hip prosthesis

..Use of fluoride containing bone cement did not improve the stem fixation compared with a conventional cement used up to 5 years, but resulted in more pronounced loss of bone mineral density in the medial cortex...

..Such a protocol-also including other recognized clinical outcome parameters-will reduce the risk of implanting potentially inferior prostheses on a large scale...

..We therefore analyzed implant survival of cemented and uncemented THA, and whether the modes of failure differ between the two methods of fixation...

..We therefore studied patient- and surgery-related risk factors for revision due to infection after primary THA in a population-based setting...

..In the presence of a competing risk such as death, KM is known to overestimate the probability of revision. We investigated the degree to which the risk of revision is overestimated in registry data...

..There were 7 (4.5%) postoperative complications all unrelated to the acetabular component...

..We are concerned that with time the incidence of these pseudotumours may increase. Further investigation is required to define their cause...

..5 to 93.5) and for impending revision 55.3% (95% confidence interval 40.6 to 70) at 16 years. Uncemented acetabular components with polyethylene liners undergo silent lysis and merit regular long-term radiological review...

..This constrained image is the basis for an image-based projection completion procedure. The algorithm was validated on simulations, phantom and patient data, and compared with other metal artifact reduction algorithms...

..8) (0 to 48 worst-to-best scale) and the mean combined Harris pain and function score was 73.2 (SD 16.9). Radiological review showed excellent preservation of bone stock in the proximal femur and no failures of the femoral component...

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..The results from this study can be compared with those from novel cementless stem designs to help predict the long-term outcome one may expect from new cementless stem designs...

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..7 years, was 100% (end point: revision for any cause). Fitek cup showed good clinicoradiographic results...

..This correlation appears to be stronger and is more clearly established for surgeon volumes than it is for hospital volumes...

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..Within the last few years, new software systems have been developed to solve this problem. We compared the precision of 3 RSA systems in migration analysis of the acetabular component...

..The tissue features may help distinguish reactions to high wear from those with suspected metal hypersensitivity...

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..We studied long-term outcome based on data in the Norwegian Arthroplasty Register...

..11-0.86, p < 0.03); those treated with adequate antimicrobial therapy had a better success rate (87% vs. 50%, p < 0.01). CONCLUSION: The proposed algorithm defines a rational surgical/antibiotic treatment strategy...

..Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence...

..Our observations suggest that alternative shapes could be possible on future polished femoral stem designs...

..With the end point reoperation for aseptic stem loosening, the survivorship is 93.5% (95% confidence interval, 90.0%-97.0%). The reoperation rate for aseptic femoral component loosening is 3.23% into the 33rd year of follow-up...

..The present trial was primarily designed to evaluate whether a single infusion of 4 mg of zoledronic acid prevented early implant migration in patients with osteonecrosis of the femoral head...

..Our findings have also shown that rapid posterior head migration is predictive of premature loosening and a better predictor than subsidence...

..In this retrospective study, we wanted to gain information on initial stability and wear after revision with the Burch-Schneider ring...

..4% +/- 1.9% for press-fit cups with screws and 100% +/- 0.1% for press-fit cups. Despite an increasing incidence of polyethylene wear-related revisions, porous-coated acetabular components have demonstrated excellent long-term fixation...

..For the stem/head, the survival rate was 98% (95% confidence interval, 94%-99%). In 95.2% of patients, no operative revision was required. The rate of aseptic loosening was 2% for the acetabular and 1% for the femoral component...

..The bridging of the interface gaps (up to 5 mm) by the trabecular metal monoblock acetabular component indicates the strong osteoconductive, and possibly osteoinductive, properties of trabecular metal...

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..Mid-term results were recorded so that recommendations can be made on the use of certain bearings, which minimise wear and thus the danger of subsequent aseptic loosening...

..5%. Wear was greater in cups with an inclination greater than 45 degrees and in metal-polyethylene pairings compared with ceramic-polyethylene pairings. This cup design performs well over the long term...

..Metal-on-metal resurfacing THA performs well at short to mid-term followup in young, active adults despite high activity levels...

