Load Scenarios Influence Fluid Absorption of Polyethylene

2005 ◽  
Author(s):  
T. Schwenke ◽  
C. Rieker ◽  
M. A. Wimmer
Keyword(s):  
Wear Testing ◽  
Fluid Absorption ◽  
Joint Replacements ◽  
Wear Rates ◽  
Total Joint Replacements ◽  
Fluid Uptake ◽  
Dynamically Loaded ◽  
Low Wear ◽  
Lubrication Conditions

Wear of total joint replacements is determined gravimetrically in simulator studies. A mix of bovine serum, distilled water, and additives is intended to replicate the lubrication conditions in-vivo. Weight gain due to fluid absorption during testing of UHMWPE components is corrected using a load soak station. In this study six sets of UHMWPE pins were tested for their fluid soak behavior. The samples were subjected to three different loading scenarios while being submersed in two types of commonly used lubricants. After two million cycles or 23.1 days, respectively, the different fluids lead to significantly different soaking results. Test groups that were dynamically loaded gained more weight than unloaded or statically loaded samples. The results suggest that dynamically loaded soak control stations are required during wear testing of UHMWPE components. Otherwise the fluid uptake masks the wear measurement, especially for new polyethylene materials with low wear rates. Furthermore, an agreement on detailed lubricant specifications is desirable.

The Effect of Motion Path on the Wear Rate of UHMWPE for Orthopaedic Implants

1999 ◽  
Author(s):  
Jeff A. Sprague ◽  
Willard L. Sauer
Keyword(s):  
Wear Rate ◽  
Wear Test ◽  
Axial Rotation ◽  
Wear Testing ◽  
Motion Path ◽  
Orthopaedic Implant ◽  
Wear Rates ◽  
Nonlinear Motion ◽  
Pin On Disk

Abstract The effect of adding a second axis of motion was investigated for pin-on-disk wear testing of ultra-high-molecular-weight polyethylene (UHMWPE) for orthopaedic implant applications. In addition to linear reciprocation of the UHMWPE or metal disk, axial rotation of the metal or UHMWPE pin was conducted. The added rotation reproduces the cross-shear on the UHMWPE surface that is generated in clinically relevant wear simulator tests and in vivo. The wear rates that result from the multi-axis pin-on-disk tests are significantly higher (one to two orders of magnitude) than those seen in the linear-only tests. This supports the findings of other researchers (Bragdon et al., 1996; McKellop, 1995; Walker et al., 1996; Wang et al. 1997) in that the application of nonlinear motion increases the wear of UHMWPE substantially. This is further validated by the comparison of a hip simulator wear test conducted with three axes of motion — rotation, flexion, and abduction — to a test conducted with two axes of motion — rotation and flexion. The absence of the abduction eliminated a significant degree of nonlinear motion (cross-shear) and, consequently, the wear rate was significantly lower than that seen in the test with abduction.

A General Adhesive Wear Simulation for Total Joint Replacements: Application to the Patellofemoral Joint

2001 ◽  
Author(s):  
Anthony J. Petrella ◽  
Mark C. Miller
Keyword(s):  
Patellofemoral Joint ◽  
Adhesive Wear ◽  
Total Joint Replacement ◽  
Wear Testing ◽  
Wear Simulation ◽  
Joint Replacements ◽  
Total Joint Replacements ◽  
Routine Basis ◽  
Total Knee ◽  
Ultra High Molecular Weight

Abstract Advances in design, materials, and fixation have increased the longevity of total joint replacements and significantly reduced the incidence of mechanical failure or loosening of implant components. Wear of the ultra-high molecular weight polyethylene (UHMWPE) bearing material used in most implants is now among the most important problems in total joint replacement. Wear tests in joint simulators are the gold standard for evaluation of wear resistance and are performed on a routine basis in many research laboratories. Physical wear testing, however, is labor intensive and time consuming. Numerical wear simulations have been developed and applied to the hip joint to evaluate adhesive wear of polyethylene liners [1,2]. The purpose of this project was to develop a general adhesive wear simulation applicable to any articulating joint with arbitrary geometry and subject to arbitrary relative motion. Validation of the model was established through application to the patellofemoral joint of a total knee replacement.

