass transport, and kinetics, but none of these is likely to be limiting if conventional OPC cements are employed in repository construction. Nevertheless: Low-pH cements may supply approximately 50 % less hydroxyl ions than conventional OPC for a given volume of cement, but mass balance constraints are complicated by the uncertainty concerning the type of secondary minerals produced during cement-bentonite interaction. The change of aqueous

  7. Study of the three-dimensional orientation of the labrum: its relations with the osseous acetabular rim

    Science.gov (United States)

    Bonneau, Noémie; Bouhallier, July; Baylac, Michel; Tardieu, Christine; Gagey, Olivier

    2012-01-01

    Understanding the three-dimensional orientation of the coxo-femoral joint remains a challenge as an accurate three-dimensional orientation ensure an efficient bipedal gait and posture. The quantification of the orientation of the acetabulum can be performed using the three-dimensional axis perpendicular to the plane that passes along the edge of the acetabular rim. However, the acetabular rim is not regular as an important indentation in the anterior rim was observed. An innovative cadaver study of the labrum was developed to shed light on the proper quantification of the three-dimensional orientation of the acetabulum. Dissections on 17 non-embalmed corpses were performed. Our results suggest that the acetabular rim is better represented by an anterior plane and a posterior plane rather than a single plane along the entire rim as it is currently assumed. The development of the socket from the Y-shaped cartilage was suggested to explain the different orientations in these anterior and posterior planes. The labrum forms a plane that takes an orientation in between the anterior and posterior parts of the acetabular rim, filling up inequalities of the bony rim. The vectors VL, VA2 and VP, representing the three-dimensional orientation of the labrum, the anterior rim and the posterior rim, are situated in a unique plane that appears biomechanically dependent. The three-dimensional orientation of the acetabulum is a fundamental parameter to understand the hip joint mechanism. Important applications for hip surgery and rehabilitation, as well as for physical anthropology, were discussed. PMID:22360458

  8. Analysis of acetabular version in the native hip: comparison between 2D axial CT and 3D CT measurements

    Energy Technology Data Exchange (ETDEWEB)

    Dandachli, Wael [Department of Orthopaedic Surgery, Imperial College London Hospitals, London (United Kingdom); Ul Islam, Saif; Tippett, Richard; Hall-Craggs, Margaret A.; Witt, Johan D. [University College London Hospitals, London (United Kingdom)

    2011-07-15

    To compare two-dimensional (2D) axial with three-dimensional (3D) computerized tomography (CT) measurements of acetabular version in native hips. CT scans of 34 hips in 17 consecutive patients being investigated for femoroacetabular impingement were analyzed. Acetabular version was measured using 2D CT at two different axial levels, one cranial (slice 2) and the other at the equator (slice 3). The measurements were repeated after correction for pelvic tilt. The results were compared to the measurements of anatomical version obtained using a 3D CT method that automatically corrects for pelvic tilt. The mean acetabular version using the 3D CT method was 15.7 (SD 6.9 ). The mean version using slice 2 was 9.3 (SD 6.5 ) before correction for pelvic tilt and 15.7 (SD 8.0 ) after the correction. The mean version using slice 3 was 16.4 (SD 4.2 ) before tilt correction and 19.0 (SD 5.0 ) after the correction. In relation to the 3D method, the intraclass correlation coefficient (ICC) was 0.58 for the uncorrected and 0.93 for the corrected slice 2 method. For the uncorrected and corrected slice 3 methods, the ICC was 0.64 and 0.89, respectively. The 2D axial methods produced variable results. The results that correlated best with the 3D method were those of the cranial slice (slice 2) after correction for pelvic tilt. Interpretation of 2D axial CT measurements of acetabular version should be done with caution. The level at which the measurement is done and the presence of pelvic tilt appear to be significant factors. (orig.)

  9. Oil Palm Fiber as Partial Replacement Aggregates for Normal Concrete

    OpenAIRE

    1Wasiu John,; 2 Salami Victor ,; 3Awolusi T.F

    2015-01-01

    This study is focused on assessing the effectiveness of palm kernel shell (PKS) as partial replacement aggregates for normal concrete. The tests carried out on PKS concrete at a constant water cement ratio of 0.5 with mix ratios 1:2:4 and 1:1 : 3 with PKS varied from 0%-30%. The results of the slump and compaction factor test showed that all mixes were workable for all replacement levels considered. The compressive strength values obtained ranges between 32.2N...

  10. Investigation on the Effect of Recycled Asphalt Shingle (RAS in Portland Cement Mortar

    Directory of Open Access Journals (Sweden)

    Jinwoo An

    2016-04-01

    Full Text Available Tear-off roofing shingle, referred to as Reclaimed asphalt shingle (RAS, is the byproduct of construction demolition and it is a major solid waste stream in the U.S. Reuse of this byproduct in road construction sector can contribute to the success of materials sustainability as well as landfill conservation. Ground RAS has similar particle distribution as sand and its major component includes aggregate granules, fibers, and asphalt. To promote the beneficial utilization of RAS, this study evaluates the effect of RAS in cement mortar when used as replacement of sand. In addition, the study investigates how cellulose fibers from RAS behave under high alkaline environment during cement hydration process, which may significantly affect mortar’s strength performance. The laboratory study includes measurements of physical, mechanical, and durability behaviors of cement mortar containing RAS replacing sand up to 30%. It was found that the optimum mixture proportions are 5% and 10% for compressive strength and toughness, respectively.

  11. O uso de enxerto homólogo na revisão de artroplastias do quadril com cimentação do componente acetabular Use of homologous graft in hip arthroplasty reviews with acetabular component cementation

    Directory of Open Access Journals (Sweden)

    Fábio Stuchi Devito

    2006-01-01

    Full Text Available A artroplastia total do quadril representa um grande avanço no tratamento das enfermidades ortopédicas que acometem o quadril. A soltura asséptica desta prótese pode causar lesões e perdas ósseas, representando um grande desafio para a reconstrução cirúrgica destas artroplastias. Uma das alternativas para a reconstrução é o uso do enxerto ósseo de banco de ossos, podendo este ser usado em bloco ou na forma picada. Este estudo, baseado em uma revisão da literatura sobre enxertos ósseos, teve como objetivo uma análise quanto à reconstrução com enxertos em bloco e picado e sua integração. O enxerto picado mostrou melhores resultados quanto à integração quando se consegue estabilidade da reconstrução. Quando não conseguimos uma boa estabilidade, o enxerto em bloco associado aos anéis de reforço sobressai como a melhor opção.Hip total arthroplasty represents a breakthrough in the treatment of orthopaedic illnesses affecting the hip. The aseptic loosening of this prosthesis may cause injuries and bone losses, representing a great challenge for the surgical reconstruction of those arthroplasties. One alternative to reconstruction is the use of bone graft sourced by bone bases, which may be used as a block or in pieces. This study, based on a literature review addressing bone grafts, had as an objective to analyze reconstruction with grafts in blocks and in pieces and its union. The graft in pieces showed better results concerning union when reconstruction stability is achieved. When a good stability cannot be achieved, the graft in block combined with reinforcement rings is highlighted as the best option.

  12. Absence or interruption of the supra-acetabular line: a subtle plain film indicator of hip pathology

    Energy Technology Data Exchange (ETDEWEB)

    Major, N.M. [Department of Radiology, University of California San Francisco, Box 0628, San Francisco, CA 94143 (United States); Helms, C.A. [Department of Radiology, University of California San Francisco, Box 0628, San Francisco, CA 94143 (United States)

    1996-08-01

    Objective. To show that absence or interruption of the supraacetabular line is a subtle plain film indicator of pathology in the acetabulum. Design. Nineteen hips from 17 patients with known disease processes involving the acetabulum as demonstrated by subsequent magnetic resonance imaging, bone scan or plain film follow-up were evaluated with antero-posterior (AP) plain films of the pelvis. Three additional cases were diagnosed prospectively using interruption of the supra-acetabular line as the criterion for inclusion. Fifty AP plain films of the pelvis in patients without hip pain were examined prospectively to determine normal imaging criteria. Results and conclusions. The normal supra-acetabular line measures 2-3 mm in thickness superiorly and is a thin sclerotic line in the medial aspect. In all 22 hips (with pathology) in this series, the line was interrupted or absent. Loss or interruption of the supra-acetabular line may thus be a subtle pain film indicator of a disease process involving the acetabulum. This plain film sign has not previously been reported. (orig.). With 8 figs., 1 tab.

  13. Effect of addition of sugar cane biomass ash in properties of fresh state in cement slurries for oil wells; Efeito da adicao de cinza de biomassa de cana-de-acucar nas propriedades no estado fresco de pastas de cimento para pocos de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Galvao, Lornna L.A.; Santos, Herculana T.; Souza, Pablo Diego Pinheiro; Freitas, Julio Cezar Oliveira [Universidade Federal do Rio Grande do Norte (UFRN), RN (Brazil); Nascimento, Julio Cesar S. [Universidade Federal da Bahia (UFBA), BA (Brazil); Amorim, Natalia M.M. [Universidade Potiguar (UNP), RN (Brazil); Martinell, Antonio E. [Mcgill University (MCGILL) (Canada); Universidade Federal do Rio Grande do Norte (UFRN), RN (Brazil)

    2012-07-01

    Recent studies have shown that ashes from biomass, in particular those generated by the alcohol industry have pozzolanic activity and can replace cement in many applications, reducing the consumption of cement and, consequently, the environmental impact caused by the production of this material. The present work evaluated the behavior of ash sugarcane biomass partially replacing Portland cement in concentrations of 10, 20 and 40% BWOC in oil well slurries. The results of rheology, thickening time and stability showed that the addition of 40% of biomass ash in oil well slurries significantly improves their properties, enabling the replacement of cement by ash. (author)

  14. Radiation Source Replacement Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, Jeffrey W.; Moran, Traci L.; Bond, Leonard J.

    2010-12-01

    This report summarizes a Radiation Source Replacement Workshop in Houston Texas on October 27-28, 2010, which provided a forum for industry and researchers to exchange information and to discuss the issues relating to replacement of AmBe, and potentially other isotope sources used in well logging.

  15. Replacement nuclear steam generators

    International Nuclear Information System (INIS)

    This paper reviews past and current practices in the replacement of nuclear steam generators. Plants where steam generator replacement has occurred are reviewed to see what changes have been made, and how the evolving technology has significantly reduced outage time and man-rem exposures. Current preferences in design and material are reviewed. 3 refs., 3 tabs., 2 figs

  16. Cementation of Loose Sand Particles based on Bio-cement

    Institute of Scientific and Technical Information of China (English)

    RONG Hui; QIAN Chunxiang

    2014-01-01

    Loose sand particles could be cemented to sandstone by bio-cement (microbial induced magnesium carbonate). The bio-sandstone was firstly prepared, and then the compressive strength and the porosity of the sandstone cemented by microbial induced magnesium carbonate were tested to characterize the cementation effectiveness. In addition, the formed mineral composition and the microstructure of bio-sandstone were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The experimental results show that the feasibility of binding loose sand particles using microbial induced magnesium carbonate precipitation is available and the acquired compressive strength of bio-sandstone can be excellent at certain ages. Moreover, the compressive strength and the porosity could be improved with the increase of microbial induced magnesium carbonate content. XRD results indicate that the morphology of magnesium carbonate induced by microbe appears as needles and SEM results show that the cementation of loose sand particles to sandstone mainly relies on the microbial induced formation of magnesium carbonate precipitation around individual particles and at particle-particle contacts.

  17. Reprodutibilidade da classificação de Tile para fraturas do acetábulo Reproducibility of Tile's classification of acetabular fractures

    Directory of Open Access Journals (Sweden)

    Marcos Almeida Matos

    2006-01-01

    Full Text Available Classificar corretamente as fraturas acetabulares é crucial para bom planejamento pré-operatório e para redução cirúrgica eficiente. Entretanto, para cumprir seus objetivos, qualquer sistema de classificação deve ser simples e reprodutível. O objetivo deste artigo é avaliar a reprodutibilidade interobservador da classificação de Tile para fraturas do acetábulo. Foram utilizadas 30 imagens radiográficas de 10 fraturas acetabulares nas incidências de Judet, analisadas por 10 observadores, sendo cinco especialistas em cirurgia de quadril e cinco residentes do terceiro ano de ortopedia. A concordância global obtida foi de 72,44% com Kappa (K = 0,52 (0,48 entre residentes e 0,57 entre especialistas. Conclui-se que a classificação de Tile para fraturas acetabulares apresenta moderada concordância interobservador, não havendo diferença estatisticamente significante entre residentes e especialistas.Properly classifying acetabular fractures is crucial for a good preoperative planning and for an efficient surgical reduction. However, in order to accomplish its objectives, any classification system must be simple and reproducible. The objective of this article is to assess inter-observer reproducibility of Tile’s classification concerning acetabular fractures. Thirty X-ray images of 10 acetabular fractures at Judet planes were used and assessed by 10 observers, being five hip surgery experts and five 3rd-grade orthopaedic residents. The global consistency achieved was 72.44% to Kappa (K = 0.52 (0.48 among resident doctors and 0.57 among experts. It was concluded that the Tile’s classification of acetabular fractures reveals a moderate inter-observer consistency, with no statistically significant difference between resident doctors and experts.

