Stapes Prosthesis Length: One Size Fits All?

Abstract

Background: The insertion of the stapes piston into the vestibule provides the physical basis for a successful stapedotomy. In routine clinical practice, two different ways to handle prosthesis length are performed: (1) an individualized measurement of the stapes prosthesis length or (2) a standard prosthesis length for all cases. Objective: The objective of this study was to compare both ways of handling prosthesis length and the effect of these methods on insertional prosthesis depth. Material and Method: We retrospectively evaluated 39 patients after performing a stapedotomy for radiologically estimated vestibular stapes prosthesis insertion depth. The individual measured length data were hypothetically changed to a standard length of 4.75, 5, 5.25, and 5.5 mm, and the insertion depths were compared. Results: The individually measured prosthesis lengths led to an insertion depth between 0.2 and 1.6 mm (mean 0.74 mm). The ratio of insertion depth/vestibular depth was between 8 and 59.1% (mean 26.6%). The different assumed standard lengths led to different rates of the vestibulum positions and possible bony contacts at the vestibulum floor. Conclusion: The individual measurement led to a zero rate of the vestibulum positions of stapes prosthesis pistons with a low insertion depth/vestibular depth ratio.

Use of a Flexible Ruler in Measuring the Length of Artificial Stapes During Stapedotomy Under Otoendoscopy

“…If the prosthesis is too short, it cannot provide effective vibration and can easily fall out. If it is too long, it can contribute to dizziness and sensorineural hearing loss [ 16 – 18 ]. Common reasons for reoperation after stapes prosthesis implantation include prosthesis dysfunction, dislocation or displacement, inaccurate prosthesis length, erosion of the incus, fibrous adhesions, or refixation of the stapes footplate [ 19 – 22 ].…”

“…Multi-slice spiral CT had a greater overestimation value of 0.68 mm for the prosthesis length [ 26 ]. Improper selection of prosthesis length is a common cause of surgical failure, with a high incidence of the prosthesis being too short or too long [ 16 ].…”

Hearing Improvement in the Patients Operated on Otosclerosis by Right-Handed Surgeons

“…Piston-type prostheses available for otosurgeons can be fixed by operators by manually tightening the loop on the long process of the incus or using a self-tightening element. 11,12 The stapes prostheses are self-tightening, being retained on the long process of the incus, and thanks to this structure, the clamping stage-one of the most difficult and unpredictable stages of stapes plastic surgery-is eliminated. The standard attachment on the incus, with no ''dangerous tightening,'' seems to make the operation principle of the selftightening element the optimal solution.…”