Determination of Low Wear Rates in Metal-On-Metal Hip Joint Replacements Based on Ultra Trace Element Analysis in Simulator Studies

2009 ◽  
Vol 37 (1) ◽  
pp. 23-29 ◽  
Author(s):  
J. P. Kretzer ◽  
M. Krachler ◽  
J. Reinders ◽  
E. Jakubowitz ◽  
M. Thomsen ◽  
...  
Keyword(s):  
Hip Joint ◽  
Trace Element Analysis ◽  
Element Analysis ◽  
Joint Replacements ◽  
Wear Rates ◽  
Metal On Metal ◽  
Low Wear ◽  
Ultra Trace ◽  
Hip Joint Replacements

scholarly journals Towards Functional Silicon Nitride Coatings for Joint Replacements

Coatings ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 73 ◽  
Author(s):  
Luimar Filho ◽  
Susann Schmidt ◽  
Klaus Leifer ◽  
Håkan Engqvist ◽  
Hans Högberg ◽  
...  
Keyword(s):  
Silicon Nitride ◽  
Magnetron Sputtering ◽  
Photoelectron Spectroscopy ◽  
Negative Bias ◽  
Joint Replacements ◽  
Wear Rates ◽  
Substrate Rotation ◽  
Joint Implants ◽  
Low Wear ◽  
Vertical Scanning Interferometry

Silicon nitride (SiNx) coatings are currently under investigation as bearing surfaces for joint implants, due to their low wear rate and the good biocompatibility of both coatings and their potential wear debris. The aim of this study was to move further towards functional SiNx coatings by evaluating coatings deposited onto CoCrMo surfaces with a CrN interlayer, using different bias voltages and substrate rotations. Reactive direct current magnetron sputtering was used to coat CoCrMo discs with a CrN interlayer, followed by a SiNx top layer, which was deposited by reactive high-power impulse magnetron sputtering. The interlayer was deposited using negative bias voltages ranging between 100 and 900 V, and 1-fold or 3-fold substrate rotation. Scanning electron microscopy showed a dependence of coating morphology on substrate rotation. The N/Si ratio ranged from 1.10 to 1.25, as evaluated by X-ray photoelectron spectroscopy. Vertical scanning interferometry revealed that the coated, unpolished samples had a low average surface roughness between 16 and 33 nm. Rockwell indentations showed improved coating adhesion when a low bias voltage of 100 V was used to deposit the CrN interlayer. Wear tests performed in a reciprocating manner against Si3N4 balls showed specific wear rates lower than, or similar to that of CoCrMo. The study suggests that low negative bias voltages may contribute to a better performance of SiNx coatings in terms of adhesion. The low wear rates found in the current study support further development of silicon nitride-based coatings towards clinical application.

Inhibition of proximal tubular fluid absorption by nitric oxide and atrial natriuretic peptide in rat kidney

1998 ◽  
Vol 274 (4) ◽  
pp. C1075-C1080 ◽  
Author(s):  
Eveline Eitle ◽  
Siriphun Hiranyachattada ◽  
Hui Wang ◽  
Peter J. Harris
Keyword(s):  
Nitric Oxide ◽  
Rat Kidney ◽  
Ang Ii ◽  
Fluid Absorption ◽  
No Donor ◽  
Fluid Uptake ◽  
Similar Dose ◽  
Proximal Tubular ◽  
Atrial Natriuretic

