Modern surgical treatment of otosclerosis - Helda - Helsinki.fi

Department of Otorhinolaryngology 

University of Helsinki, Finland 

and 


Seinäjoki Central Hospital, Finland 

Modern surgical treatment of otosclerosis 

Juuso Kujala 

ACADEMIC DISSERTATION 

To be publicly discussed, with the permission of the Medical Faculty of the University 

of Helsinki, in the Seminar room 3 of Biomedicum Helsinki, Haartmaninkatu 8, on 12 

July 2009, at 12 noon. 

Helsinki 2009

Supervised by: 

Docent Timo P. Hirvonen 


University of Helsinki 

Helsinki, Finland 

Reviewed by: 

Docent Kyösti Laitakari 


University of Oulu 

Oulu, Finland 

and 

Docent Jaakko Pulkkinen 


University of Turku 

Turku, Finland 

Dissertation opponent: 

Docent Hannu Valtonen 


University of Helsinki 

Helsinki, Finland 

and 


University of Kuopio 

Kuopio, Finland 

ISBN 978-952-92-5480-4 (paperback) 

ISBN 978-952-10-5487-7 (PDF) 

http://ethesis.helsinki.fi 

Helsinki University Printing House 

Helsinki 2009

To my Family

Contents 

LIST OF ORIGINAL PUBLICATIONS 7 

ABBREVIATIONS 8 

ABSTRACT 9 

TIIVISTELMÄ (FINNISH SUMMARY) 11 

1 INTRODUCTION 13 

2 REVIEW OF THE LITERATURE 15 

2.1 Definition of otosclerosis 15 

2.2 Histology of otosclerosis 15 

2.4 Epidemiology 16 

Histological otosclerosis 16 

Clinical otosclerosis 17 

2.3 Aetiology 17 

Genetic inheritance 18 

Viral aetiology 18 

Endocrinological factors 19 

Immunological factors 19 

2.5 Clinical findings and pathogenesis of otosclerosis 20 

Conductive hearing loss 20 

Sensorineural hearing loss 21 

Vestibular symptoms 22 

Tinnitus 22 

Otosclerosis and Meniere’s disease 23 

2.6 Diagnosis 23 

Audiological evaluations 23 

Radiological evaluations 24 

2.7 Surgical treatment 25 

Stapedectomy versus stapedotomy 26 

Prosthesis 26 

Sealing 28 

Lasers in primary surgery 28 

4

Stapedius tendon preservation 29 

Results of primary and revision surgery 30 

Surgical treatment of bilateral otosclerosis 31 

Cochlear implantation 33 

2.8 Complications 33 

Perioperative complications 33 

Sensorineural hearing loss 34 

Perilymph fistula 35 

Reparative granuloma 36 

Vertigo 36 

Taste disturbance 37 

Facial paresis 37 

Suppurative labyrinthitis and meningitis 38 

Radiological evaluation of postoperative SNHL 38 

2.9 Conservative treatment 39 

Hearing aid 39 

Medical treatment 39 

3 AIMS OF THE STUDY 41 

4 MATERIALS AND METHODS 42 

4.1 Study design 42 

Study I 42 

Study II 42 

Studies III and IV 43 

4.2 Surgery 43 

4.3 Objective measurements and analysis 44 

Video-oculography 44 

Visual feedback posturography 45 

Audiogram 45 

Statistical analysis 45 

4.4 Ethical aspects 46 

5 RESULTS AND COMMENTS 48 

5.1 Simultaneous bilateral surgery (I) 48 

5.2 Outpatient surgery (II) 50 

5

5.3 Video-oculography studies (III, IV) 52 

Long-term evaluation (III) 52 

Short-term evaluation (IV) 54 

6 DISCUSSION 56 

6.1 Simultaneous bilateral surgery (I) 56 

6.2 Outpatient surgery (II) 58 

6.3 Video-oculography studies (III, IV) 60 

7 CONCLUSIONS 63 

8 ACKNOWLEDGEMENTS 64 

9 REFERENCES 66 

APPENDIX 83 

ORIGINAL PUBLICATIONS 84 

6

List of original publications 

The thesis is based on the following original publications referred to in the text by their 

Roman numerals. 

I. Kujala J, Aalto H, Ramsay H, Hirvonen TP. Simultaneous bilateral stapes surgery. 

Acta Oto-Laryngologica 128(4): 347-51, 2008. 

II. Vasama J-P, Kujala J, Hirvonen TP. Is small-fenestra stapedotomy a safer outpatient 

procedure than total Stapedectomy? ORL 68(2): 99-102, 2006. 

III. Kujala J, Aalto H, Hirvonen TP. Video-oculography findings in patients with 

otosclerosis. Otology&Neurotology 26(6): 1134-7, 2005. 

IV. Kujala J, Aalto H, Hirvonen TP. Video-oculography findings and vestibular 

symptoms on the day of stapes surgery. Submitted. 

These articles have been reprinted with the kind permission of their copyright holders. 

7

Abbreviations 

AB-GAP air-bone gap 

AC air conduction 

BC bone conduction 

BHI binaural hearing impairment 

BI balance index 

CO2 carbon dioxide 

COG center of gravity 

CT computed tomography 

CTN chorda tympani nerve 

ENG electronystagmography 

Er:YAG erbium yttrium aluminum garnet 

GBP Glasgow benefit plot 

HLA human leucocyte antigen 

HSN head-shaking nystagmus 

IWP impairment of whole person 

KTP potassium-titanyl-phosphate 

LDV laser-Doppler vibrometry 

LWS loose-wire syndrome 

MHC major histocompatibility complex 

MRI magnetic resonance imaging 

PLF perilymphatic fistula 

PTA four-tone pure-tone average 

QBP quartile benefit plot 

RF resonance frequency 

RNA ribonucleic acid 

SD standard deviation 

SDT severe disabling tinnitus 

SDS speech discrimination score 

SNHL sensorineural hearing loss 

SPV slow phase velocity 

STAMP stapedotomy minus prosthesis 

UCL uncomfortable level 

VAS visual analogue scale 

VEMP vestibular-evoked myogenic potentials 

VFP visual feedback posturography 

VOG video-oculography 

8

Abstract 

Abstract 

The era of modern surgical treatment of otosclerosis started in 1956, when Shea 

successfully removed stapes and reconstructed the ossicular chain with a Teflon prosthesis 

after sealing the oval window with a thin skin graft. Total stapedectomy is still used 

successfully, but more commonly today only a small opening is made in the stapes 

footplate with a micro-drill or laser. Through the small stapedotomy opening a piston 

prosthesis attached to the long process of the incus can be introduced into the vestibulum 

and only the stapes superstructure is removed. Both techniques are effective in long-term 

restoration of hearing. Surgical treatment still contains the risk of inner ear damage, but 

with in last few decades the risk of sensorineural hearing loss (SNHL) has decreased 

significantly. This could be due to technical evolution in equipment (laser, microscope, 

instruments, prosthesis) used in surgery, but also the trend favouring stapedotomy might 

have some effect. In the early stages of stapes surgery, only one ear was operated on 

because of the fear of SNHL. Nowadays, more surgeons are willing to operate on both 

sides since the safety of stapes surgery has increased markedly. Simultaneous bilateral 

surgery has not been reported in stapes surgery, but has been introduced with success in 

ophthalmology and orthopaedic surgery. Simultaneous surgery would give the patient the 

opportunity to gain advantages of bilateral hearing within one session, with less time spent 

in hospital and on sick leave. Although SNHL after surgery is rare, vestibular symptoms 

are common. Fortunately, vestibular symptoms are usually mild and short lasting, but in 

some cases they can prevent the patient to be treated as outpatient. The mechanism for 

vestibular symptoms and the exact end organ affected is still unveiled. This thesis presents 

the results of experimental simultaneous bilateral stapes surgery, and vestibular symptoms 

and findings before and after unilateral stapes surgery. In addition, we explore reasons for 

outpatient failures in otosclerosis surgery. 

Study I examines the outcome of simultaneous bilateral surgery. Both ears of patients 

suffering from bilateral otosclerosis were operated on in a single session. Hearing and 

balance of patients were objectively measured during the one-year follow-up. Hearing was 

evaluated with standard pure tone and speech audiograms and vestibular apparatus with 

visual feedback posturography (VFP). Subjective estimation of hearing, vestibular 

symptoms and quality of life were assessed with questionnaires. In study II, reasons for 

outpatient failures in stapes surgery were explored. Forty-seven consecutive stapedotomies 

and stapedectomies performed by the same surgeon as outpatient surgeries were included. 

Applicability of these two operative methods for outpatient surgery was examined and the 

effect of failures on hearing results were analysed. Postoperative vestibular symptoms and 

the end organ(s) affected were investigated in studies III and IV. With video-oculography 

(VOG), eye movements were measured preoperatively and at one week, one month and 3 

months postoperatively in the first phase (III). In the second phase (IV), recordings were 

obtained at a mean of four hours postoperatively. 

9

Abstract 

The hearing results of the simultaneous bilateral surgery were comparable with those of 

the unilateral surgeries reported in the literature. No significant or bilateral complications 

occurred. Recovery from the operation was fast, and all patients were discharged from 

hospital on the first postoperative day, as planned. Half of the patients had vestibular 

symptoms within the first postoperative week, but no one estimated these as having more 

than a mild to moderate influence on their daily activities. All vestibular symptoms 

resolved and VFP results returned to normal levels in all patients. Significant 

improvement in performance and quality of life was noted already month after operation 

in subjective evaluations provided in the questionnaires, and the effect persisted 

throughout the study period. In evaluation of unplanned admissions in Study II, 

significantly more outpatient failures occurred for medical reasons in the stapedectomy 

group (13%) than in the stapedotomy group (2%). All of these patients suffered from 

vestibular symptoms, but in every case patients were discharged from hospital on the first 

postoperative day in good health. Patients with unplanned admission had similar 

postoperative hearing results as the rest of the study group. VOG measurements in Study 

III did not present any specific type of nystagmus in patients having vestibular symptoms 

postoperatively. However, VOG measurements immediately after surgery (IV) revealed 

nystagmus consistent with a minor disturbance of the semicircular canals in 33% of the 

patients. Subjectively, half of the patients reported vestibular symptoms that could have 

originated from both otolith and semicircular canal parts of the vestibular organ. 

Based on the results of Study I, simultaneous bilateral surgery is a suitable approach in 

bilateral otosclerosis. But at an early stage of introduction of a new treatment protocol, one 

should remain conservative and advocate this treatment only to voluntary patients with 

primary operations and normal anatomical conditions. Because there were significantly 

more unplanned admissions with stapedectomy in Study II, stapedotomy should be 

favoured if outpatient surgery is planned. Signs of semicircular canal disturbance were 

present in Study IV, but no specific nystagmus pattern could be detected in patients with 

vestibular symptoms after the surgery in Studies III and IV. This leads to the conclusion 

that vestibular symptoms probably have diverse origins. 

10

Tiivistelmä (Finnish summary) 


Moderni otoskleroosikirurgian aikakausi alkoi 1956, jolloin Shea poisti ensimmäistä 

kertaa onnistuneesti jalustimen ja korvasi sen keinotekoisella proteesilla. Syntyneen 

sisäkorva-avanteen hän sulki ohuella ihosiirteellä. Täydellinen jalustimen poisto 

(stapedektomia) on edelleen kliinisessä käytössä, mutta nykyisin useammin jalustimen 

levyyn tehdään pieni reikä (stapedotomia) laseria tai poraa käyttäen. Jalustimessa olevan 

reiän läpi alasimeen toisesta päästä kiinnitetty mäntämäinen proteesi ulottuu sisäkorvaan 

ja ainoastaan jalustimen haarakkeet poistetaan. Kuulonparannus saavutetaan hyvin 

molemmilla tekniikoilla ja tulokset ovat pitkäaikaisseurannoissa olleet pysyviä. 

Kirurgiseen hoitoon liittyy edelleenkin pysyvän sisäkorvavaurion riski, mutta vuosien 

saatossa riski sisäkorvakuulon heikkenemiselle vaikuttaa selvästi pienentyneen. Tämä 

positiivinen muutos voi johtua kehityksestä välineistössä (laser, mikroskooppi, kirurgiset 

instrumentit, proteesit), mutta myös stapedotomian yleistyminen saattaa vaikuttaa asiaan. 

Alkuvaiheessa ainoastaan potilaan toinen korva leikattiin koska pelättiin mahdollista 

sisäkorvakuulon heikkenemistä. Nykyisin yhä useammat korvakirurgit leikkaavat 

molemmat korvat, koska myöhemmin julkaistuissa seurannoissa riski sisäkorvakuulon 

heikkenemiselle on pienentynyt verrattuna alkuvaiheen tuloksiin. Samanaikaista 

molemminpuolista leikkausta ei otoskleroosikirurgiassa ole aiemmin kuvattu, vaikka esim. 

silmäkirurgiassa ja ortopediassa samanaikainen molemminpuolinen kirurgia on 

osoittautunut käyttökelpoiseksi. Samanaikainen molempien korvien leikkaaminen 

mahdollistaisi potilaalla stereokuulon hyödyt heti yhden leikkauksen jälkeen ja vähemmän 

aikaa kuluisi sairaalassa ja sairaslomalla. Vaikka sisäkorvakuulon heikkeneminen 

leikkauksen jälkeen on harvinaista, tasapainoelinoireet leikkauksen jälkeen ovat yleisiä. 

Useimmiten nämä kuitenkin ovat lieviä ja lyhytkestoisia, mutta joskus kotiutus lykkäytyy 

seuraavaan päivään päiväkirurgiseksi suunnitellulla potilaalla huimauksen takia. 

Huimauksen syntymekanismi ja siihen liittyvät tasapainoelimen osa(t) ovat selvittämättä. 

Tässä väitöskirjassa esitetään tulokset kokeellisesta samanaikaisesta molemminpuolisesta 

otoskleroosikirurgiasta. Lisäksi esitetään minkälaisia tasapainoelinoireita ja löydöksiä 

liittyy perinteiseen yhden korvan leikkaamiseen sekä syitä, jotka johtavat päiväkirurgisen 

hoidon epäonnistumiseen. 

Ensimmäinen tutkimus (I) keskittyy samanaikaiseen molemminpuoliseen leikkaukseen. 

Molemminpuolista otoskleroosia sairastavien potilaiden korvat leikattiin peräkkäin 

samana päivänä. Potilaiden kuulotuloksia ja tasapainoelimen toimintaa seurattiin 

objektiivisin mittarein vuoden ajan. Kuulontutkimuksina tehtiin standardoidut äänes- ja 

puhekuulonmittaukset ja tasapainoelimen toimintaa seurattiin tasapainolevyn avulla. 

