Scratching Vulnerability of Conventional vs Highly Cross-Linked Polyethylene Liners Because of Large Embedded Third-Body Particles

Abstract

The hypothesis of this study was that acetabular liner vulnerability to scratching from femoral heads, roughened by third bodies embedded in the liner, is not significantly lower for highly crosslinked polyethylene (HXPE) than for conventional polyethylene (CPE). Six CPE and six HXPE acetabular liners were each reproducibly embedded with five CoCrMo beads, then run for 10,000 cycles in a joint simulator. By visual rank-ordering, there was low association between liner scratch severity and polyethylene type. The CPE and HXPE liner scratches were not significantly different in scratch peak-valley height or width, or in liner roughness in the vicinity of the embedded beads. This model indicated that high crosslinking of polyethylene does not offer appreciable protection against severe scratching induced by large embedded third body particles.

The current state of bearing surfaces in total hip replacement

“…Scratch height and width were also slightly higher for XLPE liners. 142 These findings are consistent with retrieval studies THE BONE & JOINT JOURNAL of XPLE liners that showed similar surface damage when compared with conventional UHMWPE. 23,24 In an effort to combine the surface hardness and desirable scratch profile of ceramics with the resistance to fracture of metal, oxidized zirconium (OxZr) (Oxinium, Smith & Nephew, Memphis, Tennessee) has been developed.…”

“…141 The scratching vulnerability of XLPE versus conventional UHMWPE liners has been compared in vitro. 142 Using visual inspection, there was a weak association with increased severity of scratching of XLPE liners. Scratch height and width were also slightly higher for XLPE liners.…”

The Current Concepts of Total Hip Arthroplasty

“…On the other hand, resistance against fatigue fracture is reduced as wear-resistant improves, and failure has emerged as a problem due to reduced liner thickness and repeated impingement resulted from a recent trend towards increasing femoral head size41). Furthermore, damaged femoral bearing surface and third body rather lead to an increase in wear rates42), and more small wear particles could speed up the process of osteolysis.…”

Aseptic loosening of femoral components – Materials engineering and design considerations

“…Although XLPE offers a number of advantages for the surgeon, such as familiarity with the material and modularity, there remain concerns regarding the brittleness of XLPE, particularly in association with component mal-positioning and impingement [36]. Moreover, the risk of scratching and 'third-body' wear [37], and lower wear reductions in metal-XLPE articulations compared with ceramic-ceramic ones have been reported [38]. Generally, design improvements and better quality of UHMWPE can address concerns associated with fatigue wear of the PE insert, however, there exist problems related to adhesive and abrasive wear caused by the hard counter face femoral component [39].…”