Therapy of infected hip prosthesis should always be based on a structured treatment concept...

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..Hydroxyapatite (HA) is the main inorganic component of bone, and HA coating is widely used on acetabular cups in hip arthroplasty. It has been suggested that this surface finish improves cup survival...

..As a result, the AOANJRR has one of the largest series of resurfacing procedures. This study was undertaken to determine the results of this series and the risk factors associated with revision...

..We present an in vivo method of computed tomography (CT) assisted osteodensitometry after THA that differentiates between cortical and cancellous bone density (BD) and area around the femoral component...

..None of the metal-backed uncemented acetabular components with ultra-high-molecular-weight polyethylene liners in our study had satisfactory long-term results because of high rates of wear, osteolysis, aseptic loosening and dislocation...

..8 years were reviewed. Thirty-five infections were on knee prosthesis and 18 were on hip prosthesis. The mean ± SD duration of intravenous and oral antibiotics was 10.6 ± 6.7 and 88 ± 45.9 days, respectively...

..We analyzed the causes of total and site-specific mortality among a cohort of patients with MM and with metal-on-polyethylene (MP) THA after a long follow-up time...

..04) and in all SF-36 domains (p < 0.05). Patients undergoing BHR report a significantly greater improvement in general health compared with those with a THR...

..There were no revisions for aseptic loosening of the cup, and no osteolytic defects were found around the cup. Patient satisfaction was high and the clinical results were very good...

..In the present study, we analyzed population-based survival rates of the cemented and cementless total hip replacements in patients under the age of 55 years with primary osteoarthritis in Finland...

..The subtle differences in designs may explain the different patterns of migration. Comparable migration with the Exeter stem suggests that the CPCS design will perform well in the long term...

..We observed smaller regions of superficial ON in the majority of the remaining femoral remnants with periprosthetic fractures and in hips that failed for reasons other than fracture...

..These data have revealed a significant reduction in dislocations associated with the use of large femoral head sizes, with no change in the 18-month revision rate...

..Successful treatment of prosthetic hip joint infection (PI) means elimination of infection and restored hip function. However, functional outcome is rarely studied. We analyzed the outcome of the strict use of a treatment algorithm for PI...

..These bearing surfaces are associated with unique risks and benefits and higher costs. However the relative risks of these three bearings in an older population is unknown...

..We investigated whether design-related factors play any role in the risk of non-aseptic revision of the 3 most frequently used primary cemented stem designs in the Swedish Hip Arthroplasty Register...

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..However, additional followup strategies are recommended to determine any possible long-term deleterious effects associated with the dissemination of metallic ions...

..Proliferative desquamative synovitis might constitute another morphologic feature associated with the delayed type hypersensitivity reaction...

..Combined with the ability to use modular augments for added support and stability, this technology may change the way major defects are reconstructed...

..Patients with a short-term infection but with a stable implant, no sinus tract and a known pathogen may be successfully treated by retention of the implant and the use of a standardised regimen of antimicrobial treatment...

..We investigated the hypothesis that many total hip arthroplasty revisions that are classified as aseptic are in fact low-grade infections missed with routine diagnostics...

..To perform a retrospective review of all the conventional radiographic and magnetic resonance imaging (MRI) studies performed in patients with early postoperative pain following cobalt-chrome metal-on-metal total hip arthroplasty...

..The technique of impaction grafting appears to be reliable, can be learned rapidly and produces a predictably low incidence of aseptic loosening...

..Femoral impaction grafting requires vigorous impaction to obtain adequate stability without risk of fracture, but the force of impaction has not been determined. We determined this threshold force in a preliminary study using animal femurs...

..0); and manganese, 1.6-fold (CI, 1.3-2.0). In the metal-on-polyethylene group, a smaller but significant increase in the concentrations of cobalt and nickel occurred, whereas concentrations of the other ions did not change significantly...

..Periprosthetic BD changes at the five year follow-up are suggestive of stable stem osteointegration with proximal femoral diaphysis load transfer and metaphyseal stress shielding...