Potilaat antoivat omat subjektiiviset arviot kuulostaan, huimausoireistaan ja 

elämänlaadusta kyselykaavakkeiden avulla. Toinen tutkimus (II) selvittää syitä, jotka 

johtavat päiväkirurgisen hoidon epäonnistumiseen. Neljäkymmentäseitsemän peräkkäistä 

päiväkirurgiseksi suunniteltua saman kirurgin leikkaamaa stapedotomia ja stapedektomia 

potilasta otettiin mukaan tutkimukseen. Selvitimme, miten eri leikkaustekniikat soveltuvat 

päiväkirurgisesti tehtäviksi sekä sairaalaan jäännin syitä ja näiden vaikutusta 

kuulotuloksiin. Tutkimuksissa III ja IV selvitetään leikkauksen jälkeisen huimauksen 

11


luonnetta ja määrää sekä mahdollista tasapainoelimen osaa oireiden takana. Videookulografian 

(VOG) avulla mitattiin nystagmusta ennen ja jälkeen leikkauksen. 

Ensimmäisessä vaiheessa (III) tehtiin mittauksia ennen leikkausta sekä viikko, kuukausi ja 

3 kuukautta leikkauksen jälkeen. Seuraavassa vaiheessa (IV) mittaukset tehtiin potilaille 

noin neljä tuntia leikkauksen jälkeen. 

Samanaikaisen molemminpuolisen leikkauksen tulokset kuulon osalta ovat samanlaiset 

kuin kirjallisuudessa raportoidut toispuolisen leikkauksen tulokset. Tutkimussarjassa ei 

esiintynyt molemminpuolisia komplikaatioita. Potilaat palautuivat leikkauksesta nopeasti 

ja kaikki kotiutettiin leikkausta seuraavana päivänä kuten oli suunniteltu. Puolella 

potilaista oli tasapainoelinoireita ensimmäisen viikon aikana, mutta oireilla ei ollut 

merkitsevää vaikutusta potilaiden päivittäiseen elämiseen. Kaikilla potilailla 

tasapainoelinoireet hävisivät ja tasapainolevytulokset palautuivat normaalille tasolle. Jo 

kuukausi leikkauksen jälkeen potilaat ilmoittivat elämänlaadun parantuneen merkitsevästi 

ja tämä vaikutus säilyi tutkimuksen loppuun saakka. Päiväkirurgiaa selvittävässä 

tutkimuksessa (II) potilailla, joille tehtiin stapedektomia, oli merkitsevästi enemmän 

lääketieteellisistä syistä johtuvia sairaalaan jäämisiä kuin potilailla, joille tehtiin 

stapedotomia (13% vs. 2%). Kaikilla näillä potilailla oli sairaalaan jäämisen syynä 

tasapainoelinoireet. Kuitenkin kaikki potilaat voitiin kotiuttaa leikkausta seuraavana 

päivänä hyväkuntoisina. Kuulotuloksissa ei ollut eroa päiväkirurgisesti hoidettujen ja 

sairaalaan jääneiden välillä. VOG-mittaukset tutkimuksessa III eivät paljastaneet tietyn 

tyyppistä nystagmuslöydöstä tasapainoelinoireisilla potilailla. VOG-mittaukset 

välittömästi leikkauksen jälkeen osoittivat kuitenkin merkkejä kaarikäytävien ärsytyksestä 

33 % potilaista. Puolella potilaista oli subjektiivisesti tasapainoelinoireita, jotka kliinisesti 

voitiin arvioida syntyneiksi joko kaarikäytävä- tai otoliittielinärsytyksen takia. 

Tutkimuksen I tulosten perusteella voi päätellä, että samanaikainen molemminpuolinen 

leikkaaminen on sovellettavissa otoskleroosikirurgiaan. Kuitenkin koska kokemuksia on 

kertynyt vasta vähän, tulee samanaikaista molempien korvien leikkaamista tarjota vain 

vapaaehtoisille potilaille, joilla korvia ei ole aiemmin leikattu ja anatomia on normaali. 

Koska stapedektomia johti merkitsevästi useammin potilaan suunnittelemattoman 

jäämisen sairaalaan, on suositeltavaa valita stapedotomia leikkaustekniikaksi 

päiväkirurgisiksi suunnitelluilla potilailla. Vaikka välittömästi leikkauksen jälkeisissä 

mittauksissa oli löydöksiä kaarikäytävä-ärsytyksestä, tutkimuksissa III tai IV ei löytynyt 

tasapainoelinoireisilta potilailta erityistä yhteistä nystagmustyyppiä. Tästä voi päätellä, 

että tasapainoelinoireilla on monitahoinen syntymekanismi. 

12

1 Introduction 

Introduction 

Otosclerosis is a disease of the otic capsule and middle ear ossicles. It is more common in 

Caucasian populations. Histological incidence in Caucasians varies between studies from 

3.4% to 13% (Guild 1944, Schuknecht and Kirchner 1975, Hueb et al. 1991, Declau et al. 

2007). Histologically, alternating phases of bone formation and resorption occur. After 

repeated cycles of remodelling, highly mineralized sclerotic bone is created. If a 

stapediovestibular joint is invaded by the disease, a clinical picture of conductive hearing 

loss is formed. Only about 10% of patients develop clinical otosclerosis with conductive 

hearing loss with or without a sensorineural component (Menger and Tange 2003). 

Valsalva was the first to describe hearing loss due to stapes ankylosis in 1704 (Politzer 

1981, Hausler 2007). About 140 years later, Meniere described a patient whose hearing 

was temporarily improved by tapping on the stapes with a small gold rod. In the late 19th 

century, many surgeons have performed stapes mobilization. However, in 1899, at the 6th 

international otology congress, leading otologists of the time proclaimed stapes surgery 

useless, dangerous and unethical and banned the procedure (Shambaugh and Glasscock 

1980, Hausler 2007). Thus, the development of stapes surgery halted for 50 years. During 

these five decades, a fenestration operation for otosclerosis was performed. Passow 

presented the idea of a third window that could be created in the promontory and covered 

with tympanic membrane in 1897. It did not become common practise, but did evolve to 

the one stage operation of semicircular canal fenestration described by Lembert in 1932. 

In 1952, while performing Lembert's fenestration operation, Rosen accidentally mobilized 

the stapes and rediscovered its positive effect on hearing. The advantages of stapes 

surgery, as compared with fenestration, were a reduction in the time needed for immediate 

recovery and the absence of a large postoperative cavity. Stapes surgery once again 

became acceptable (Shambaugh and Glasscock 1980, Hausler 2007). 

In addition to Rosen’s discovery, innovations in the early 20th century improved operative 

results and made more advanced procedures possible. An important technical step forward 

was the introduction of the electric head light and the surgical microscope (Shambaugh 

and Glasscock 1980). Another large advance in medicine was the beginning of the clinical 

use of antibiotics in the 1930s' (Huovinen and Vaara 2005). 

The era of modern stapes surgery began in 1956, when Shea successfully removed stapes 

and reconstructed the ossicular chain with a Teflon prosthesis after sealing the oval 

window with a thin skin graft (Shea 1956). In 1958, Shea presented a technical note of 

stapedectomy, where the oval window was sealed with vein graft and reconstruction was 

performed with the posterior crus of stapes or with a polyethylene tube. This new state-ofthe-art 

reconstruction of the ossicular chain was found to be far superior to the former 

mobilization operations, and thus, became the standard. Many modifications of 

stapedectomy have been developed using different sealing materials such as fat, fascia, 

gelatin foam and perichondrium, and the prosthesis has been constructed with such 

material as steel, tantalum, platinum and bone. Some methods were more prone to 

13

Introduction 

complications, for example the use of a polyethylene tube prosthesis and gelatin foam as a 

sealing material (Shambaugh and Glasscock 1980, Shea 1988, Hausler 2007). The 

fenestration of the oval window had also evolved. Partial stapedectomy was suggested by 

Plester to diminish inner ear irritation, and by the 1960s small-opening stapedotomy was 

also introduced for the same reason (Shea 1988, Hausler 2007). Both techniques, total 

removal of the footplate (stapedectomy) and small-opening stapedotomy, are still in use 

and have proven successful in the long-term restoration of hearing (House et al. 2002, 

Aarnisalo et al. 2003). 

Unfortunately, stapes surgery has a risk of inner ear damage, leading to SNHL or balance 

problems. Studies presented during the last decades have shown a significantly lower risk 

of inner ear damage than earlier studies (Ludman and Grant 1973, Daniels et al. 2001, 

Vincent et al. 2006). This could be due to technical advancements (laser, microscope, 

instruments, prosthesis) in surgery, but the trend favouring stapedotomy may also have an 

effect. Formerly, surgery was performed on only one of the patient’s ears. This was due to 

the risk of SNHL which could occur even years after surgery (Ludman and Grant 1973, 

Hammond 1976, Smyth et al. 1975). Nowadays, more surgeons are willing to operate on 

both sides, probably because of the improved safety record of stapes surgery (Raut et al. 

2002). Simultaneous bilateral surgery has not been reported in stapes surgery, even though 

simultaneous surgery in ophthalmology has been performed for decades (Guo et al. 1990, 

Beatty et al. 1995, Arshinoff et al. 2003, Sarikkola et al. 2004). Both types of surgeries 

involve major sensory organs and, as such, have a similar profile of complications. If 

bilateral complications were to occur for either sense, the result would be a major 

deterioration in perception, the only difference being that in the case of blindness there are 

markedly less opportunities for rehabilitation. 

Although sensorineural hearing loss after surgery is unusual, vestibular symptoms after 

surgery are very common. Fortunately, vestibular symptoms are usually mild and short 

lasting (Aantaa and Virolainen 1978, Birch and Elbrond 1985, Wang et al. 2005). The 

exact end organ affected is unknown. The number of studies focusing on vestibular 

symptoms is limited, despite there being many studies on postoperative hearing. This is 

probably because long-lasting symptoms are rare, and these symptoms have not been 

shown to be related to hearing results (Aantaa and Virolainen 1978). Naturally, hearing 

improvement has been the main interest of surgeons and patients. Today's trend towards 

outpatient surgery has however, made studies concerning vestibular symptoms more 

important. A patient with major postoperative vestibular symptoms cannot be treated as an 

outpatient. 

This thesis concentrates on three different areas of stapes surgery. First, the results of 

simultaneous bilateral stapes surgery are presented and discussed. There is no current 

literature addressing this issue. Second the applicability of stapes surgery in an outpatient 

setting is evaluated, and differences between operative methods are compared. Third, 

video-oculography (VOG) is used to investigate the cause of vestibular symptoms. 

14

2 Review of the literature 

2.1 Definition of otosclerosis 

Review of the literature 

Otosclerosis is a disorder of the bony labyrinth and middle ear ossicles (Schuknecht 

1974). A distinction should be made between histological (nonclinical) and clinical 

otosclerosis. Patients may have histological otosclerosis without any clinical symptoms 

(Guil 1944). Schuknecht and Kirchner (1974) defined clinical otosclerosis as stapes 

fixation due to an otosclerotic lesion. In the literature, the term "cochlear otosclerosis" has 

an ambiguous meaning. Cochlear otosclerosis can mean the disease has replaced part of 

the endosteal layer of cochlear bone (Schuknecht and Kirchner 1974) or it can be used to 

describe SNHL assumed to be caused by otosclerosis (Balle and Linthicum 1984). 

2.2 Histology of otosclerosis 

In 1912, Siebenmann, using a microscope, found that patients with otosclerosis presented 

with spongiform foci in temporal bone. This is why the term otospongiosis is also used in 

literature. In these spongiform lesions, endochondral bone is resorbed by osteoclasts and 

osteolytic osteocytes. Lesions extend into the surrounding bone as lacunae. These lacunae 

contain a vascular space rich in fibroblasts and osteoblasts. Multitinuclear osteoclasts are 

also present in the centre and osteolytic osteocytes at the advancing edges. As a result, the 

bone is disorganized, containing an enlarged marrow, where new immature bone is 

produced and again resorbed. After many remodelling cycles, sclerotic, highly mineralized 

bone is created. It has a mosaic-like appearance caused by irregular patterns of resorption 

and subsequent deposition of fatty tissue in marrow spaces. An otosclerotic focus typically 

contains areas of differing activity (Linthicum 1993, Schuknecht 1974, Declau et al. 

2001). 

An otosclerotic focus is found only in the temporal bone and middle ear ossicles 

(Schuknecht 1974, Wang et al. 1999). Although otosclerosis may involve any area of 

temporal bone, the place of predilection is in the oval window region. Early studies by 

Guil (1944) and Nylen (1949) showed that 80-90% of foci occur in this area. Multiple foci 

are present in 35-45% of ears, but more than three foci are rare. Another common site is 

the round window area, which is involved in 30-40% of patients (Guil 1944, Nylen 1949). 

Otosclerosis may also involve the middle ear ossicles. A solid otosclerotic focus of stapes 

without involvement of the stapediovestibular joint was found in 12% of patients in Guil's 

(1944) study. An otosclerotic focus in the incus or malleus is rare. A study of 144 

temporal bones described three instances of a malleolar focus and one case involving the 

incus (Hueb et al. 1991). Otosclerosis is usually bilateral. Hueb et al. (1991) reported a 

bilateral incidence of 76%, which is consistent with previous studies (Guil 1944, Nylen 

1949). 

15


The stapes footplate encloses the oval window. The articulation between the footplate and 

the oval window is a syndesmotic joint, which is held together by an annular ligament 

(Schuknecht 1974). An otosclerotic focus may invade this joint. The process begins with 

the calcification of the ligament, leading to diminished mobility. If the active process 

continues, the ligament and joint are replaced by otosclerotic bone, completely 

immobilizing the joint. The entire footplate and joint may be replaced, leading to a 

"obliterated footplate" (Linthicum 1993). The otosclerotic process may also invade the 

cochlea and labyrinth. Atrophy and hyalinization of the spiral ligament are seen in areas in 

close contact with a lesion. But even in advanced cochlear otosclerosis, the original 

anatomical configuration of the bony labyrinth is usually preserved (Schuknecht 1974, 

Linthicum 1993). 

2.4 Epidemiology 

Histological otosclerosis 

Otosclerosis is more common in Caucasians than in Black, Asian or Native North 

American populations (Guild 1944, Altmann et al. 1967). The incidence of histological 

otosclerosis among Caucasian populations in different studies has varied from 3.4% to 

13% (Guild 1944, Schuknecht and Kirchner 1974, Hueb et al. 1991, Declau et al. 2001). 

Histological studies have shown a female predominance, with the highest incidence 

between the ages of 30 and 49 years (Guild 1944, Altmann et al. 1967). In Guilds' (1944) 

study, 84 Caucasians under the age of 10 years were also included, and two cases of 

histological otosclerosis were found in this group. Bilateral involvement was present in 

70% of the cases, with a noticeable male predominance. Histological otosclerosis occurred 

bilaterally in 88% of male and 44% of female patients. This was contrary to the study by 

Hueb et al. (1991), who observed bilateral occurrence to be more common among women 

(89%) than men (65%). The total incidence of bilateral disease, 76%, was in keeping with 

Guild's (1944) results. Although discrepancies exist concerning the female:male ratio in 

histological studies, the epidemiological results are compelling. In Lithuania, 73% of the 

974 patients with clinical otosclerosis were females, yielding a ratio of 3:1 (Gapany- 

Gapanavicius 1975). In Norway, the overall female:male ratio was 3:2, with variation 

from 1:1 to 2:1 between different areas of Norway (Hall 1974). In a recent study of 64 112 

patients in Germany between 1993 and 2004, the overall distribution was 1.6:1 

(female:male) (Arnold et al. 2007). 

