In Vitro Wear Behavior of Knee Implants at Different Load Levels: The Impact of the Test Fluid
Calf serum is defined as a test fluid for in vitro knee wear simulation studies in the ISO standard. However, protein degradation typically occurs during in vitro wear simulation. The current study should indicate whether increased loads change the rheological properties of the test fluid and may, t...
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-11-01
|
| Series: | Lubricants |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2075-4442/11/11/474 |
| _version_ | 1797458678189654016 |
|---|---|
| author | Stefan Schroeder Maximilian Uhler Mareike Schonhoff Timo A. Nees Tanja Wonerow Jens Nuppnau Frank Mantwill Jan Philippe Kretzer |
| author_facet | Stefan Schroeder Maximilian Uhler Mareike Schonhoff Timo A. Nees Tanja Wonerow Jens Nuppnau Frank Mantwill Jan Philippe Kretzer |
| author_sort | Stefan Schroeder |
| collection | DOAJ |
| description | Calf serum is defined as a test fluid for in vitro knee wear simulation studies in the ISO standard. However, protein degradation typically occurs during in vitro wear simulation. The current study should indicate whether increased loads change the rheological properties of the test fluid and may, therefore, lead to favorable tribological behavior and reduced wear. Three different load levels were simulated in a displacement-controlled knee wear simulation study. The gravimetric wear rates were determined, pressure measurements were performed, and the dynamic viscosity of the test fluids were analyzed after the simulation of 0.5 × 10<sup>6</sup> cycles. The lowest load level led to the lowest wear rate, and the lowest contact pressure and contact area, compared to the medium and high-load level. Although, the high-load level led to the highest contact pressure and contact area, the wear rates were comparable to the medium-load level. The rheological measurements revealed the highest dynamic viscosity for the high-load level and no differences could be found between the medium and low loading condition. To perform realistic wear simulation studies, the reproduction of the in vivo interrelationships between the shear forces and wear are necessary. |
| first_indexed | 2024-03-09T16:40:35Z |
| format | Article |
| id | doaj.art-e5d9f49d9a1c4f8cbf3965ba8b4e55be |
| institution | Directory Open Access Journal |
| issn | 2075-4442 |
| language | English |
| last_indexed | 2024-03-09T16:40:35Z |
| publishDate | 2023-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Lubricants |
| spelling | doaj.art-e5d9f49d9a1c4f8cbf3965ba8b4e55be2023-11-24T14:52:47ZengMDPI AGLubricants2075-44422023-11-01111147410.3390/lubricants11110474In Vitro Wear Behavior of Knee Implants at Different Load Levels: The Impact of the Test FluidStefan Schroeder0Maximilian Uhler1Mareike Schonhoff2Timo A. Nees3Tanja Wonerow4Jens Nuppnau5Frank Mantwill6Jan Philippe Kretzer7Laboratory of Biomechanics and Implant Research, Department of Orthopaedics, Heidelberg University Hospital, Schlierbacher Landstraße 200a, 69118 Heidelberg, GermanyLaboratory of Biomechanics and Implant Research, Department of Orthopaedics, Heidelberg University Hospital, Schlierbacher Landstraße 200a, 69118 Heidelberg, GermanyLaboratory of Biomechanics and Implant Research, Department of Orthopaedics, Heidelberg University Hospital, Schlierbacher Landstraße 200a, 69118 Heidelberg, GermanyDepartment of Orthopaedics, Heidelberg University Hospital, Schlierbacher Landstraße 200a, 69118 Heidelberg, GermanyDepartment of Mechanical Engineering, Machine Elements and Computer-Aided Product Development, Helmut-Schmidt-University, 22043 Hamburg, GermanyDepartment of Mechanical Engineering, Machine Elements and Computer-Aided Product Development, Helmut-Schmidt-University, 22043 Hamburg, GermanyDepartment of Mechanical Engineering, Machine Elements and Computer-Aided Product Development, Helmut-Schmidt-University, 22043 Hamburg, GermanyLaboratory of Biomechanics and Implant Research, Department of Orthopaedics, Heidelberg University Hospital, Schlierbacher Landstraße 200a, 69118 Heidelberg, GermanyCalf serum is defined as a test fluid for in vitro knee wear simulation studies in the ISO standard. However, protein degradation typically occurs during in vitro wear simulation. The current study should indicate whether increased loads change the rheological properties of the test fluid and may, therefore, lead to favorable tribological behavior and reduced wear. Three different load levels were simulated in a displacement-controlled knee wear simulation study. The gravimetric wear rates were determined, pressure measurements were performed, and the dynamic viscosity of the test fluids were analyzed after the simulation of 0.5 × 10<sup>6</sup> cycles. The lowest load level led to the lowest wear rate, and the lowest contact pressure and contact area, compared to the medium and high-load level. Although, the high-load level led to the highest contact pressure and contact area, the wear rates were comparable to the medium-load level. The rheological measurements revealed the highest dynamic viscosity for the high-load level and no differences could be found between the medium and low loading condition. To perform realistic wear simulation studies, the reproduction of the in vivo interrelationships between the shear forces and wear are necessary.https://www.mdpi.com/2075-4442/11/11/474wearrheologyknee wear simulationpolyethylenecontact pressureprotein degradation |
| spellingShingle | Stefan Schroeder Maximilian Uhler Mareike Schonhoff Timo A. Nees Tanja Wonerow Jens Nuppnau Frank Mantwill Jan Philippe Kretzer In Vitro Wear Behavior of Knee Implants at Different Load Levels: The Impact of the Test Fluid Lubricants wear rheology knee wear simulation polyethylene contact pressure protein degradation |
| title | In Vitro Wear Behavior of Knee Implants at Different Load Levels: The Impact of the Test Fluid |
| title_full | In Vitro Wear Behavior of Knee Implants at Different Load Levels: The Impact of the Test Fluid |
| title_fullStr | In Vitro Wear Behavior of Knee Implants at Different Load Levels: The Impact of the Test Fluid |
| title_full_unstemmed | In Vitro Wear Behavior of Knee Implants at Different Load Levels: The Impact of the Test Fluid |
| title_short | In Vitro Wear Behavior of Knee Implants at Different Load Levels: The Impact of the Test Fluid |
| title_sort | in vitro wear behavior of knee implants at different load levels the impact of the test fluid |
| topic | wear rheology knee wear simulation polyethylene contact pressure protein degradation |
| url | https://www.mdpi.com/2075-4442/11/11/474 |
| work_keys_str_mv | AT stefanschroeder invitrowearbehaviorofkneeimplantsatdifferentloadlevelstheimpactofthetestfluid AT maximilianuhler invitrowearbehaviorofkneeimplantsatdifferentloadlevelstheimpactofthetestfluid AT mareikeschonhoff invitrowearbehaviorofkneeimplantsatdifferentloadlevelstheimpactofthetestfluid AT timoanees invitrowearbehaviorofkneeimplantsatdifferentloadlevelstheimpactofthetestfluid AT tanjawonerow invitrowearbehaviorofkneeimplantsatdifferentloadlevelstheimpactofthetestfluid AT jensnuppnau invitrowearbehaviorofkneeimplantsatdifferentloadlevelstheimpactofthetestfluid AT frankmantwill invitrowearbehaviorofkneeimplantsatdifferentloadlevelstheimpactofthetestfluid AT janphilippekretzer invitrowearbehaviorofkneeimplantsatdifferentloadlevelstheimpactofthetestfluid |