  18. A comparative study of "plasmacup" and "porous-coated" acetabular components: survival after 10 to 12 years of follow-up

    Directory of Open Access Journals (Sweden)

    José Ricardo Negreiros Vicente

    2010-01-01

    Full Text Available OBJECTIVES: Our primary aim was to compare the long-term survivorship rates and the rates of successful osseointegration between two different types of uncemented acetabular components. INTRODUCTION: Two types of alloys have primarily been used for the manufacture of the uncemented acetabular components: titanium-based and cobalt-based alloys. A titanium-based alloy appears to be more effective with regard to interface stress transfer to the host bone because of its lower elastic modulus relative to a cobalt-based alloy. This supposed mechanical advantage of a titanium-based alloy component motivated this comparative study. METHODS: Two uncemented acetabular components, a porous-coated acetabulum and a Plasmacup®, were compared with a focus on long-term prosthesis survivorship and the development of acetabular osseointegration. Five radiographic signs of osseointegration were evaluated at the last follow-up appointment: (1 absence of radiolucent lines, (2 presence of a superolateral buttress, (3 medial stress-shielding, (4 radial trabeculae, and (5 an inferomedial buttress. We considered the presence of any three of these radiographic signs, in the absence of acetabular dislocation or symptoms, to be indicative of successful acetabular osseointegration. RESULTS: Among 70 patients implanted with the porous-coated acetabulum, 80% achieved osseointegration over a mean follow-up time of 11.9 years versus 75.3% of the 73 patients who received a Plasmacup insert over a mean of 10.7 years. Prosthesis survivorship rates were not different between the two groups. Revision surgery due to mild or severe acetabular osteolysis, polyethylene wear, and aseptic loosening occurred in eight patients (11.4% with a PCA versus nine (12.3% with a Plasmacup. CONCLUSIONS: We conclude that, during the first ten years after surgery, there is no significant difference between these two types of uncemented cups with regard to either prosthesis survivorship or successful

  19. 21 CFR 888.3027 - Polymethylmethacrylate (PMMA) bone cement.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Polymethylmethacrylate (PMMA) bone cement. 888... Polymethylmethacrylate (PMMA) bone cement. (a) Identification. Polymethylmethacrylate (PMMA) bone cement is a device...: Polymethylmethacrylate (PMMA) Bone Cement.”...

  20. Effect of Expansive Admixtures on the Shrinkage and Mechanical Properties of High-Performance Fiber-Reinforced Cement Composites

    OpenAIRE

    Won-Chang Choi; Hyun-Do Yun

    2013-01-01

    High-performance fiber-reinforced cement composites (HPFRCCs) are characterized by strain-hardening and multiple cracking during the inelastic deformation process, but they also develop high shrinkage strain. This study investigates the effects of replacing Portland cement with calcium sulfoaluminate-based expansive admixtures (CSA EXAs) to compensate for the shrinkage and associated mechanical behavior of HPFRCCs. Two types of CSA EXA (CSA-K and CSA-J), each with a different chemical composi...

  1. Modifications induced by adding natural zeolitic pozzolans to cement paste

    Directory of Open Access Journals (Sweden)

    Blanco-Varela, M. T.

    2005-12-01

    Full Text Available Volcanic pozzolans owe their pozzolanic activity chiefly to the presence of vitreous or zeolitic material rich in SiO2, and Al20y compounds that react with the portlandite produced during cement hydration to generate amorphous gels with cementitious properties. The present study analyzes the modifications taking place in the composition, structure and micro structure of the hydra ted cement paste when 20% of the cement by weight is replaced by two finely ground zeolitic rocks from Cuban deposits. Hydrated cement pastes were prepared with a CEM I35 cement, as well as with mixes of the cement and two Cuban zeolitic rocks (20% by weight. After eight months of hydration, the pastes were characterized -mineralogically, chemically and microstructurally- with XRD, FTIR, 29Si and 27Al MAS NMR, DTA/TG, back scattered electron microscopy and mercury porosimetry techniques. The replacement of 20% by weight of the cement with two finely ground zeolitic rocks significantly modified the composition, structure, quantity and microstructure of the hydrated cement paste reaction product. The C-S-H gel formed in these pastes differed in quantity, which was larger, and composition from the original cement gel. Moreover, the gel formed in addition-free cement had a higher Ca and a lower Al content and shorter silicate chains than the C-S-H product formed in the pastes made with zeolitic rocks. Finally, the pastes with pozzolan additions had fewer and smaller pores.

    La actividad de las puzolanas de origen volcánico procede fundamentalmente de la presencia de material vitreo o zeolítico rico en SiO2 y Al2Oy que son los que reaccionan con la portlandita producida en la hidratación del cemento generando geles amorfos con propiedades cementantes. El objetivo del presente trabajo es estudiar las modificaciones que produce la sustitución del 20% en peso de cemento por dos

  2. Rheology and zeta potential of cement pastes containing calcined silt and ground granulated blast-furnace slag

    OpenAIRE

    B. Safi; A. Benmounah; Saidi, M.

    2011-01-01

    This study aimed to analyse the re-use of dam silt as a supplementary binder for self-compacting concrete (SCC). When burnt, silt becomes more reactive because the kaolin it contains is converted into metakaolin. Portland cement, calcined or burnt silt and ground granulated blast furnace slag were used in this research. Cement pastes were prepared with blends containing two or three of these materials. The replacement ratio for burnt silt in both cases was 10 % and 20 % by cement weight and t...

  3. Efficient radiologic diagnosis of pelvic and acetabular trauma; Rationelle bildgebende Diagnostik von Becken- und Azetabulumverletzungen

    Energy Technology Data Exchange (ETDEWEB)

    Kreitner, K.F.; Mildenberger, P.; Thelen, M. [Mainz Univ. (Germany). Klinik und Poliklinik fuer Radiologie; Rommens, P.M. [Mainz Univ. (Germany). Klinik und Poliklinik fuer Unfallchirurgie

    2000-01-01

    In spite of the widespread availability of CT scanners, conventional X-ray radiographs remain the basic imaging modality in patients with pelvic and/or acetabular trauma. However, the extent of their use will depend on local utilities (e.g., availability of CT scanners) and on the patient's clinical condition. Regarding the inaccuracy of conventional radiography in the diagnosis of injuries of the dorsal pelvic ring and of the acetabulum, computed tomography represents the most important imaging modality in the clinically stable patient. CT provides an exact staging of the extent of trauma and allows for differentiation of pelvic instabilities. CT clearly demonstrates the severity of acetabular trauma and is superior in the detection of local complicating factors, i.e., impressions fractures and (sub-)luxations of the femoral head as well as free intraarticular fragments. CT findings provide the basis for definite treatment regimens of the injured patient. By extension of the examination, all relevant organs and systems (craniospinal, cardiovascular, gastrointestinal, respiratory, genitourinary) can be imaged during one session. The speed of spiral CT scanners and their diagnostic accuracy will play a major role in the management of, especially, polytraumatized patients. The indication for angiography with the option of therapeutic embolization exists if a pelvic bleeding persists even after reposition and operative fixation of the injury. (orig.) [German] Bei der Klaerung einer Verletzung des Beckens oder des Azetabulums stellen konventionelle Uebersichtsaufnahmen weiterhin die Basis der bildgebenden Diagnostik dar. Art und Umfang werden bestimmt von lokalen Gegebenheiten (z.B. Verfuegbarkeit von CT-Geraeten) sowie vom klinischen Zustand des Patienten. Aufgrund der diagnostischen Ungenauigkeit der konventionellen Roentgendiagnostik gerade im Bereich des stabilitaetsbedeutsamen dorsalen Beckenringes und des Azetabulums schliesst sich beim klinisch stabilen

  4. A modified PMMA cement (Sub-cement) for accelerated fatigue testing of cemented implant constructs using cadaveric bone.

    Science.gov (United States)

    Race, Amos; Miller, Mark A; Mann, Kenneth A

    2008-10-20

    Pre-clinical screening of cemented implant systems could be improved by modeling the longer-term response of the implant/cement/bone construct to cyclic loading. We formulated bone cement with degraded fatigue fracture properties (Sub-cement) such that long-term fatigue could be simulated in short-term cadaver tests. Sub-cement was made by adding a chain-transfer agent to standard polymethylmethacrylate (PMMA) cement. This reduced the molecular weight of the inter-bead matrix without changing reaction-rate or handling characteristics. Static mechanical properties were approximately equivalent to normal cement. Over a physiologically reasonable range of stress-intensity factor, fatigue crack propagation rates for Sub-cement were higher by a factor of 25+/-19. When tested in a simplified 2 1/2-D physical model of a stem-cement-bone system, crack growth from the stem was accelerated by a factor of 100. Sub-cement accelerated both crack initiation and growth rate. Sub-cement is now being evaluated in full stem/cement/femur models. PMID:18774136

  5. A preliminary study of CO2 sequestration of cement paste

    Science.gov (United States)

    Choi, Y.; Lee, H.; Hwang, J.; Oh, J.; Lee, J.

    2013-12-01

    CSH by replacement of Ca by Mg. Almost all portlandites change to calcites in the pulverized cement paste (carbonation method. The carbonation of CSH is slightly progressed. With the addition of NaCl and MgCl2, the carbonation efficiency of CSH is not increased. However, the leaching test result with MgCl2 solution indicates that MgCl2 can be an efficient additive in indirect aqueous carbonation method.

  6. Seating load parameters impact on dental ceramic reinforcement conferred by cementation with resin-cements.

    LENUS (Irish Health Repository)

    Addison, Owen

    2010-09-01

    Cementation of all-ceramic restorations with resin-cements has been demonstrated to reduce the incidence of fracture in service. The aim was to investigate the influence of loading force and loading duration applied during cementation on the reinforcement conferred by a resin-cement on a leucite reinforced glass-ceramic.

  7. Shrinkage and Cracking Sensitivity of Cement Mortar Containing Fly Ash, Granulated Blast-furnace Slag and Silica Fume

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A laboratory study was undertaken to investigate drying shrinkage and cracking sensitivity subjected to restrained shrinkage of mortar containing fly ash (FA), granulated blast-furnace slag (GBFS) and silica fume (SF). Six mortar mixtures including control Portland cement (PC) and FA,GBFS and SF mortar mixtures were prepared. FA replaced the cement on mass basis at the replacement ratios of 20% and 35%, GBFS replaced the cement at the replacement ratios of 40%, SF replaced the cement at the replacement ratios of 8% and the blended mixtures with 20% FA, 20% GBFS and 8% SF. Water-cementitious materials ratio and sand-cementitious materials ratio were 0.4 and 2.0 for all mixtures, respectively. The mixtures were cured at 65% relative humidity and 20℃. The drying shrinkage value, initial cracking time and cracking width of the mortar samples were measured. The results show that all the mortar mixture containing FA exhibited the decrease of drying shrinkage.Moreover, initial cracking time was markedly delayed, and the crack width of the initial crack was reduced. However, the incorporations of various ratios of GBFS and SF led to an increase of drying shrinkage, initial cracking time and cracking width as compared to control mixture.

  8. Acetabular retroversion as a rare cause of chronic hip pain: recognition of the ''figure-eight'' sign

    Energy Technology Data Exchange (ETDEWEB)

    Banks, Kevin P. [Brooke Army Medical Center, Department of Radiology, Fort Sam Houston, TX (United States); Grayson, David E. [Wilford Hall Medical Center, Department of Radiology, Lackland Air Force Base, TX (United States)

    2007-06-15

    While well-recognized in the orthopedic literature as a cause of chronic hip pain, acetabular retroversion has not been specifically described in the radiologic literature. Acetabular retroversion represents a particular form of hip dysplasia characterized by abnormal posterolateral orientation of the acetabulum. This pathophysiology predisposes the individual to subsequent anterior impingement of the femoral neck upon the anterior acetabular margin and fibrous labrum. Without treatment, cases may progress to damage of the anterior labrum and cartilage, with eventual early onset of osteoarthritic disease. This impinging condition has been described as occurring in isolation or as part of a complex dysplasia. We describe two cases of acetabular retroversion diagnosed by conventional radiographic evaluation of the pelvis, one in isolation and one occurring in the setting of a larger congenital syndrome. These cases illustrate the utility of the ''figure-eight'' sign in identifying abnormalities of acetabular version and thus assisting clinicians in properly identifying these individuals so that appropriate therapy may be instituted. (orig.)

  9. Cement radwaste solidification studies third annual report

    International Nuclear Information System (INIS)

    This report summarises cement radwaste studies carried out at AEE Winfrith during 1981 on the encapsulation of medium and low active waste in cement. During the year more emphasis has been placed on the work which is directly related to the solidification of SGHWR active sludge. Information has been obtained on the properties of 220 dm3 drums of cemented waste. The use of cement grouts for the encapsulation of solid items has also been investigated during 1981. (U.K.)