16

Clinical otosclerosis 


According to Altmann et al. (1967), 12% of temporal bones with histological otosclerosis 

also have an ankylosis of the stapediovestibular joint. Histological otosclerosis was found 

in 8.3% of the bones. This translates into a prevalence of approximately 1% for clinical 

otosclerosis in the general population. The prevalence of clinical otosclerosis in 

epidemiological studies has been significantly less. Hall (1974) reported a prevalence of 

0.3% in the Norwegian general population. Similar results of 0.2% and 0.1% have been 

observed by others (Pearsson et al. 1974, Gapany-Gapanavicius 1975). Declau et al. 

(2001) criticize earlier histological studies because extrapolated clinical prevalences were 

not in concordance with epidemiological studies. Declau postulated that temporal bones 

used in those studies might be biased, as they were collected on request by an otologist. 

There would probably be more otological diseases when compared to the general 

population. He collected 118 pairs of temporal bones from the allograft temporal bone 

bank. Donors fulfilled selection criteria for donating tympano-ossicular grafts, and 

because of this, 46% of bones did not include the stapes footplate. The histological 

incidence was 3.4%, which translates into a clinical prevalence of 0.3-0.4% when the 

figures from Altmann et al. (1967) are used (Declau et al. 2001). 

Although epidemiological studies in Finland have not been done, during 2000-2006 an 

annual average of 577 patients were hospitalized due to otosclerosis (ICD10: H80.0-80.9) 

(STAKES 2007). This figure provides a mean incidence of 0.01% for this period. If one 

assumes that otosclerosis mostly occurs during a 50-year period of life, the computational 

prevalence would be 0.5%. This is close to the results of Vartiainen and Vartiainen 

(1997b), who reported a prevalence of 0.33% in the Finnish population (living in Kuopio) 

born between 1948 and 1962. The mean age at time of surgery was between 40 and 50 

years in Finland (Vartiainen 1999, Aarnisalo et al. 2003) as well as in Germany 

(Niedermeyer et al. 2001). Niedermeyer et al. (2001) also showed a decreased incidence of 

otosclerosis between the ages of 20-40, which shifts the patients’ mean age closer to 50 

during 1978-1999. No comparable data have been gathered in Finland. 

2.3 Aetiology 

The aetiology of otosclerosis has not been fully unveiled despite numerous studies. 

Epidemiological studies have shown a genetic pattern of autosomal dominant inheritance 

with reduced penetrance. There are also environmental factors affecting the manifestation 

of otosclerosis. The interaction between these factors is very poorly understood. Recent 

gene expression analysis of human otosclerotic stapedial footplates showed 110 genes that 

were expressed differently compared with controls. These genes showed multiple 

pathways that could lead to bone remodelling, for example interleukin signalling, 

inflammation, p53 signalling, apoptosis, epidermal growth factor receptor signalling and 

an oxidative stress response (Ealy et al. 2008). Thus, otosclerosis appears to have multiple 

aetiologies. 

17

Genetic inheritance 


In epidemiological studies, a familial component has been well established. The majority 

of epidemiological studies on families with otosclerosis suggest autosomal dominant 

inheritance with approximately 40% reduced penetrance (Moumoulidis et al. 2007, 

Markou and Goudakos 2008). Fowlers’ (1966) study of 40 identical twins is considered be 

pivotal in demonstrating genetic aetiology. Fowlers found that in all but one case both 

twins suffered from clinical otosclerosis, and in 40% of cases there was a family history of 

otosclerosis. Current genetic linkage studies have been able to map the presence of nine 

different loci. But the causative genes associated with these loci have not been identified, 

and the molecular process is unknown (Moumoulidis et al. 2007, Markou and Goudakos 

2008). Therefore, it is not known whether genetic factors influence the histological 

manifestation of the disease, the progression to clinical disease, or both. One gene 

associated with otosclerosis is COLA1, the error of which leads to osteogenesis imperfecta 

(type I). Histological similarities exist between these two entities, and some authors have 

suggested that otosclerosis is a local manifestation of osteogenesis imperfecta (type I) 

(McKenna et al. 2002). Although a familial link is well established, 40-50% of clinical 

cases are sporadic (Sabitha et al. 1997, Moumoulidis et al. 2007, Markou and Goudakos 

2008). 

Viral aetiology 

The best-established environmental factor connected to otosclerosis is the measles virus. 

Viral aetiology was first associated with Paget's disease. The similarities between 

otosclerosis and Paget's disease have led researchers to study the viral aetiology of 

otosclerosis (Mills and Singer 1976). McKenna and Mills (1986) found pleomorphic 

filamentous structures on the otosclerotic focus in an electron microscopy study. These 

structures resembled the nucleocapsids of subacute sclerosing panencephalitis, a variant of 

the measles virus. Arnold and Friedmann (1987) demonstrated the antigenic expression of 

measles and rubella at the otosclerotic focus, and these results were confirmed by 

McKenna and Mills (1989, 1990). Elevated antimeasles antibodies have been detected in 

perilymph samples collected during stapedectomy (Niedermeyer and Arnold 1995). On 

the other hand, lower levels of circulating antimeasles antibodies have been found in 

patients with otosclerosis (Lolov et al. 2001). The former is thought to demonstrate 

specific immune reactions stemming from the endolymphatic sac, which are evoked by 

antigens in the otosclerotic focus near the perilymphatic space (Niedermeyer and Arnold 

1995). The latter may demonstrate patients' susceptibility to measles infection or 

activation, but whether diminished circulating humoral response is a cause or a 

consequence of local measles infection is unclear (Lolov et al. 2001). A specific virus has 

not been isolated, but measles virus ribonucleic acid (RNA) has been detected within the 

otosclerotic focus of the stapes footplate. In a study of 116 patients with stapedectomy, 

Karosi et al. (2007) observed measles virus RNA in all footplates with a histological 

focus. There were also 29 stapediovestibular joint fixations where histological 

18


examination revealed annular stapediovestibular calcification or fibrosis without 

histological otosclerotic focus. These latter specimens and all 25 control bones lacked 

evidence of measles RNA. Similarly, the expression of a virus binding receptor (CD46) 

was increased substantially in footplates with a histological focus. Measles virus RNA has 

been thought to be evidence of the presence of a vital virus because without active viral 

replication, RNA rapidly disintegrates. 

Epidemiological reports of a decreased incidence of otosclerosis after a measles 

vaccination programme also support the presence of a viral aetiology (Vrabec and Coker 

2004, Arnold et al. 2007). Arnold et al. (2007) presented a study of 64 112 patients with 

otosclerosis in Germany in 1993-2004. He found a significantly decreased incidence of 

hospital treatments for otosclerosis in vaccinated patients during this time period as 

compared with unvaccinated individuals. The effect was more marked among men than 

among women. In Germany, the measles vaccine has been available since 1974 (Arnold et 

al. 2007). Paradoxically, there is actually a lower incidence of otosclerosis in undeveloped 

countries, where measles continues to be widespread (Uzicanin et al. 2002, Tshifularo and 

Joseph 2005). 

Endocrinological factors 

Pregnancy has been suggested to cause onset or progression of otosclerosis. The incidence 

of the disease is more common in women, and some studies have shown that pregnancy 

can aggravate symptoms (Precechtel 1967, Gristwood and Venables 1983). Lippy et al. 

(2005) criticized former studies for being uncontrolled and lacking age-adjustment. His 

age-adjusted study of 94 otosclerotic women revealed no negative effect on any outcome 

measurements (hearing levels, age at time of surgery, incidence) caused by pregnancy 

(Lippy et al. 2005). Abnormal parathyroid hormone function is another factor postulated 

to be involved in the aetiopathogenesis of otosclerosis. Grayelin et al. (1999) showed that 

expression and function of parathyroid hormone receptors in otosclerotic stapes footplates 

were lower than in bones collected from the external ear canal. However, in the same 

article, he concluded that this is probably not the triggering event in pathogenesis, but a 

consequence of abnormal regulation of bone matrix protein metabolism caused by another 

aetiological factor like measles infection. Similarly, glucocorticoids and the reninangiotensin-aldosterone 

system have altering effects on bone remodelling of otosclerotic 

bone in in vitro studies, but these are more likely to be epiphenomena of the disease 

(Imauchi et al. 2006, 2008). 

Immunological factors 

Otosclerosis being an autoimmune disease was suggested by Yoo (1984). He detected 

elevated levels of the collagen II antibody in otosclerotic patients compared with controls. 

In a study of rats with lesions resembling human otosclerosis, raised titres of antibody to 

19


type II collagen were present after immunization with bovine cartilage collagen (Yoo 

1984). Sørensen et al. (1988) found no differences in antibody titres or histological 

evidence in otosclerosis-like lesions with type II collagen autoimmunity. However, many 

researchers have since detected elevated antibody levels (Reshetnikov and Popova 1992, 

Bujia et al. 1994, Lolov et al. 1998). Lolov et al. (1998) postulate that the elevated 

amounts of antibodies demonstrate a transient foreign antigen response to antigen turnover 

in the active otosclerotic lesion rather than an actual cause of the disease. This is supported 

by the histological study of Niedermeyer (2007) in which 30 footplates were collected 

during stapedectomy and compared with 30 control specimens obtained from autoptic 

temporal bones. No differences were seen in expression of type II collagen, and no 

inflammation was present in the cartilage tissue. 

Human leucocyte antigen (HLA) is an international designation for the region comprising 

the major histocompatibility complex (MHC). By analysing HLA antigenic determinants 

of the MHC, one can find an association between specific HLA genotypes and 

autoimmune diseases. Once again, there is diversity in the literature concerning 

otosclerosis and the HLA system (Pedersen et al. 1983, Dahlqvist et al. 1985, Singhal et 

al. 1999). No consistent association between these two has been established (Moumoulidis 

et al. 2007). 

In summary, the aetiology of otosclerosis in individual patients remains unveiled in most 

cases. Genetic inheritance is demonstrated in about half of the cases, but the pathological 

process and the influence of environmental factors probably vary in different families. The 

connection between measles virus and otosclerosis is well established. The low incidence 

of otosclerosis in undeveloped countries, where measles continues to be widespread, 

demonstrates the need of genetic susceptibility. At the moment, no reliable connections 

exist between environmental or endogenous factors – other than measles virus – and 

otosclerosis. Pathological processes other than otosclerosis may have biased aetiological 

studies if the diagnosis has only been made clinically because in 25% of patients with 

clinically diagnosed otosclerosis treated with stapedectomy, no histological proof for 

otosclerosis was found (Karosi et al. 2007). 

2.5 Clinical findings and pathogenesis of otosclerosis 

Conductive hearing loss 

In clinical otosclerosis, there is conductive hearing loss due to stapes fixation (Schuknecht 

and Kirchner 1974). Conductive hearing loss is attributable to decreased motility in the 

stapediovestibular joint. At early stages, only low-frequency hearing loss is noticeable. 

But if the disease remains active and the footplate becomes increasingly immobile, 

20


hearing loss will eventually occur across all frequencies. If there is no SNHL, the total 

hearing loss due to otosclerosis is limited to a maximum of 60-65 dB (Maureen 1993). 

Sensorineural hearing loss 

Otosclerotic patients may also suffer from SNHL. Whether SNHL is connected to 

otosclerosis is still under debate (Nelson and Hinojosa 2004). Audiological study of 122 

patients with otosclerosis by Feldman (1960) demonstrated no connection between SNHL 

and duration of disease when age adjusted presbyacusis was noticed. Since the patients 

had no surgical interventions, patients without otosclerosis may have been included. Many 

authors have evaluated long-term hearing results of otosclerosis after stapes surgery. Birch 

et al. (1986) presented results showing that in a group of 925 patients 15 years after 

surgery bone conduction decrement was comparable with presbyacusis. These results have 

been confirmed by other authors (Del Bo et al. 1987, Aarnisalo et al. 2003, Vincent et al. 

2006). Surgery may affect the inner ear. If postoperative results show more regression 

than expected with presbyacusis, the question would be whether this regression is caused 

by surgery or by the otosclerosis itself. Shin et al. (2001) presented preoperative results of 

437 patients and found a significant correlation between otosclerosis with endosteal 

involvement and SNHL. Endosteal extension of the pericochlear focus was observed by 

computed tomography (CT) scan, and clinical diagnosis was confirmed at the time of 

surgery. Another large study by Topsakal et al. (2006) examined the preoperative hearing 

results of 1064 patients and found significant SNHL in patients with otosclerosis that 

exceeded presbyacusis. In all cases, diagnosis was confirmed during surgery. 

Many mechanisms have been suggested to cause SNHL in patients with otosclerosis. The 

earliest of these, presented by Siebenmann in 1899, was the suggestion that SNHL was 

caused by the liberation of toxic metabolites into inner ear (Balle and Linthicum 1984). 

Proteolytic enzymes were later detected in inner ear fluids (Chevance et al. 1970, Causse 

and Chevance 1978), supporting Siebenmann’s theory. Otosclerosis with endosteal 

involvement in the cochlea may lead to the diffusion of metabolites harmful to hair cells 

into the perilymph (Causse et al. 1989). Other authors have suggested that vascular shunts 

between the otosclerotic focus and spiral capillaries leads to venous congestion of the 

modiolus and distortion of the cochlear capsule, with a relaxation of the basilar membrane 

might be the cause of SNHL (Ruedi 1969, Balle and Linthicum 1984). Conflicting results 

have emerged concerning the correlation between histological findings and hair cell loss 

and atrophy of cochlear neurons. Histological support for the cochlear otosclerosis theory 

is offered by Parahy and Linthicum (1983), who, after analysing 46 otosclerotic bones, 

found a significant correlation between active otospongiotic foci and spiral ligament 

hyalinization, leading to atrophy of stria vascularis. This was supported by Abd el- 

Rahman (1990) and Doherty and Linthicum (2004). However, many authors have found 

no significant correlation between cochlear otosclerosis and hair cell loss or cochlear 

damage (Guil 1944, Elonka and Applebaum 1981, Schuknecht and Barber 1985, Hinojosa 

and Marion 1987, Nelson and Hinojosa 2004). 

