Model-based RSA
•Not necessary to adapt prosthesis
•However, marking of bone remains necessary
•3D surface model of prosthesis from manufacturer or by means of reversed engineering
At our department, we have developed a new technique called Model-based RSA.
For this technique, the following procedure is used:
- First, the contour of the prosthesis is detected in the roentgen images.
- Second, a virtual projection of a 3D surface model of the implant is made.
- Third, the difference between the virtual projection and the detected contour is minimized by changing the pose of the 3D model.
In the next section, I will further explain these three steps.
Model-based RSA has the advantage that it is not necessary to attach markers to the prosthesis.
The 3D surface model that is necessary for this technique can be obtained from the CAD model of the manufacturer, but it is also possible to reconstruct such a model using laser scanning. This technique is also known as reversed engineering.