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Full-Text Articles in Engineering
Development Of A Gel Content Analysis Protocol For Ultra High Molecular Weight Polyethylene, Max Harold Jeanty
Development Of A Gel Content Analysis Protocol For Ultra High Molecular Weight Polyethylene, Max Harold Jeanty
Theses
A modified procedure based upon ASTM (D 2765 - 90) to determine the gel content of crosslinked polyethylene plastics was developed. The new procedure was applied to ram extruded Ultra High Molecular Weight (UHMWPE) implant components processed under different manufacturing conditions. This new evaluation tool provides consistent results with greater accuracy and consistency compared to the American Society for the Testing of Materials (ASTM) method. Using the same tool, several relationships between the UHMWPE processing conditions and gel content were established. The amount of gel content is related to the crosslinked material. It has been shown that the more crosslinking …
The Morphology Of Uhmwpe Wear Debris Generated By A Hip Joint Simulator, Aaron P. Essner
The Morphology Of Uhmwpe Wear Debris Generated By A Hip Joint Simulator, Aaron P. Essner
Theses
The size, quantity and shape of total hip replacement wear debris may identify wear mechanisms as well as play a role in osteolysis. Characterization of wear particles generated from a hip joint simulator was conducted followed by comparison with literature reported in vivo results. The effect of counterface material and lubricant type on particle morphology was assessed. Biomaterial pairs including UHMWPE articulated against CoCr, Alumina and Zirconia were considered. Deionized (D.I.) water and bovine serum were used as lubricants. Particles generated from Alumina/UHMWPE in serum were slightly larger than those for CoCr and Zirconia against UHMWPE in serum. Particle shape …
Wear Of Polyethylene And Hylamer On Cobalt-Chromium : A Knee Simulator Study, Alessandro F. Canonaco
Wear Of Polyethylene And Hylamer On Cobalt-Chromium : A Knee Simulator Study, Alessandro F. Canonaco
Theses
Two tests were conducted to examine the wear characteristics of tibial bearings used in total knee replacement systems. Each test consisted of six A/P Glide Tibial Bearings each having a conical control arm. The plastic portion of the conical bearings were all made of UHMWPe. Each of these bearing systems was mounted onto a Co-Cr alloy tibial platform and Co-Cr alloy LCS (low contact stress) femoral component . These test samples were mounted onto the New Jersey Mark III Knee Simulator System. The simulator was configured to produce flexion and axial rotation to simulates normal gait. Each test ran at …
Wear And Friction Of Hylamer And Polyethylene Against Cobalt Chromium A Pin-On-Disc Study, Jerry D'Alessio, Ii
Wear And Friction Of Hylamer And Polyethylene Against Cobalt Chromium A Pin-On-Disc Study, Jerry D'Alessio, Ii
Theses
Understanding friction and wear of biomaterials is essential to the success of any prosthetic joint. A pin-on-disc wear tester is used to find the friction and wear of pins of one material on a coupon of medical grade cobalt chrome. In this experiment six pins of UHMWPe (ultra high molecular weight polyethylene) and six pins of Hylamer® from Du Pont Manufacturing were tested. Four separate runs were made. The tests were performed for ten million cycles, stopping every one to one and a half million cycles for data acquisition. Volumetric wear, wear rate, and coefficients of friction were measured. Both …
Wear And Friction Of Titanium Nitride On Ultra High Molecular Weight Polyethylene Under Oscillating Motion For Evaluation Of Use In Articulating Orthopedic Applications, David Scott Jacobson
Wear And Friction Of Titanium Nitride On Ultra High Molecular Weight Polyethylene Under Oscillating Motion For Evaluation Of Use In Articulating Orthopedic Applications, David Scott Jacobson
Theses
Materials are a factor in the performance of articulating orthopedic implants. An oscillating tribometer is utilized to investigate mechanisms of wear and friction of TiN (titanium nitride) coated on Ti-6Al-4V (titanium) alloy against UHMWPe (ultra high molecular weight polyethylene). Three thicknesses of TiN coating (1.76 pm, 4.15 µm, and 10.5 µm) are used to evaluate the performance of each in UHMWPe wear reduction and coating integrity. An uncoated Co-Cr (cobalt chromium) coupon is used against UHMWPe pins for control purposes. Oscillations are carried out to 10 million cycles to discover and evaluate short- and long-term wear mechanisms. Mass differentials and …