21

Vestibular symptoms 


There are no characteristic vestibular symptoms in otosclerosis. Cody and Baker (1978) 

present an analysis of vestibular symptoms in 500 patients with otosclerosis. Of their 

patients, 46% suffered from vestibular symptoms. They identified six different types of 

vertigo. The frequency and severity of these symptoms were connected to SNHL. The 

most common type was a recurrent attack of true vertigo or severe imbalance without a 

hallucination of motion followed by postural imbalance. Recurrent attacks were usually 

associated with nausea and vomiting, typically lasting from one or two hours to several 

days. Frequency varied from daily to annually. In these cases, otosclerosis was usually 

diagnosed with an audiological examination and a CT scan (Cody and Baker 1978). Their 

results may have been biased by other otological diagnoses because there were no surgical 

confirmations and the incidence was higher than in later studies. Aantaa and Virolainen 

(1978) reported a prevalence of vestibular symptoms of only 5%, and Birch (1985) 11% in 

a study involving 722 patients. In both of these studies, the diagnosis was confirmed at 

surgery. The exact mechanism causing these symptoms has not been defined, but Cody 

and Baker (1978) hypothesized that it is similar to the mechanism that causes SNHL. 

Tinnitus 

The prevalence of tinnitus in patients with otosclerosis is reported to be 65-92% 

(Gristwood and Venables 2003, Oliviera 2007). A clear relationship has been found 

between tinnitus and gender, females more often being affected (Gristwood and Venables 

2003). In addition, in their study of 1014 patients with otosclerosis, bone conduction and 

air-conduction levels were paradoxically connected to tinnitus. Patients with more 

profound hearing loss had a decreased prevalence of tinnitus. Other characteristics 

investigated (age, duration of hearing loss, Schwartze sign, footplate macroscopic 

appearance) showed no association with tinnitus. Tinnitus may be present at a low 

intensity and with a negligible effect on daily life, but in some cases it can be severely 

disabling. Oliviera (2007) used a visual analogue scale (VAS) to quantify intensity. 

Intensity values of 7-10 demonstrate severe disabling tinnitus (SDT). The term SDT refers 

to symptoms sufficiently severe to disrupt the patient's routine and prevent them from 

performing their daily tasks (Shulman et al. 1995). In the study by Oliviera (2007), 40% of 

the 48 consecutive patients with otosclerosis had SDT. The intensity of tinnitus was not 

significantly related to preoperative hearing results. Females more frequently reported 

SDT than males (56% vs. 16%). The mechanism of tinnitus according to the 

neurophysiological model of tinnitus by Jastreboff (1990) is compensatory activity of the 

neuronal network induced by hearing loss. 

22

Otosclerosis and Meniere’s disease 


An association exist between otosclerosis and Meniere’s disease. In histological 

evaluation of associated otopathologies in 182 otosclerotic temporal bones, there were 

signs of endolymphatic hydrops in 37 bones, and in six patients (8 bones) clinical 

diagnosis of Meniere’s disease had been made (Paparella et al. 2007) The causal 

relationship between these diseases is still under debate. There are histological reports 

showing occlusion of the endolymphatic duct due otosclerotic foci, leading to 

cochleosaccular hydrops and clinical Meniere’s disease (Franklin et al. 1990, Pollak 

2007). Johnsson et al. (1995) have presented histological signs of cochleosaccular hydrops 

in otosclerotic bones without clear occlusion of the vestibular aqueduct, suggesting a 

possible immunological or biochemical mechanism. This is supported by Klockars and 

Kentala (2007), who in a report of two Finnish families, found Meniere’s disease and 

otosclerosis to be inherited independently. The suggestion was made that these patients 

represent different outcomes of the same gene mutation. Therefore, cochleovestibular 

symptoms of a patient with otosclerosis may be due to Meniere’s disease, which is either 

caused by otosclerosis or exists coincidentally. 

2.6 Diagnosis 

An office-based otomicroscopic examination may reveal the reddening of the promontory, 

which is known as the Schwartze sign, and an otherwise normal otoscopy. If the 

otosclerosis has advanced far enough, tuning fork tests will demonstrate conductive 

hearing loss in the affected ear. As stated previously, the patient may have vestibular 

symptoms or tinnitus. Most patients will present a history of slowly decreased hearing and 

possibly a family history (House and Cunningham 2005). A definitive diagnosis of clinical 

otosclerosis can only be made during surgery, which allows fixation of the 

stapediovestibular joint to be observed and histological samples to be taken. Karosi et al. 

(2007) performed histological examination after 116 stapedectomies, and in 29 cases nonotosclerotic 

ankylosis of stapediovestibular joint was present. These included 21 annular 

stapediovestibular calcifications and 8 polar joint fibroses with a thickened stapedial 

mucosal layer. However, these conditions can be successfully treated surgically. Clinical 

evaluations, which are useful and provide support for diagnosis, are discussed in detail 

below. 

Audiological evaluations 

A standard pure-tone audiogram demonstrates conductive hearing loss and possibly 

SNHL. If serial audiograms are available, a small air-bone gap is first noticed at the lower 

frequencies, which will gradually increase and expand through all frequencies over time. 

A sensorineural decrease at 2 kHz, called the Carhart notch, is often found, but it does not 

23


represent true SNHL, instead being due to a mechanical artefact (Hannley 1993, Probst 

2007). 

A tympanogram is a graphic representation of the change in admittance of sound energy 

through the middle ear as a function of air pressure applied to the sealed ear canal. In most 

cases, patients with otosclerosis represent a normal Type A configuration, where the peak 

compliance is +/-100 daPa, since the middle ear aeration is unaffected. However, a 

lowering of the peak (Type As) as a result of stiffening of the ossicular chain may occur 

(Jerger 1970, Hannley 1993). Stapedius reflex measurements register how the contraction 

of the middle ear muscle affects transmission efficiency. Since clinical otosclerosis 

partially or totally fixates the stapes, the muscular effect is modulated. Typically, at the 

beginning of disease, patients have increased compliance at onset and offset of response. 

Later, when the stapes has become totally fixed, no change in compliance due to sound 

stimulus can be seen. Only offset of compliance change is thought to be pathognomonic 

for early stapes fixation, otherwise stapedius reflex changes are not distinguishable in 

different types of hearing loss due to middle ear pathology (Hannley 1993). 

During standard tympanometry and stapedius reflex measurements a probe tone frequency 

of 226 Hz is commonly used. In multifrequency multicomponent tympanometry, a large 

range of frequencies is used to evaluate the different components of middle ear 

admittance, especially mass and compliant susceptance. Resonance frequency (RF) is the 

frequency at which susceptance due to mass of the eardrum and ossicles is equal to 

compliant susceptance due to stiffness of ligaments and the eardrum. RF has been shown 

to increase in otosclerosis, but results for normal and otosclerotic patients overlap 

considerably (Miani et al. 2000). Laser-Doppler vibrometry (LDV) is another method that 

uses multiple frequencies for testing middle ear dynamics. In LDV, the vibration of the 

tympanic membrane is evaluated with the aid of a laser. This method has shown promising 

results for distinguishing stapes ankylosis, malleus fixation and partial or total ossicular 

interruption (Huber et al. 2001b, Rososwski et al. 2003). A total of 45 patients with 

conductive hearing loss were evaluated in these studies. Larger studies have not yet been 

presented, and the high price of this equipment (70 000 USD, Rososwki et al. 2003) has 

probably slowed the introduction of this method. Otoacoustic emissions are usually not 

present in ears with clinically important conductive hearing loss, but otosclerosis cannot 

be distinguished from other causes (Zhao et al. 2003). 

Radiological evaluations 

Although diagnosis of otosclerosis is based on clinical criteria, CT scan can be used in 

unclear cases. Audiometric findings may be very similar in Pagets' disease, superior 

semicircular canal dehiscence, middle ear malformations, congenital stapes fixation and 

tympanosclerosis. CT has proven valuable in differential diagnostics (Mafee et al. 1985, 

Belden et al. 2003). High-resolution CT can detect an otosclerotic focus in up to 85% of 

patients with clinical otosclerosis (Naumann et al. 2005). The size of the otosclerotic focus 

24


is positively correlated with conductive hearing loss, but cochlear involvement and extent 

of SNHL do not correlate (Derks et al. 2001, Nauman et al. 2005). Although the CT is the 

most valuable radiological examination, magnetic resonance imaging (MRI) is also 

effective in the detection of especially active otospongiotic lesions. Lesions in the lateral 

wall of the labyrinth are sometimes more visible with MRI than with CT, where a partialvolume 

effect can be troublesome (Ziyeh et al. 1997). In cochlear otosclerosis, a mild to 

moderate enhancement after gadoliniun administration is frequently seen on T1-weighted 

images, but an increased signal might also be seen in T2-images (Ziyeh et al. 1997, Goh et 

al. 2002). In a recent case report on the three-dimensional fluid attenuated inversion 

recovery MRI of a patient with SNHL, an enhancement of the inner ear fluid after 

gadolinium administration was noted. This suggests a breakdown of the blood-labyrinth 

barrier, which is a potential reason for SNHL (Sugiura et al. 2008). 

2.7 Surgical treatment 

Modern surgical treatment of otosclerosis began in 1956, when Shea reported the 

successful total removal of stapes (stapedectomy) and replacement with a Teflon 

prosthesis after sealing the opening with a tissue graft. In 1958, he presented a surgical 

treatment rationale for otosclerosis, in which a polyethylene tube was placed over the vein 

graft and the other end was stretched to the head of the long process of the incus. He also 

demonstrated the possibility of using the posterior crus as a prosthesis over the vein graft. 

In this technique, the incudostapedial joint was left intact, but the stapedius tendon was cut 

and the posterior crus repositioned to the centre of the sealed oval window (Shea 1958). 

Schuknecht (1960) introduced a technique in which he used a wire-adipose tissue 

prosthesis with a shaft made of stainless steel or tantalum and adipose tissue to seal the 

oval window. The prosthesis was prepared during the surgery and contained a loop that 

attached to the long process of the incus. A wire-loop prosthesis is still in use today with a 

different sealing material (vein, fascia, perichondrium, fat), but polyethylene tubes are no 

longer used owing to the frequency of incus erosion and occasional slippage of the 

prosthesis into the vestibule (Rizer and Lippy 1993). The operative technique has evolved 

during recent decades towards stapedotomy, where the piston prosthesis is inserted into 

the small fenestra of the stapes footplate, performed with a micro-drill or laser. This was 

preceded by partial stapedectomy, where only part of the stapes footplate was removed 

together with the superstructure. At present, all techniques (total/partial stapedectomy and 

stapedotomy) are used successfully (Rizer and Lippy 1993, House et al. 2002, Aarnisalo et 

al. 2003). The operation can be done using either local or general anaesthesia. According 

to the national guidelines in Finland, surgical treatment is indicated if the patient has a 

mean conductive hearing loss of 15 dB (0.5-2.0 kHz) or more, and at the same frequencies 

the mean air conduction threshold is 30 dB or more. The Rinne test should be negative. 

The patient should be expected to reach a mean postoperative hearing threshold of 30 dB 

or better or at least a mean threshold within 15 dB of that of the better hearing ear 

(Laitakari et al. 2005). In this section, the technical aspects of surgical treatment and their 

effect on outcomes are discussed. 

25

Stapedectomy versus stapedotomy 


Today, stapedotomy is favoured by most surgeons. This method is thought to reduce 

trauma to the inner ear and to decrease the risk of postoperative vertigo and SNHL (Fisch 

1982). Shea (1982) reported that the hearing results of stapedotomy were slightly better 

than those of stapedectomy and concluded that the former is preferable because it is easier 

to perform and there are no complications due to migration of the prosthesis and/or the 

oval window seal. Bailey showed similar results, with reduced postoperative vertigo and 

no SNHL with stapedotomy as compared with stapedectomy (Bailey et al. 1983). Rizer 

and Lippy criticized the earlier studies because the prosthesis, oval window seal, or 

amount of the footplate removed is often changed during follow-up of studies. In their 

study 225, patients were divided into stapedectomy, partial stapedectomy and 

stapedotomy groups. The sealing, prosthesis (Robinson stainless steel piston) and surgeon 

were the same in all operations. No significant complications or prolonged hospital stays 

occurred in any of the groups, but unfortunately, they do not provide details on the 

incidence of different complications (Rizer and Lippy 1993). 

Although hearing results are good with either technique, they have some characteristic 

differences in outcome. Stapedotomy has been shown to give better high-frequency gain 

and postoperative speech discrimination scores (Fisch 1982, Bailey et al. 1983, Cremers et 

al. 1991, Spandow et al. 2000, Kos et al. 2001). Stapedectomy in turn, may give better 

gain at the lower frequencies (Persson et al. 1997, Kos et al. 2001). Most of the studies 

have demonstrated good short- and/or long-term hearing results, without statistically 

significant differences between the techniques (Fisch 1982, Esguivel et al. 2002, House et 

al. 2002, Aarnisalo et al. 2003). 

Prosthesis 

Many recent studies have focused on the diameter of the piston prosthesis and hearing 

outcome. Diameters less then 0.4 mm are not recommended (Grolman et al. 1997, 

Huttenbrink 2003). At the moment, piston prostheses with diameters of up to 0.8 mm are 

available. Many, but not all, authors have stated that a piston prosthesis with a larger 

diameter provides greater hearing improvement, especially at lower frequencies (Fich 

1982, Grolman et al. 1997, Shabana et al. 1999, Sennaroglu et al. 2001, Marchese 2007). 

These results are expected because a similar suggestion has been made for stapedectomy 

and stapedotomy, and this is also supported by mechanical and acoustic models of the 

human middle ear (Rosowski and Merchant 1995). One explanation for the contradictory 

results concerning prosthesis diameter may be found in the effect of the tissue seal on the 

vibrational energy in the fenestra. The size of the fenestra and the sealing material have 

not been standardized in most studies (Rosowski and Merchant 1995, Huttenbrink 2003). 

The mass of the prosthesis has some impact on hearing outcome due to the shift in 

resonance frequency. Heavier prostheses (steel, gold) give better results at low frequencies 

26


and light-weight materials (Teflon) at higher frequencies, but this is of negligible 

importance in the overall results (Rosowski and Merchant 1995, Huttenbrink 2003). 

Another issue of great interest is the crimping of the prosthesis. Inaccurate crimping may 

lead to loose-wire syndrome (LWS). McGee (1981) presented 43 patients with one or 

more symptoms from the triad that is typical for LWS (hearing loss, poor speech 

discrimination, distortion of sound). Symptoms could be temporarily improved by middle 

ear inflation. At revision surgery, a loose attachment of the prosthesis at the long process 

of the incus was found. Fear of incus erosion or necrosis due to over-crimping is 

unwarranted. Lesisnki (2002) evaluated findings of 260 patients with revision stapes 

surgery. Varying degrees of incus erosion were found in 91% of patients. He observed that 

the most likely mechanism for erosion is fixation of the prosthesis to the solid otic capsule 

bone or residual footplate. Erosion of the incus is due to the continuous vibration of 

biological bone against the fixed prosthesis. The mechanism causing prosthesis migration 

was found to be contraction of the sealing material with a lifting of the prosthesis from 

fenestration, contraction from adhesions, faulty crimping of the incus or use of a 

prosthesis that was shorter than required (Lesinski 2002). Huber et al. (2003) reported 

acoustical-mechanical properties of sound transmission at the incus-prosthesis interfaces. 

