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Journal of Applied Biomaterials &... Sep 2013The purpose of this study was to assess a new metal component finishing designed to improve total knee prosthesis durability. Wear of ultrahigh molecular-weight...
PURPOSE
The purpose of this study was to assess a new metal component finishing designed to improve total knee prosthesis durability. Wear of ultrahigh molecular-weight polyethylene (UHMWPE), with generation of submicrometer- and micrometer-sized particles, has been associated with osteolysis and artificial joint failure. Wear extent is influenced by several factors, some of which are related to manufacturing.
METHODS
UHMWPE wear was assessed in metal prosthesis components finished with the Microloy® technology and in traditionally finished components by wear simulation experiments (pin on disk and knee simulator tests) and analysis of wear debris.
RESULTS
Microloy®-finished prosthesis showed a 48.5% reduction in UHMWPE total weight loss compared with traditional components (P=0.002). A statistically significant (P<0.05) reduction of UHMWPE debris were detected from the Microloy®-finished compared with the traditionally finished components.
CONCLUSIONS
These findings suggest the Microloy® metal finishing may enhance the long-term performance of knee prostheses.
Topics: Arthroplasty, Replacement, Knee; Equipment Failure Analysis; Humans; Knee Prosthesis; Metals; Particle Size; Polyethylene; Polyethylenes; Prosthesis Design; Prosthesis Failure
PubMed: 23728542
DOI: 10.5301/JABFM.5000153 -
Advances in Oto-rhino-laryngology 2010This article describes a surgical technique using porous polyethylene as the framework material for ear reconstruction. In comparison to the use of rib cartilage, porous...
This article describes a surgical technique using porous polyethylene as the framework material for ear reconstruction. In comparison to the use of rib cartilage, porous polyethylene - first described by Berghaus in 1982 - provides better definition and projection as well as congruency with the opposite side. Hospitalization time is significantly shorter. There are less surgical interventions than with traditional microtia operations that use rib cartilage, and the patient is spared the additional procedure needed to remove the rib cartilage, with all the associated complications as well as the resulting thorax scar. Also, reconstruction can take place at an earlier age, which is advantageous for those concerned. Using porous polyethylene as the frame material, a temporoparietal flap and full-thickness skin cover, we have been able to achieve very convincing results over recent years.
Topics: Age Factors; Dermatologic Surgical Procedures; Ear; Humans; Polyethylene; Polyethylenes; Prostheses and Implants; Plastic Surgery Procedures
PubMed: 20442561
DOI: 10.1159/000314562 -
Canadian Medical Association Journal Dec 1958
Topics: Humans; Infusions, Parenteral; Polyethylene; Polyethylenes; Vascular Surgical Procedures
PubMed: 13608389
DOI: No ID Found -
The Science of the Total Environment Feb 2020Wastewater-based epidemiology (WBE), the per capita normalised measurement of drugs, chemicals or metabolites in wastewater influent, relies on sampling and quantitative...
Calibration and validation of a microporous polyethylene passive sampler for quantitative estimation of illicit drug and pharmaceutical and personal care product (PPCP) concentrations in wastewater influent.
Wastewater-based epidemiology (WBE), the per capita normalised measurement of drugs, chemicals or metabolites in wastewater influent, relies on sampling and quantitative analysis to evaluate temporal and spatial trends of chemical consumption. Continuous, high-resolution, flow proportional composite sampling is optimal for accurate representations of chemical mass loads, but is rarely implemented, with conventional autosamplers providing relatively low frequency time or volume proportional samples. However, due to equipment or resource constraints at many wastewater treatment plants (WWTPs), even this may not be feasible. Passive sampling may provide an alternative sampling strategy. To investigate this, samplers comprising hollow, cylindrical Microporous Polyethylene Tubes (MPTs) containing polymeric sorbent phases of Strata-X and Strata-X in agarose were simultaneously deployed in a municipal WWTP influent stream. Samplers were extracted, analysed and evaluated for a range of illicit drugs and pharmaceuticals and personal care products (PPCPs) after 4, 7, 15, 21, and 29 day deployments. The MPT samplers were calibrated against 24-hour time proportional composite grab samples that were collected in parallel. Diffusion through the MPT governed uptake, reducing or eliminating the influence of external flow rates that may fluctuate unpredictably in a WWTP environment. Calibration data for six illicit drugs and fourteen PPCPs, including methamphetamine, benzoylecgonine, MDMA, codeine and carbamazepine, demonstrated linear accumulation in the samplers (R ≥ 0.84). Derived sampling rates for these analytes ranged from 0.25 to 17 mL d for ibuprofen and verapamil, respectively. A validation study using this sampling rate data showed the MPT could effectively quantify concentrations (≥0.1 ng mL) of a range of amphetamine-type stimulants, opioids and metabolites as well as nicotine, accounting for 95% of the variance in parallel composite grab sample concentrations of these compounds. The MPT sampler shows promise for providing essential monitoring data for WBE, informing future intervention and research strategies.
