Nitinol in Passive Ossicular Reconstruction-First Results From Temporal Bone Experiments

Partial Ossicular Reconstruction With a Novel Ball Joint Prosthesis: The mCLIP ARC Partial Prosthesis

OBJECTIVE

Middle ear surgery involves reconstruction of the ossicular chain, predominately using rigid implants. New middle ear prostheses strive to mimic the physiologic micromovements of the ossicular chain and prevent dislocation, protrusion, and preloading of the annular ligament due to pressure fluctuations.

METHODS

Thirty-five patients were included in a monocentric, prospective observational study. Patients received tympanoplasty with ossicular reconstruction using the mCLIP ARC partial prosthesis. This titanium prosthesis is equipped with a clip mechanism for coupling at the stapes and a ball joint connecting headplate and shaft. At short-term (ST) and mid-term (MT) follow-up, pure-tone audiometry was performed and the pure tone average of 0.5, 1, 2, and 3 kHz (PTA4) was calculated. The audiological outcome was compared with retrospective data of the Dresden titanium clip prosthesis.

RESULTS

The new prosthesis shows favorable clinical results. Pure-tone audiometry showed satisfactory results in ST and MT follow-up, with the PTA4 air-bone gap (ABG) decreasing from 24.5 (±11) dB to 17.4 (±7.9) dB at the ST follow-up at 27 days to 15.6 (±10.3) dB at MT follow-up at 196 days (n = 32). A PTA4-ABG value of less than 20 dB was achieved by 63% of patients at ST follow-up and by 77% at MT follow-up. There was no significant difference in PTA4 ABG compared to the Dresden titanium clip prosthesis during ST follow-up (p = 0.18).

CONCLUSION

The mCLIP ARC partial prosthesis, a new middle ear prosthesis with a balanced ball joint, shows promising audiological results and is a safe and effective choice for patients with chronic ear disease.

LEVEL OF EVIDENCE

3 Laryngoscope, 134:3323-3328, 2024.

A Partial Ossicular Replacement Prosthesis With a Concentric Ball Joint in the Headplate

OBJECTIVE

In passive middle ear prosthetics, rigid implants have proven successful in reconstructing the ossicular chain. However, these cannot fully replicate the physiology of the ossicular chain. Pressure fluctuations cause high stresses in rigid passive prostheses, which can result in dislocation, protrusion, and pre-tension in the annular ligament resulting in unsatisfactory hearing results.

METHODS

In collaboration with MED-EL, we developed a new passive middle ear prosthesis that features a balanced, centered ball joint between the headplate and shaft of the prosthesis. We compared the sound transmission properties of this new prosthesis with those of a standard rigid prosthesis. Using Laser-Doppler-Vibrometry, we measured the sound-induced velocity of the stapes footplate relative to a given acoustic stimulus.

RESULTS

The new prosthesis showed equivalent sound transmission characteristics compared to the rigid prosthesis, whereas retaining the ability to compensate for pressure fluctuations due to its ball joint. This ensures good transmission properties even during displacements of the tympanic membrane.

CONCLUSION

This development is a further step toward a physiological reconstruction of the ossicular chain.

LEVEL OF EVIDENCE

N/A Laryngoscope, 2022.