Multicenter study results of the med-el partial ossicular replacement prostheses

PURPOSE: This multicentric, retrospective study aimed to analyze the safety and effectiveness of the mXACT Partial Prosthesis, mXACT PRO Partial Prosthesis, mCLIP Partial Prosthesis, and mCLIP ARC Partial Prosthesis.

METHODS: Patients underwent partial ossicular replacement with a mXACT Partial Prosthesis, mXACT PRO Partial Prosthesis, mCLIP Partial Prosthesis, or mCLIP ARC Partial Prosthesis (MED-EL). The clinical data was retrospectively analyzed according to the coupling type, bell or clip. Follow-up examination included access to medical records (for adverse events (AE) of the patients, ear microscopy and pure-tone audiometry to determine the post-operative pure tone average of the frequencies 0.5, 1, 2 and 3 kHz (PTA4)). The post-operative PTA4 air bone gap (ABG) was used to evaluate the audiological outcome. A post-operative PTA4 ABG ≤ 20 dB was defined as successful rehabilitation. A post-operative minimum and maximum follow-up period was not defined.

RESULTS: 203 patients were implanted, 202 patients were examined for AEs (bell group: 68 patients, clip group: 134 patients), 186 patients were examined audiologically (bell group: 63 patients, clip group: 123 patients). In the bell group, 4 patients (5.9%) had 4 AE (thereof 2 revision surgeries and 2 dislocations/extrusions), and in the clip group 15 patients (11.2%) had 28 AEs (thereof 2 revision surgeries and 1 dislocation/extrusion). A post-operative PTA4 ABG of ≤ 20 dB and therefore successful rehabilitation was reached by 44 patients (69.8%) in the bell, and by 89 patients (72.4%) in the clip group. The mean post-operative PTA4 ABG was 17.8 ± 10.2 dB for patients implanted with a bell prosthesis and 16.3 ± 10.1 dB for patients implanted with a clip prosthesis. Individual bone conduction (BC) PTA4 thresholds were stable in 60 patients (95.2%) implanted with a bell prosthesis and 120 patients (97.6%) implanted with a bell prosthesis.

CONCLUSION: Clinical data demonstrated satisfactory short-term audiological results after implantation of the mXACT Partial Prosthesis, mXACT PRO Partial Prosthesis, mCLIP Partial Prosthesis, and mCLIP ARC Partial Prosthesis in the majority of patients. The partial ossicular replacement prostheses are safe and effective.