Wear testing and particle characterisation of sequentially crosslinked polyethylene acetabular liners using different femoral head sizes

Abstract

Larger femoral heads lead to a decreased risk of total hip dislocation and an improved range of motion. However, the larger diameter is associated with increased wear rates. The low wear rates of crosslinked polyethylene opens up the possibility of using larger heads. The aim of this experimental study was to evaluate the wear of conventional non-crosslinked versus sequentially crosslinked polyethylene liners in combination with different ceramic head sizes (28, 36, 44 mm). Wear testing was performed in a hip simulator according to ISO 14242. Wear particles from the polyethylene liners were characterized after wear testing. The wear measurements revealed a significant increase in the wear of crosslinked polyethylene liners with larger heads. By sequential crosslinking, however, the gravimetric wear using larger heads was reduced to a fractional amount of the wear using conventional polyethylene. Significant differences were observed for particle morphology but not for the number of particles when comparing non-crosslinked and crosslinked polyethylene.

Wear Performance of Sequentially Cross-Linked Polyethylene Inserts against Ion-Treated CoCr, TiNbN-Coated CoCr and Al2O3 Ceramic Femoral Heads for Total Hip Replacement

“…In comparison to previous in vitro studies, the results showed that wear rates of both surface modifications were at least three-fold lower than these of traditional 36 mm CoCr-on-cross-linked polyethylene bearings [24][25][26][27]. Furthermore, the polyethylene wear could be reduced to the level of alumina ceramic heads [19,26].…”

“…These ceramic heads were tested as part of a previous wear study [19] which used the same loading scenario. Within the present study, contact angle measurements have been made at these ceramic heads.…”

“…Within the present study, contact angle measurements have been made at these ceramic heads. Furthermore, the lubricant generated within the previous wear test [19] was used to analyze the ion level.…”

“…The wear results for the CoCr and ceramic femoral heads against sequentially cross-linked polyethylene inserts are presented in Figure 3a [19].…”

Force-controlled dynamic wear testing of total ankle replacements

“…The linear restraint system is characterized and discussed afterwards (see Table 4 and discussion). [64][65][66][67] wear testing of established artificial joints like the hip or the knee. Therefore, a comparably relevant wear volume is also generated for TAR.…”