He stated that firm crimping at two opposite points provided good transmission with the 

loss of only 3 dB at the interface, an amount similar to a healthy incudostapedial joint. 

However, if no firm crimping was done, losses of up to 23 dB in transmission occurred 

(Huber et al. 2003). Prostheses with elastic clips and loops with shape-memory have been 

developed to help fixation. Hearing results are similar to those for a manually crimped 

prosthesis. A longer follow-up study is required to determine whether there is any effect 

on postoperative complications (Harris and Gong 2007, Tange and Grolman 2008). 

Shea used a Teflon prosthesis in his first stapedectomy and also later in stapedotomy 

(Shea 1982). The shaft and crimping site were subsequently replaced with thinner 

materials, such as platinum and steel, to make insertion of a prosthesis possible even 

before the stapes arc is removed and to enable the prosthesis to be more adjustable (Fisch 

1982, Shea 1988). Pistons made of pure gold became available in the 1990s. Pure gold has 

antibacterial effects and due its malleability crimping over the incus is easy. Audiological 

results are comparable with those of other materials, but some reparative granulomas were 

seen after surgery (Tange et al. 1998, 2004). A titanium prosthesis is another full-metal 

prosthesis with good biocompatibility and very similar hearing results. It is not as 

malleable as gold, but this may be an advantage in the case of adhesion formation (Tange 

et al. 2004). Another benefit of titanium is the shape-memory that allows the use of a clip 

attachment to the incus (Wengen 2007). Nitinol® is an alloy of nickel and titanium. 

Teflon pistons with a nitinol loop can be crimped to the incus by heating the loop with 

bipolar current bayonet microforceps, a laser or a special heating device. Preliminary 

reports demonstrate that postoperative hearing results are similar to those of other 

materials (Harris and Gong 2007). No material has been shown to be superior in terms of 

audiological measurements, which is in accordance with acoustic models (Rosowski and 

Merchant 1995). 

27

Sealing 


Shea’s method of autologous vein graft for sealing the opening of the oval window is still 

commonly used by many surgeons (Shea 1998, Schmerber et al. 2004, Vincent et al. 

2006). Other autologous tissues successfully used for sealing include perichondrium, 

fascia, middle ear lining membrane, connective tissue, fat and blood (Schuknecht 1960, 

Perkins and Curto 1992, Shea 1998, Schmerber et al. 2004). The results with smallfenestra 

stapedotomy are good without any sealing (Somers et al. 1994). Some sealing 

materials may produce a fibrous reaction that could relocate the prosthesis. Lesinski 

(2002) found that thicker collagen sealing leads to greater dislocation, and a vein is the 

thinnest material available. Gelfoam®, introduced in the 1960s, is a gelatine sponge 

consisting of purified peptides from porcine skin, producing fibrous reactions in a manner 

similar to collagenous autologous materials. Gelfoam® has been reported to produces 

more labyrinthine fistulas in stapedectomies than other materials, and it is therefore no 

longer recommended in stapedectomies (Moon 1970, Sheehy et al. 1981, Shea 1982). 

Hearing results using different autologous sealing materials are very similar (Shea 1998, 

Schmerber et al. 2004). 

Lasers in primary surgery 

The use of an argon laser was first introduced by Perkins (1980). The use of lasers in 

stapes surgery enables fenestration of the footplate without physical contact. This 

decreases the risk of subluxating the footplate or its fragments to the vestibulum. 

However, the inner ear may still be damaged by thermal diffusion or by mechanical 

energy originating from the recoil caused by a pressure-driven expulsion of the tissue 

matrix (Frenz 2007). Argon and potassium-titanyl-phosphate (KTP) lasers both have 

wavelengths in the visual range (λ= 488 or 514 µm for argon and 532 µm for KTP) and 

are successfully used in stapes surgery (Palva 1987, Silverstein et al. 1989, Causse et al. 

1993b, Vincent et al. 2006). Both lasers can be delivered via a fiberoptic handpiece, with 

the advantage of reaching targets that are partially obscured by other structures. Also, with 

fiberoptic delivery, the power density decreases more rapidly than with a 

micromanipulator when the distance from target site is increased (Causse et al. 1993b). 

Carbon dioxide (CO2) lasers have also been used successfully in stapes surgery for many 

years. This type of laser is more readily absorbed by collagen, bone and perilymph, 

decreasing the risk of direct inner ear trauma from the laser beam because the loss of 

energy is more rapid than with lasers employing a shorter wavelength. However, this leads 

to a greater risk of heating the perilymph. The risk of boiling the perilymph is decreased 

by pulsing the laser beam in “micropips” of energy – fractions of a millisecond in 

duration. In contrast to lasers in the visible range (argon and KTP), the CO2 laser needs 

another laser beam for targeting, and it cannot be safely delivered using a fiberoptic 

device. Hearing results with CO2 lasers are comparable with those of micro-drill and other 

lasers (Lesinsk and Newrock 1993, Motta and Moscillo 2002, Badran et al. 2006). The 

erbium yttrium aluminium garnet (Er:YAG) laser is a laser in the infrared area, but with a 

28


shorter wavelength than a CO2 laser (2.94 µm vs. 10.6 or 9.6 µm). Erbium laser has a very 

restricted optical penetration depth in water and so it can be used for extremely precise 

ablation of tissue and bone – due their high water content – with a limited thermal effect 

on the surrounding tissues or liquids. However, since tissue ablation is local and 

explosive, it creates greater pressure waves. Because of this, stapedotomy with an Er:YAG 

laser has shown good long-term results, but bone conduction is depressed immediately 

after surgery (Häusler et al. 1999, Huber et al. 2001a). Häusler et al. (1999) reported 

depression of bone conduction two hours after surgery with an Er:YAG laser, but not 

when an argon laser or micro-drill was used. Although bone conduction did recover to the 

preoperative level within the first six hours following surgery, this initial hearing loss 

indicates an increased trauma to the inner ear compared with other techniques. 

Laser stapedotomy minus prosthesis (STAMP) was introduced by Silverstein (1998). It is 

limited to cases where otosclerosis affects only to the anterior part of the stapes footplate. 

In principle, it is comparable with Fowler’s anterior crurotomy with mechanical footplate 

fracture (Fowler 1956), but in STAMP the footplate is cut with a laser. Linear 

stapedotomy is done across the anterior part of the footplate and the anterior crus is cut 

with a laser to separate the fixed anterior section and mobile section of the ossicular chain. 

This technique had similar early hearing results as conventional surgery, but the incidence 

of revision surgery was 9% during a mean follow-up of two years (Silverstein et al. 2004). 

Today, lasers are commonly used and give hearing results comparable with other 

techniques in primary stapes surgery. 

Stapedius tendon preservation 

The stapedius reflex protects the inner ear from damage due to strong acoustic stimuli, and 

some authors have postulated that the stapedius tendon should be preserved or 

reconstructed if possible. The advantage of tendon preservation is better speech 

discrimination in noisy environments and an increased tolerance for high-amplitude 

sounds (Colletti and Fiorino 1994, Causse and Vincent 1997, Silverstein et al. 1999, Gros 

et al. 2000). Colletti and Fiorino (1994) showed significant differences in speech 

audiometry, with an ipsilateral masking noise favouring tendon preservation in 

stapedotomy. Gros et al. (2000) demonstrated a significant 16 dB difference in the 

uncomfortable level (UCL) three months after surgery. The stapedius reflex was evoked in 

94% of patients when the tendon was preserved. An elevated UCL increased the dynamic 

hearing range. This makes a hearing aid easier to use if later required due to presbyacusis 

or otosclerosis. Although an audiological benefit has been demonstrated, most surgeons do 

not preserve the stapedius tendon (Vincent et al. 2006). 

29

Results of primary and revision surgery 


In stapes surgery, the success rate of achieving a postoperative air-bone gap (AB-GAP) 

less than 10 dB after primary surgery is close to 95% in larger series (Shea 1998, Vincent 

et al. 2006). Shea (1998) reported an AB-GAP of less than 10 dB in 95% of 5444 

stapedectomies one year after operation. The results of 3050 stapedotomies with a mean 

follow-up of four years were reported by Vincent et al. (2006). The overall rate of failure 

to achieve an AB-GAP under 10 dB was 6.6%, but this rate increased to 12% in the case 

of obliterative otosclerosis and to 35% if simultaneous malleus ankylosis was present. Age 

had no impact on outcome; the hearing results of children (28 patients under 18 years) and 

the elderly (302 patients over 65 years) were comparable with others (Vincent et al. 2006). 

Long-term operative results are well maintained. Karhuketo et al. (2007) reported an early 

postoperative success for 83% of patients (AB-GAP < 20 dB), and a success rate of 75% 

at 32 years after the operation. The study included stapes mobilizations and many 

modifications of stapes surgery (Karhuketo et al. 2007). Similar long-term results have 

been reported by Aarnisalo et al. (2003) and Vincent et al. (2006) with 0.1 dB/year or less 

enlargement of AB-GAP as a function of time. The most common reason for conductive 

hearing loss leading to revision is prosthesis migration out of the oval window (Sheehy et 

al. 1981, Lesinski 2002). Lesinski (2002) stated that 211 (81%) of 260 patients with 

revision surgery had the prosthesis displaced due to contraction of the collagen sealing 

material, adhesions or faulty crimping. Other reasons included the prosthesis being too 

short (5%), incus dislocation (4%) and incus and/or malleus fixation (6%). A fixed 

residual stapes footplate was present in 13% of the patients (Lesinski 2002). 

The results of revision surgery are considerably inferior. Vincent et al. (2006) reported a 

55% success rate (AB-GAP within 10 dB) after the first revision in 56 patients. Lasers 

have proved to be valuable in revision surgery. Lippy et al. (2003) reviewed 522 revision 

stapedectomies and found an increase in the success rate from 70% to 80% once an argon 

laser became available in their institution. The success rate for achieving an AB-GAP less 

than 10 dB was 91% in patients undergoing laser-assisted revision (35 patients). In a metaanalysis 

by Wiet (1997), a total of 1317 revision operations were evaluated, and 170 of 

these were laser-assisted. The success rate for air-bone closure under 10 dB without a laser 

was 51% and with a laser 69%. This difference was significant (p=0.002). Bone 

conduction had deteriorated in 2.9% of patients treated with the conventional technique 

and in 0.5% in the laser group (Wiet et al. 1997). The less favourable outcome of revision 

surgery is especially related to incus necrosis, multiple revisions and indications other than 

conductive hearing loss (De La Cruz and Fayad 2000). 

The benefit of surgery not only depends on postoperative AB-GAB but is also affected by 

possible SNHL in the ear undergoing the surgery and hearing level in the other ear. Two 

commonly used methods to preoperatively estimate the possible outcomes and benefits of 

middle ear surgery are the "Belfast rule of thumb" and the Glasgow benefit plot (GBP). 

The Belfast rule of thumb is based on an analysis of 203 patients' personal assessments of 

their own hearing ability compared with the audiological results of middle ear surgery. 

30


The analysis indicated that the patient was likely to report a significant benefit if the 

postoperative hearing level was 30 dB or better (0.5-4 kHz) and the interaural difference 

was reduced to less than 15 dB (Smyth and Patterson 1985). With GBP, a surgeon can 

more easily audit personal results and make comparisons between series. GBP has also 

been used to estimate the benefits of bilateral surgery (de Bruijn et al. 1999). In GBP, the 

ear that has a hearing level better than 30 dB is considered normal or "socially 

acceptable", and an interaural difference of less then 10 dB is classified as symmetric 

(Browning et al. 1991). Toner and Smyth (1993) compared these two methods in 

agreement with patients' assessments. The Belfast rule of thumb was in agreement with 

patients' assessment in 78% of cases and GBP in 62% of cases. If normal hearing level 

with significant benefit was dropped to 40 dB in GBP, there was 71% agreement with 

patients' assessments (Toner and Smyth 1993). Recently, Schmerber et al. (2008) 

presented a new method for benefit assessment, the quartile benefit plot (QBP). In QBP, 

two additional evaluation criteria have been included in GBP, namely absence of 

postoperative SNHL (over 10 dB at 4 kHz) and closure of AB-GAP under 10 dB. In their 

evaluation of 132 bilaterally operated patients, the estimated success rate with GBP was 

52% and with QBP significantly less (39%). Evaluation of the agreement between QBP 

and patients' personal hearing assessments was not done (Schmerber et al. 2008). 

Some patients suffer from very disturbing tinnitus. The prevalence of tinnitus in patients 

with otosclerosis is 65-92% (Gristwood and Venables 2003, Oliviera 2007). Causse and 

Vincent (1995) present a complete recovery from tinnitus in 3-78% of patients one year 

postoperatively, depending on the frequency of the tone, high-pitched tinnitus being more 

resistant. The most recent studies do not confirm this. Gersdorf et al. (2000) found that 

tinnitus ceased or improved in 80% of patients and had worsened in 6% (three patients) 

one year after the operation. Pitch of tinnitus did not predict outcome, but the more 

complete closure of AB-GAP and the use of a small-fenestra technique were factors 

related to good prognosis. Ayeche et al. (2003) reported similar results, with 88% of 

patients experiencing a postoperative improvement in tinnitus. They found no factors 

predicting the course of tinnitus after surgery. The risk for escalation of tinnitus after 

surgery is reported to be 1.3-10.8% in the literature (Ayeche et al. 2003). The positive 

effect of surgery on tinnitus seems to be long-lasting. In a study of 246 patients’ 

symptoms during a mean follow-up of 56 months postoperatively, an improvement of 

tinnitus was found in 81% of the patients (Ramsay et al. 1997). 

Surgical treatment of bilateral otosclerosis 

If a patient has hearing loss on both sides that exceeds surgical criteria, it is generally 

accepted that surgery should be first performed on the side with experiencing the greater 

amount of hearing loss. Some authors have argued against performing surgery on the 

second ear due to the possibility of bilateral vestibular damage and the risk of SNHL, 

which can occur years after the surgery (Ludman and Grant 1973, Smyth et al. 1975, 

Hammond 1976). Nowadays, most surgeons will perform surgery on the second ear. 

31


However, there is no consensus on how long one should wait after a first successful ear 

surgery before operating on the second ear. Raut et al. (2002) report on the management of 

otosclerosis in the United Kingdom, where 75% of surgeons operated on both sides, but 

the duration between the surgeries varied between 1 and 180 months (median 24 months). 

Successful surgery on both ears gives the patient binaural hearing with the ability to 

localize sound (Porter et al. 1995, de Bruijn et al. 1998, 1999). Furthermore, De Bruijn et 

al. (1998) published a disability-oriented evaluation of bilateral stapedotomy. Both 

binaural hearing impairment (BHI) and the percentage of impairment of the whole person 

(IWP) are significantly decreased after the first surgery and again after surgery on the 

second ear, showing the importance of binaural hearing for the individual. 

