Audiologic Results of Ossiculoplasty Using Malleus ...

ORIGINAL ARTICLE online © ML Comm
pISSN 2092-9862 / eISSN 2093-3797
Korean J Audiol 2011;15:141-146

Audiologic Results of Ossiculoplasty Using Malleus Footplate
Assembly: The Comparison between Autologous Incus and
Hydroxyapatite

Sue Jean Mun, Joo Hyun Park, Chang Myeon Song, Kyu-Hee Han,
Jun Ho Lee, Seung Ha Oh and Sun O Chang

Department of Otolaryngology Head & Neck Surgery, Seoul National University College of Medicine, Seoul, Korea

Background and Objectives: Absence of incus is one of the most common ossicular anom-
alies and also frequently found in chronic otitis media or chornic otitis media with cholesteatoma.

Ossiculoplasty with malleus footplate assembly (MFA) can be an excellent option in the above

situations. We reviewed our procedures and evaluated the hearing results of ossiculoplasty us-

ing the MFA. Subjects and Methods: This study retrospectively reviews a series of 32 patients
who underwent MFA ossiculoplasty between September 2001 and March 2010 in an academic

tertiary referral center. The autologous incus or hydroxyapatite (HA) was used as materials for

Received November 25, 2011 reconstruction. Results: Thirteen of 32 patients (40.6%) had ossicular chain anomaly, 9 patients
Revised December 6, 2011 (28.1%) had congenital cholesteatoma and 8 patients (25.0%) had chronic otitis media with cho-
Accepted December 7, 2011
lesteatoma and 2 patients (6.3%) had chronic otitis media. The patients with ossicular chain ano-
Address for correspondence
Sun O Chang, MD maly showed the greatest air-bone gap (ABG) closure. Overall, postoperative ABG was 17.7±
Department of Otolaryngology-
Head & Neck Surgery, 11.7 dB at postoperative 6 months and 19.7±14.3 dB at postoperative 1 year, compared with
Seoul National University
College of Medicine, preoperative ABG of 37.9±9.3 dB. There was no statistical difference of ABG at postoperative
101 Daehak-ro, Jongno-gu,
Seoul 110-744, Korea 12 months, 24 months between MFA using incus (n=17) and HA (n=15)(p=0.300, and p=0.563).
Tel +82-2-2072-3649
Fax +82-55-745-2387 There was no meaningful difference of postoperative ABG between the patients with combined
E-mail [email protected]
mastoidectomy (n=10) and those without mastoidecmoy (n=22)(p=0.555). No extrusions oc-

curred. Conclusions: MFA can be an effective option in the case of absent incus expecting

good postoperative hearing results. Korean J Audiol 2011;15:141-146

KEY WORDS: Malleus footplate assembly · Ossiculoplasty · Ossicular prosthesis · Incus ·
Hydroxyapatite.

Introduction anomalies (19.7%) including a stapes without suprastructure
and an incus long process, stapes without anterior crus and an
A disruption of the ossicular chain of the middle ear causes incus long process.2) One of the most common ossicular chain
conductive hearing loss. Ossicular reconstruction is performed anomalies is the absence of an incus with or without an intact
to restore hearings in those patients with congenital ossicular stapes suprastructure. In incudostapedial deformed ears, ossi-
chain anomaly or ossicular chain disruption caused by chron- culoplasty is mandatory to restore the hearing process. Ossicu-
ic otitis media or cholesteatoma. loplasty is also needed in cases with incus long process erosion
with inflammation. As the most vulnerable ossicles, one report
A study from Japan with 52 auditory ossicular malformation said that incus erosion is found in 80% of the chronic otitis me-
revealed that 44% of the patients had a fixation of the stapes, dia.3) Austin-Kartush classified ossicular chain disruptions into
40% had incudostapedial joint defects followed by fixation of four categories after 1,151 operation on chronic otitis media.
the malleus and/or incus and defects in the incudostapedial jo- Group A ears with an intact malleus handle and a stapes supra-
int with a fixation of the stapes.1) One of the most common os- structure was found in 59.2% followed by group B ears with
sicular chain anomalies in Korea was a stapes footplate fixa- an intact malleus handle but an eroded stapes suprastructure
tion (54.5%) followed by a mobile stapes footplate with other

