A straight piece of cartilage for grafting can be harvested from the nasal septum or the ribs. Remember that the present graft in your bridge, harvested from your ears, can be straightened, diced or recontoured. The problem is not the source of the cartilage.
The graft more than likely has to be removed and replaced with something better. Rib cartilage is often good and this can come from you or a donor irradiated piece.
Based on one picture, the nasal bridge implant is not very good. What ever is there needs to be removed. Then re-assess the situation and decide what is the most appropriate surgery. As for nasal bridge build you, one can use diced cartilage, septal cartilage, or rib cartilage. All these methods have their pros and cons, that needs to be discussed with you and decide what you and the plastic surgeon can choose the most appropriate method.
Samir Shureih MD.FACS.