Page 146 - Demo

Chapter 5144Fig. 5: Representative 3D scans of explanted components of the custom temporomandibular joint total joint replacement after 9 months of mastication and rumination in a sheep model. (A) Ultrahigh molecular weight polyethylene (UHMWPE) fossa of sheep #1724 that articulated with a noncoated condyle. The maximal wear depth measures 0.81 mm. Blue arro worn out UHMWPE due to articulating with the condylar surface. Black arro scalpel-reduced non-articulating UHMWPE. Red arro anteriorly worn out UHMWPE volume due to contact with the coronoid process. (B) UHMWPE fossa of sheep #5158 that articulated with an HadSat diamond-like carbon coated condyle. The maximal wear depth measures 0.34 mm. Blue arro worn out UHMWPE due to articulating with the condylar surface. Black arro scalpel-reduced nonarticulating UHMWPE. Red arro anteriorly worn out UHMWPE volume due to contact with the coronoid process. Orange arro worn out sections due to post-mortem dissection of the overlaying soft tissues.In 4 sheep, more apparent deviant wear patterns were found. (Fig. 6 A-D) The edges of the worn volume of ewe # 2177 were far less clearly marked compared to the other samples (Fig.6 A). The fossa in sheep #4246 not only showed this distinct wear volume in the center, but also a slight additional posteriorly orientated wear track (Fig. 6 B). The fossa of ewe # 8087 showed one main wear volume, which was also more diagonally orientated and additionally three more anteriorly positioned wear ‘bodies’ (Fig. 6 C). While no clear macroscopic signs of creep were seen, 3D surface analysis revealed some warping anteriorly of these additional wear bodies. Lastly, ewe # 7998 not only developed only little wear near the center of the fossa, but there also occurred wear near the posterior lateral border of the implant, as well as some warping, anteriorly from the center wear volume. (Fig. 6 D). Thus in both cases showing warping, this occurred in non-articulating locations.While 3D scanning of the fossa surface seemed to indicate more extensive wear for UHMWPE components in contact with a non-coated Ti6Al4V condyle as compared to a coated condyle (Fig. 5 A and B), no significant Nikolas de Meurechy NW.indd 144 05-06-2024 10:14