Topics: Cosmetics; Environmental Monitoring; Illicit Drugs; Pharmaceutical Preparations; Polyethylene; Wastewater; Water Pollutants, Chemical
PubMed: 31838300
DOI: 10.1016/j.scitotenv.2019.135891 -
The Journal of Arthroplasty Oct 2006The wear characteristics of ultra-high-molecular-weight polyethylene acetabular cups irradiated with 6.0 to 7.5 Gy of gamma-irradiation were studied in a hip simulator...
The wear characteristics of ultra-high-molecular-weight polyethylene acetabular cups irradiated with 6.0 to 7.5 Gy of gamma-irradiation were studied in a hip simulator and in vivo in 70 hips for 6 to 39 months. The linear wear was 2.5% to 4.5% of the wear seen in conventional polyethylene cups. A biphasic wear pattern was observed over time with a relatively large wear in the first year and a subsequent leveling of the wear rate curve. The linear wear rate in the second phase (steady state) was 0.006 mm/y. The extent of decrease in clinical wear of 6.0-Mrad polyethylene (Aeonian, Kyocera Corp, Kyoto, Japan) cups is comparable with the decrease of the in vitro wear measured by the hip simulation test.
Topics: Acetabulum; Hip Prosthesis; Humans; Japan; Models, Anatomic; Polyethylene; Prosthesis Failure
PubMed: 17027535
DOI: 10.1016/j.arth.2006.03.009 -
Clinical Orthopaedics and Related... Feb 2008Some previous studies suggest that aging influences wear and oxidatively degraded nonsterilized ultra-high-molecular-weight polyethylene (UHMWPE) exhibits decreased wear...
Some previous studies suggest that aging influences wear and oxidatively degraded nonsterilized ultra-high-molecular-weight polyethylene (UHMWPE) exhibits decreased wear resistance. We therefore asked whether shelf-aging storage conditions influenced degradation and wear resistance of gamma-irradiated UHMWPE. We examined oxidation and wear of 100-Mrad gamma-irradiated UHMWPE (100-Mrad polyethylene) cups shelf-aged for 30 years without (n=2) or with (n=2) packages. The oxidation index of the unpackaged 100-Mrad polyethylene surface (4) was higher than that of the packaged one (2.7). The packaged 100-Mrad polyethylene cup exhibited a high wear resistance with a steady wear rate of 0.5 mg/10(6) cycles. In contrast, the unpackaged 100-Mrad polyethylene exhibited an extremely high initial wear rate of 187.9 mg/10(6) cycles over the first 0.25 x 10(6) cycles with a subsequently reduced wear rate of 5 mg/10(6) cycles after 5 x 10(6) cycles. Packaging over long periods inhibits surface oxidation and maintains the wear resistance of gamma-irradiated UHMWPE cups.
Topics: Free Radicals; Gamma Rays; Hip Prosthesis; Materials Testing; Oxidation-Reduction; Polyethylene; Product Packaging; Sterilization
PubMed: 18196416
DOI: 10.1007/s11999-007-0046-x -
American Journal of Surgery Feb 1962
Topics: Humans; Polyethylene; Polyethylenes; Sutures
PubMed: 14454370
DOI: 10.1016/0002-9610(62)90489-0 -
Canadian Medical Association Journal Oct 1958
Topics: Cardiac Catheterization; Catheterization; Congenital Abnormalities; Foreign Bodies; Heart; Humans; Polyethylene; Polyethylenes
PubMed: 13585269
DOI: No ID Found -
Journal of Applied Physiology May 1964
Topics: Biomedical Technology; Humans; Medical Laboratory Science; Physiology; Polyethylene; Polyethylenes; Technology
PubMed: 14173558
DOI: 10.1152/jappl.1964.19.3.542 -
PloS One 2017More than 60.000 hip arthroplasty are performed every year in Italy. Although Ultra-High-Molecular-Weight-Polyethylene remains the most used material as acetabular cup,...
More than 60.000 hip arthroplasty are performed every year in Italy. Although Ultra-High-Molecular-Weight-Polyethylene remains the most used material as acetabular cup, wear of this material induces over time in vivo a foreign-body response and consequently osteolysis, pain, and the need of implant revision. Furthermore, oxidative wear of the polyethylene provoke several and severe failures. To solve these problems, highly cross-linked polyethylene and Vitamin-E-stabilized polyethylene were introduced in the last years. In in vitro experiments, various efforts have been made to compare the wear behavior of standard PE and vitamin-E infused liners. In this study we compared the in vitro wear behavior of two different configurations of cross-linked polyethylene (with and without the add of Vitamin E) vs. the standard polyethylene acetabular cups. The aim of the present study was to validate a micro X-ray computed tomography technique to assess the wear of different commercially available, polyethylene's acetabular cups after wear simulation; in particular, the gravimetric method was used to provide reference wear values. The agreement between the two methods is documented in this paper.
Topics: Cross-Linking Reagents; Hip Joint; Humans; Polyethylene; Polyethylenes; X-Ray Microtomography
PubMed: 28107468
DOI: 10.1371/journal.pone.0170263