In recent years, the number of surgeons willing to operate on both ears has increased (Raut 

et al. 2002). This is probably due to the positive long-term results of stapes surgery 

without any increase in the risk of complications after surgery on the second ear (Faye- 

Lund et al. 1984, Mann et al. 1996, House et al. 2002, Aarnisalo et al. 2003). The results 

of bilateral surgery in other areas of medicine, such as ophthalmology, orthopaedics and 

thorax and vascular surgery, may have encouraged otosurgeons. In those specialties, 

simultaneous bilateral surgery has been introduced with success. Vision and hearing are 

important elements of our perception, and therefore, the complication profile of eye 

surgery is similar to that of ear surgery. However, there is less of an opportunity for 

rehabilitation if vision is lost. Bilateral surgery in one session has been successfully 

introduced in cataract surgery. The simultaneous bilateral approach has been used in 

ophthalmology for two decades (Guo et al. 1990, Beatty et al. 1995, Arshinoff et al. 2003, 

Sarikkola et al. 2004). Simultaneous bilateral joint replacement surgery is also 

increasingly performed (Huotari et al. 2007). Huotari et al. (2007) evaluated the results of 

710 simultaneous bilateral hip or knee arthroplasties and 9121 unilateral surgeries. There 

was no increased risk of postoperative infection when bilateral surgery was performed. In 

thorax and vascular surgeries, simultaneous bilateral thoracotomy has been introduced 

with less morbidity and shorter hospital stays than staged operations in paediatric 

populations (Kougias et al. 2007). Simultaneous surgeries of the major arteries and 

coronary arteries have been introduced successfully in vascular surgery (Zarroug et al. 

2006). Bilateral cochlear implantation in the case of bilateral sensorineural deafness has 

recently been debated. Bilateral implantation gives the advantages of bilateral hearing, but 

arguments against bilateral operations have included the fear of bilateral vestibular 

damage and the possibility of preserving the contralateral ear for future rehabilitative 

methods. Gantz et al. (2002) placed cochlear implants bilaterally during the same 

operation in outpatient settings. There was no nystagmus or complaints of vertigo after 

surgery. Patients recovered from the surgery similarly to those of unilateral approach, and 

9 out of 10 patients were treated as outpatients. A recent review article by Papsin and 

Gordon (2008) evaluated the current literature and recommended simultaneous bilateral 

implantation for children as a standard. Simultaneous bilateral mastoidectomy has had 

good postoperative results in selected cases (Klemens et al. 2007). However, Klemens' 

survey exploring the opinions of 452 otologists, members of the American Neurotology 

Society, revealed a strong aversion to performing bilateral, simultaneous mastoidectomy. 

32


Twenty-eight (23%) of the 121 responders replied "absolutely not" to simultaneous 

surgery, and only about half of the otologists found some indications for the simultaneous 

approach (Klemens et al. 2007). No reports of simultaneous bilateral stapes surgery exist 

in the literature. 

Cochlear implantation 

An indication for cochlear implantation in otosclerosis is profound bilateral SNHL. In 

very far-advanced otosclerosis, stapedotomy and rehabilitation with a hearing aid are 

normally the initial treatment, because these are simple, safe and low-cost procedures. 

Patients should be informed that there is the possibility that the surgery may not be 

sufficient to improve hearing to a level that would be effective with a hearing aid. If 

satisfactory hearing is not achieved, cochlear implantation is the next option (Glasscock et 

al. 1996, Khalifa et al. 1998, Calmels et al. 2007). Hearing results of cochlear implantation 

in otosclerotic patients are comparable with those for other indications (Ruckenstein et al. 

2001, Mosnier et al. 2007). Operative problems may be encountered due to changes in 

anatomical contour of the otic capsule. A relatively high number of partial insertions and 

misplacements of the electrode array demanded revision surgery (8% of patients) in a 

multicentre study by Rotteveel et al. (2004). A greater number of facial nerve stimulations 

were found in patients with otosclerosis (38%) than in reports in the general literature 

(0.9%-14.6%). This increased incidence is thought to be due to a lowered electrical 

impedance of the bone caused by disease or reduced distance from the electrode to the 

facial nerve because of loss of bone and cavity formation (Rotteveel et al. 2004). 

2.8 Complications 

Perioperative complications 

Perioperative complications include tympanic membrane perforation, but this does not 

preclude completion of the operation. A simultaneous myringoplasty with tissue graft is 

recommended, although some otologists leave it to heal without treatment (Causse and 

Causse 1980a, Wiet et al. 1993). During surgery, the ossicles may be dislocated due to 

manipulation. If the incus is subluxated, its anatomical position needs to be restored before 

completing the surgery. Some physicians prefer to wait several months to allow the 

incudomalleal joint to re-fixate before prosthesis insertion. The incus can also be bypassed 

with malleostapedoplasty. The stapes footplate may be mobilized, leading to a "floating 

footplate", and attempts to remove it may submerge the footplate or its parts in the 

vestibulum (Causse and Causse 1980a, Wiet et al. 1993). Nowadays, with the availability 

of lasers and small-opening stapedotomy being performed, ossicular problems are more 

easily avoided. A "gusher" is a situation where there is profuse flow of perilymph and 

33


cerebrospinal fluid immediately after opening the oval window. Gushers are relatively 

rare, with an incidence of 0.03%, and are more common in congenital footplate fixation. 

A widened cochlear aqueduct or internal auditory canal are potential connections to 

intracranial spaces through which fluid may emerge. The opening should be sealed with 

tissue graft and insertion of a prosthesis, rather than packing the middle ear without 

restoring the ossicular chain. Head elevation and CSF lumbar drain also relieve 

perilymphatic pressure (Causse and Causse 1980a, Wiet et al. 1993). 

Sensorineural hearing loss 

The most worrisome complication is SNHL. Ludman and Grant presented an evaluation of 

139 patients with bilateral stapedectomies in 1973. In this group, there was a total of 322 

stapes operations, 3.4% of which resulted in dead ears during the first postoperative year, 

and another seven cases occurring at a later point, three occurring more than six years after 

the surgery. An analysis of 1681 stapes operations performed by Jean Marquet 

between1961 and 1991 showed a 0.9% (23 cases) rate of severe SNHL, half of these 

having a hearing level of less than 80 dB. Nine cases appeared during first the 

postoperative year, and the remaining occurred up to 11 years after the surgery (Somers et 

al. 1994). Both of these studies included revision surgeries, and the operative protocol had 

evolved greatly over the years. In Vincents’ (2006) report of 3050 stapedotomies 

performed between 1991 and 2004, SNHL was seen in 0.5% of the patients (13/2525 

patients). There were two dead ears (0.07%) and the rest suffered from an SNHL of 15-55 

dB. The incidence of SNHL was considerably greater (4.8%) when obliterative 

otosclerosis was found during surgery. Another large study reports on bilateral partial 

stapedectomy performed by William Lippy on 1800 patients between 1974 and 1998. No 

dead ears resulted, but the incidences of other SNHLs were not reported (Daniels et al. 

2001). Although the incidence of SNHL has been reduced in more recent studies, in which 

stapedotomy has usually been the preferred technique, comparative studies have shown no 

differences between stapedectomy and stapedotomy. Long-term reports have 

demonstrated that bone conduction deteriorates at a rate similar to that of presbyacusis 

with both stapedectomy and stapedotomy (House et al. 2002, Aarnisalo et al. 2003, 

Vincent et al. 2006). 

In histological examinations, the reactions leading to SNHL are found to be hydrops 

formation, atrophy of scala media due to fluid imbalance, adhesion formation in the 

vestibulum, perilymph fistula, granulation formation, acoustic trauma due to extensive 

drilling and labyrinthitis (aseptic or suppurative). The cochlea may be traumatized as a 

result of direct trauma from instruments or bone fragments. Also, a sudden release of 

enzymes into the inner ear from the active otosclerotic focus is postulated to be a cause of 

SNHL (Shucknecht 1962, Linthicum 1971, Causse 1980). In the case of postoperative 

SNHL, corticosteroids, vasodilatators, antibiotics, carbogen (5% carbon dioxide and 95% 

oxygen) and sodium fluoride have been used as conservative treatments (Causse 1980, 

Mann et al. 1996). In Causse’s (1980) review of 1160 patients, slightly more than 2% 

34


demonstrated SNHL, but this was permanent in only 0.2% of cases. The most common 

cause of SNHL was prosthesis displacement further into the vestibulum due to negative 

ear pressure in the middle ear, found in 2% patients. Symptoms were similar to Meniere’s 

syndrome, including tinnitus, vestibular symptoms and SNHL at low frequencies. The 

treatment was oral corticosteroids and active aeration of the middle ear. The same triad of 

symptoms is seen in patients with a sudden release in perilymph pressure during surgery 

in patients with simultaneous endolymphatic hydrops and otosclerosis. However, these 

patients do not respond as well to treatment. The treatment protocol for these patients 

includes bedrest with the head elevated to 30º for two days and corticoids and intravenous 

osmotic agents. Another two aetiological factors for SNHL suggested by Causse (1980) 

were impaired cochlear blood flow and the sudden release of enzymes into the perilymph. 

Surgical intervention for postoperative SNHL is recommended in the case of fistula or 

granulation formation and if an excessively long prosthesis penetrates too deeply into the 

vestibulum (Seicshnaydre et al. 1994, Mann et al. 1996). 

Perilymph fistula 

In a perilymph fistula (PLF), fluid leaks from the inner ear, leading to a disturbance of the 

cochlear and vestibular function. Some leakage always occurs during stapedectomy, and if 

this persists, the fistula is referred to as a primary fistula, but if it occurs after the window 

has been successfully sealed for a period of time, it is called a secondary fistula. Moon 

(1970) explored 49 perilymph fistulas after stapedectomy and the most common symptom 

was disequilibrium, which was present in 77% of primary and 61% of secondary fistulas. 

Hearing loss was found in 71% and 77% of cases (primary/secondary), and almost half of 

the patients suffered from tinnitus. Fistulas were more common when polyethylene tube 

prosthesis and gelatin foam sealant were used. Other factors contributing to fistula, include 

the displacement or poor fit of the prosthesis (Moon 1970, Sheehy et al. 1981, Shea 1982). 

Althaus and House (1973) report a fistula incidence of 89/15648 cases, or 0.6%, from 

stapes surgery. More than half of these (57%) were in ears that received a polyethylene 

tube prosthesis. An evaluation of 20 893 stapedectomies with a living tissue graft and a 

Teflon prosthesis revealed a PLF incidence of 0.02% (Causse and Causse 1980b). Some 

authors have even favoured the use of no sealing agent. Five cases of secondary fistulas 

occurring with a mean delay of five years were found in 1911 stapedotomies without 

sealing performed by Marquet (Somers et al. 1994). Clinically, inner ear hydrops present 

symptoms similar to PLF. In differential diagnostics, the CT can be helpful if fluid in the 

middle ear and/or pneumolabyrinth is shown. These are suggestive of PLF (Ayache et al. 

2007). The results of revision surgeries due to PLF are poor. In Moon’s (1970) study, 

hearing afterwards was worse or immutable in 43% of patients, 25% still suffered from 

tinnitus and 8% continued to have vestibular symptoms. 

35

Reparative granuloma 


The incidence of reparative granuloma has been estimated to be 0.1% after stapedectomy 

and 0.07% after stapedotomy (Seicshnaydre et al. 1994). If a granuloma invades the 

vestibulum after an initial period of hearing improvement, there is either gradual or sudden 

deterioration 1-6 weeks postoperatively. The tympanic membrane may show a reddish 

discoloration in the posterosuperior quadrant. Patients present with SNHL and/or 

conductive hearing loss. They may have vestibular symptoms (Kaufman and Schuknect 

1967, Gacek 1970). The aetiology initiating granuloma formation has not been 

determined. It is thought that this is the tissue’s reaction to glove powder, sealing material, 

prosthesis, inner ear fluid leaking from the PLF or overuse of lasers (Seicshnaydre et al. 

1994). Delivery of gastric content into the middle ear as a result of postoperative nausea 

has also recently been proposed as a possible reason for granuloma formation (Batman et 

al. 2007). The incidence is greater if gelatin foam or fat is used as a sealant. No consensus 

exist on the treatment of reparative granuloma. Some authors recommend conservative 

treatment with steroids and antibiotics (Hough and Dyer 1993), but early surgical 

intervention combined with steroids is recommended by most otologists (Gacek 1970, 

Seicshnaydre et al. 1994, Fenton et al. 1996). 

Vertigo 

The early prevalence of vertigo is quite common, with an incidence of up to 45% 

postoperatively in earlier reports (Birch and Elbrond 1985, Wang et al. 2005). 

Spontaneous or positional nystagmus was measured with electronystagmography in 73% 

of patients one week after surgery (Fisch 1965). There is a wide range in the incidence in 

the literature, probably due to different grading and nomenclature of vertigo. There may 

also be differences in how patients are mobilized postoperatively. In objective 

measurements, the equipment varies and the criteria for pathological nystagmus may also 

differ. Long-lasting vestibular symptoms are rare, and in most cases symptoms disappear 

during the first postoperative week (Birch and Elbrond 1985, Causse et al. 1988, Wang et 

al. 2005). In a study of 722 patients, 37% suffered from postoperative vertigo, but in only 

4%, did this last for more than four weeks. In the same study, after a mean follow-up of 15 

years, 17% (58/347) of patients showed an abnormal caloric test, and twenty-one patients 

had complete canal paresis (Birch and Elbrond 1985). Thus, a significant number of 

patients developed permanent vestibular hypofunction, which was rapidly compensated. 

Causse (1988) presents a number of aetiological factors that may affect the vestibular 

apparatus. These are similar to those thought to lead to SNHL, namely proteolytic 

enzymes, antigen-antibody reaction, disturbed labyrinth fluid pressure and diminished 

blood supply to the labyrinth. To prevent the influx of enzymes and/or antigens into the 

inner ear fluid, the anterior part of the footplate, which is the most common site for 

otosclerotic focus, should be left intact (Causse et al. 1988). Anatomically, the utricle and 

saccule are located close to the stapes footplate, and the prosthesis may mechanically 

36


disturb these structures. This might be due to insertion of a prosthesis that is too long or to 

adhesions or negative middle ear pressure forcing the prosthesis deeper into the inner ear. 

Membranous connections are also found between the stapes footplate and the utricle in a 

one-quarter of otherwise normal temporal bones, and breakage of these might be one 

cause for vestibular symptoms (Backous et al. 1999). In Wang’s (2005) report of the 

microanatomy of the vestibulum, the mean distance between the undersurface of the 

footplate and the saccule was 1.1 mm (SD=0.48 mm), and between the footplate and the 

utricle 1.67 mm (SD=0.31 mm). Previous studies of Caucasian populations have provided 

similar results of the microanatomy of the vestibular area (Pauw et al. 1991, Backous et al. 

