Classification of ossicular fixation based on a computational simulation of ossicular mobility

Area of Science:

• Biomedical Engineering
• Otolaryngology
• Computational Modeling

Background:

• Ossicular fixation causes conductive hearing loss, often diagnosed via subjective intraoperative palpation.
• Accurate diagnosis requires objective quantification of ossicular mobility and evidence-based criteria.
• Surgeons' experience influences palpation-based diagnosis, highlighting the need for quantitative methods.

Purpose of the Study:

• To develop and validate a finite-element (FE) model for simulating ossicular mobilities in pathological cases.
• To establish quantitative diagnostic criteria for ossicular fixation based on simulated ossicular compliances.
• To classify different types of ossicular fixation and guide surgical decisions.

Main Methods:

• Simulated ossicular mobilities (compliances) for 92 pathological cases using a human middle ear FE model.
• Validated FE model results against cadaveric measurements using an intraoperative mobility measurement system.
• Classified simulated cases into four groups using cluster analysis based on ossicular compliances.

Main Results:

• FE model accurately simulated ossicular mobilities, validated by cadaveric measurements.
• Fixation-induced hearing changes correlated with FE model stapedial velocities and patient data.
• Cluster analysis of ossicular compliances differentiated pathologies, including combined malleus/incus fixation with otosclerosis, guiding surgical approaches (malleo-stapedotomy vs. stapedotomy).

Conclusions:

• Quantitative measurement of ossicular compliances via FE modeling enables objective diagnosis of ossicular fixation.
• Cluster analysis of compliances aids in pathological characterization and surgical planning.
• This approach offers an effective, evidence-based diagnostic tool for ossicular fixation.