Atrial natriuretic factor (ANF) and nitric oxide (NO) stimulate production of guanosine 3′,5′-cyclic monophosphate (cGMP) and are natriuretic. Split-drop micropuncture was performed on anesthetized rats to determine the effects of ANF and the NO donor sodium nitroprusside (SNP) on proximal tubular fluid absorption rate ( J va). Compared with control solutions, SNP (10−4 M) decreased J va by 23% when administered luminally and by 35% when added to the peritubular perfusate. Stimulation of fluid uptake by luminal angiotensin II (ANG II; 10−9 M) was abolished by SNP (10−4 and 10−6 M). In proximal tubule suspensions, ANF (10−6 M) increased cGMP concentration to 143%, whereas SNP (10−6, 10−5, 10−4, 10−3 M) raised cGMP to 231, 594, 687, and 880%, respectively. S-nitroso- N-acetylpenicillamine (SNAP) also raised cGMP concentrations with similar dose-response relations. These studies demonstrate inhibition by luminal and peritubular NO of basal and ANG II-stimulated proximal fluid absorption in vivo. The ability of SNP to inhibit basal fluid uptake whereas ANF only affected ANG II-stimulated transport may be because of production of higher concentrations of cGMP by SNP.

Bone-Bonding Ability of Ce-TZP/Al2O3 Nanocomposite with a Microporous Surface and Calcium Phosphate Coating

2005 ◽  
Vol 284-286 ◽  
pp. 987-990 ◽  
Author(s):  
Mitsuru Takemoto ◽  
Shunsuke Fujibayashi ◽  
J. Suzuki ◽  
Tadashi Kokubo ◽  
Takashi Nakamura
Keyword(s):  
Calcium Phosphate ◽  
Tetragonal Zirconia ◽  
Calcium Phosphate Coating ◽  
Control Group ◽  
Phosphate Coating ◽  
Joint Replacements ◽  
Total Joint Replacements ◽  
Al2o3 Composite ◽  
High Bone

The nano-composite of a ceria-stabilized tetragonal zirconia polycrystals (Ce-TZP) and alumina (Al2O3) polycrystals (Ce-TZP/Al2O3) is attractive as a load-bearing bone substitute because of its mechanical properties and phase stability. We have developed a new method of hydrofluoric acid and heat treatment (HFT) to give a microporous structure to the surface of this Ce-TZP/Al2O3 nanocomposite ceramic. Bone-bonding ability of a microporous surface and calcium phosphate coating on Ce-TZP/Al2O3 composite has been investigated through in vivo detaching model. Thin calcium phosphate coating layer was added by alternate soaking process, and thick CaP layer was produced by soaking in simulated body fluid for 5 days. HFT treated Ce-TZP/Al2O3 composite showed high bone-bonding ability compared with the control group. Thick and thin CaP coating accelerated bone-bonding ability in early post-implantation period. The submicron microporous surface was beneficial for achieving mechanical interlocking between the ceramic and surrounding bone. These results suggest the possibility of using a Ce-TZP/Al2O3 nanocomposite ceramic with microporous surface and calcium phosphate coating as the bearing material for uncemented total joint replacements.

scholarly journals An Antibiotic-Releasing Bone Void Filling (ABVF) Putty for the Treatment of Osteomyelitis

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5080
Author(s):  
Raquib Hasan ◽  
Abbey Wohlers ◽  
Jacob Shreffler ◽  
Pranothi Mulinti ◽  
Hunter Ostlie ◽  
...  
Keyword(s):  
Bone Growth ◽  
Release Kinetics ◽  
Control Group ◽  
Joint Replacements ◽  
Total Joint Replacements ◽  
Press Fitting ◽  
Antibiotic Release ◽  
Bone Void

