A randomised radiostereometric study comparing SmartSet HV and Palacos R acrylic bone cements.

The fixation of components in total hip arthroplasty has a significant effect on the long-term survival of the prostheses. Bone cement in total joint replacement acts as an anchoring medium for the prosthesis and provides a barrier to the ingress of wear debris into bone surfaces. However, there are significant differences in cement behaviour among differing types of cement. A clinical study based on the Norwegian Arthroplasty Register demonstrated that there is an increased rate of revision due to aseptic loosening of femoral components implanted with low-viscosity cement compared with that of high-viscosity.

Studies have shown that high early migration for certain designs of femoral prosthesis can be a predictor for clinical loosening. RSA is a technique enabling calculation of the three-dimensional translational and rotational movements of the implant relative to the bone, and therefore provides an ideal technique to detect early micromotion of implants.

Inclusion Criteria:

• patients in need for total hip arthroplasty

Exclusion Criteria:

• patients with an existing condition such as malignancy, pregnancy, severe osteoporosis and disabling musculoskeletal problems (other than in the hips),
• patients on corticosteroid treatment,
• patients who had already participated in a clinical study with an investigational product in the last 6 months.