Page 144 - Demo

Chapter 5142The surface roughness was determined by 3D non-contact profilometry using a confocal laser microscope (µSurf Explorer, NanoFocus AG, Oberhausen, Germany). For each sample, a 4.5 x 1.5 mm² worn area of the condylar surface was selected and polynomial filters were applied to remove form of the condyles. 3D surface roughness amplitude parameters (average roughness Sa, arithmetic mean of the absolute values of the surface departures from the mean plane, and root mean square height Sq, the root mean square value of the surface departures) were determined. In addition, a 2D profile was generated along the long direction of the scanned area (multiple profiles were extracted and averaged) and 2D surface roughness amplitude parameters were defined (average roughness Ra, the arithmetic average of the absolute values of the profile heights, and maximum height of the profile, Rt, the vertical distance between the highest and lowest points of the profile). One pristine (i.e. not implanted) coated condyle was assessed. It served as a reference for both the noncoated and coated condyles as the application of the DLC coating does not alter the surface smoothness. In addition, the surface of both types of condyles was also investigated using a light microscope (Vertex 251UC, Micro-Vu, Windsor, CA, USA) at magnifications of 19x, 37x, 204x, and 425x. Furthermore, the surfaces of the DLC-coated condyles were visualized using scanning electron microscopy (SEM, Nova NanoSEM 450, FEI Company, Hillsboro, OR, USA) operated at standard high-vacuum settings at 5 mm working distance and 10 keV accelerating voltage. ResultsAnalysis of the UHMWPE fossa componentMacroscopically, all fossae exhibited UHMWPE wear in the center as well as in the middle of the anterior border, where the polyethylene came into contact with the coronoid process (Fig. 4 A and B). No macroscopically visible signs of UHMWPE delamination, warping, or fracturing were seen. There was some soft tissue adhesion on the medial and lateral side of the fossa, where the UHMWPE was pressed against the titanium, however upon closer inspection, this soft tissue adhesion remained strictly Nikolas de Meurechy NW.indd 142 05-06-2024 10:14