Partial ossicular reconstruction: comparison of three different prostheses in clinical and experimental studies.

OBJECTIVE

To compare the reconstruction results of a long incus process defect using 3 different partial ossicular replacement prostheses (PORP).

STUDY

DESIGN

Temporal bone experiments and retrospective case review.

SETTING

Tertiary referral center. EXPERIMENTAL MATERIAL AND PATIENTS: The experimental study was performed on 18 temporal bones; 66 patients with retraction pockets, chronic otitis media with or without cholesteatoma.

INTERVENTIONS: Ossiculoplasty using 3 different PORP: titanium angle prosthesis, autologous incus interposition, and titanium clip prosthesis.

MAIN OUTCOME MEASURES: Laser Doppler vibrometry in temporal bones measured transmission properties of the PORP. Patients were retrospectively assessed up to 5 years after surgery. Audiologic data were analyzed for preoperative and postoperative air conduction and air-bone gap at 0.5, 1, 2, 3, and 4 kHz. Statistical analyses compared the outcome in the experimental and clinical setting.

RESULTS

Experimentally, the titanium PORP showed similar transmission properties because the overall difference to the intact specimen was -4.14 +/- 0.59 dB for the titanium angle prosthesis and -4.61 +/- 0.57 dB for the titanium clip prosthesis. The transmission after an autologous incus interposition was significantly worse (-9.32 +/- 0.39 dB, p < or = 0.001) compared with the other prostheses. Patients' mean postoperative air-bone gap was 25.5 +/- 1.2 dB and less than 20 dB in at least 66% of cases without any significant differences between the groups.

CONCLUSION

In the clinical setting, the confounding factors that influence the acoustic outcome after partial ossiculoplasty obscure the prosthesis-related transmission factors that can otherwise be derived in the experimental setting. The results do not generally favor the use of 1 specific prosthesis, rather they suggest that the correct choice of a prosthesis be based on the anatomic and pathophysiologic conditions found in the individual patient.