Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4662889 | Knee joint prosthesis | Ludwig Zichner, Erhard Dorre, Horst von Borries | 1987-05-05 |
| 4538306 | Implantable elbow joint | Erhard Dorre, Ludwig Zichner | 1985-09-03 |
| 4312079 | Femur head cap for endoprosthesis | Erhard Dorre, Ludwig Zichner | 1982-01-26 |