1999). There is a cleft between the utricle and the saccule located along the vertical plane 

of the anterior crura, with a 45-60º angle facing the saccule. A modified piston prosthesis 

with a slope of 45º at its tip to adapt to the anatomical configuration of the vestibulum was 

compared with the conventional piston by Wang et al. (2005). When the modified 

prosthesis was used, the incidence of vertigo was significantly decreased and 

postoperative symptoms were milder and alleviated faster. Similarly, the occurrence of 

spontaneous nystagmus and its mean slow phase velocity were reduced in the group 

receiving the modified piston (Wang et al. 2005). However, these results have not been 

confirmed by other authors and are not in concordance with studies on objective 

evaluations of the saccule after stapes surgery, in which vestibular evoked myogenic 

potentials (VEMP) originating from the saccule did not decrease after surgery (Singbartl et 

al. 2006, Stapleton et al. 2008). 

Taste disturbance 

The chorda tympani nerve (CTN) is within the operative field and it is usually necessary 

to manipulate it in order to achieve free access to the oval window. Patients with an injury 

to the CTN present with symptoms of a metallic or sweet taste and numbness or tingling 

of the tongue (Mahendran et al. 2005). In a study of 55 stapedotomies by Mahendran et al. 

(2005), the CTN was transected in 22 cases and preserved in 33 cases. In patients in whom 

the CTN was transected, 95% complained of symptoms, and in patients in whom the nerve 

was preserved 52% had symptoms. If the CTN was transected, the symptoms were more 

severe and long-lasting. Although electrogustometry showed total loss of chorda function 

in almost every instance where the nerve was transected after a postoperative mean of 38 

months, only half of the patients had mild to moderate symptoms for more than six 

months (Mahendran et al. 2005). 

Facial paresis 

There are two types of facial palsy after stapes surgery: immediate, due to local 

anaesthetic or direct trauma to the nerve, and delayed. Local anaesthetic may produce 

facial palsy that resolves within hours. The risk of direct trauma increases if there is an 

anomalous course of the facial nerve, but normally it should be easy to avoid (Wellin et al. 

37


1992). The aetiology for delayed facial palsy is probably reactivation of the herpes 

simplex or varicella zoster virus. Shea and Ge (2001) found 11 cases of delayed facial 

palsy after 2152 stapedectomies, thus an incidence of 0.5%. Delayed facial palsy occurred 

anywhere from 5 to 16 days postoperatively. Serological evaluations were done in six 

cases and anti-varicella antibody titres were elevated in all of these. Anti-herpes antibody 

titres were also elevated in all but one case. A similar incidence of 0.5% was presented by 

Smith et al. (1990) for six cases out of more than 1300 uncomplicated stapedectomies. A 

bony facial canal dehiscence with bare or bulging facial nerve and chorda tympani nerve 

manipulation may potentially predispose to this type of complication. Because of 

postulated viral aetiology, anti-viral medication is proposed for the treatment of delayed 

facial palsy. Some authors have also suggested the use of prophylactic anti-viral 

medication for patients with a history of herpes labialis reactivation or immunodepression 

(Shea and Ge 2001, Salvinelli et al. 2004). 

Suppurative labyrinthitis and meningitis 

Because the inner ear is opened during surgery, there is a potential risk for microbial 

colonization, especially if PLF persists. Suppurative labyrinthitis leads to loss of hearing 

with a risk of meningitis. Fortunately, both are rare complications in the era of 

stapedotomy with only a single report in the literature (Nielsen and Thomsen 2000). 

Infection commonly occurs in the early phases of healing, but delayed meningitis may also 

arise from secondary PLF (Snyder et al. 1979, Jablokow and Kathuria 1982, Nielsen and 

Thomsen 2000). Most surgeons postpone surgery if a patient has a respiratory tract 

infection, and some physicians recommend the use of prophylactic antibiotic for surgery 

(Causse et al. 1983). Studies on the use of prophylactic antibiotic in uncontaminated ear 

surgery have demonstrated no significant effect, and this practice is therefore not generally 

recommended (Govaerts et al. 1998, Verschuur et al. 2004). Animal studies have shown 

an increased risk of SNHL after stapedotomy in ears with otitis media by Pseudomonas 

aeruginosa. This effect was not seen in otitis media with Streptococcus pneumoniae. 

However, the risk for suppurative complications increased in all animals with otitis media 

(Falcone et al. 2003). 

Radiological evaluation of postoperative SNHL 

CT is the primary method for imaging after stapes surgery when aetiology for SNHL is 

being assessed. CT can show conditions requiring prompt surgical management, such as 

PLF, granuloma formation and an excessively long prosthesis penetrating too deeply into 

the vestibulum (Seicshnaydre et al. 1994, Mann et al. 1996, Ayache et al. 2007). If CT 

does not provide findings that contribute to the diagnosis, MRI may give additional 

information. Intralabyrinthine reparative granuloma or labyrinthitis are not visible or may 

yield non-specific findings in CT. However, both are seen in MRI with extensive 

enhancement in post-contrast T1-weighted images and with hypointensity in T2-weighted 

38


images. Intralabyrinthine haemorrhage gives a high signal in both T1- and T2-weighted 

images, but is undetectable with CT (Ayache et al. 2007). Safety of MRI in patients with 

metallic implants has been a concern because implants may move or become heated 

during imaging. However, although prostheses made from low-magnetic stainless steel did 

move in highly magnetized fields, this was not clinically or statistically significant in in 

vivo measurements in cadaveric temporal bones when 4.7 T MRI was used. This is 

because the mass of the prosthesis is small, and it has a three-dimensional bony fixation 

when placed in a small-fenestra stapedotomy (Williams et al. 2001). 

2.9 Conservative treatment 

Hearing aid 

Most patients with otosclerosis can be rehabilitated with the use of a hearing aid. Simple 

amplification of sound produces good results in cases without SNHL because there is no 

regression of speech discrimination (Johnson 1993). Thus, before surgery, this possibility 

should also be discussed with the patient. The use of a hearing aid is preferred if the 

patient refuses surgery or if there is an increased risk associated with surgery. If hearing 

without the use of a hearing aid cannot be achieved postoperatively and patient can be 

rehabilitated successfully with a hearing aid, surgery should not be executed. On the other 

hand, if a patient has far-advanced otosclerosis, rehabilitation with a hearing aid may not 

be successful. The term "far-advanced otosclerosis" was introduced by House and Sheehy 

(1961) to describe clinical otosclerosis with a non-measurable bone conduction level and 

an air conduction level of 85 dB or greater. Most of these patients benefit from stapes 

surgery in that they are able to achieve a level of hearing that can be rehabilitated with a 

hearing aid (Glasscock et al. 1995, Khalifa et al. 1998, Calmels et al. 2007). 

Medical treatment 

Medications that suppress bone remodelling in the temporal bone would probably have a 

beneficial effect on otosclerosis. Sodium fluoride is in clinical use, but bisphosphonates 

and cytokine inhibitors have also been suggested to have an effect on active otosclerosis 

(Chole and McKenna 2001). One two-year prospective, double-blind study with 

bisphosphonates found no significant effect on hearing (Kennedy et al. 1993). Brookler 

and Tanyeri (1997) evaluated the effect of etidronates in a retrospective case review of 

896 otosclerotic patients with primary neurotological symptoms of dizziness, tinnitus, 

SNHL and/or Meniere’s syndrome. Patients were treated primarily with sodium fluoride, 

but if the treatment was ineffective or not tolerated by the patient, etidronate was 

introduced. They concluded that etidronate is more effective than sodium fluoride alone, 

but the study lacked a control group, was not blinded and the results did not include a 

39


statistical analysis. No clinical studies are available on the use of cytokine inhibition in 

otosclerosis. 

The use of fluoride as a treatment for otosclerosis was first suggested in 1964 by 

Shambaugh and Scott. Fluoride was thought to benefit by neutralizing proteolytic 

enzymes in spongiotic bone or by interfering with the calcium/phosphate ratio in bone 

with reduced remodelling activity (Bretlau et al. 1981, Causse et al. 1993a). In a doubleblind, 

placebo-controlled study, 40 mg of sodium fluoride daily significantly decreased 

deterioration of hearing compared with placebo. The study included 95 patients who were 

followed up for two years (Bretlau et al. 1981). Derks et al. (2001) found no difference 

between a four-year and one- to two-years treatment with fluoride, and there was 

significantly less deterioration in bone conduction at all frequencies compared with 

patients receiving no treatment. The dosage was 75 mg of sodium fluoride or 152 mg of 

sodium monofluorophosphate daily. Vartiainen and Vartiainen (1996, 1997a, 1997b) 

evaluated the effect of low-dosage sodium fluoride intake (1-3 mg/daily) from fluoridated 

tap water comparing patients living in areas with natural water with very low sodium 

fluoride content. Low-sodium fluoride intake was ineffective in preventing otosclerosis, 

but if patients developed otosclerosis, a low dosage of fluoride from tap water had a 

beneficial effect on hearing deterioration in non-operated ears. This benefit was not seen 

after stapedectomy (Vartiainen and Vartiainen 1996, 1997a, 1997b). Although fluoride has 

been shown to have beneficial effect on otosclerosis, the optimal dosages and treatment 

remain to be elucidated. 

40

3 Aims of the study 

Aims of the study 

1. To evaluate the applicability of simultaneous bilateral surgery for patients with bilateral 

otosclerosis. 

2. To compare the suitability of stapedectomy and stapedotomy as outpatient surgeries. 

3. To investigate changes in vestibular function in patients with otosclerosis, especially 

after surgery. 

41

4 Materials and methods 

Materials and methods 

This thesis consists of four original studies that evaluate and discuss surgical treatment of 

otosclerosis. Three major aspects of stapes surgery were evaluated, namely, simultaneous 

bilateral surgery, outpatient surgery and vestibular effects of the surgery. In the following 

sections, the design and execution of each study are described. Methods are given in detail 

in the original papers (I-IV). 

4.1 Study design 

Study I 

Patients with sufficient bilateral conductive hearing loss were informed about the study in 

writing. Patients interested in participating had a preoperative appointment with the 

surgeon and were scheduled for either a standard unilateral or an experimental 

simultaneous bilateral stapes surgery according to the patient’s preferences. During the 

pilot stage, eight patients suffering from bilateral otosclerosis and one from osteogenesis 

imperfecta were included. After results of the pilot study were analysed, another nine 

patients with bilateral otosclerosis were included and the results of these two groups were 

evaluated one year postoperatively. Outcome measures included a standard audiogram and 

a vestibular assessment with visual feedback posturography (VFP). Patients estimated 

their own hearing improvement, intensity of vestibular symptoms and quality of life with a 

questionnaire over follow-up period (Appendix 1). 

Study II 

Ninety-four consecutive patients with outpatient stapes surgery were retrospectively 

analysed. All surgeries were initially scheduled as outpatient procedures. All patients were 

carefully assessed to rule out any cardiovascular, pulmonary or metabolic disorders, 

particularly severe diabetes. Mild cardiovascular problems or diabetes were not a 

contraindication for outpatient surgery. To be included, the patient had to live within 50 

kilometres of the hospital and had to have someone to escort them from the hospital and 

someone who to take care of them at home overnight. An equal number of patients (n=47) 

were included in the stapedotomy and stapedectomy groups. Total stapedectomy was done 

if a laser was unavailable and in two cases with an unintended fracture of the footplate. An 

argon laser was used in all stapedotomies. Each patient's pain and vestibular symptoms 

were clinically evaluated during hospitalization. The reasons for needing to spend the first 

postoperative night in hospital were then analysed. Audiological measurements were 

performed three months postoperatively to evaluate the differences between these two 

operative methods. 

42

Studies III and IV 


These two studies differ from each other mainly in the timing of the VOG measurements. 

Study III included 33 patients scheduled for a stapedotomy due to otosclerosis, and Study 

IV included 21 patients scheduled for a stapedotomy or tympanoplasty with the objective 

of opening the oval window. In Study III, in four of the cases, the other ear had already 

been operated on due to otosclerosis, and in one case both ears had been operated on, but 

revision surgery was necessary. In Study IV, two patients had staged tympanoplasty after 

primary cholesteatoma surgery, and one patient had fractured stapes crura caused by head 

trauma. All other operations were due to otosclerosis. In all cases, the inner ear fluid 

compartment was opened during surgery. Five patients with otosclerosis had their other 

ear operated on previously, and for one patient the surgery was a revision of a previous 

procedure. Both studies were prospective, and VOG was recorded during standard pre- 

and postoperative visits. The patients did not have any other neurotological diseases or 

medications. In Study III, eye position curves were recorded with VOG preoperatively as 

well as at one week, one month and 3-4 months postoperatively. Data about subjective 

vestibular symptoms were collected during every visit using a questionnaire (Appendix 1). 

In Study IV, VOG was measured, on average, four hours after the surgery. VOG 

measurements are described later in the VOG section and in the original papers. 

Postoperative hearing was assessed, and the associations between vestibular symptoms, 

hearing results and VOG findings were evaluated. 

4.2 Surgery 

In Study I, the general anaesthetic was used for all patients. The surgical approach was 

either transcanal (26 ears) or endaural (10 ears). Special care was taken to avoid 

postoperative infection. All patients had a single dose of cefuroxime 1.5 g or ceftriaxone 2 

g as an antibiotic prophylaxis during surgery. The same surgeon operated on both ears, 

and dressings and instruments were changed after surgery on the first ear was concluded. 

The second side was then prepared for surgery. Stapedotomy was done using a laser (5 

ears) or a micro-drill (31 ears). In two cases, a partial stapedectomy was performed 

because of an unintended fracture of the footplate. Patients received prostheses selected 

from different manufacturers or quality lots on each side in order to minimize the risk of 

infection or other mechanical complications due to the prosthesis. Titanium (n=30) or steel 

(n=6) piston prostheses with a diameter of 0.4-0.6 mm were used. All prostheses were 

crimped manually to the long process of the incus. After inserting the prosthesis, the 

opening on the footplate was sealed with small pieces of fascia or with blood. All patients 

were treated as inpatients. 

In Study II, a Schucknecht piston with a diameter of 0.6 mm was placed over the fascia 

after the complete removal of the footplate in the total stapedectomy group. In the 

stapedotomy group, the same prosthesis was inserted using an argon laser-made fenestra. 

43


A drop of blood was used as a sealing material after stapedotomy. All surgeries were 

performed with local anaesthesia using an endaural incision. 

Study III included 29 stapedotomies done with a laser (21 ears) or a micro-drill (8 ears). In 

four cases, a partial stapedectomy was performed due to an unintended fracture of the 

footplate. Piston prostheses were applied and small pieces of fascia (n=19), fat (n=3), or 

blood (n=11) were used as a sealant. All but one patient received local anaesthesia. In 

Study IV, 19 of the procedures were performed using a local anaesthetic, and in two cases 

a general anaesthetic was preferred by the patient. The surgical approach was either 

transcanal (18 ears) or endaural (3 ears). Stapedotomy was performed with a laser on four 

patients and with a micro-drill on 16 of the patients. A titanium piston prosthesis with a 

diameter of 0.4-0.6 mm was applied and small pieces of fascia or blood were used as a 

sealant. One patient had cholesteatoma, which had previously been operated on and the 

ossicular chain had been reconstructed with incus interposition. The interpositioned incus 

was removed and the stapes footplate was found to be mobile but fractured. A 

reconstruction was done using a titanium total ossicular replacement prosthesis and 

cartilage. Three patients in Study III and one in Study IV lived alone and were scheduled 

as inpatients, but all other patients were scheduled as outpatients. 

