Restoring hearing using total ossicular replacement prostheses--analysis of 3D finite element model

Area of Science:

• Otolaryngology
• Biomedical Engineering
• Auditory Implants

Background:

• Ossicular chain reconstruction is vital for hearing restoration in middle ear pathologies.
• Total ossicular replacement prostheses (TORPs) are used when the incus and malleus are absent.
• Optimal prosthesis placement is critical for successful surgical outcomes.

Purpose of the Study:

• To investigate the impact of TORP placement on the stapes footplate or oval window membrane on hearing restoration.
• To determine the ideal position for TORP attachment to maximize auditory functional recovery.

Main Methods:

• A 3D finite element model of a healthy volunteer's ear was created using CT data.
• Digitalized data were processed using PATRAN software.
• Harmonic response analysis was performed using NASTRAN software to simulate TORP attachment at various positions.

Main Results:

• TORP attachment to the center of the stapes footplate yielded results comparable to a normal ear's stapes footplate displacement.
• Placement on the anterior stapes footplate showed near-normal displacement, while posterior placement resulted in significant deviations.
• Attachment to the oval window membrane also led to abnormal stapes footplate displacement.

Conclusions:

• Retaining the stapes footplate during TORP surgery improves auditory functional recovery.
• Centering the TORP on the stapes footplate provides the best hearing restoration outcomes.
• Accurate prosthesis positioning is paramount for successful middle ear reconstruction.