Page 157 - Demo

Animal experiment: Surface wear analysis1555disadvantage to the use of a DLC coating is the relatively poor adhesion between the DLC layer and the Ti surface (37,40–43). This can lead to plastic deformation of the softer Ti when the implant is subjected to high forces. This in turn can lead to chipping or delamination of the DLC coating (38,41,43), which may result in a significant increase in Raand subsequent wear. Other surface modification techniques, such as titanium nitride (TiN) coatings, also have this limitation, as delamination and third body wear can occur after physical vapor deposition (PVD) of the TiN coating (14,44,45). Several techniques have been developed to overcome this problem. One technique involves the use of a gradient coating in which the carbon concentration increases towards the surface. Another technique is to use plasma nitriding on the Ti first, and then apply the DLC coating through magnetron sputtering (37,41). In this study, this limitation was addressed by using the patented HadSat-coating; no delamination was observed on the surfaces of any of the coated condyles.LimitationsIn total hip prostheses, the unworn volume of the acetabular component can be reconstructed when conducting a CMM measurement, out of an unworn surface, no such application exists at this moment for reconstruction of the fossa (7). Thus it would have been preferable to scan the pre-wear UHMWPE component of the fossa before implantation, to limit any error margin. However due to sterilization issues, it was not Fig. 9: Representative 3D roughness profiles of the condylar surface of the custom TMJ TJR. A: Condylar surface of pristine, non-implanted, coated condyle. B: Condylar surface of a non-coated condyle of sheep #1724, explanted after 9 months of mastication and rumination in a sheep model.C: Condylar surface of a H-DLC coated condyle of sheep #5185, explanted after 9 months of mastication and rumination in a sheep modelNikolas de Meurechy NW.indd 155 05-06-2024 10:14