..We did not find an increased number of complications compared to the literature. Further long-term follow-up, however, is essential...

..and implant-related complications of a cementless, collarless, proximally coated, distally tapered femoral hip prosthesis. The clinical and radiographic results for 129 hips in 116 patients after total hip arthroplasty with a Fiber ..

..The customised stem induced a strain pattern more similar to that of the intact femur than the standard, anatomical stem...

..Revision for radiological changes alone must be accepted if gross loss of bone stock is to be avoided. Improvements in the design, materials and operative technique, based on the long-term outcome, are highlighted...

..The technique has been used successfully in many cases over a 5-year period...

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..Our findings suggest there is no evidence to support withholding total hip replacement from obese patients with arthritic hips on the grounds that their outcome will be less satisfactory than those who are not obese...

..In future comparative bone remodelling studies using DEXA, patients should be matched for preoperative bone quality and gender...

..Aseptic loosening has been a major problem in several uncemented series with earlier designs. The objective for this study was to investigate how the host bone adapts to a loose stem compared with a well-fixed stem after a long time...

..62 between the 2 stages to 97.83 at final follow-up. Two-stage reconstruction using an antibiotic-loaded cement spacer was found to give satisfactory results for the treatment of hip infections with various etiologies...

..The importance of this data is related to cup implantation techniques. The hip COR can be moved superiorly and/or medially to permit cup inclination below 45 degrees with correct cup coverage...

..The purpose of the present study was to evaluate the minimum ten-year results of primary total hip arthroplasty performed with use of a proximally porous-coated, plasma-sprayed, straight-stemmed, titanium-alloy femoral component...

..These differences were noted at the end of the first post-operative year and remained stable, except in zone 7, where they were progressive. There is little evidence that the modified stem reduces femoral bone density loss...

..There was no ceramic breakage and no need for revision surgery due to the ceramic liner. The alumina bearing couples proved to be as reliable as CoCr/HXLPE...

..9 N, p < 0.001). We conclude that MOM bearings are more stable to dislocation than COP bearings as a result of the interfacial forces provided by a thin, lubricating fluid...

..At an averagefollow-up of 30 months, no liner or head chips or fractures were observed in this group...

..Our failures were mainly due to femoral resorption under the prosthetic femoral component...

..However, the cost effectiveness of MoM HRA compared with THA is unclear...

..Furthermore, we compared the prevalence of metal allergy in dermatitis patients with and without THA...

..All femoral stems appeared to have bony integration radio-graphically. Tapered femoral stems provide a cementless alternative in patients with a narrow femoral canal without undue risk of perioperative fracture or thigh pain...

..Complications included hip dislocation in 17 (19%) patients. The median Harris hip score was 78 (16-100) points, and the median radiographic stem migration was 2.7 mm at follow-up...

..7 (20-40), and there was no evidence of stem loosening radiologically. There were 3 acetabular revisions and 3 liner changes at 10 years, with a further 5 cup revisions and 9 liner changes at final follow-up...

..There have been no in vivo studies showing that this distance is either achieved in clinical practice or needed for clinically satisfying results. Thus, we assessed the femoral stem-bone anchorage of the MP prosthesis using CT...

..In this article we will discuss the possible role of a bacterial biofilm and the importance of the local surrounding environment in "aseptic" loosening of hip prostheses...

..2% (95% confidence interval, 72.7 to 87.6) and 77.5% (95% confidence interval, 69.7 to 85.2), respectively. Despite these good clinical results, further follow-up is needed to determine whether these prostheses will loosen with time...

..We evaluated the population-based survival of uncemented THA for primary osteoarthritis (OA) in patients under 55 years of age and the factors affecting survival...

..The limited contact between implant and host bone does not seem to compromise implant survival in the 7- to 11-year perspective...

..5 (sd 13.5) (physical). The mean satisfaction score was 90.5 (sd 15.3). Two-stage revision for hip infection using a Prostalac interim spacer offers a predictable and lasting solution for patients with this difficult problem...