  10. Hormone Replacement Therapy

    Science.gov (United States)

    ... before and during menopause, the levels of female hormones can go up and down. This can cause ... hot flashes and vaginal dryness. Some women take hormone replacement therapy (HRT), also called menopausal hormone therapy, ...

  11. Knee joint replacement - slideshow

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/presentations/100088.htm Knee joint replacement - series To use the sharing features ... 4 out of 4 Normal anatomy Overview The knee is a complex joint. It contains the distal ...

  12. Total Knee Replacement

    Science.gov (United States)

    ... following total knee replacement include unlimited walking, swimming, golf, driving, light hiking, biking, ballroom dancing, and other ... to the final success of your surgery. To learn more about the full value of total knee ...

  13. Neutron Scattering Studies of Cement

    Science.gov (United States)

    Allen, Andrew

    2010-03-01

    Despite more than a century of research, basic questions remain regarding both the internal structure and the role of water in Ordinary Portland cement (OPC) concrete, the world's most widely used manufactured material. Most such questions concern the primary hydration product and strength-building phase of OPC paste, the calcium silicate hydrate (C-S-H) gel. When cement and water are mixed, this phase precipitates as clusters of nanoscale (nearly amorphous) colloidal particles with an associated water-filled inter-particle pore system. Most attempts to characterize the C-S-H gel and the behavior of the associated water involve drying or other processes that, themselves, change the bound water content within and around the gel. Neutron scattering methods do not suffer from this disadvantage. Furthermore, the neutron isotope effect and the neutron's sensitivity to molecular motion have enabled considerable progress to be made in recent years by: (i) determining the C-S-H composition, density and gel structure in small-angle neutron scattering (SANS) H/D contrast variation studies; (ii) elucidating the changing state of water within cement as hydration progresses using quasielastic neutron scattering (QENS); and (iii) measuring the production and consumption of nanoscale calcium hydroxide (CH), a by-product of cement hydration that co-exists with the C-S-H gel, using inelastic neutron scattering (INS). These experiments have provided new insights into the physics and chemistry of cement hydration, and have implications for the design of new concretes with pozzolanic cement additions that are intended to address environmental concerns and sustainability issues.

  14. Finite element analysis of stresses in fixed prosthesis and cement layer using a three-dimensional model

    Directory of Open Access Journals (Sweden)

    Arunachalam Sangeetha

    2012-01-01

    Full Text Available Context: To understand the effect of masticatory and parafunctional forces on the integrity of the prosthesis and the underlying cement layer. Aims: The purpose of this study was to evaluate the stress pattern in the cement layer and the fixed prosthesis, on subjecting a three-dimensional finite element model to simulated occlusal loading. Materials and Methods: Three-dimensional finite element model was simulated to replace missing mandibular first molar with second premolar and second molar as abutments. The model was subjected to a range of occlusal loads (20, 30, 40 MPa in two different directions - vertical and 30° to the vertical. The cements (zinc phosphate, polycarboxylate, glass ionomer, and composite were modeled with two cement thicknesses - 25 and 100 μm. Stresses were determined in certain reference points in fixed prosthesis and the cement layer. Statistical Analysis Used: The stress values are mathematic calculations without variance; hence, statistical analysis is not routinely required. Results: Stress levels were calculated according to Von Mises criteria for each node. Maximum stresses were recorded at the occlusal surface, axio-gingival corners, followed by axial wall. The stresses were greater with lateral load and with 100-μm cement thickness. Results revealed higher stresses for zinc phosphate cement, followed by composites. Conclusions: The thinner cement interfaces favor the success of the prosthesis. The stresses in the prosthesis suggest rounding of axio-gingival corners and a well-established finish line as important factors in maintaining the integrity of the prosthesis.

  15. Influence of natural pozzolan, colemanite ore waste, bottom ash, and fly ash on the properties of Portland cement

    Energy Technology Data Exchange (ETDEWEB)

    Targan, S.; Olgun, A.; Erdogan, Y.; Sevinc, V. [Dumlupinar University, Kutahya (Turkey). Dept. of Chemistry

    2003-08-01

    The effect of natural pozzolan (NP), colemanite ore waste (CW), coal fly ash (FA), and coal bottom ash (BA) on the properties of cement and concrete was examined. The parameters studied included compressive strength, bending strength, volume expansion, and setting time. A number of cements were prepared (in the presence of fixed quantity of 10% FA, 10% BA, and 4% CW) by the replacement of Portland cement (PC) with NP in range of 5 - 30%. The results showed that the final setting time of cement pastes were generally accelerated when the NP replaced part of the cement. However, NP exhibited a significant retarding effect when used in combination with CW. The results also showed that the inclusion of NP at replacement levels of 5% resulted in an increase in compressive strength of the specimens compared with that of the control concrete. The replacement of PC by 10 - 15% of NP in the presence of fixed quantity of CW improves the bending strength of the specimens compared with control specimens after 60 days of curing age.

  16. Transcatheter Pulmonary Valve Replacement

    OpenAIRE

    Ghawi, Hani; Kenny, Damien; Hijazi, Ziyad M.

    2012-01-01

    Transcatheter pulmonary valve replacement (tPVR) has evolved into a viable alternative to surgical conduit or bioprosthetic valve replacement. This procedure has paved the way for a more advanced approach to congenital and structural interventional cardiology. Although many successes have been noted, there are still a number of challenges with this procedure, including large delivery systems, the need for a conduit or a bioprosthetic valve as a landing zone for the valve, optimal timing of th...

  17. PERFORMANCE OF PULVERIZED SLAG-SUBSTITUTED CEMENT

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The Portland cement is equivalently substituted by slag micropowders with various specific areas. The workability,activity and acid-corrosion resistance of the slag-substituted cements are investigated,the activation of gypsum is discussed,also the porosity and pore distribution of mortars of the slag micropowders cement are determined by mercury intrusion porosimetry.

  18. 21 CFR 872.3275 - Dental cement.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Dental cement. 872.3275 Section 872.3275 Food and... DENTAL DEVICES Prosthetic Devices § 872.3275 Dental cement. (a) Zinc oxide-eugenol—(1) Identification... filling or as a base cement to affix a temporary tooth filling, to affix dental devices such as crowns...

  19. ADVANCED CEMENTS FOR GEOTHERMAL WELLS

    Energy Technology Data Exchange (ETDEWEB)

    SUGAMA,T.

    2007-01-01

    Using the conventional well cements consisting of the calcium silicate hydrates (CaO-SiO{sub 2}-H{sub 2}O system) and calcium aluminum silicate hydrates (CaO-Al{sub 2}O{sub 3}-SiO{sub 2}-H{sub 2}O system) for the integrity of geothermal wells, the serious concern confronting the cementing industries was their poor performance in mechanically supporting the metallic well casing pipes and in mitigating the pipe's corrosion in very harsh geothermal reservoirs. These difficulties are particularly acute in two geological regions: One is the deep hot downhole area ({approx} 1700 m depth at temperatures of {approx} 320 C) that contains hyper saline water with high concentrations of CO{sub 2} (> 40,000 ppm) in conjunction with {approx} 100 ppm H{sub 2}S at a mild acid of pH {approx} 5.0; the other is the upper well region between the well's surface and {approx} 1000 m depth at temperatures up to 200 C. The specific environment of the latter region is characterized by highly concentrated H{sub 2}SO{sub 4} (pH < 1.5) brine containing at least 5000 ppm CO{sub 2}. When these conventional cements are emplaced in these harsh environments, their major shortcoming is their susceptibility to reactions with hot CO{sub 2} and H{sub 2}SO4, thereby causing their deterioration brought about by CO{sub 2}-catalyzed carbonation and acid-initiated erosion. Such degradation not only reduced rapidly the strength of cements, lowering the mechanical support of casing pipes, but also increased the extent of permeability of the brine through the cement layer, promoting the rate of the pipe's corrosion. Severely carbonated and acid eroded cements often impaired the integrity of a well in less than one year; in the worst cases, casings have collapsed within three months, leading to the need for costly and time-consuming repairs or redrilling operations. These were the reasons why the geothermal well drilling and cementing industries were concerned about using conventional well

  20. Characterization of Mechanical and Bactericidal Properties of Cement Mortars Containing Waste Glass Aggregate and Nanomaterials

    Directory of Open Access Journals (Sweden)

    Pawel Sikora

    2016-08-01

    Full Text Available The recycling of waste glass is a major problem for municipalities worldwide. The problem concerns especially colored waste glass which, due to its low recycling rate as result of high level of impurity, has mostly been dumped into landfills. In recent years, a new use was found for it: instead of creating waste, it can be recycled as an additive in building materials. The aim of the study was to evaluate the possibility of manufacturing sustainable and self-cleaning cement mortars with use of commercially available nanomaterials and brown soda-lime waste glass. Mechanical and bactericidal properties of cement mortars containing brown soda-lime waste glass and commercially available nanomaterials (amorphous nanosilica and cement containing nanocrystalline titanium dioxide were analyzed in terms of waste glass content and the effectiveness of nanomaterials. Quartz sand is replaced with brown waste glass at ratios of 25%, 50%, 75% and 100% by weight. Study has shown that waste glass can act as a successful replacement for sand (up to 100% to produce cement mortars while nanosilica is incorporated. Additionally, a positive effect of waste glass aggregate for bactericidal properties of cement mortars was observed.

  1. Characterization of composite materials based on cement-ceramic powder blended binder

    Science.gov (United States)

    Kulovaná, Tereza; Pavlík, Zbyšek

    2016-06-01

    Characterization of newly developed composite mortars with incorporated ceramic powder coming from precise brick cutting as partial Portland cement replacement up to 40 mass% is presented in the paper. Fine ceramic powder belongs to the pozzolanic materials. Utilization of pozzolanic materials is accompanied by lower request on energy needed for Portland clinker production which generally results in lower production costs of blended binder and lower CO2 emission. In this paper, the ceramic powder is used in cement based mortar composition in amount of 8, 16, 24, 32, and 40 mass% of cement. Chemical composition of ceramic powder is analyzed by X-Ray Fluorescence and X-Ray Diffraction. The particle size distribution of ceramics is accessed on laser diffraction principle. For 28 days cured mortar samples, basic physical and mechanical properties are experimentally determined. The obtained results demonstrate that ceramic powder has potential to replace a part of Portland cement in composition of cement based composites and to reduce negative environmental impact of their production.

  2. Microscale Investigation of Arsenic Distribution and Species in Cement Product from Cement Kiln Coprocessing Wastes

    OpenAIRE

    Yufei Yang; Jingchuan Xue; Qifei Huang

    2013-01-01

    To improve the understanding of the immobilization mechanism and the leaching risk of Arsenic (As) in the cement product from coprocessing wastes using cement kiln, distribution and species of As in cement product were determined by microscale investigation methods, including electron probe microanalysis (EPMA) and X-ray absorption spectroscopy. In this study, sodium arsenate crystals (Na3AsO412H2O) were mixed with cement production raw materials and calcined to produce cement clinker. Then, ...

  3. The comparison between sulfate salt weathering of portland cement paste and calcium sulfoaluminate cement paste

    OpenAIRE

    Liu, Zanqun; Deng, Dehua; De Schutter, Geert

    2015-01-01

    In this paper, the damage performances of sulfate salt weathering of Portland cement paste and calcium sulfoaluminate (CSA) cement paste were compared according to authors' previous studies. It was found that the evaporation zone of speciments partially immersed in 10% Na2SO4 solution were both severely deteriorated for Portland cement and CSA cement. However, the differences were more significant: (1) the CSA cement paste were damaged just after 7 days exposure compared to the 5 months expos...

  4. A very rare case with neglected hip dislocation coexisted with posterior acetabular lip fracture

    Directory of Open Access Journals (Sweden)

    Samet Karabulut

    2011-06-01

    Full Text Available Neglected hip dislocation is a rare situation among children. The coexistence of acetabulum fracture is less common. The result of treatment depends on the time of diagnosis. Early treatment is mandatory in such cases. Seven years old female brought to our outpatient clinic with the complaints of right hip pain and walking difficulty. Her parents said that she had fallen from a horse one month ago. X-ray and CT showed a posterior dislocation of her right hip and a fracture on her right posterior acetabular lip. We performed an open reduction via posterior approach. Because the hip was unstable we fixed the femoral head to the acetabulum by a Kirshner wire. Pelvipedal cast was applied after the operation for 6 weeks. After 6 months avascular necrosis (AVN developed on her right femoral head, the range of motion (ROM of the hip was restricted and she had minimal pain on her right hip. J Clin Exp Invest 2011;2(2:228-31

  5. The effect of femoro-acetabular impingement on the kinematics and kinetics of the hip joint.

    Science.gov (United States)

    Alshameeri, Zeiad; Khanduja, Vikas

    2014-08-01

    Gait analysis is an objective tool that has been used to assess and monitor treatment for many musculoskeletal conditions. Recently, it has been used to assess the impact of femoro-acetabular impingement (FAI) on the hip and lower limb movements. There have been a fairly limited number of studies published so far reporting unexpected and inconsistent results, which calls for more research to be conducted in this arena. In the light of the limited data available, it has been challenging to reconcile the contradictions in some of these results, and therefore no coherent conclusions could be drawn. In this short article, we attempt to explain some of the abnormal kinematic and kinetic patterns associated with FAI by highlighting similarities between the gait seen in early osteoarthritis (OA) and that of FAI. We also propose an approach for future research in this field and emphasise the importance of quantifying early OA in FAI based on magnetic resonance imaging (MRI) scans and the amount of chondral damage seen during open or arthroscopic surgery. PMID:24687267

  6. Properties of Cement Based Materials Containing Copper Tailings

    OpenAIRE

    Onuaguluchi, Obinna

    2012-01-01

    ABSTRACT: Increasing demands for copper and copper allied products have made the processing of low grade ores with high volume waste output unavoidable. Presently, billions of tons of copper tailings can be found in major copper producing countries. This study explored the possibility of using these copper tailings either as a cement replacement or additive material in pastes, mortars and concretes of 0.65, 0.57 and 0.50 w/b ratios. Fresh properties of mixtures such as paste consistencies an...

