The biomechanical objective in total knee prostheses with mobile bearings was, and still is, to reduce UHMWPE wear and fracture. This does not mean that such prostheses do not produce polyethylene debris.

In our clinical experience we have used several types of prosthesis, in which over time, plastic materials have become diversified and various methods of sterilisation have been used, the prostheses becoming more and more sophisticated.

In our work we present the results of using a posterior cruciate ligament-retaining prosthesis with two mobile bearings (follow up 7–14 years), a posterior cruciate ligament-sacrificing prosthesis with a rotating platform (follow up 10 years to today) and a posterior cruciate ligament-retaining prosthesis with a rear-front translation platform (follow up 7 years to today).

Data on fractures and dislocation are only presented for the posterior cruciate ligament-retaining prosthesis with two mobile bearings. In no other cases were fractures or dislocation observed, except for one patient who had a dislocation after suffering a rotational tendon tear.

Our results show that larger surfaces tolerate the prosthesis stress better, although the type of polyethylene (with or without stearate, more or less crosslinked, sterilisation with or without air, sterilisation by high energy radiation or using gamma radiation, etc.) can influences debris production.