In our study both the friction coefficient and wear resistance in
the Ti6Al4V–UHMWPE friction pair were measured under PVP
solutions with different concentrations. The friction coefficient
was reduced significantly (about 50%) by increasing PVP, from
0.090 to 0.042 for the deionized water solution and from 0.12 to
0.060 for the bovine serum solution. The wear resistance of the
UHMWPE disc was also improved significantly under the 15 wt%
PVP solutions compared to that under the 0 wt% PVP solutions
(Fig. 5). These measurements signify PVP contribute to the lubricating
properties of the artificial knee joint pairs. According to
both its low toxicity [14] and good lubricating properties, moderate
PVP concentrations (i.e., 10 wt% or 15 wt%) might be appropriate
to be used as a promising lubricating additive in the artifi-
cial knee joints.