  7. Cement with silica fume and granulated blast-furnace slag: strength behavior and hydration

    Directory of Open Access Journals (Sweden)

    Bonavetti, V. L.

    2014-09-01

    Full Text Available This paper analyses the influence of portland cement replacement by silica fume (up to 10% and/or granulated blast furnace slag (up to 70% on the hydration cement (XRD, heat of hydration, non evaporable water content and calcium hydroxide content curing under sealed conditions and their effect on the mechanical strength. The obtained results indicate that binary cements containing silica fume and ternary cements there was a significant increase of hydration rate at early age. At later ages, most of studied cements have an equivalent or greater strength that those obtained in the plain portland cement.En este trabajo se analiza la influencia de la incorporación al cemento portland de humo de sílice (hasta 10% y/o escoria granulada de alto horno (hasta 70% sobre la hidratación (DRX, calor de hidratación, contenido de agua no evaporable y de hidróxido de calcio, bajo condiciones de curado sellado y su incidencia sobre la resistencia mecánica. Los resultados obtenidos indican que en los cementos binarios con humo de sílice y en los cementos ternarios se produce un importante aumento de la velocidad de hidratación en las primeras edades, mientras que a edades más avanzadas la mayor parte del dominio estudiado alcanza o supera la resistencia obtenida por el cemento portland sin adición.

  8. DSC and TG Analysis of a Blended Binder Based on Waste Ceramic Powder and Portland Cement

    Science.gov (United States)

    Pavlík, Zbyšek; Trník, Anton; Kulovaná, Tereza; Scheinherrová, Lenka; Rahhal, Viviana; Irassar, Edgardo; Černý, Robert

    2016-03-01

    Cement industry belongs to the business sectors characteristic by high energy consumption and high {CO}2 generation. Therefore, any replacement of cement in concrete by waste materials can lead to immediate environmental benefits. In this paper, a possible use of waste ceramic powder in blended binders is studied. At first, the chemical composition of Portland cement and ceramic powder is analyzed using the X-ray fluorescence method. Then, thermal and mechanical characterization of hydrated blended binders containing up to 24 % ceramic is carried out within the time period of 2 days to 28 days. The differential scanning calorimetry and thermogravimetry measurements are performed in the temperature range of 25°C to 1000°C in an argon atmosphere. The measurement of compressive strength is done according to the European standards for cement mortars. The thermal analysis results in the identification of temperature and quantification of enthalpy and mass changes related to the liberation of physically bound water, calcium-silicate-hydrates dehydration and portlandite, vaterite and calcite decomposition. The portlandite content is found to decrease with time for all blends which provides the evidence of the pozzolanic activity of ceramic powder even within the limited monitoring time of 28 days. Taking into account the favorable results obtained in the measurement of compressive strength, it can be concluded that the applied waste ceramic powder can be successfully used as a supplementary cementing material to Portland cement in an amount of up to 24 mass%.

  9. MR-arthrography of the acetabular labrum - radiologic-pathologic correlation in 20 cadaveric hip joints; MR-Arthrographie des Labrum acetabulare - Radiologisch-anatomische Korrelation an 20 Leichenhueften

    Energy Technology Data Exchange (ETDEWEB)

    Brossmann, J.; Steffens, J.C.; Heller, M. [Kiel Univ. (Germany). Klinik fuer Diagnostische Radiologie; Ploetz, G.M.J.; Hassenpflug, J. [Kiel Univ. (Germany). Klinik fuer Orthopadie

    1999-08-01

    Purpose: To investigate frequency of acetabular labral lesions in elderly hip joints, and to determine sensitivity and specificity of MR arthrography (MRa) for the detection of these abnormalities. Materials and Methods: Twenty cadaveric hip joints were examined by MRa. For MRa, 15 ml of a solution of iodinated contrast solution (Solutrast 300) and Gd-DTPA (100:1) were injected under fluoroscopic guidance. MR imaging was performed on a 1.5 TM scanner (Vision, Siemens; FOV 16 cm, matrix 256x256, fat-suppressed 3D-FLASH). Multiplanar image reconstructions were done perpendicular to the acetabulum in the oblique-coronal, oblique-axial, and radial planes. The labral specimens were examined macroscopically. Results: In 12/20 hips (60%), a labral lesion was found on pathologic examination. In 7 specimens, the labrum was partially or completely detached in the weight-bearing superior region. One flap-like variant of the labrum was seen; in 4 hip joints, the labrum was degenerated (one cystic degeneration). Pathologic findings were confirmed by MRa in 8/12 specimens (sensitivity 67%). All degenerated labra were correctly diagnosed on MRa. Three small labral detachments and the flap-like variant were misinterpreted as being normal. There were no false positive findings (specificity 100%). The accuracy was 80%. Labral lesions were seen in 6/8 and in 6/12 of hips with and without osteoarthritis, respectively. Conclusion: MRa is well suited to delineate the acetabular labrum and to diagnose labral abnormalities. Detection of small labral detachments and anatomic variants is difficult and requires some experience. Labral lesions are correlated to osteoarthritis of the hip, but may be frequently seen in the elderly without underlying osteoarthritis. (orig.) [German] Ziel: Feststellung der Haeufigkeit von Laesionen des Labrum acetabulare bei aelteren Hueftgelenkspraeparaten und Untersuchung der Sensitivitaet und Spezifitaet der MR-Arthrographie (MRa) fuer die Darstellung dieser

  10. High belite cement from alternative raw materials

    Directory of Open Access Journals (Sweden)

    Ghorab, H. Y.

    2014-05-01

    Full Text Available Three high belite laboratory clinkers were prepared from traditional and alternative raw materials. Reference clinker was obtained from 77% limestone, 11% sandy clays, 11% fatty clays and 1% iron scales. The fatty clays were replaced by red brick powder in the raw meal of the second clinker and were lowered to 2% with the replacement of 10% of the limestone by egg shells in the third clinker. The SEM examination revealed clear presence of crossed striae and twinning in the rounded belite grains of the reference clinker caused by the transformation of the α´-belite to the β polymorph. Striae were weaker in the second and third clinkers indicating a probable stabilization of the α ‘-belite polymorph. Compressive strength of the respective cements were attained first after 28 days and the early strength did not improve with increasing fineness. Higher compressive strength values were found for the cement prepared from second clinker.Se han preparado tres clinkeres de laboratorio con altos contenidos en belita a partir de materias primas tradicionales y alternativas. El clinker de referencia se obtuvo a partir de una mezcla de caliza, arcillas arenosas y grasas y limaduras de hierro. Las arcillas grasas fueron sustituidas por polvo de ladrillo rojo en la preparación del segundo clinker, y en el tercero el contenido de arcilla grasa fue de solo un 2% y parte de la caliza fue sustituida por cascara de huevo. El estudio realizado por SEM muestra superficies estriadas alrededor de los granos de belita que indican una transformación del polimorfo α´ a la forma β-C₂S, durante el enfriamiento. Esas estrías son menos marcadas en el segundo y tercer clinker, indicando, una estabilización del polimorfo α´-C₂S. Los valores de resistencias a compresión de los correspondientes cementos, a 28 días de curado, no se ven incrementados por la finura de dichos cementos. Las mayores resistencias se obtuvieron en el cemento preparado a partir del cl

  11. Should money follow the patient: Financial implication for being the National Centre for the Treatment and Management of Pelvic and Acetabular Fractures in Ireland.

    LENUS (Irish Health Repository)

    Kelly, M E

    2013-03-13

    BACKGROUND: Pelvic and acetabular fractures are complex injuries requiring specialist treatment. Our institution is the National Centre for Treatment and Management of these injuries. AIM: To audit all referrals to our institution over a 6-month period and calculate the cost incurred by being the national referral centre. METHODS: Retrospective review of database, and subsequent allocation of Casemix points to assess total cost of treatment for each patient referred to our institution. RESULTS: 103 patients referred with pelvic or acetabular fracture for operative management. The furthest referral distance was 181miles. Over-all, the length of stay was 15.4 days. The average inclusive cost for a referral to our unit for operative management was €16,302. CONCLUSION: Pelvic and acetabular fractures are complex injuries that require specialist referral unit management. However for these units to remain sustainable money needs to "follow the patient".

  12. Influence of fly ash fineness on water requirement and shrinkage of blended cement mortars

    Directory of Open Access Journals (Sweden)

    Vanissorn Vimonsatit

    2015-12-01

    Full Text Available In this paper, the influence of fly ash fineness on water requirement and shrinkage of blended cement mortar was studied. The results indicate that the water requirement and shrinkage characteristic of the blended cement mortar are dependent on fly ash fineness and replacement level. The use of coarse fly ash slightly reduces the water requirement but greatly reduced the drying and the autogenous shrinkage of the blended cement mortars and the reduction is more with an increase in the fly ash replacement level. The finer fly ashes further reduce the water requirement, but increase the drying and the autogenous shrinkages as compared with coarser fly ash. The incorporation of superplasticizer drastically reduces the water requirement, but the effect on the drying and autogenous shrinkages of the normal Portland cement mortar is small. However, for the fly ash mortar, the use of superplasticizer results in a decrease in drying shrinkage and in a substantial increase in the autogenous shrinkage particularly for the fine fly ash at a high replacement level.

  13. Thoughts on the Current Cement Industry Development

    Institute of Scientific and Technical Information of China (English)

    Gan Zhihe

    2003-01-01

    According to the analysis of cement capacity andits relations with macro economy running index, the mainreasons for the present rapid development of cement capacityare the rapid development of economy and the shot up ofwhole society fixed asset investment. According to the presentspeed of economy development, cement still enjoys a po-tential increase, So here has not been an overall excessivepopularity of cement industry. The best way to prevent lowlevel repeated construction is to promote the development ofnew dry- process cement as well as try to get rid of blindness.

  14. Effect of temporary cements on the shear bond strength of luting cements

    Directory of Open Access Journals (Sweden)

    Marco Fiori-Júnior

    2010-02-01

    Full Text Available OBJECTIVE: The purpose of this study was to evaluate, by shear bond strength (SBS testing, the influence of different types of temporary cements on the final cementation using conventional and self-etching resin-based luting cements. Material and Methods: Forty human teeth divided in two halves were assigned to 8 groups (n=10: I and V (no temporary cementation; II and VI: Ca(OH2-based cement; III and VII: zinc oxide (ZO-based cement; IV and VIII: ZO-eugenol (ZOE-based cement. Final cementation was done with RelyX ARC cement (groups I to IV and RelyX Unicem cement (groups V to VIII. Data were analyzed statistically by ANOVA and Tukey's test at 5% significance level. RESULTS: Means were (MPa: I - 3.80 (±1.481; II - 5.24 (±2.297; III - 6.98 (±1.885; IV - 6.54 (±1.459; V - 5.22 (±2.465; VI - 4.48 (±1.705; VII - 6.29 (±2.280; VIII - 2.47 (±2.076. Comparison of the groups that had the same temporary cementation (Groups II and VI; III and VII; IV and VIII showed statistically significant difference (p0.05 for the different luting cements (RelyX TM ARC and RelyX TM Unicem. The groups that had no temporary cementation (Groups I and V did not differ significantly from each other either (p>0.05. CONCLUSION: When temporary cementation was done with ZO- or ZOE-based cements and final cementation was done with RelyX ARC, there was an increase in the SBS compared to the control. In the groups cemented with RelyX Unicem, however, the use of a ZOE-based temporary cement affected negatively the SBS of the luting agent used for final cementation.

  15. False set in aireated cements

    Directory of Open Access Journals (Sweden)

    Vázquez, T.

    1986-06-01

    Full Text Available The influence of aireation on the appearance or elimination of the false setting in industrial portland cements is studied by means of infrared spectroscopy.

    Se estudia por medio de la espectroscopia infrarroja la influencia de la aireación sobre la aparición o eliminación del fraguado, en cemento portland industriales.

