A New, Promising Experimental Ossicular Prosthesis : A Human Temporal Bone Study With Laser Doppler Vibrometry

Objective: We compared the sound transmission using different types of total ossicular replacement prostheses (TORP); we then studied the performance of a new TORP that we designed inspired by the columella, the single ossicle found in birds. Methods: Stapedial vibrations were measured on nine freshly frozen human temporal bones with laser Doppler vibrometry. We then compared the performances of eight common TORP positions or designs as well as the new silver prototype of bird-type prosthesis, designed also according to our digital holography patterns of the human tympanic membrane (TM). Results: The TORPs placed in lateral contact with both the TM and the malleus handle outperformed, at most frequencies, those placed only in contact with the TM. The new bird-type prosthesis performed equally well or better than all other prostheses. Conclusion: If the malleus handle can be retained when placing a TORP, the best sound transmission can be achieved by placing the TORP in contact with both the distal part of the malleus handle and the TM. The good performance of our bird-type prosthesis suggests that there is still room for future improvement of prosthesis design to further optimize hearing outcomes after surgery.