Copyright © 2011 The Korean Audiological Society 141

Malleus Footplate Assembly

group.4) In the group of a tympanic membrane and malleus pre- excluded in order to provide consistency within the analysis.
served but a stapes suprastructure eroded, ossicular continuity Finally, 32 cases were enrolled into the study. All procedures
can be restored between the stapes footplate and manubrium were conducted by a single surgeon. All data including previ-
of the malleus with the method of malleus footplate assembly ous operations, follow-up duration, age, sex, etiology, mate-
(MFA) using either the incus body or if the incus is unavail- rials which were used in the operation, combined mastoidec-
able, a biocompatible material such as hydroxyapatite (HA).5-7) tomy, complications, and revision operations were analyzed.
Until now, MFA has proven to be the safe and effective way to Eustachian tube function was analyzed according to the re-
restore hearings in such patients.8-12) sults of the Eustachian tube test. The status of the middle ear
mucosa was described as either ‘healthy’ or ‘inflamed’ accord-
Though successful results using MFA with either incus body ing to the operation records. Demographic data are presented
or biocompatible material are reported world widely, there in Table 1.
were a few reports on audiologic results after MFA ossiculo-
plasty in Korea. Authors reviewed our procedure and report Analysis of audiologic data
hearing results of ossiculoplasty with MFA using either incus Preoperative and postoperative hearing results were evalu-
or HA. In this paper, a single-surgeon series of 32 MFA oper-
ations was analyzed. The cases were limited to autologous in- ated according to the guidelines of the Committee on Hearing
terposition grafts performed on Austin-Kartush group B ears and Equilibrium of the American Academy of Otolaryngolo-
in order to provide consistency within the analysis. gy-Head Neck Surgery Foundation13) and Classification and
Hearing Result Reporting Guideline in Chronic Otitis Media
Subjects and Methods Surgery published in 2006, Korea.14) The air conduction (AC),
bone conduction (BC) as well as air-bone gap (ABG) at 0.5,
Data collection 1, 2, and 3 kHz were calculated before surgery and at 3 months,
A retrospective evaluation has been carried out on patients 6 months, 1 year, and 2 years after surgery. Closure of the aver-
age ABG to within 20 dB was defined as successful outcomes
who underwent MFA ossiculoplasty between September 2001 in this study.
and March 2010 in Seoul National University Hospital. A total
of 55 patients with Austin-Kartush type B defect repaired Operation methods
with incus body or HA were identified. Of those, 20 were ex- Ossicular reconstruction was performed using either autol-
cluded due to a failure to recover operation records or a lack
of no more than 1 year postoperative audiograms. Three pa- ogous incus body or the HA. Autologous incus was used in 17
tients who had undergone MFA with a homologous incus were cases and HA was used in 15 cases. The prosthesis was fitted

Table 1. Demographics and clinical characteristics of the total, incus and HA MFA group

Total Incus HA p-value

No. 32 17 15

Sex (male : female) 24 : 08 13 : 04 11 : 04 0.579

Age 23.3±19.4 20.9±20.3 25.9±18.7 0.230

Site (right : left) 24 : 08 13 : 04 11 : 04 0.579

Valsalva (intact : not intact) 28 : 03 15 : 01 13 : 02 0.600

E-tube function (intact : not intact) 28 : 02 15 : 00 13 : 02 0.483

MEC mucosa (healthy : inflamed) 13 : 03 08 : 00 05 : 03 0.200

Mastoidectomy (yes : no) 10 : 22 05 : 12 05 : 10 0.555

Preoperative AC 48.7±10.7 46.7±11.9 50.9±09.2 0.313

Preoperative BC 11.9±07.5 13.0±09.1 10.8±05.3 0.654

Preoperative ABG 37.9±09.3 35.4±10.1 40.6±08.0 0.140

Etiology 0.323

Ossicular chain anomaly 13 07 06

Congenital cholesteatoma 09 07 02

COM with cholesteatoma 08 02 06

Chronic otitis media 02 01 01

MFA: malleus footplate assembly, HA: hydroxyapatite, E-tube: Esutachian tube, MEC: middle ear cavity, AC: air conduction, BC:
bone conduction, ABG: air-bone gap, COM: chronic otitis media

142 Korean J Audiol 2011;15:141-146

Mun SJ, et al.