..Contemporary bearing surfaces in association with such stems may provide long-lasting total hip arthroplasties, even in young, active patients...

..This study examines the incidence of early prosthesis related complications after UAM and Cemented Thompson (CT) hemiarthroplasty procedures for the management of femoral neck fractures...

..Obviously, other considerations will influence the minimum thickness to be recommended...

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..appearance, and serum metal concentrations after a minimum 10 years follow-up with a metal-on-metal hip prosthesis: 105 cementless primary total hip prostheses with metal-on-metal articulating surfaces were implanted in 98 ..

..CLINICAL RELEVANCE: Dogs with lucency in > or =2 zones of analysis should be evaluated more frequently for clinical signs of implant loosening. Further investigation of serial radiographs after ZCTH arthroplasty is warranted...

..CONCLUSION: This method has a significantly higher accuracy than routine plain radiography in detecting acetabular cup migration and could be used in clinical practice. It gives both a visual and a numerical correlate to migration...

..These uses, as well as the study limitations, are discussed in detail...

..Four patients have been revised for recurrent hip instability, and one has been revised for infection. The need to convert to an acetabular component with screw fixation because of poor press-fit is <1%...

..of a single test that is highly accurate, and cost effective in the management of patients with painful total hip prosthesis. Current diagnostic tests including routine radiography, laboratory studies, and nuclear medicine procedures, ..

..Should these aims be met, the proposed model will be of great use in pre-clinical testing of novel cemented stem designs. ..

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..As a result, patient pain, suffering and morbidity will be minimized. ..

..Additionally, variable immunologic responses induced by implant degradation products (i.e. lymphocyte response to metal ions and monocyte/macrophage response to particulate debris) will be correlated with the development of osteolysis ..

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..Realistic finite element analysis is an ideal vehicle for systematically assessing the complex interactions of the many factors influencing dislocation propensity, toward the goal of reducing this troublesome complication. ..

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..Based on the kinematic and kinetic in vivo data derived in the motion laboratory, we will calculate contact forces using a mathematical model of the artificial knee. ..

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..Thus, successful achievement of the proposed research will provide essential information on TDR implant performance and on clinical outcomes, which are needed for informed health care decisions. ..

..The purpose of this proposed research is to examine the influence of mechanical degradation after implantation on the clinical performance of metal-backed acetabular components for total hip arthroplasty. ..

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..Realistic finite element analysis is an ideal vehicle for systematically assessing the complex interactions of the many factors influencing dislocation propensity, toward the goal of reducing this troublesome complication. ..

..These achievements should reduce the incidence of restorative failures associated with tooth fracture, resulting in billions of dollars in savings of health care costs, as well as a reduction in human suffering. ..

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..It is important to find ways to minimize these 3rd body particles, and to develop implants that are more resistant to 3rd body damage. ..

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..These achievements should reduce the incidence of restorative failures associated with tooth fracture, resulting in billions of dollars in savings of health care costs, as well as a reduction in human suffering. ..

..This partnership proposes to bring together a critical mass of engineers and surgeons, to achieve clinically grounded advances in nonlinear numerical simulations of surgery of the hip. ..

..At the project's conclusion, we expect to have filled a longstanding need in the field of osteonecrosis research: an animal model suitable for systematic study of human-implementable interventions to forestall femoral head collapse. ..

..Type I microcracks directly contribute to the loosening of a femur stem constructs. Type II microcracks function as energy absorbers and thereby retard the loosening process. ..

..The methodological advances from this research will enable mental health researchers and policy makers to better characterize usual care and to expand the inferences drawn from clinical trials. ..

..These novel and innovative methods will improve the assessment of treatment effects and will contribute to improving the health of the population. ..

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..When combined, the experimental and computational approaches will provide design guidelines that could significantly reduce revision rates of cemented hip replacements due to implant loosening. ..

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..The methodological advances from this research will enable researchers, policy makers, and methodologists to better characterize factors impacting technology innovation/exnovation and to expand the inferences for usual care. ..