  16. Evaluation of sulfate resistance of cement mortars containing black rice husk ash.

    Science.gov (United States)

    Chatveera, B; Lertwattanaruk, P

    2009-03-01

    In this paper, black rice husk ashes (BRHAs), which are agrowastes from an electricity generating power plant and a rice mill, were ground and used as a partial cement replacement. The durability of mortars under sulfate attack including expansion and compressive strength loss were investigated. For parametric study, BRHA were used as a Portland cement Type 1 replacement at the levels of 0%, 10%, 30%, and 50% by weight of binder. The water-to-binder ratios were 0.55 and 0.65. For the durability of mortar exposed to sulfate attack, 5% sodium sulfate (Na2SO4) and magnesium sulfate (MgSO4) solutions were used. As a result, when increasing the percentage replacement of BRHA, the expansion and compressive strength loss of mortar decreased. At the replacement levels of 30% and 50% of BRHA, the expansion of the mortars was less than those mixed with sulfate-resistant cement. However, the expansion of the mortars exposed to Na2SO4 was more than those exposed to MgSO4. Increasing the replacement level of BRHA tends to reduce the compressive strength loss of mortars exposed to Na2SO4 attack. In contrary, under MgSO4 attack, when increasing the replacement level of BRHA, the compressive strength loss increases from 0% to 50% in comparison to Portland cement mortar. Results show that ground BRHA can be applied as a pozzolanic material to concrete and also improve resistance to sodium sulfate attack, but it can impair resistance to magnesium sulfate attack.

  17. Electrodialytically treated MSWI APC residue as substitute for cement in mortar

    DEFF Research Database (Denmark)

    Kirkelund, Gunvor Marie; Geiker, Mette Rica; Jensen, Pernille Erland

    2014-01-01

    /or electrodialytic remediation, were used in Portland cement mortar. Mortar bars with 15 % weight replacement of cement by APC residues showed compressive strengths up to 40 MPa after 28/32 days. Heavy metal and salt leaching from both crushed and monolithic mortars with APC residues was generally similar...... and comparable to both the reference mortar and mortar with coal fly ash. These results indicate that electrodialytic remediation could be used a pre-treatment method for MSWI APC residues prior to reuse in mortar....

  18. Hydrated phases and pore solution composition in cement solidified saltstone waste forms

    International Nuclear Information System (INIS)

    The mineral phases and pore solution composition of hydrated cement solidified synthetic saltstone waste forms are quantified using thermogravimetric analysis, quantitative X-ray powder diffraction, and inductively coupled plasma atomic emission spectroscopy. Although the synthetic waste contained additional sulfate, the overall chemistry of the system suppressed the formation of sulfate-bearing mineral phases. This was corroborated by the pore solution analysis that indicated very high sulfur concentrations. After one year of hydration, the mineral phases present and the composition of the pore solution are stable, and are generally consistent with expectations based on the hydration of high volume portland cement replacement mixtures. (authors)

  19. Leaching of tritium from a cement composite

    International Nuclear Information System (INIS)

    Leaching of tritium from cement composites into an aqueous phase has been studied to evaluate the safety of incorporation of the tritiated liquid waste into cement. Leaching tests were performed by the method recommended by the International Atomic Energy Agency. The Leaching fraction was measured as functions of waste-cement ratio (Wa/C), temperature of leachant and curing time. The tritium leachability of cement in the long term test follows the order: alumina cement portland cement slag cement. The fraction of tritium leached increases with increasing Wa/C and temperature and decreasing curing period. A deionized water as a leachant gives a slightly higher leachability than synthetic sea water. The amount leached of tritium from a 200 l drum size specimen was estimated on the basis of the above results. (author)

  20. Understanding cement mechanical behavior in SAGD wells

    Energy Technology Data Exchange (ETDEWEB)

    Xie, J.; Zahacy, T. A. [C-FER Technologies (Canada)

    2011-07-01

    In the heavy oil industry, the steam assisted gravity drainage process is often used to enhance oil recovery but it can cause cracks in the cement sheath. These cracks are the result of high steam temperatures and thermal expansion. In order to mitigate this risk, improved well designs are required. The aim of this paper is to present the mechanical behavior of the cement sheath during the heating phase. An analysis of the impact of design and operating parameters was conducted through thermal hydraulic and thermal mechanical analyses to assess cement integrity. These analyses were then performed on an example of an SAGD project in the southern part of the Athabasca oilsands region to assess the performance of the cement sheath. Results showed that potential damage to the cement can be reduced by slow heating and a lower Young's modulus cement blend. This paper makes recommendations for optimizing cement design in thermal recovery wells.

  1. Performance of portland limestone cements: Cements designed to be more sustainable that include up to 15% limestone addition

    Science.gov (United States)

    Barrett, Timothy J.

    In 2009, ASTM and AASHTO permitted the use of up to 5% interground limestone in ordinary portland cement (OPC) as a part of a change to ASTM C150/AASHTO M85. When this work was initiated a new proposal was being discussed that would enable up to 15% interground limestone cement to be considered in ASTM C595/AASHTO M234. This work served to provide rapid feedback to the state department of transportation and concrete industry for use in discussions regarding these specifications. Since the time this work was initiated, ASTM C595/AASHTO M234 was passed (2012c) and PLCs are now able to be specified, however they are still not widely used. The proposal for increasing the volume of limestone that would be permitted to be interground in cement is designed to enable more sustainable construction, which may significantly reduce the CO2 that is embodied in the built infrastructure while also extending the life of cement quarries. Research regarding the performance of cements with interground limestone has been conducted by the cement industry since these cements became widely used in Europe over three decades ago, however this work focuses on North American Portland Limestone Cements (PLCs) which are specifically designed to achieve similar performance as the OPCs they replace.This thesis presents a two-phase study in which the potential for application of cements containing limestone was assessed. The first phase of this study utilized a fundamental approach to determine whether cement with up to 15% of interground or blended limestone can be used as a direct substitute to ordinary portland cement. The second phase of the study assessed the concern of early age shrinkage and cracking potential when using PLCs, as these cements are typically ground finer than their OPC counterparts. For the first phase of the study, three commercially produced PLCs were obtained and compared to three commercially produced OPCs made from the same clinker. An additional cement was tested

  2. Mesoscale texture of cement hydrates.

    Science.gov (United States)

    Ioannidou, Katerina; Krakowiak, Konrad J; Bauchy, Mathieu; Hoover, Christian G; Masoero, Enrico; Yip, Sidney; Ulm, Franz-Josef; Levitz, Pierre; Pellenq, Roland J-M; Del Gado, Emanuela

    2016-02-23

    Strength and other mechanical properties of cement and concrete rely upon the formation of calcium-silicate-hydrates (C-S-H) during cement hydration. Controlling structure and properties of the C-S-H phase is a challenge, due to the complexity of this hydration product and of the mechanisms that drive its precipitation from the ionic solution upon dissolution of cement grains in water. Departing from traditional models mostly focused on length scales above the micrometer, recent research addressed the molecular structure of C-S-H. However, small-angle neutron scattering, electron-microscopy imaging, and nanoindentation experiments suggest that its mesoscale organization, extending over hundreds of nanometers, may be more important. Here we unveil the C-S-H mesoscale texture, a crucial step to connect the fundamental scales to the macroscale of engineering properties. We use simulations that combine information of the nanoscale building units of C-S-H and their effective interactions, obtained from atomistic simulations and experiments, into a statistical physics framework for aggregating nanoparticles. We compute small-angle scattering intensities, pore size distributions, specific surface area, local densities, indentation modulus, and hardness of the material, providing quantitative understanding of different experimental investigations. Our results provide insight into how the heterogeneities developed during the early stages of hydration persist in the structure of C-S-H and impact the mechanical performance of the hardened cement paste. Unraveling such links in cement hydrates can be groundbreaking and controlling them can be the key to smarter mix designs of cementitious materials. PMID:26858450

  3. Effect of ultrasonic vibration time on the retention of prefabricated posts luted with two different cements

    Directory of Open Access Journals (Sweden)

    Dastnaei Peimaneh Hosseini

    2015-01-01

    Full Text Available   Background and Aims: In case of nonsurgical endodontic re-treatment or replacing a restoration, one of the best methods for removing post from the canal is using an ultrasonic vibration. The aim of this study was to evaluate the effect of ultrasonic vibration time on the retention of post luted with zinc phosphate or glass ionmer cements.   Materials and Methods: 96 sound extracted lower premolars were selected. The coronal section of specimen was removed and the roots were endodontically treated. A 9-mm post space was prepared in each specimens and a stainless steel Parapost XP was cemented into the post space. Half of the specimens were cemented with the Zinc phosphate cement and the other by g lass ionomer cement. After 7 days of storage, both groups were equally divided into 4 subgroups of 12 teeth. Control group did not receive any treatment. The other subgroups subjected to ultrasonic vibration for 4, 8 or 12 minutes. The retention of all specimens was evaluated and data were analyzed using ANOVA and Tukey tests.   Results: In control (no ultrasonic group and 4 minute ultrasonic group, the retention of posts luted with Zinc phosphate cement were not significantly differen t from those luted with g lass ionomer cement. (P=0.372. On the other hand , applying of ultrasonic vibration for 8 and 12 minutes in zinc phosphate and 12 minutes in g lass ionomer caused a significant reduction in the retention of posts (P=0.01.   Conclusion: Although, the initial retention of two cements was not different, the ultrasonic vibration had more catastrophic effect on zinc phosphate in comparison to glass ionomer.

  4. Product Platform Replacements

    DEFF Research Database (Denmark)

    Sköld, Martin; Karlsson, Christer

    2012-01-01

    shed light on this unexplored and growing managerial concern, the purpose of this explorative study is to identify operational challenges to management when product platforms are replaced. Design/methodology/approach – The study uses a longitudinal field-study approach. Two companies, Gamma and Omega......Purpose – It is argued in this article that too little is known about product platforms and how to deal with them from a manager's point of view. Specifically, little information exists regarding when old established platforms are replaced by new generations in R&D and production environments. To...... distinguishing between platform replacement “height” and “width”. Seven groups of managerial measures for dealing with the issues are recommended. Originality/value – The study aims to contribute to the existing literature by taking a managers' perspective of product platform development. Its specific...

  5. Simultaneous Periprosthetic Acetabular Fracture and Contralateral B-Type Compression Injury of the Pelvic Ring: A Case Report of a Rare Injury Combination

    Directory of Open Access Journals (Sweden)

    Sven Märdian

    2013-01-01

    Full Text Available The periprosthetic fracture of the acetabulum is a rare injury, and its management is only sporadically reported in the literature. A few case reports are available which mainly focus on periprosthetic acetabular fractures in the elderly population. In our case, a 32-year-old patient suffered from a periprosthetic acetabular fracture in combination with a pelvic ring injury following a high velocity accident. The fracture morphology allowed a salvage of the prosthesis with an open reduction and internal fixation with a good radiographic and functional outcome one year after trauma.

  6. The acetabular fossa hot spot on 18F-FDG PET/CT: epidemiology, natural history, and proposed etiology

    International Nuclear Information System (INIS)

    To describe a benign focus of increased activity in the acetabular fossa (the acetabular fossa hot spot, AFHS) on 18F-FDG PET/CT that can mimic a neoplasm. 18F-FDG PET/CT images from four patient populations were examined. Group 1 (n = 13) was collected from a search of radiology reports and used to define the AFHS and for hypothesis generation. Group 2 (n = 1,150) was used for prevalence of AFHS. Group 3 (n = 1,213) had PET/CT and MRI pelvis within a week of each other and was used to correlate metabolic and anatomic findings. Group 4 (n = 100) was used to generate the control group. Data were collected on demographics, common comorbidities, underlying cancer diagnosis and status, and hip symptoms. Prevalence of AFHS was 0.36 % (95 % CI 0.10-0.91 %). None progressed to malignancy or was associated with cancer status. The majority (71 %) were on the left, and 6 % were bilateral. Mean SUVmax of the AFHS was 4.8 (range, 2.7-7.8). Male patients were more likely to have the AFHS (OR = 8.69, 95 % CI 1.88-40.13). There was no difference with respect to other collected data, including hip symptoms. Average minimum duration of AFHS was 346 days (range, 50-1,010 days). Readers did not detect corresponding hip abnormalities on MRIs. AFHS is a benign finding that may be caused by subclinical ligamentum teres injury, focal synovitis, or degeneration of acetabular fossa fat. Despite uncertainty regarding its etiology, recognition of AFHS as a benign finding can prevent morbidity associated with unnecessary biopsy or initiation of therapy. (orig.)

