Effect of phospholipidic boundary lubrication in rigid and compliant hemiarthroplasty models
| Autor: | G L Powell, P F Williams, J R Foy, Martine LaBerge, Kazuhiko Ishihara, Nobuo Nakabayashi |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Cartilage
Articular Materials science Thermoplastic 1 2-Dipalmitoylphosphatidylcholine Friction Surface Properties Polyurethanes Biocompatible Materials Elastomer Models Biological Reciprocating motion chemistry.chemical_compound Reference Values Lubrication Materials Testing Copolymer Animals Arthroplasty Replacement Composite material Phospholipids Polyurethane chemistry.chemical_classification Borosilicate glass Mechanical Engineering General Medicine chemistry Cattle Glass Metacarpus Material properties Compliance |
| Zdroj: | Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine. 213:5-18 |
| ISSN: | 2041-3033 0954-4119 |
| Popis: | Hemiarthroplasty may benefit from materials which produce lower friction and improved boundary lubrication protection during start-up conditions. The purpose of this study was to evaluate the effect of phospholipidic boundary lubrication in both rigid and compliant hemiarthroplasty. An in vitro model was designed to dissociate the relative contribution of implant material compliance and the presence of phospholipid to the overall friction of a hemiarthroplasty contact using bovine articular cartilage. Normal bovine articular cartilage was articulated against four flat materials using reciprocating motion: (a) borosilicate glass; (b) borosilicate glass coated with dipalmitoylphosphatid-ylcholine (DPPC); (c) polyurethane (PU) elastomer (Tecoflex®SG93A, a medical-grade aliphatic thermoplastic PU, Thermedics Incorporated, Woburn, Massachusetts); and (d) surface-coated PU (Tecoflex®SG93A substrate coated with lipid-attracting copolymer poly[methacryloyloxyethyl phosphorylcholine (MPC)-co-butyl methacrylate (BMA)]). Tests were conducted in physiologically simulated tribological conditions for a non-conformal point contact. Friction and lubrication analysis was performed using both static and kinetic coefficients of friction μ measured for each group as a function of time for a sliding distance of up to 60 m. Results showed that the inclusion of supplemental phospholipid, DPPC, on a rigid substrate significantly decreased μ in comparison with the control (cartilage-glass). Additionally, removal of phospholipid components from the articular cartilage surface produced a significantly greater start-up μ in comparison with normal cartilage at the test onset. The use of a material with a lower modulus resulted in lower μ for the entire duration of the test. Polyurethane elastomer coated with the lipid-attracting copolymer, poly(MPC-co-BMA), resulted in the lowest frictional response. As seen in this study, the improvement of low-modulus hemiarthroplasty may involve the optimization of chemical modification and incorporation of lipid-attracting MPC copolymers onto compliant materials. However, further tests are warranted to determine whether lipid-attracting MPC copolymers perform as well during long-time, in vivo wear studies. |
| Databáze: | OpenAIRE |
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