Analysis of wear, wear particles, and reduced inflammatory potential of vitamin E ultrahigh‐molecular‐weight polyethylene for use in total joint replacement

Abstract

Vitamin E (VE) has been added to ultrahigh-molecular-weight polyethylene (UHMWPE) acetabular cups and tibial trays primarily to reduce oxidative damage to the polymer. The aim of this study was to investigate the relative wear rates of UHMWPE-containing VE compared with virgin UHMWPE. The ability of VE to reduce the amount of inflammatory cytokines produced from stimulated peripheral blood mononuclear cells (PBMNCs) was also investigated. Stimulation was achieved by exposure of PBMNCs to either lipoplysaccharide (LPS) or VE-containing UHMWPE (VE-UHMWPE). In the present study, results showed that the wear rates of UHMWPE with or without VE were not significantly different. Particles generated by UHMWPE with and without VE were not significantly different in size distribution. The production of osteolytic mediators, tumor necrosis factor-alpha, interleukin 1β (IL-β), IL-6, and IL-8 were significantly reduced in (PBMNCs) stimulated with either LPS + VE compared with LPS or VE-UHMWPE particles compared to virgin UHMWPE particles. This trend was also observed when VE was added as a liquid to UHMWPE wear particle-stimulated PBMNCs. The exact mechanism of how VE affects the release of inflammatory mediators from particle-stimulated macrophages is not yet understood. It is likely to involve the anti-inflammatory and/or antioxidant effects of VE.

Analysis of UHMWPE wear particles produced in the simulation of hip and knee wear mechanisms with the RandomPOD system

“…Crosslinking of UHMWPE reduces the wear and risk of osteolysis efficiently [21][22][23][24]. The addition of vitamin E to UHMWPE not only improves oxidative stability but also reduces the biologic activity of the wear particles [25,26]. The latter advantage is however controversial [27].…”

Interplay between surface properties of standard, vitamin E blended and oxidised ultra high molecular weight polyethylene used in total joint replacement and adhesion ofStaphylococcus aureusandEscherichia coli

“…1,9,20 In particular, it has been demonstrated that oxidative degradation of UHMWPE gamma-sterilized in air increased its wear while decreasing mechanical strength, constituting the main cause of the dramatic implant failures occurred in the last years. [21][22][23] As a consequence, many efforts have been made to improve UHMWPE quality and performance, for example through the reduction or elimination of the oxidation.…”

“…7,20,23,24 VE, a free radical scavenger and well established biological antioxidant, prevented oxidation and delamination and had a favorable long-term effect on fatigue performance of the UHMWPE, increasing the resistance to fatigue cracks associated with oxidation without negatively altering the biocompatibility of the implant. 20,24 Moreover, it has been shown that VE when added to UHMWPE does not have any cytotoxic effects and acts as an effective anti-inflammatory. 9 In this study we quantified the adhesion of well-characterized biofilm producing collection strains of S. aureus and E. coli, as pathogens mostly associated with periprosthetic infection, to standard UHMWPE, to VE blended UHMWPE and to oxidized UHMWPE taking into account that for a given material surface, different bacterial species and strains adhere differently since different species and strains have different physicochemical characteristics: 14,15 slime producer S. epidermidis and S. aureus have a comparatively thicker and more rigid peptidoglycan layer respect to a fimbriae producer E. coli, and extensive contact of their external cell-structure with the implant surface may be quite different.…”

Interplay between surface properties of standard, vitamin E blended and oxidised ultra high molecular weight polyethylene used in total joint replacement and adhesion of Staphylococcus aureus and Escherichia coli

“…The VE stabilization of UHMWPE has been recently proposed to improve oxidation resistance while maintaining wear resistance and fatigue strength. 7,20,23,24 VE, a free radical scavenger and well established biological antioxidant, prevented oxidation and delamination and had a favorable long-term effect on fatigue performance of the UHMWPE, increasing the resistance to fatigue cracks associated with oxidation without negatively altering the biocompatibility of the implant. 20,24 Moreover, it has been shown that VE when added to UHMWPE does not have any cytotoxic effects and acts as an effective anti-inflammatory.…”

“…In contrast, a significant decreased bacterial adhesion was registered for both bacteria on VE-PE, in comparison with that observed on PE, within 48h of observation ( Figure 3 A and B), underlying the role of VE, probably related to its well established antioxidant properties. 9,20 The mechanism by which VE may affect the bacterial adherence to UHMWPE it is currently unknown, even if potential effects of VE on infection are currently investigated. 25 The CA measurements showed no significant variations in hydrophilicity between PE and VE-PE suggesting that other, concurrent factors must be involved in the different bacterial adhesion.…”