between the malleus neck and the footplate. The tendon of were analyzed using Fisher’s exact test and there were no
the tensor tympani was severed to facilitate insertion of the significant statistical differences between the incus and the
prosthesis and to relieve tension in the reconstruction system. HA groups.
The distance between the malleus and the footplate was mea-
sured to decide on the adequate length of the incus body or Mean preoperative AC was 48.7±10.7 dB with a range of
the HA. When the incus body is remained and useful, it was 24 to 66 dB. Mean preoperative BC was 11.9±7.5 dB with a
removed and remodeled. A groove was made on the incus ac- range of 1 to 35 dB. Mean preoperative ABG was 37.9±9.3
etabulum with a 1 mm diamond burr for positioning of the dB with a range of 16 to 58 dB and there was no significant
malleus handle. If the incus was not feasible, HA was used statistical difference between the incus and HA groups.
with a groove on the head of the HA. The shaft of the HA was
placed on the footplate and sliced tragal cartilage was inter- Significant improvements in AC and ABG were observed at
posed between the HA and the tympanic membrane to prevent 3 months, 6 months, 12 months and 24 months after the op-
prosthesis extrusion. eration, compared with preoperative pure tone audiometry.
There was no significant change in BC before and after the
Statistical analysis surgery (Fig. 1). The closure of ABG to within 20 dB occurred
SPSS version 18.0 software (SPSS, Chicago, IL, USA) was in 59.3% of the patients at postoperative 1 year and 73.9% at
postoperative 2 years.
used for analyses and a p-value＜0.05 was considered to be
significant. The preoperative and postoperative hearing results Although there was no statistical significance of postoper-
were compared using Wilcoxon signed rank test. The hearing ative ABG, the HA group showed a smaller ABG, compared
results between incus and HA were compared using Mann- to the incus group (14.8±11.6 dB in HA and 19.4±12.3 dB in
Whitney U test and Fisher’s exact test. Audiologic results
among etiologies were analyzed using Kruskall-Wallis test. 50

Ethic consideration 40
The study was approved as a review exemption by Institu-
30
tional Review Board of Seoul National University Hospital,
Seoul, Korea. 20

Results 10

Demographic data of MFA patients with either incus and 0
HA are presented in Table 1. Age ranged from 3 to 63 years.
Mean follow-up period was 32.6±20.8 months. Three patients PreOp 3 Mo 6 Mo 12 Mo 24 Mo
underwent revision ossiculoplasty due to the unsatisfactory
hearing results. The ossicular chain reconstruction was perfor- AC ABG BC
med during the second stage of a planned two-stage procedure
in two patients diagnosed as congenital cholesteatoma and one Fig. 1. Mean preoperative and postoperative audiologic results
patient with chronic otitis media with cholesteatoma. Twenty- after MFA. MFA: malleus footplate assembly, AC: air conduction,
two patients (68.8%) underwent MFA without mastoidectomy. BC: bone conduction, ABG: air-bone gap, preOp: preoperative,
Canal wall up mastoidectomy was performed in 8 patients Mo: month.
(25.0%) and canal wall down mastoidectomy, in 2 patients
(6.2%). 50

The etiology of the ossicular disruption was ossicular chain 40
anomaly in 13 patients (40.6%), congenital cholesteatoma in 9
patients (28.1%), chronic otitis media with cholesteatoma in 8 30
patients (25.0%), and chronic otitis media in 2 patients (6.3%).
20
Preoperative valsalva results and Eustachian tube function
test, intraoperative middle ear mucosa status, and combined 10
mastoidectomy, which can affect the result of the operation,
0

PreOp 3 Mo 6 Mo 12 Mo 24 Mo

Incus HA

Fig. 2. Postoperative ABG according to the materials used for MFA
ossiculoplasty. ABG: air-bone gap, MFA: malleus footplate assem-
bly, Incus: MFA using incus, HA: hydroxyapatite, preOp: preopera-
tive, Mo: month.

www.audiology.or.kr 143

Malleus Footplate Assembly

incus in 2 years; p=0.563)(Fig. 2). gery. The other three incus bodies also showed displacement
Audiologic results were compared according to the etiolo- and were realigned. The revision surgery included adhesioly-
sis and rearrangement in one HA case due to fibrous tissue
gy. Postoperative 3 months and 1 year ABG showed statisti- around the prosthesis and the other HA was remodeled and
cally significant decrease in ossicular chain anomaly, compared realigned in the revision surgery. One patient underwent the
to other disease entities (p=0.002 and p=0.012, respectively) revision surgery due to a recurrence of chronic otitis media
(Fig. 3). with cholesteatoma.