  7. The acetabular fossa hot spot on {sup 18}F-FDG PET/CT: epidemiology, natural history, and proposed etiology

    Energy Technology Data Exchange (ETDEWEB)

    Kubicki, Shelby L. [Trinity University, San Antonio, TX (United States); Richardson, Michael L. [University of Washington, Department of Radiology, Seattle, WA (United States); Martin, Thomas [X-Ray Associates of New Mexico, Department of Radiology, Albuquerque, NM (United States); Rohren, Eric [The University of Texas M.D. Anderson Cancer Center, Department of Diagnostic Radiology, Division of Nuclear Medicine, Houston, TX (United States); Wei, Wei [The University of Texas M.D. Anderson Cancer Center, Department of Biostatistics, Houston, TX (United States); Amini, Behrang [The University of Texas M.D. Anderson Cancer Center, Department of Diagnostic Radiology, Division of Musculoskeletal Radiology, Houston, TX (United States)

    2015-01-15

    To describe a benign focus of increased activity in the acetabular fossa (the acetabular fossa hot spot, AFHS) on {sup 18}F-FDG PET/CT that can mimic a neoplasm. {sup 18}F-FDG PET/CT images from four patient populations were examined. Group 1 (n = 13) was collected from a search of radiology reports and used to define the AFHS and for hypothesis generation. Group 2 (n = 1,150) was used for prevalence of AFHS. Group 3 (n = 1,213) had PET/CT and MRI pelvis within a week of each other and was used to correlate metabolic and anatomic findings. Group 4 (n = 100) was used to generate the control group. Data were collected on demographics, common comorbidities, underlying cancer diagnosis and status, and hip symptoms. Prevalence of AFHS was 0.36 % (95 % CI 0.10-0.91 %). None progressed to malignancy or was associated with cancer status. The majority (71 %) were on the left, and 6 % were bilateral. Mean SUV{sub max} of the AFHS was 4.8 (range, 2.7-7.8). Male patients were more likely to have the AFHS (OR = 8.69, 95 % CI 1.88-40.13). There was no difference with respect to other collected data, including hip symptoms. Average minimum duration of AFHS was 346 days (range, 50-1,010 days). Readers did not detect corresponding hip abnormalities on MRIs. AFHS is a benign finding that may be caused by subclinical ligamentum teres injury, focal synovitis, or degeneration of acetabular fossa fat. Despite uncertainty regarding its etiology, recognition of AFHS as a benign finding can prevent morbidity associated with unnecessary biopsy or initiation of therapy. (orig.)

  8. Study on the effects of white rice husk ash and fibrous materials additions on some properties of fiber-cement composites.

    Science.gov (United States)

    Hamzeh, Yahya; Ziabari, Kamran Pourhooshyar; Torkaman, Javad; Ashori, Alireza; Jafari, Mohammad

    2013-03-15

    This work assesses the effects of white rice husk ash (WRHA) as pozzolanic material, virgin kraft pulp (VKP), old corrugated container (OCC) and fibers derived from fiberboard (FFB) as reinforcing agents on some properties of blended cement composites. In the sample preparation, composites were manufactured using fiber-to-cement ratio of 25:75 by weight and 5% CaCl(2) as accelerator. Type II Portland cement was replaced by WRHA at 0%, 25% and 50% by weight of binder. A water-to-binder ratio of 0.55 was used for all blended cement paste mixes. For parametric study, compressive strength, water absorption and density of the composite samples were evaluated. Results showed that WRHA can be applied as a pozzolanic material to cement and also improved resistance to water absorption. However, increasing the replacement level of WRHA tends to reduce the compressive strength due to the low binding ability. The optimum replacement level of WRHA in mortar was 25% by weight of binder; this replacement percentage resulted in better compressive strengths and water absorption. OCC fiber is shown to be superior to VKF and FFB fibers in increasing the compressive strength, due to its superior strength properties. As expected, the increase of the WRHA content induced the reduction of bulk density of the cement composites. Statistical analysis showed that the interaction of above-mentioned variable parameters was significant on the mechanical and physical properties at 1% confidence level.

  9. Composite cements containing natural pozzolan and granulated blast furnace slag

    Directory of Open Access Journals (Sweden)

    Irassar, E. F.

    2006-09-01

    Full Text Available For reasons of market demand and Portland cement production,the manufacture of cements with two or more separately ground additions to produce customized cements is becoming common practice.When pozzolan or slag content in this type of cements is high, however, the initial strength of the resulting product may be adversely impacted. This problem can be minimized by activating one or both of the replacement materials. The present study analyzes the effect of Portland cement additions such as physically activated natural pozzolan(up to 20% and/or granulated blast furnace slag (up to 35% on mortar flexural and compressive strength. The results show that higher strength is attained in ternary than binary cements. Initially (2 and 7 days, the highest compressive strengths are reached by mortars with up to 13% natural pozzolan and 5% slag, whereas at later ages mortars with larger proportions of additions are found to perform best.Debido a las exigencias del mercado y de la producción de cemento Portland, es cada vez más frecuente la elaboración de cementos con dos o más adiciones a partir de la molienda separada de sus constituyentes, dando origen a la formulación de los cementos a medida.Cuando el contenido de adiciones es alto, la utilización de puzolana y escoria en este tipo de cementos presenta la peculiaridad de disminuir la resistencia inicial del cemento resultante. Sin embargo, si algunas o ambas adiciones se activan, este problema puede minimizarse. En este trabajo se analiza la influencia de la incorporación al cemento Portland de puzolana natural (hasta 20% activada físicamente y/o escoria granulada de alto horno (hasta 35% sobre la resistencia a flexión y a compresión de morteros. Los resultados indican que los cementos ternarios presentan un mejor comportamiento resistente que los cementos binarios. Las máximas resistencias a compresión en las primeras edades (2 y 7 díasse alcanzan con hasta 13% de puzolana natural y 5% de

  10. The cement recycling of the earthquake disaster debris by Hachinohe Cement Co., Ltd

    International Nuclear Information System (INIS)

    A tremendous quantity of earthquake disaster debris and tsunami sediment was resulted by the Great East Japan Earthquake on March 11, 2011. Hachinohe Cement Co., Ltd., a Sumitomo Osaka Cement subsidiary, was the first cement industry company to receive and process such waste materials outside of their usual prefecture area, while the company is performing their treatment and recycling services locally in Hachinohe City and Aomori Prefecture. This report provides an explanation about the recycling mechanism of waste materials and by-products in cement manufacturing process, and introduces an example of actual achievements for the disaster debris treatment by utilizing the cement recycling technologies at the Hachinohe Cement Plant. (author)

  11. Properties and durability of metakaolin blended cements

    Directory of Open Access Journals (Sweden)

    Ezzat, El-Sayed

    2010-09-01

    Full Text Available This paper evaluates the optimal calcination temperature and replacement ratio to ensure high metakaolin (MK pozzolanicity in blended cement. The MK used was prepared by firing two types of local at temperatures ranging from 700 to 850 ºC. Dry blends of ordinary Portland cement (OPC and varying proportions of MK were mixed with the amount of water required to ensure optimal consistency of the resulting pastes. The specimens were cured at 100% RH for 24 h and then immersed in water for 3, 7, 28, 90 or 180 days. At each test time, the degree of hydration and compressive strength of the hardened cement pastes were measured The findings showed that the most suitable calcination temperature to obtain metakaolin is 700 ºC, while the optimal replacement ratio ranges from 25 to 30%. DTA was used to determine the phases comprising the hydration products forming at the ages studied. Pure OPC and OPC-MK specimens were immersed in 3% NaCl and 5% MgSO4 solutions for 30, 90 and 180 days to measure their durability. The OPC-MK pastes immersed in the 3% NaCl solution were observed to be highly resistant to chloride attack.

    El presente trabajo evalúa el comportamiento puzolánico de metacaolín (MK, producto de la calcinación a distintas temperaturas de dos tipos de caolín local de composiciones químicas diferentes, al incorporarse al cemento en diferentes proporciones. Se preparó un cemento adicionado mediante la mezcla en seco de cemento Portland ordinario (OPC y metacaolín (MK, a los que se añadió la cantidad óptima de agua para obtener una pasta de la consistencia deseada. Las probetas se curaron a una HR del 100% durante 24 horas, sumergiéndose posteriormente en agua durante 3, 7, 28, 90 o 180 días. A cada tiempo de ensayo se controló el grado de hidratación de las pastas endurecidas y se comprobó la resistencia a la compresión de las probetas cúbicas a las edades de curado establecidas. Los resultados obtenidos indican que la

  12. Protrusio of a ceramic femoral head through the acetabular metallic shell, extensive metallosis and 'bubble sign'.

    Science.gov (United States)

    Malizos, Konstantinos; Roidis, Nikolaos T; Poultsides, Lazaros; Basdekis, George; Moraitis, Theofanis; Xenakis, Theodoros

    2009-02-01

    A 24-year-old patient with a history of juvenile rheumatoid arthritis underwent a primary cementless left total hip arthroplasty (THA). The original THA consisted of an Optifix 54 cup with a 3-mm thick polyethylene liner, an Optifix size 4 stem (Smith & Nephew Richards, Memphis, Tennessee) and a Biolox aluminum 32-mm femoral head. Fourteen years later, radiographs demonstrated extensive wear of the polyethylene liner resulting in direct articulation and abrasion wear of the ceramic femoral head on the cup and a bubble sign. This article presents a case of a catastrophic failure of a ceramic/polyethylene bearing with destruction of the polyethylene liner and the metallic shell and protrusio of the nonfractured ceramic head through the metallic shell. To our knowledge this is the first description of extensive metallosis and subsequent radiograph bubble sign not presenting as a result of wear of a metal-on-metal articulation. At the time of revision surgery-Hydrocel TNT Monoblock 58 cup (Zimmer, Warsaw, Indiana), Wagner 265/14 stem (Zimmer), and a Co/Cr 28-mm head-copious metallic debris was seen both macroscopically and histologically, with the ceramic head protruding behind the metallic shell. Multiple factors may have been responsible for this failure including a thin polyethylene shell, a suboptimal locking mechanism, gamma in air sterilization for polyethylene, multiple screw-holes that reduce the contact surface between shell and polyethylene, the rough surface on the inside of the shell and non-articular wear at the metal polyethylene interface within the acetabular component and the high demands of this active young patient. PMID:19301791

  13. Replacing a Missing Tooth

    Science.gov (United States)

    ... the extra bulk and removable nature of the partial denture and report that it feels unnatural. This type of prosthesis is best as a temporary replacement as described above. The second option in a patient without a bone graft is a fixed bridge. The missing tooth is restored with an ...

  14. Analysis of Femoral Components of Cemented Total Hip Arthroplasty

    Science.gov (United States)

    Singh, Shantanu; Harsha, A. P.

    2015-10-01

    There have been continuous on-going revisions in design of prosthesis in Total Hip Arthroplasty (THA) to improve the endurance of hip replacement. In the present work, Finite Element Analysis was performed on cemented THA with CoCrMo trapezoidal, CoCrMo circular, Ti6Al4V trapezoidal and Ti6Al4V circular stem. It was observed that cross section and material of femoral stem proved to be critical parameters for stress distribution in femoral components, distribution of interfacial stress and micro movements. In the first part of analysis, designs were investigated for micro movements and stress developed, for different stem materials. Later part of the analysis focused on investigations with respect to different stem cross sections. Femoral stem made of Titanium alloy (Ti6Al4V) resulted in larger debonding of stem at cement-stem interface and increased stress within the cement mantle in contrast to chromium alloy (CoCrMo) stem. Thus, CoCrMo proved to be a better choice for cemented THA. Comparison between CoCrMo femoral stem of trapezium and circular cross section showed that trapezoidal stem experiences lesser sliding and debonding at interfaces than circular cross section stem. Also, trapezium cross section generated lower peak stress in femoral stem and cortical femur. In present study, femur head with diameter of 36 mm was considered for the analysis in order to avoid dislocation of the stem. Also, metallic femur head was coupled with cross linked polyethylene liner as it experiences negligible wear compared to conventional polyethylene liner and unlike metallic liner it is non carcinogenic.

