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Cartilage ‘shoe’: a new technique for stabilisation Neudert M., Bornitz M., Lasurashvili N., Schmidt U.,
of titanium total ossicular replacement prosthesis at centre Beleites Th., Zahnert Th.
of stapes footplate
Published: Otology & Neurotology: October 2016, Volume 37
Beutner D., Luers J. C., Hüttenbrink K.-B. Doi: 10.1097/MAO.0000000000001064

Published: J Laryngol Otol. 2008 Jul; 122(7):682-6. Hypothesis: Prosthesis’ length creates tension in ossicular reconstructions,
DOI: 10.1017/S0022215108002545 which directly effects the middle ear sound transmission. Background:
Relatively long prostheses are often used to stabilize the middle ear recon-
Objective: After tympanoplasty using a total ossicular replacement prosthesis, struction to prevent dislocation. Thereby, tension on the flexible compo-
many unsatisfactory hearing results are due to dislocation of the prosthesis. nents such as the tympanic membrane (TM) and the annular ligament (AL)
is increased. Only little is known on the amount of displacement-related
Material and Methods: We developed a cartilage guide for stabilising the stiffening of the TM and AL, as well as the consecutive reduction in middle
total ossicular replacement prosthesis in the oval window niche. An oval- ear transfer function (METF).
shaped piece of cartilage measuring 2.5 x 3.5 mm with a central hole was
precisely punched out of a thin cartilage plate. The cartilage was placed in Methods: An expandable total ossicular replacement prosthesis was ten-
the oval niche, and its hole centred the prosthesis on the stapes footplate. sionfree inserted in nine cadaveric temporal bones between the malleus
handle and the stapes footplate. Upon heat activation the prosthesis was
Results: Hearing results in 52 patients confirmed acoustically the effective- lengthened, thus inducing tension on the reconstruction. The METF was as-
ness of this method of total ossicular replacement prosthesis stabilisation sessed before and after elongation. TM's and AL's stiffness were determined
on the stapes footplate. Subsequent ‘second-look’ surgery revealed stable by measuring their force–displacement characteristics.
ingrowth of the cartilage ‘shoe’ into the oval niche.
Results: Upon activation the prostheses were elongated between 50 and
Conclusion: Such a cartilage shoe might address one of the causes of un- 200 μm. A frequency-dependent METF reduction was measured with a
satisfactory hearing following ossicular chain reconstruction with a total decrease of 5 to 25 dB below 1.0 kHz. At frequencies >2.0 kHz the reduc-
ossicular replacement prosthesis. tion was less prominent or the METF showed even an improvement of up
to 10 dB. TM's stiffness remained constant during the elongation-induced
displacement, whereas the AL's stiffness increased. The METF reduction
The Cartilage Guide: A solution for Anchoring below 1.0 kHz correlated with the increasing AL's stiffness.
a Columella-Prosthesis on Footplate
Conclusion: Tension has a significant impact on the METF after middle ear
Hüttenbrink K.-B., Zahnert Th., Beutner D., Hofmann G. reconstruction. As little tension as possible should be used to enable best
sound transmission. Stabilization of prosthesis should be achieved with dis-
Published: Laryngorhinootologie 2004; 83: 450-456. location devices to ensure secure coupling to the ossicular remnants without
DOI: 10.1055/s-2004-814447 creating additional tension.
Background: A torp (columella-prosthesis) is the typical ossicular recon-
struction in cases of a destroyed stapedial arch. Yet, many unsatisfactory Optimum tension for partial ossicular replacement prosthesis
hearing results are due to the lack of a stable, reliable anchoring of the base reconstruction in the human middle ear
of the prosthesis on the footplate. Some solutions have been postulated,
amongst them the perforation of the footplate with a tiny spike at the lower Morris D.P., Bance M., van Wijhe R.G., Kiefte M., Smith R.
end of the prosthesis, which, however, many otosurgeons regard as too dan-
gerous for the inner ear. Specially designed silicone sheets cannot guarantee Published: Laryngoscope. 2004 Feb;114(2):305-8.
a permanent guide of the columella. DOI: 10.1097/00005537-200402000-00024
Methods: From our good experience with cartilage in different reconstruc- Objective: Hearing results from ossiculoplasty are unpredictable. There are
tion procedures, we therefore developed a cartilage guide for the oval win- many potentially modifiable parameters. One parameter that has not been
dow niche. An oval 2,5 x 3,5 mm cartilage with a central hole is cut out of adequately investigated in the past is the effect of tension on the mechanical
a thin (0,2 - 0,3 mm) cartilage plate with a help of a cartilage punch, which functioning of the prosthesis. Our goal was to investigate this parameter fur-
we had designed in collaboration with Heinz Kurz manufacture. The carti- ther, with the hypothesis that the mechanical functioning of partial ossicular
lage is placed into the oval niche and its hole guides the prosthesis onto the replacement prostheses (PORP) from the stapes head to the eardrum will be
centre of the footplate. affected by the tension that they are placed under.

Results: Temporal bone experiments demonstrated a reliable sound transport Methods: Fresh temporal bones were used to reconstruct a missing incus
through this guide. Revision surgery revealed a stable ingrowth of the carti- defect with a PORP-type prosthesis. Three different lengths of PORP were
lage plate into the oval niche, its perforation securely guiding the prosthesis used, and the stapes vibrations were measured with a laser Doppler vibro-
similar to a piston on to the footplate. The first short time hearing results meter using a calibrated standard sound in the ear canal. Eight temporal
(max. 1 year) in 22 patients confirmed the acoustic quality of this stabilisa- bones were used.
tion of a columella on the footplate as compared to a matched control group.
Results: Tension had a very significant effect on stapes vibration. In gen-
Conclusion: The stabilization of the columella with a cartilage-guide might eral, loose prostheses resulted in the best overall vibration transmission.
solve one of the many problems with unsatisfactory hearing results after the The effects were most marked at the lower frequencies. There was a slight
reconstruction of a completely destroyed ossicular chain. advantage to tight prostheses in the higher frequencies, but much less than
the decrement in lower frequencies with tight prostheses.

Conclusion: In ossicular reconstruction, best stapes vibration results in our
TENSION model are achieved by shorter prostheses, which result in lower tension.

Impact of Prosthesis Length on Tympanic Membrane's Comparison of the mechanical performance
and Annular Ligament's Stiffness and the Resulting Middle Ear of ossiculoplasty using a prosthetic malleus-to-stapes
Sound Transmission head with a tympanic membrane-to-stapes head assembly
in a human cadaveric middle ear model

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