Although no significant difference of postoperative ABG Discussion
was observed between the primary and the revision ossiculo-
plasty, the primary cases showed smaller ABG than the revi- In 1978, Austin15,16) identified five categories of anatomic
sion cases in postoperative 1 year and 2 years (p=0.161 and p= defects in the middle ear sound-conducting system and de-
0.294, respectively)(Fig. 4). scribed them. According to the classification, an ossicular inter-
ruption with an intact tympanic membrane resulted in a maxi-
There was no significant difference between the combined mal conductive hearing loss of 55 to 60 dB. An intact eardrum
tympanomastoidectomy and the tympanoplasty (p=0.555). reflected sound energy back into the external auditory canal,
causing an additional 17 dB conductive loss beyond what was
There was no prosthesis extrusion as a complication. How- expected from the removal of the hydraulic and catenary lever
ever, 6 patients needed revision surgery due to poor surgical action. The decreased sound pressure also reached the round
audiologic outcomes. Among them, 4 cases previously had and oval windows nearly simultaneously, inducing a phase
performed the MFA with incus body, and 2 cases, with the cancellation in the labyrinthine fluids. To restore the ossicular
HA. One of the incus bodies was displaced and replaced to the chain, many techniques have been proposed. Mostly, long col-
HA and showed better hearing results after the revision sur- umella using an autologous incus or a total ossicular recon-
struction prosthesis (TORP) is used in the case of the absence
40 of a stapes suprastructure and an incus long process between
the tympanic membrane and the stapes footplate.3) Though
30 these methods are effective in reestablishing hydraulic lever
action, a catenary lever action, which yields a two-fold hearing
20 gain, cannot be established by a long columella or TORP. The-
oretically using MFA between the malleus and stapes footplate
10 can convey sound from the tympanic membrane to the malle-
us and then the stapes footplate, and can obtain the catenary
0 effect. It is supposed to be the audiologically physiologic
method of sound transfer. A study on a cadavaric model has
PreOp 3 Mo 6 Mo 12 Mo 24 Mo reported that a malleus to stapes head sound transfer with the
HA was better than a tympanic membrane to stapes head
Chronic otitis media Congenital cholesteatoma sound transfer.17) These results suggest that malleus is more im-
COM with cholesteatoma Ossicular chain anomaly portant for the middle ear mechanics than stapes although sta-
pes attributes the stability of ossicular prosthesis. In our study,
Fig. 3. Postoperative ABG according to the etiology of the hearing two MFA methods were compared. Though the results were
loss. ABG: air-bone gap, COM: chronic otitis media, preOp: preop- not compared with long columellization or TORP, similar re-
erative, Mo: month. sults are expected and will be continued in our future study.

50 Among the two MFA methods, no significant differences
were found between the incus and the HA groups. However,
40 there was a tendency of decreasing ABG in the HA group,
compared to the incus group in postoperative 2 years. When
30 exploring the cases with revision, 4 cases were the incus MFA
cases, compared to the 2 cases of HA MFA cases. Most of them
20 were due to a displacement of the MFA and one HA needed

10

0

PreOp 3 Mo 6 Mo 12 Mo 24 Mo

Revision ossiculoplasty Primary ossiculoplasty

Fig. 4. Comparison of postoperative ABG between primary and re-
vision ossiculoplasty. ABG: air-bone gap, preOp: preoperative, Mo:
month.

144 Korean J Audiol 2011;15:141-146

Mun SJ, et al.

adhesiolysis due to fibrous tissue. It is suspected that though gal cartilage interposition which can avoid direct contact of
a groove was made for the placement for the malleus handle,
the alignment can be changed during the absorption period prosthetic materials with the tympanic membrane and drum
of inner packings and during postoperative activity. As HA is
very symmetrical and premade in its shape, it is suspected erosion works well to prevent the extrusion of the prosthesis.
that displacement rarely occurs. The authors regarded that
HA can result in much inflammation or fibrosis due to bio- However, a long-term follow-up is needed to draw the 5 year
logical reactions, but, at the operation field of revision sur-
gery, only one HA case had adhesion with soft tissue. Thus, a results.
longer follow-up with audiologic results is mandatory.
Conclusion
The ideal prosthesis is considered to be easy for modeling
and handling, biocompatible, stable after the ossiculoplasty and There was no ABG difference in between incus and HA, but
delivers optimal sound. HA is easy to insert and remodel al-
though a possibility of decreased biocompatibility and some reasonable hearing gain was obtained in either method. In the
rate of immunologic reaction exist18,19) and cost is higher com-
pared to autologous incus. On the other hand, autologous incus MFA, either incus or HA can be an option to restore hearing in
is biocompatible so there is a reduced risk of inflammation
or immunologic reaction and does not increase price. Howev- patients with erosion of an incus long process or ossicular
er, it is time consuming work to prepare autologous incus with
the sculpturing of an appropriate shape. A homologous os- chain anomaly.
sicular prosthesis could be another option, but there is a risk
of transmitted disease such as hepatitis, syphilis, AIDS, and Acknowledgment
Creutzfeldt-Jacob disease.20) In this study, a homologous incus The work was funded by Seoul National University Hos-
was excluded due to suspicious different demineralization
rate with an autologous incus by time. pital finances No. 0420100680 in 2010.

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