  15. Alkali-silica reaction resistant concrete using pumice blended cement

    Science.gov (United States)

    Ramasamy, Uma

    Durability of structures is a major challenge for the building industry. One of the many types of concrete deterioration that can affect durability is alkali-silica reaction (ASR). ASR has been found in most types of concrete structures, including dams, bridges, pavements, and other structures that are 20 to 50 years old. The degradation mechanism of ASR produces a gel that significantly expands in the presence of water as supplied from the surrounding environment. This expansion gel product can create high stresses and cracking of the concrete, which can lead to other forms of degradation and expensive structural replacement costs. The four essential factors that produce an expansive ASR gel in concrete are the presence of alkalis, siliceous aggregate, moisture, and free calcium hydroxide (CH). If concrete is starved of any one of these essential components, the expansion can be prevented. Reducing CH through the use of a supplementary cementitious material (SCM) such as natural pozzolan pumice is the focus of this research. By using a pozzolan, the amount of CH is reduced with time based on the effectiveness of the pozzolan. Many pozzolans exist, but one such naturally occurring pozzolanic material is pumice. This research focuses on determining the effect of a finely ground pumice as a SCM in terms of its resistance to ASR expansion, as well as improving resistance to other potential concrete durability mechanisms. In spite of having high alkali contents in the pumice, mixtures containing the SCM pumice more effectively mitigated the ASR expansion reaction than other degradation mechanisms. Depending on the reactivity of the aggregates and fineness of the pumice, 10-15% replacement of cement with the pumice was found to reduce the ASR expansion to the acceptable limits. The amount of CH remaining in the concrete was compared to the ASR expansion in order to improve understanding of the role of CH in the ASR reaction. Thermo-gravimetric analysis (TGA) and X

  16. An evaluation of commercial and experimental resin-modified glass-ionomer cements

    Science.gov (United States)

    Kanchanavasita, Widchaya

    Glass-ionomer cement (GIG) has become widely accepted as a restorative material due to its bonding ability and sustained release of fluoride. The cement is, however, sensitive to moisture imbalance and lacks toughness. Recently, resin-modified glass-ionomer cements (RMGIC) have been introduced. These materials contain monomeric species, such as 2-hydroxyethyl methacrylate (HEMA) in addition to the components of the conventional glass-ionomer cements. Disadvantages of RMGICs include a relatively high contraction and exotherm on polymerisation. HEMA is known to be cytotoxic, leading to problems of biocompatibility, and polyHEMA swells on exposure to water, leading to dimensional instability of the cements. Addressing these problems is important in the development of the RMGICs. Using alternative monomers to replace or reduce the amount of HEMA used in the current RMGIC formulations would be appropriate. This study was divided into two parts. Initially certain properties such as water sorption, micro-hardness, flexural strength and polymerisation exotherm of commercially available RMGICs were evaluated. Long-term storage of RMGICs in aqueous solutions resulted in their high water uptakes and solubilities and large volumetric expansions. However, the surface hardness and strengths of the restorative grade RMGICs were not affected on storage in distilled water. When the materials were immersed in artificial saliva, significantly higher water uptake were obtained; the equilibrium water uptake were not reached after 20 months. As a consequence, plastic behaviour and reduced surface hardness were observed. The RMGICs also produced high exotherm during polymerisation. The second part of the study investigated the use of an experimental resin as an alternative to HEMA. The experimental resin has the advantage of low toxicity to the pulp and relatively low polymerisation shrinkage. This study compared the polymerisations of the resin and HEMA, and of mixtures of these two

  17. Strength development in concrete with wood ash blended cement and use of soft computing models to predict strength parameters

    Directory of Open Access Journals (Sweden)

    S. Chowdhury

    2015-11-01

    Full Text Available In this study, Wood Ash (WA prepared from the uncontrolled burning of the saw dust is evaluated for its suitability as partial cement replacement in conventional concrete. The saw dust has been acquired from a wood polishing unit. The physical, chemical and mineralogical characteristics of WA is presented and analyzed. The strength parameters (compressive strength, split tensile strength and flexural strength of concrete with blended WA cement are evaluated and studied. Two different water-to-binder ratio (0.4 and 0.45 and five different replacement percentages of WA (5%, 10%, 15%, 18% and 20% including control specimens for both water-to-cement ratio is considered. Results of compressive strength, split tensile strength and flexural strength showed that the strength properties of concrete mixture decreased marginally with increase in wood ash contents, but strength increased with later age. The XRD test results and chemical analysis of WA showed that it contains amorphous silica and thus can be used as cement replacing material. Through the analysis of results obtained in this study, it was concluded that WA could be blended with cement without adversely affecting the strength properties of concrete. Also using a new statistical theory of the Support Vector Machine (SVM, strength parameters were predicted by developing a suitable model and as a result, the application of soft computing in structural engineering has been successfully presented in this research paper.

  18. Strength development in concrete with wood ash blended cement and use of soft computing models to predict strength parameters.

    Science.gov (United States)

    Chowdhury, S; Maniar, A; Suganya, O M

    2015-11-01

    In this study, Wood Ash (WA) prepared from the uncontrolled burning of the saw dust is evaluated for its suitability as partial cement replacement in conventional concrete. The saw dust has been acquired from a wood polishing unit. The physical, chemical and mineralogical characteristics of WA is presented and analyzed. The strength parameters (compressive strength, split tensile strength and flexural strength) of concrete with blended WA cement are evaluated and studied. Two different water-to-binder ratio (0.4 and 0.45) and five different replacement percentages of WA (5%, 10%, 15%, 18% and 20%) including control specimens for both water-to-cement ratio is considered. Results of compressive strength, split tensile strength and flexural strength showed that the strength properties of concrete mixture decreased marginally with increase in wood ash contents, but strength increased with later age. The XRD test results and chemical analysis of WA showed that it contains amorphous silica and thus can be used as cement replacing material. Through the analysis of results obtained in this study, it was concluded that WA could be blended with cement without adversely affecting the strength properties of concrete. Also using a new statistical theory of the Support Vector Machine (SVM), strength parameters were predicted by developing a suitable model and as a result, the application of soft computing in structural engineering has been successfully presented in this research paper. PMID:26644928

  19. Strength development in concrete with wood ash blended cement and use of soft computing models to predict strength parameters.

    Science.gov (United States)

    Chowdhury, S; Maniar, A; Suganya, O M

    2015-11-01

    In this study, Wood Ash (WA) prepared from the uncontrolled burning of the saw dust is evaluated for its suitability as partial cement replacement in conventional concrete. The saw dust has been acquired from a wood polishing unit. The physical, chemical and mineralogical characteristics of WA is presented and analyzed. The strength parameters (compressive strength, split tensile strength and flexural strength) of concrete with blended WA cement are evaluated and studied. Two different water-to-binder ratio (0.4 and 0.45) and five different replacement percentages of WA (5%, 10%, 15%, 18% and 20%) including control specimens for both water-to-cement ratio is considered. Results of compressive strength, split tensile strength and flexural strength showed that the strength properties of concrete mixture decreased marginally with increase in wood ash contents, but strength increased with later age. The XRD test results and chemical analysis of WA showed that it contains amorphous silica and thus can be used as cement replacing material. Through the analysis of results obtained in this study, it was concluded that WA could be blended with cement without adversely affecting the strength properties of concrete. Also using a new statistical theory of the Support Vector Machine (SVM), strength parameters were predicted by developing a suitable model and as a result, the application of soft computing in structural engineering has been successfully presented in this research paper.

  20. Base Course Modification through Stabilization using Cement and Bitumen

    Directory of Open Access Journals (Sweden)

    S. M. Marandi

    2009-01-01

    Full Text Available The main objectives of this research was to analyze the use of combined cement and bitumen emulsion in base course stabilization in details and examine its replacement with conventional pavement in regions with low quality materials and limited construction period. To conduct the objectives, the research divided into three phases. Phase I involved the optimization of cement and bitumen emulsion. In this case, a series of Indirect Tensile Strength (ITS, Unconfined Compressive Strength (UCS and Marshal Tests carried out. In the second phase, various alternative roadway sections examined for minimizing the pavement thickness and increasing the bearing capacity and finally in third phase, a Falling Weight Deflectometer (FWD machine used to examine the pavement bearing capacity for three sections of the roadway. It was found that, the optimum values to eliminate the creation of shrinkage cracks in the whole project and minimize the execution period and construction costs were 3% for both binders in stabilization and its replacement with conventional pavement method (i.e., stabilized layer with conventional sub-base and base layers. Also, FWD results showed that, the bearing capacity of the constructed pavement using stabilization method is far beyond the predicted values in pavement design. Furthermore, it was found that, with high inflation rate and political situation in the region, base stabilized method decreased the final roadway construction costs in compare with conventional pavement method.

  1. Properties of cement-fly ash grout admixed with bentonite, silica fume, or organic fiber

    International Nuclear Information System (INIS)

    A detailed laboratory study was conducted to investigate the properties of cement-fly ash grout mixtures as barriers for isolation of hazardous and low-level radioactive wastes. In the grout studied, fly ash was used to replace 30 percent by mass of cement. Three additives including bentonite, silica fume, and polypropylene fiber were used individually in the grout mixes to improve the properties of the grouts in different aspects. The flowability, bleeding, and setting time of freshly mixed grouts were determined; and the unconfined compressive strength, pore size distribution, and water permeability were determined for hardened grouts at various curing durations up to 120 days. Finally, the durability of cement-fly ash grouts was carefully examined in terms of the changes in their physical properties after different levels of exposure to sulfate attack and wet-dry cycles

  2. Calcium phosphate cements properties with polymers addition; Propriedades do cimento de fosfato de calcio com adicao de polimeros

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, J.M.; Trajano, W.T.; Escobar, C.F.; Santos, L.A., E-mail: julianafernandes2@yahoo.com.br [Universidade Federal do Rio Grande do Sul (UFRGS), RS (Brazil)

    2012-07-01

    Calcium phosphate cements (CPC) have attracted great interest to use in orthopedics and dentistry as replacements for damaged parts of the skeletal system, showing good biocompatibility and osseointegration, allowing its use as bone graft. Several studies have shown that the addition of polymer additives have a strong influence on the cement properties. The low mechanical strength is the main obstacle to greater use of CPC as an implant material. The objective of this study was to evaluate properties of a cement based on α-tricalcium phosphate (α-TCP), added polymers. PVA (10%, 8%, 6%), sodium alginate (2%) and polyacrylate ammonia (3%), all in weight, were added to the synthesized α-TCP powder. The samples were molded and evaluated for density, porosity in vitro test (Simulated Body Fluid), crystalline phases and mechanical strength. The results show increased the mechanical properties of the cement when added these polymers.

  3. Fatigue crack growth rate does not depend on mantle thickness: an idealized cemented stem construct under torsional loading.

    Science.gov (United States)

    Hertzler, Justin; Miller, Mark A; Mann, Kenneth A

    2002-07-01

    Retrieval studies indicate that cemented stem loosening in femoral components of total hip replacement can initiate at the stem-cement interface. The etiology of the crack propagation process from the stem-cement interface is not well understood, but cracks are typically associated with thin cement mantles. In this study, a combination of experimental and computational methods was used to investigate the fatigue crack propagation process from the stem-PMMA cement interface using a novel torsional loading model. Constructs with thin (1 mm), medium (3 mm) or thick (7 mm) cement mantles were evaluated. Crack growth was stable for all cases and the rate of crack growth diminished with increasing crack length. Crack growth rate did not depend on mantle thickness (p > 0.05) over the first 1 mm of crack length, but cracks in thin mantles reached the full thickness of the mantle in the fewest number of loading cycles. The fracture mechanics-based finite element models indicated decreased stress intensity factors with increasing crack length and were consistent with the experimental findings. When combined with a fatigue crack growth Paris-law for PMMA cement, the finite element models provided reasonable predictions of the crack growth process.

  4. WHITE CEMENT IN SUSTAINABLE DEVELOPMENT

    OpenAIRE

    Y.C.P RAMANA BABU; B.SAI DOONDI; N. M .V .VAMSI KRISHNA; K.Prasanthi

    2013-01-01

    India is one among the fast developing countries in the world in the areas of Infrastructure. Now a day, Carbon monoxide (CO) and carbon dioxide (CO2) are the temporary atmospheric pollutants in the environment chiefly emitted from the fuel burning vehicles and street lights which lead to global warming and pose a major threat tothe survival and sustainable development. This paper deals with the principal purpose of use of white cement in pavement design which will take care of the Green hous...

  5. ROTARY SCREW SYSTEMS IN CEMENT

    OpenAIRE

    Taratuta V. D.; Belokur K. A.; Serga G. V.

    2016-01-01

    The article presents results of research of rotary-screw systems in relation to the creation of rotary kilns for the annealing of-cuttings in the preparation of cement clinker. Using the proposed design, in comparison with known designs of similar purpose, it significantly improves performance, reduces size and power consumption through the use of rotary screw systems in the form of screw rotors and drums made hollow with sidewalls assembled from separate strips or plates of different geometr...

  6. Three-dimensional magnetic resonance imaging analysis of hip morphology in the assessment of femoral acetabular impingement

    Energy Technology Data Exchange (ETDEWEB)

    Kavanagh, E.C. [Department of Radiology, Mater Misericordiae Hospital, Dublin (Ireland); Read, P.; Carty, F.; Zoga, A.C. [Department of Radiology, Thomas Jefferson University Hospital, Philadelphia, PA (United States); Parvizi, J. [The Rothman Institute of Orthopedics, Philadelphia, PA (United States); Morrison, W.B., E-mail: William.Morrison@Jefferson.edu [Department of Radiology, Thomas Jefferson University Hospital, Philadelphia, PA (United States)

    2011-08-15

    Aim: To determine a possible association between femoral-acetabular impingement (FAI) volume and the development of labral tear using a three-dimensional (3D) model reconstruction of the acetabulum and the femoral head. Materials and methods: Magnetic resonance arthrography images of the hip in 42 patients with pain and suspected labral tear were acquired using a 1.5 T MRI machine. Using 3D analysis software, outlines of the acetabular cup and femoral head were drawn and 3D reconstruction obtained. To control for differences in patient size, ratios of acetabulum : femoral head volume (AFV) and acetabulum : femoral head surface area (AFA) were used for analysis. The association between volume of acetabulum : femoral head and FAI was investigated using ANOVA analysis. Results: There were 19 men and 23 women with a mean age of 39 years (range 18-78 years). The average AFV was 0.64 (range 0.37-1.05, SD 0.16) and AFA was 0.73 (range 0.36-1.26, SD 0.23). Herniation pit was significantly associated with a small AFV. Conclusion: Femoral neck herniation pits are associated with a low AFV. Gross volume and surface area ratios do not appear to correlate with labral tears or cartilage loss. This technique will enable more advanced analysis of morphological variations associated with FAI.

