Figure 2.

Uniplanar RSA measurement setup. (a) The X-ray tubes were each oriented at a 20° angle to the horizontal and the film to focus distance was 160 cm. The carbon calibration box was under the examination table. (b) Implant migration was calculated by rigid body kinematics using up to ten tantalum beads, which were inserted into the bone surrounding the implant and serving as fixed reference.