In Vitro Wear Testing of a CoCr-UHMWPE Finger Prosthesis with Hydroxyapatite Coated CoCr Stems
A finger prosthesis consisting of a Cobalt-chromium (CoCr) proximal component and an Ultra-high-molecular-weight-polyethylene (UHMWPE) medial component (both mounted on hydroxyapatite coated stems) was evaluated to 5,000,000 cycles in an in vitro finger simulator. One “test” prosthesis was cycled th...
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| Format: | Article |
| Language: | English |
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MDPI AG
2015-04-01
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| Series: | Lubricants |
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| Online Access: | http://www.mdpi.com/2075-4442/3/2/244 |
| _version_ | 1811184393898688512 |
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| author | Andrew Naylor Sumedh C. Talwalkar Ian A. Trail Thomas J. Joyce |
| author_facet | Andrew Naylor Sumedh C. Talwalkar Ian A. Trail Thomas J. Joyce |
| author_sort | Andrew Naylor |
| collection | DOAJ |
| description | A finger prosthesis consisting of a Cobalt-chromium (CoCr) proximal component and an Ultra-high-molecular-weight-polyethylene (UHMWPE) medial component (both mounted on hydroxyapatite coated stems) was evaluated to 5,000,000 cycles in an in vitro finger simulator. One “test” prosthesis was cycled through flexion-extension (90°–30°) with a dynamic load of 10 N, whilst immersed in a lubricant of dilute bovine serum. Additionally, a static load of 100 N was applied for 45 s every 3000 cycles to simulate a static gripping force. A second “control” prosthesis was immersed in the same lubricant to account for absorption. Gravimetric and Sa (3D roughness) measurements were taken at 1,000,000 cycle intervals. Micrographs and Sa values revealed negligible change to the CoCr surfaces after 5,000,000 cycles. The UHMWPE also exhibited no distinctive Sa trend, however the micrographs indicate that polishing occurred. Both the CoCr and UHMWPE test components progressively decreased in weight. The CoCr control component did not change in weight, whilst the UHMWPE component gained weight through absorption. To account for the disparity between surface and gravimetric results, the hydroxyapatite coatings were examined. Micrographs of the test stems revealed that the hydroxyapatite coating was partially removed, whilst the micrographs of the control stems exhibited a uniform coating. |
| first_indexed | 2024-04-11T13:12:31Z |
| format | Article |
| id | doaj.art-56b6694355b947f0a0184928032f52b6 |
| institution | Directory Open Access Journal |
| issn | 2075-4442 |
| language | English |
| last_indexed | 2024-04-11T13:12:31Z |
| publishDate | 2015-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Lubricants |
| spelling | doaj.art-56b6694355b947f0a0184928032f52b62022-12-22T04:22:33ZengMDPI AGLubricants2075-44422015-04-013224425510.3390/lubricants3020244lubricants3020244In Vitro Wear Testing of a CoCr-UHMWPE Finger Prosthesis with Hydroxyapatite Coated CoCr StemsAndrew Naylor0Sumedh C. Talwalkar1Ian A. Trail2Thomas J. Joyce3School of Mechanical and Systems Engineering, Newcastle University, Newcastle upon Tyne, England NE1 7RU, UKUpper Limb Research Unit, Wrightington Hospital, Wigan, England WN6 9EP, UKUpper Limb Research Unit, Wrightington Hospital, Wigan, England WN6 9EP, UKSchool of Mechanical and Systems Engineering, Newcastle University, Newcastle upon Tyne, England NE1 7RU, UKA finger prosthesis consisting of a Cobalt-chromium (CoCr) proximal component and an Ultra-high-molecular-weight-polyethylene (UHMWPE) medial component (both mounted on hydroxyapatite coated stems) was evaluated to 5,000,000 cycles in an in vitro finger simulator. One “test” prosthesis was cycled through flexion-extension (90°–30°) with a dynamic load of 10 N, whilst immersed in a lubricant of dilute bovine serum. Additionally, a static load of 100 N was applied for 45 s every 3000 cycles to simulate a static gripping force. A second “control” prosthesis was immersed in the same lubricant to account for absorption. Gravimetric and Sa (3D roughness) measurements were taken at 1,000,000 cycle intervals. Micrographs and Sa values revealed negligible change to the CoCr surfaces after 5,000,000 cycles. The UHMWPE also exhibited no distinctive Sa trend, however the micrographs indicate that polishing occurred. Both the CoCr and UHMWPE test components progressively decreased in weight. The CoCr control component did not change in weight, whilst the UHMWPE component gained weight through absorption. To account for the disparity between surface and gravimetric results, the hydroxyapatite coatings were examined. Micrographs of the test stems revealed that the hydroxyapatite coating was partially removed, whilst the micrographs of the control stems exhibited a uniform coating.http://www.mdpi.com/2075-4442/3/2/244wear analysis/testingjoint simulatorsbiotribologybiomechanical testing/analysissurfaces |
| spellingShingle | Andrew Naylor Sumedh C. Talwalkar Ian A. Trail Thomas J. Joyce In Vitro Wear Testing of a CoCr-UHMWPE Finger Prosthesis with Hydroxyapatite Coated CoCr Stems Lubricants wear analysis/testing joint simulators biotribology biomechanical testing/analysis surfaces |
| title | In Vitro Wear Testing of a CoCr-UHMWPE Finger Prosthesis with Hydroxyapatite Coated CoCr Stems |
| title_full | In Vitro Wear Testing of a CoCr-UHMWPE Finger Prosthesis with Hydroxyapatite Coated CoCr Stems |
| title_fullStr | In Vitro Wear Testing of a CoCr-UHMWPE Finger Prosthesis with Hydroxyapatite Coated CoCr Stems |
| title_full_unstemmed | In Vitro Wear Testing of a CoCr-UHMWPE Finger Prosthesis with Hydroxyapatite Coated CoCr Stems |
| title_short | In Vitro Wear Testing of a CoCr-UHMWPE Finger Prosthesis with Hydroxyapatite Coated CoCr Stems |
| title_sort | in vitro wear testing of a cocr uhmwpe finger prosthesis with hydroxyapatite coated cocr stems |
| topic | wear analysis/testing joint simulators biotribology biomechanical testing/analysis surfaces |
| url | http://www.mdpi.com/2075-4442/3/2/244 |
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