  7. Supra-acetabular fixation and sacroiliac screws for treating unstable pelvic ring injuries: preliminary results from 20 patients☆

    Science.gov (United States)

    Guimarães, Rodrigo Pereira; de Góes Ribeiro, Arthur; Ulson, Oliver; de Ávila, Ricardo Bertozzi; Ono, Nelson Keiske; Polesello, Giancarlo Cavalli

    2016-01-01

    Objective To analyze the treatment results from 20 patients who underwent an alternative osteosynthesis method as definitive treatment for pelvic ring fractures. Methods A retrospective analysis was conducted on a series of 20 patients with pelvic ring fractures (Tile type C) and a high risk of postoperative infection, who were treated at Santa Casa de Misericórdia de São Paulo between August 2004 and December 2012. The patients underwent percutaneous supra-acetabular external fixation in association with cannulated 7.0 mm iliosacral screws. Results The patients’ mean age was 40 years (range 22–77 years) and the mean length of follow-up was 18.5 months (range 3–69 months). At the end of the treatment, ten patients (50%) were classified as having good results, nine patients (45%) had fair results and one patient (5%) did not have any improvement. Six patients presented complications, and paresthesia of the lateral femoral cutaneous nerve was the most frequent of these (two patients). Conclusion Supra-acetabular external fixation in association with iliosacral percutaneous osteosynthesis is a good definitive treatment method for patients with a high risk of postoperative infection. PMID:27069879

  8. WHITE CEMENT IN SUSTAINABLE DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    Y.C.P RAMANA BABU

    2013-04-01

    Full Text Available India is one among the fast developing countries in the world in the areas of Infrastructure. Now a day, Carbon monoxide (CO and carbon dioxide (CO2 are the temporary atmospheric pollutants in the environment chiefly emitted from the fuel burning vehicles and street lights which lead to global warming and pose a major threat tothe survival and sustainable development. This paper deals with the principal purpose of use of white cement in pavement design which will take care of the Green house gases (i.e., CO and CO2 and also saves lot of money in the long run process. A small amount of these gases in environment can cause major problems over time. Use of white cement in composite pavement design where there is heavy traffic loads are acting as well as number of vehicles are more such as junctions, bus stops, check posts etc., can perform better and acts asenvironment friendly. Its light colour reflects more than bituminous pavement so that it can be easily identified and avoid accidents to some extent. White cement helps to lower the average bus stop, junction temperature providing comfort to the people because it has high solar reflectance there by reducing “urban heat island” effect. In addition to this it has some more advantages which increase the sustainability, durability and workability of the pavements.

  9. Scanning electron microscopy analysis of dental cements

    Directory of Open Access Journals (Sweden)

    Radosavljević Radivoje D.

    2009-01-01

    Full Text Available The aim of this study was to compare in vitro the characteristics of different types of luting cements (zinc phosphate, glass-ionomer and resin based composite cement using scanning electron microscopy (SEM analysis and microleakage for the quality range of materials. Dental cements were mixed in accordance with the manufacturer's instructions and formed with posts in dental root canals of extracted teeth. The quality of cement was determined by SEM observation on horizontal sectioned roots with fixed posts according to specific pore and marginal gap diameter. The microleakage was measured on specimens immersed in Lofler (methylene blue solution. The mean values of the maximal diameter of pores, marginal gaps and microleakage of conventional cements are remarkably larger in comparison with composite luting agents. In conclusion, the quality and efficiency of composite luting agents in comparison with conventional cements are more successful in protecting the interior of tooth from penetration of oral fluids, bacteria and bacterial toxins into unprotected dentine.

  10. Celotex (Registered) Replacement Study

    Energy Technology Data Exchange (ETDEWEB)

    Couture, S; Hafner, R

    2002-10-01

    The AL-R8 is the pit storage container in most widespread use at Pantex. The AL-R8 container family consists of standard 20-in.-diameter steel drums, 30 to 60 in. in height, with insulation inserts made of Celotex{reg_sign}--a fiberboard product made from processed sugar cane. Celotex is an acceptable material for inserts in many radioactive material shipping and storage containers. It is a good shock mitigator/insulator, does a fair job in fire protection (when oxygen is excluded), shielding, and criticality, and is inexpensive and easily available. However, the fiberboard absorbs water in humid environments which, when combined with chemical residues in the fiberboard, forms corrosive compounds that can shorten the life of the container and affect container contents. To protect the contents from this potentially damaging environment, the AL-R8 SI was developed to isolate the contents within a sealed stainless steel vessel inside the AL-R8. Although the SI protected the contents, corrosion studies indicated the SI lid bolts might corrode over time and surveillance showed that areas of the outer drum were still subject to corrosion. To address this potential problem, DOE/Albuquerque sponsored bolt and Celotex replacement studies. The bolt replacement study was assigned to Mason and Hanger's Pantex Facility and this Celotex Replacement Study to Lawrence Livermore National Laboratory. The Celotex Replacement Study evaluated options for replacing Celotex with a material that is chemically compatible with the AL-R8 SI container. The evaluation was limited to materials either used previously in nuclear materials shipping and storage containers or materials with known properties in a low-radiation environment. This limitation was set to ensure that the long-term aging effect on the new material is known a priori. Initial material evaluations narrowed the material choices to foam and cork. Although cork performed better than foam in some tests, cork was considered a

  11. Renal Replacement Therapy

    OpenAIRE

    Zaccaria Ricci; Stefano Romagnoli; Claudio Ronco

    2016-01-01

    During the last few years, due to medical and surgical evolution, patients with increasingly severe diseases causing multiorgan dysfunction are frequently admitted to intensive care units. Therapeutic options, when organ failure occurs, are frequently nonspecific and mostly directed towards supporting vital function. In these scenarios, the kidneys are almost always involved and, therefore, renal replacement therapies have become a common routine practice in critically ill patients with acute...

  12. Sustainable Development of the Cement Industry and Blended Cements to Meet Ecological Challenges

    OpenAIRE

    Konstantin Sobolev

    2003-01-01

    The world production of cement has greatly increased in the past 10 years. This trend is the most significant factor affecting technological development and the updating of manufacturing facilities in the cement industry. Existing technology for the production of cement clinker is ecologically damaging; it consumes much energy and natural resources and also emits pollutants. A new approach to the production of blended or high-volume mineral additive (HVMA) cement helps to improve its ecologi...

  13. Renal Replacement Therapy.

    Science.gov (United States)

    Ricci, Zaccaria; Romagnoli, Stefano; Ronco, Claudio

    2016-01-01

    During the last few years, due to medical and surgical evolution, patients with increasingly severe diseases causing multiorgan dysfunction are frequently admitted to intensive care units. Therapeutic options, when organ failure occurs, are frequently nonspecific and mostly directed towards supporting vital function. In these scenarios, the kidneys are almost always involved and, therefore, renal replacement therapies have become a common routine practice in critically ill patients with acute kidney injury. Recent technological improvement has led to the production of safe, versatile and efficient dialysis machines. In addition, emerging evidence may allow better individualization of treatment with tailored prescription depending on the patients' clinical picture (e.g. sepsis, fluid overload, pediatric). The aim of the present review is to give a general overview of current practice in renal replacement therapies for critically ill patients. The main clinical aspects, including dose prescription, modality of dialysis delivery, anticoagulation strategies and timing will be addressed. In addition, some technical issues on physical principles governing blood purification, filters characteristics, and vascular access, will be covered. Finally, a section on current standard nomenclature of renal replacement therapy is devoted to clarify the "Tower of Babel" of critical care nephrology. PMID:26918174

  14. Lower limb joint replacement in rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    Clement Nicholas D

    2012-06-01

    Full Text Available Abstract Introduction There is limited literature regarding the peri-operative and surgical management of patients with rheumatoid disease undergoing lower limb arthroplasty. This review article summarises factors involved in the peri-operative management of major lower limb arthroplasty surgery for patients with rheumatoid arthritis. Methods We performed a search of the medical literature, using the PubMed search engine (http://www.pubmed.gov. We used the following terms: ‘rheumatoid’ ‘replacement’ ‘arthroplasty’ and ‘outcome’. Findings The patient should be optimised pre-operatively using a multidisciplinary approach. The continued use of methotrexate does not increase infection risk, and aids recovery. Biologic agents should be stopped pre-operatively due the increased infection rate. Patients should be made aware of the increased risk of infection and periprosthetic fracture rates associated with their disease. The surgical sequence is commonly hip, knee and then ankle. Cemented total hip replacement (THR and total knee replacement (TKR have superior survival rates over uncemented components. The evidence is not clear regarding a cruciate sacrificing versus retaining in TKR, but a cruciate sacrificing component limits the risk early instability and potential revision. Patella resurfacing as part of a TKR is associated with improved outcomes. The results of total ankle replacement remain inferior to THR and TKR. RA patients achieve equivalent pain relief, but their rehabilitation is slower and their functional outcome is not as good. However, the key to managing these complicated patients is to work as part of a multidisciplinary team to optimise their outcome.

  15. Global Cement Industry: Competitive and Institutional Dimensions

    OpenAIRE

    Selim, Tarek; Salem, Ahmed

    2010-01-01

    The cement industry is a capital intensive, energy consuming, and vital industry for sustaining infrastructure of nations. The international cement market –while constituting a small share of world industry output—has been growing at an increasing rate relative to local production in recent years. Attempts to protect the environment in developed countries –especially Europe—have caused cement production plants to shift to countries with less stringent environmental regulations. Along with con...

  16. Premixed calcium silicate cement for endodontic applications

    OpenAIRE

    Persson, Cecilia; Engqvist, Håkan

    2011-01-01

    Calcium silicate-based materials (also called MTA) are increasingly being used in endodontic applications. However, the handling properties of MTA are not optimal when it comes to injectability and cohesion. Premixing the cements using glycerol avoids these issues. However, there is a lack of data on the effect of common cement variables on important properties of premixed cements for endodontic applications. In this study, the effects of liquid-to-powder ratio, amount of radiopacifier and am...

  17. Water dynamics in glass ionomer cements

    Science.gov (United States)

    Berg, M. C.; Jacobsen, J.; Momsen, N. C. R.; Benetti, A. R.; Telling, M. T. F.; Seydel, T.; Bordallo, H. N.

    2016-07-01

    Glass ionomer cements (GIC) are an alternative for preventive dentistry. However, these dental cements are complex systems where important motions related to the different states of the hydrogen atoms evolve in a confined porous structure. In this paper, we studied the water dynamics of two different liquids used to prepare either conventional or resin-modified glass ionomer cement. By combining thermal analysis with neutron scattering data we were able to relate the water structure in the liquids to the materials properties.

  18. Retention of Root Canal Posts: Effect of Cement Film Thickness, Luting Cement, and Post Pretreatment.

    Science.gov (United States)

    Sahafi, A; Benetti, A R; Flury, S; Peutzfeldt, A

    2015-01-01

    The aim of this study was to investigate the effect of the cement film thickness of a zinc phosphate or a resin cement on retention of untreated and pretreated root canal posts. Prefabricated zirconia posts (CosmoPost: 1.4 mm) and two types of luting cements (a zinc phosphate cement [DeTrey Zinc] and a self-etch adhesive resin cement [Panavia F2.0]) were used. After removal of the crowns of 360 extracted premolars, canines, or incisors, the root canals were prepared with a parallel-sided drill system to three different final diameters. Half the posts did not receive any pretreatment. The other half received tribochemical silicate coating according to the manufacturer's instructions. Posts were then luted in the prepared root canals (n=30 per group). Following water storage at 37°C for seven days, retention of the posts was determined by the pull-out method. Irrespective of the luting cement, pretreatment with tribochemical silicate coating significantly increased retention of the posts. Increased cement film thickness resulted in decreased retention of untreated posts and of pretreated posts luted with zinc phosphate cement. Increased cement film thickness had no influence on retention of pretreated posts luted with resin cement. Thus, retention of the posts was influenced by the type of luting cement, by the cement film thickness, and by the post pretreatment. PMID:25764045

  19. The mechanical effects of different levels of cement penetration at the cement-bone interface.

    NARCIS (Netherlands)

    Waanders, D.; Janssen, D.; Mann, K.A.; Verdonschot, N.J.J.

    2010-01-01

    The mechanical effects of varying the depth of cement penetration in the cement-bone interface were investigated using finite element analysis (FEA) and validated using companion experimental data. Two FEA models of the cement-bone interface were created from micro-computed tomography data and the p

  20. The influence of ultrasound on removal of prefabricated metal post cemented with different resin cements

    Directory of Open Access Journals (Sweden)

    Atiyeh Feiz

    2013-01-01

    Conclusion: Ultrasonic energy did not decrease the retention of posts cemented with Panavia or Maxcem Elite cements. Furthermore, it seems that there is no significant difference between removal force of self-etch (Panavia and the self-etch self-adhesive (Maxcem Elite resin cements.