From objective measures of the form and shape of the proximal humerus - e.g. diameter and center of the humerus head, proximal shaft axis,
retrotorsion angle - the position and orientation of a humerus endoprosthesis for an anatomical reconstruction of the humerus can be determined.

The implantation itself is simulated using the computer-based visualization and planning tool VisualMediJa. The animation shows the planned resection cut (green plane) as well as the position of the endosprosthesis shaft and head (orange).

In a cadaver study the planned implantation was realized in a navigated intervention:

The humerus shaft is prepared using a rasp. The instrument's orientation is controled by the surgeon with help of an infra-red optical tracking system. Its active locator is mounted onto the rasp.

After the preparation step the prosthesis fit to the bone is controlled.

On the prosthesis' shaft a humerus head - a semi-sphere - is fixed in the planned orientation.

Co-operation: Hannover Medical School, Orthopedic Clinic, Hannover, Germany (Annastift)