Comparative roentgen stereophotogrammetry wear analysis between the X-3 PE insert and the N2Vac PE insert in the Trident metal backed hemispherical cup with attached markers in primary uncemented total hip arthroplasty with the ABGII femoral stem

The replacement of the hip is done in patients that experience pain and have a
reduced function in the joint and it is done to improve function and better
return in the community. The last couple of years a lot of research has been
done to lengthen the survival of prothesis, in which the patient can postpone
the revision surgery. During a ervision surgery a part of the prosthesis will
be replaced because of wear or loosening. When the prosthesis is used wear
could be seen in the polyethyleen part, when wear is visible patients could
experience inconvenience of the prosthesis. A new cup is developed with highly
crossed linked polyethyleen that will probably have lesser wear. If this can be
determined a revision is not always necessary.

The objective is to compare the wear during the years in the two different
cups. And if the wear measured on the X-rays is comparable with the daily
inconvenience and satisfaction of the patient.

During the study the patients included in the study will have the same routine
control moments (6 weeks, 1, 2, 3 and 5 years) as patients not included in the
study.

One group receives an ABGII Stem with a X-3 PE insert and an Trident cup and
the other group receives an ABGII stem with a N2VAc PE insert and an Trident
cup

The patients will have the same risks and benefits as patients not included in
the study and receiving an total hip prosthesis. The difference between study
patients and patients not included in the study is that study patients have to
make an extra roentgen foto (RSA-photo) when they have their control moments to
detect the wear. On these photos wear is better visible. This will cause no
more or other harm than the standard X-rays.