mAXIS Stapes Prosthesis, mLOOP Stapes Prosthesis, mZAM Stapes Prosthesis and mFIX Stapes Prosthesis

The MED-EL PMEI Stapesplasty Prostheses (mAXIS, mLOOP, mZAM, mFIX) are partial ossicular replacement prostheses designed to restore sound transmission to the oval window by replacing the stapes arch and/or stapes arch and incus. They are implanted in the middle ear during stapedectomy or stapedotomy procedures to treat congenital or acquired stapes defects, otosclerosis, and inadequate conductive hearing from prior stapes surgery. The devices are single-use, sterile, and implanted by qualified ENT surgeons.

All four MED-EL devices are made of medical-grade titanium and differ primarily in coupling structure design: mAXIS uses a broad perforated spiral-shaped loop (0.5 mm width) with crimping; mLOOP and mZAM use narrower spiral-shaped loops (0.3 mm and 0.20 mm respectively) with crimping; mFIX uses a clip-type coupling (0.2 mm) with clipping attachment. All share identical piston diameters (0.4–0.6 mm), comparable functional lengths (3.5–10.0 mm range), MRI conditional labeling (1.5–7.0 T), and EN ISO 10993 biocompatibility.

MRI environment (ASTM F2119, F2052, F2182); biocompatibility (EN ISO 10993); shelf-life (EN ISO 11607); sterilization validation (EN ISO 11137-1, EN ISO 11137-2); packaging validation (EN ISO 11607); and mechanical testing. Clinical data from a large multicenter retrospective post-market clinical follow-up study with 168–188 patients.

MED-EL devices are substantially equivalent because they have identical materials, biocompatibility, attachment methods, packaging, and MRI characteristics to their predicate devices (Heinz Kurz prostheses). Although loop widths and designs vary slightly among MED-EL models, these variations fall within the range of existing predicate device designs and do not create different safety or effectiveness questions. Clinical outcomes (91.7% achieving postoperative air-bone gap ≤20 dB; 66.1% ≤10 dB) match state-of-the-art performance. The only difference—lack of an optional KURZ-Meter measuring tool—does not affect safety or effectiveness because alternative surgical tools are commercially available.