The number of total joint replacements (TJR) is on the rise with a corresponding increase in the number of infected TJR, which necessitates revision surgeries. Current treatments with either non-biodegradable, antibiotic-releasing polymethylmethacrylate (PMMA) based bone cement, or systemic antibiotic after surgical debridement do not provide effective treatment due to fluctuating antibiotic levels at the site of infection. Here, we report a biodegradable, easy-to-use “press-fitting” antibiotic-releasing bone void filling (ABVF) putty that not only provides efficient antibiotic release kinetics at the site of infection but also allows efficient osseointegration. The ABVF formulation was prepared using poly (D,L-lactide-co-glycolide) (PLGA), polyethylene glycol (PEG), and polycaprolactone (PCL) as the polymer matrix, antibiotic vancomycin, and osseointegrating synthetic bone PRO OSTEON for bone-growth support. ABVF was homogenous, had a porous structure, was moldable, and showed putty-like mechanical properties. The ABVF putty released vancomycin for 6 weeks at therapeutic level. Furthermore, the released vancomycin showed in vitro antibacterial activity against Staphylococcus aureus for 6 weeks. Vancomycin was not toxic to osteoblasts. Finally, ABVF was biodegradable in vivo and showed an effective infection control with the treatment group showing significantly higher bone growth (p < 0.001) compared to the control group. The potential of infection treatment and osseointegration makes the ABVF putty a promising treatment option for osteomyelitis after TJR.

Simulation of Fretting Wear at Orthopaedic Implant Interfaces

2005 ◽  
Vol 127 (3) ◽  
pp. 357-363 ◽  
Author(s):  
Edward Ebramzadeh ◽  
Fabrizio Billi ◽  
Sophia N. Sangiorgio ◽  
Sarah Mattes ◽  
Werner Schmoelz ◽  
...  
Keyword(s):  
Cortical Bone ◽  
Wear Debris ◽  
Fretting Wear ◽  
Orthopaedic Implant ◽  
Joint Replacements ◽  
Total Joint Replacements ◽  
Wear Simulator ◽  
Plasma Sprayed ◽  
Fiber Mesh

Osteolysis due to wear debris is a primary cause of failure of total joint replacements. Although debris produced by the joint articulating surfaces has been studied and simulated extensively, fretting wear debris, produced at nonarticulating surfaces, has not received adequate attention. We developed a three-station fretting wear simulator to reproduce in vivo motion and stresses at the interfaces of total joint replacements. The simulator is based on the beam bending theory and is capable of producing cyclic displacement from 3to1000microns, under varying magnitudes of contact stresses. The simulator offers three potential advantages over previous studies: The ability to control the displacement by load, the ability to produce very small displacements, and dynamic normal loads as opposed to static. A pilot study was designed to test the functionality of the simulator, and verify that calculated displacements and loads produced the predicted differences between two commonly used porous ingrowth titanium alloy surfaces fretting against cortical bone. After 1.5 million cycles, the simulator functioned as designed, producing greater wear of bone against the rougher plasma-sprayed surface compared to the fiber-mesh surface, as predicted. A novel pin-on-disk apparatus for simulating fretting wear at orthopaedic implant interfaces due to micromotion is introduced. The test parameters measured with the fretting wear simulator were as predicted by design calculations, and were sufficient to measure differences in the height and weight of cortical bone pins rubbing against two porous ingrowth surfaces, plasma-sprayed titanium and titanium fiber mesh.

Wear of Artificial Joint Materials III

1981 ◽  
Vol 10 (3) ◽  
pp. 137-142 ◽  
Author(s):  
R W Treharne ◽  
R W Young ◽  
S R Young
Keyword(s):  
Wear Rate ◽  
Contact Area ◽  
Inverse Relationship ◽  
Wear Testing ◽  
Artificial Joint ◽  
Knee Prostheses ◽  
Wear Rates ◽  
Knee Simulator ◽  
Total Knee

This paper describes a new method for testing total knee prostheses under simulated in vivo conditions. Previous knee simulator work has been summarized and described. The major variables of testing are also described in detail. The results of wear testing five types of knee prostheses were that the wear rate was nearly an inverse relationship with contact area— knees with a higher contact area had lower wear rates.

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