Influence of Cross-Shear and Contact Pressure on Wear Mechanisms of PEEK and CFR-PEEK in Total Hip Joint Replacements

Abstract

With the increasing market demand for artificial hip joints, total hip joint replacement has gradually become an effective means of treating a series of hip joint diseases. In order to improve the service life of artificial hip joints, some new artificial hip joint materials, including polyetheretherketone (PEEK) and carbon fiber reinforced polyetheretherketone (CFR-PEEK), have been developed. In this paper, pin-on-plate wear tests under different cross-shear ratios and contact pressures were carried out to study the wear mechanism and worn surface topography of PEEK and CFR-PEEK. The experimental results showed that the wear of PEEK was associated with cross-shear, while CFR-PEEK was not. When the cross-shear ratio was 0.039 and contact pressure was 3.18 MPa, PEEK had poor wear resistance and its wear factor was about eight times that of ultra-high molecular weight polyethylene (UHMWPE). The wear resistance of CFR-PEEK had a significant advantage, since its wear factor was about 30% of that of PEEK. The wear factors of PEEK and CFR-PEEK increased as the contact pressure increased. The arithmetic average of the height amplitude of the surface, Sa, also increased gradually according to the topography of the worn surface. The wear mechanisms of PEEK and CFR-PEEK were scratching, plough cutting, and abrasion Since CFR-PEEK had good wear resistance and insensitivity to cross-shear motion, it is suitable for making artificial hip joints under low contact pressure condition.

In Silico Contact Pressure of Metal-on-Metal Total Hip Implant with Different Materials Subjected to Gait Loading

“…The evaluation of contact pressure on implants as a preliminary study was extensively carried out in previous studies before the evolution of wear [21][22][23]. This is because contact pressure has a correlation with wear according to the Archard wear equation [24] as shown in Equation (1), where W L is linear wear, K w is wear coefficient, P is contact pressure, and s is sliding distance.…”

Minimizing Risk of Failure from Ceramic-on-Ceramic Total Hip Prosthesis by Selecting Ceramic Materials Based on Tresca Stress

“…The use of conventional polyethylene as a coupling material with a hard-on-soft combination, such as metal-on-polyethylene and ceramic-on-polyethylene, has begun to be limited due to the high number of wear cases that affect long-term performance [6]. Additionally, polyethylene wear particles give a negative body response to implant users [7]. Although the use of metal-on-metal couplings was once an option, the relatively high number of failure cases found compared to other material combinations made this coupling less desirable.…”