4.3 Objective measurements and analysis 

Video-oculography 

Eye movements were recorded using a rubber mask-mounted video camera in a dimly lit 

room (Figure 1). The other eye was either uncovered, allowing vision, or covered. Eye 

position curves for horizontal and vertical planes were calculated by using software (2D 

VOG, Version 3.0, Sensomotoric Instruments, Berlin, Germany). The recordings were 

also stored on a standard VHS videotape, allowing visual evaluation of the rotatory 

component. The nystagmus was characterized by maximal slow phase velocity (SPV) and 

direction. 

During the VOG, the patients were prone and their heads were faced straight ahead. We 

first recorded spontaneous nystagmus with one eye uncovered. We then measured 

spontaneous nystagmus with the gaze forward, the gaze approximately 30 º to the left or 

right, and after 20 seconds of passive head shaking with the eyes covered. In Study IV, the 

head shaking provocation was not done. Each test condition lasted 30 seconds, and for a 

positive finding, at least five nystagmus beats were required. The limit for an abnormal 

SPV was 1 º/s for horizontal and 2 º/s for vertical components of spontaneous nystagmus. 

After head shaking, the corresponding normal limits were 6.1 and 6.8 º/s. The normative 

values were based on a previous study of healthy persons using the same equipment (Levo 

et al. 2004). 

44


Study III included 33 patients. On 11 of these patients, preoperative VOG was performed. 

Most of the patients had VOG measurements taken at one week (27 patients) and one 

month (28 patients) after the operation. Nineteen of the patients were also measured 3-4 

months postoperatively. Patients in Study IV had a single recording on average four hours 

postoperatively. 

Visual feedback posturography 

The vestibular function of patients with bilateral otosclerosis was measured using visual 

feedback posturography (VFP) in Study I. The VFP equipment was a custom-made force 

platform described in detail in Hirvonen et al. (2002) (Figure 2). While standing on the 

platform, the patient’s center of gravity (COG) was calculated and movement of the COG 

marker was displayed on a computer screen. Patients were instructed to move their COG 

marker by leaning their body as fast and as accurately as possible to given targets shown 

one at a time on the computer screen. A balance index (BI) was calculated by dividing hit 

delay (s) to the targets with hold percentage (%) within the targets. VFP was performed 

preoperatively as well as at one week, three months and one year after surgery. According 

to our previous study, a BI ≤ 2.5 s/% is considered normal (Hirvonen et al. 2002). 

Audiogram 

The audiological examinations were carried out using a clinical audiometer, calibrated 

according to ISO standards. Mean thresholds at frequencies of 0.5, 1, 2 and 4 kHz were 

used to calculate four-tone pure-tone average (PTA). Air conduction (PTA-AC) and bone 

conduction (PTA-BC) thresholds were recorded, and the air-bone gap (AB-GAP) was 

calculated. The postoperative AB-GAP was calculated by subtracting the postoperative 

BC from the corresponding AC. To analyse possible inner ear damage, mean preoperative 

BC at 1, 2 and 4 kHz minus postoperative BC values was used to calculate overclosure in 

Studies I, III and IV. Speech discrimination audiograms were performed pre- and 

postoperatively in Study I. 

Statistical analysis 

Statistical analysis was performed with SPSS version 11.0 or later software (SPSS Inc., 

Chicago, IL, USA), and a p-value of ≤0.05 was considered statistically significant. 

Audiometric data were analysed using paired Student’s t-test (I-II) or paired Wilcoxon 

signed-rank test (IV) to compare results within groups. An unpaired t-test (II) or nonpaired 

Mann-Whitney test (IV) was used to compare differences between groups. For noncontinuous 

parameters, Kendall’s W-test was used in Study I and Mann-Whitney U-test in 

Studies II and III. In Study IV, χ2 -test was used to compare the prevalence of nystagmus 

45


between the study group and control group detailed elsewhere (Levo et al. 2004). The 

correlation between prevalence of nystagmus and vestibular symptoms was analysed with 

Spearman’s correlation test. 

4.4 Ethical aspects 

The Ethics Committee of Helsinki University Central Hospital approved all of study 

protocols, and each patient provided written consent to participate in studies where 

required (I, III and IV). In Study II, only patients treated as inpatients provided written 

informed consent. 

Figure 1. A rubber mask-mounted video camera used in VOG. 

46


Figure 2. Visual feedback posturography equipment. 

47

5 Results and comments 

Results and comments 

5.1 Simultaneous bilateral surgery (I) 

One year after the surgery, the mean improvement in PTA-AC was 18 dB (range 1-41 

dB), with a mean PTA-AC of 25 dB (range 13-46 dB). The AB-GAP was within 10 dB in 

81% (29/36) and PTA-AC within 30 dB in 75% (27/36) of the ears. Table 1 summarizes 

the hearing results of both sides, with no statistically significant postoperative differences 

between the ears. A preoperative difference between ears was present, and the worse ear 

was operated on first, as in the unilateral standard protocol. After surgery, none of the 

patients had significantly (15%) lowered speech discrimination scores or had suffered 

significant (over 10 dB) sensorineural hearing impairment. Subjectively, 72% (13/18) of 

the patients assessed their own hearing as good or excellent one year after surgery. The 

remaining 28% reported moderate hearing ability after one year. The mean hearing score 

improved significantly from a preoperative value of 2.3 to 4.1 (p


improved significantly, from a preoperative score of 3.4 to 1.3 at the end of the study, one 

year after the surgery (p30 dB 6 (33) 3 (17) 

Postoperative SDS in % (range) 99 (92-100) 98 (84-100) 

Number of patients with revision 0 1 

Table 2. Subjective evaluation of the impact of general health on the quality of life on a 

five-point qualitative scale. *Significantly different from preoperative condition 

(p

5.2 Outpatient surgery (II) 


Eleven (12%) of 94 patients had to stay overnight at hospital. Two of the patients who had 

undergone stapedotomy were required to stay at hospital because they otherwise would 

have been alone during the night following surgery. One patient from both groups was 

required to stay due to surgery that had been scheduled late in the day. Only seven patients 

(7%) had a medical reason for inpatient treatment. These seven patients experienced 

vestibular symptoms and nausea; six belonged to the stapedectomy group and one to the 

stapedotomy group. Vestibular symptoms diminished during the night following surgery, 

and all patients were discharged on the first postoperative day. The differences in 

outpatient failure due to vestibular symptoms were significant (p=0.05) between the two 

groups. 

Hearing results were similar in both groups, with no significant differences in mean results 

or in individual frequencies (Table 3). A postoperative AB-GAP of less than 10 dB was 

achieved in 70% (33/47) of stapedectomy patients and in 83% (39/47) of stapedotomy 

patients. Two patients (4%) had an AB-GAP over 20 dB in the stapedectomy group and 

one (2%) in the stapedotomy group. Outpatient failure had no impact on hearing results. 

After surgery, no patients suffered from significant (over 10 dB) SNHL. Five patients 

(11%) had mild SNHL (5-8 dB) in the stapedectomy group compared with only two (4%) 

in the stapedotomy group (6 and 7 dB). The groups did not differ significantly (p=0.24) 

from one another. 

Statistically significant differences were present in outpatient failures due to vestibular 

symptoms, but hearing results did not differ between the groups. Both techniques can be 

used successfully, but stapedotomy is the preferred method in an outpatient setting. 

50


Table 3. Hearing thresholds (dB) for stapedectomy and stapedotomy patients. AC=air 

conduction, BC=bone conduction, GAB=AC-BC, GAIN=preGAP-postGAP, Mean= the 

mean of 0.5 - 4 kHz. 

Stapedectomy group 

Frequency Preoperative Postoperative 

(kHz) AC BC GAP AC BC GAP GAIN 

0.125 51.5 26.8 

0.25 53.0 6.3 46.6 26.3 7.9 18.4 28.2 

0.5 52.9 19.0 33.9 24.5 15.5 9.0 24.9 

1 53.4 26.6 26.8 27.0 19.3 7.7 19.1 

2 47.2 36.3 10.9 31.0 28.3 2.7 8.2 

4 50.2 26.6 23.3 39.7 29.1 10.6 12.7 

8 48.6 53.8 

Mean 50.9 27.1 23.8 30.6 23.1 7.5 16.3 

Stapedotomy group 

Frequency Preoperative Postoperative 

(kHz) AC BC GAP AC BC GAP GAIN 

0.125 55.7 27.3 

0.25 57.2 8.4 48.8 26.7 9.0 17.7 31.1 

0.5 56.7 21.0 35.7 25.9 18.4 7.5 28.2 

1 54.9 25.3 29.6 26.4 19.1 7.3 22.3 

2 49.0 37.6 11.4 30.0 27.9 2.1 9.3 

4 51.7 27.6 24.1 39.1 27.8 11.3 12.8 

8 51.4 54.8 

Mean 53.1 27.9 25.2 30.4 23.3 7.1 18.2 

51


5.3 Video-oculography studies (III, IV) 

Long-term evaluation (III) 

Three (27%) of the 11 patients measured preoperatively had spontaneous nystagmus with 

an SPV of 1.3-3.3 º/s when the eyes were covered. There was no preoperative headshaking 

nystagmus (HSN) in any of the patients. After the operation, 11-15% of the 

patients had HSN (SPV 6.6-17.8 º/s), but statistically, this was not significantly different 

from the preoperative level (p=0.18). None of the patients had spontaneous nystagmus 

when fixation was allowed. The number of patients with nystagmus and the dimensions of 

nystagmus are shown in Table 4. 

Nine patients (27%) experienced some vestibular symptoms, especially during rapid head 

or body movements during the first postoperative week. One of these patients had nausea 

and vomiting during the first week. Only three of these patients had pathological findings 

in the VOG. Two patients had horizontal HSN (SPV 11.1 º/s and 8.9 º/s). One patient had 

horizontal nystagmus that followed Alexander’s law for peripheral nystagmus, with an 

increasing SPV (2.4-6.7 º/s) when the gaze was in the same direction as the nystagmus. In 

all of these patients, the nystagmus was directed away from the operated ear. There were 

also four patients with pathological horizontal spontaneous nystagmus who experienced 

no vestibular symptoms. Three of these patients had nystagmus directed towards the 

operated ear and in one patient it was directed away from the operated ear. The remaining 

patients who experienced HSN (SPV 13.3 º/s) towards the operated ear had no vestibular 

symptoms. 

After one month, only one patient (3%) had subjective vestibular symptoms. This patient 

still reported minor dizziness five months after the operation, but only during rapid head 

movements. She had horizontal nystagmus beating away from the operated side after head 

shaking, with an SPV of 8.8 º/s, which appeared in the VOG recordings one month after 

the surgery. 

After one month, three patients (11%) had spontaneous horizontal nystagmus (SPV 1.3- 

3.8 º/s), and in all cases it was directed away from the operated ear. Two of these patients 

had vertically oriented nystagmus without a horizontal component one week following 

surgery. One of these was the patient with nystagmus that followed Alexander’s law one 

week after operation who now had spontaneous nystagmus with an SPV of 1.3 º/s. Two 

patients had HSN, but no vestibular symptoms one month after the operation. One of these 

had no nystagmus one week after the operation, but did experience vestibular symptoms at 

that time. She now had HSN with an SPV of 8.9 º/s directed away from the operated ear. 

The second one had HSN with an increased SPV of 17.8 º/s (13.3 º/s one week 

postoperatively) directed towards the operated ear. 

52


A final follow-up visit was held 3-4 months postoperatively. Only one of the 

aforementioned patients still suffered from vestibular symptoms. Two patients (11%) had 

spontaneous horizontal nystagmus, one beating towards the operated ear with an SPV of 

1.3 º/s and the other beating away from the operated ear with an SPV of 2.7 º/s. The latter 

also had HSN directed towards the operated ear. It evolved postoperatively with an SPV 

of 13.3-17.8-7.3 º/s. Another patient had HSN beating away from the ear, which was 

operated on, diminishing SPV to 6.6 º/s. The number of patients that had vertically 

oriented nystagmus was equal when comparing pre- and postoperative results. 

Postoperatively, there was no change in the direction of the nystagmus in any patient. 

Torsional nystagmus was not found pre- or postoperatively. 

Three (33%) of the patients suffering from vestibular symptoms during the first 

postoperative week had had previous middle ear surgery on the other ear due to 

otosclerosis. Two of the four patients whose planned stapedotomy was converted to a 

stapedectomy had vestibular symptoms one week after the operation, in one case lasting 

throughout the study period. However, neither the second ear operation or stapedectomy 

for technical reasons (p=0.06) nor the use of a laser instead of a micro-drill (p=0.07) 

presented a statistically significant risk for experiencing postoperative vertigo. 

Audiological measurements were done 3-4 months postoperatively. The postoperative 

average for the AB-GAP diminished to 6 dB (range 0-31 dB) from a preoperative value of 

25 dB (range 7-47 dB). The average overclosure was 4 dB (range -7-18 dB). A 

postoperative AB-GAP under 10 dB was achieved in 76% (25/33) and a AB-GAP under 

20 dB in 94% (31/33) of patients. 

No significant correlation between vertigo and type of nystagmus was found. Vestibular 

symptoms seem to be more prevalent in a second ear operation and with stapedectomy, 

but the difference was not statistically significant. Vestibular symptoms were mild and 

usually short-lasting, consistent with previous reports. 

53


Table 4. The number and percentage of patients with different planes of pre- and 

postoperative nystagmus recorded while the eyes are covered. Percentage values are 

calculated from all patients recorded for that time period. HSN=head-shaking nystagmus. 

Nystagmus Spontaneous HSN 

Preoperative Horizontal 1 (9%) 0 

Vertical 1 (9%) 0 

Both 1 (9%) 0 

One week postoperative Horizontal 4 (15%) 3 (11%) 

Vertical 1 (4%) 1 (4%) 

Both 1 (4%) 0 

One month postoperative Horizontal 2 (7%) 3 (11%) 

Vertical 1 (4%) 0 

Both 1 (4%) 0 

3-4 months postoperative Horizontal 2 (11%) 1 (5%) 

Vertical 1 (5%) 1 (5%) 

Both 0 1 (5%) 

Short-term evaluation (IV) 

In this study, VOG was measured on average four hours (range 1.5-6 hours) after the 

operation. No nystagmus was found when fixation was allowed, and three patients (14%) 

had pathological nystagmus when the eyes were covered. Two patients had spontaneous 

horizontal nystagmus with an SPV of 1.9 º/s and 1.5 º/s. In both cases, the fast phase 

beated away from the operated ear, and with the latter patient there was also a minute 

torsional component. The third patient had vertical nystagmus with a maximum SPV of 

2.2 º/s, and the fast phase beated upwards. The nystagmus was persistent when the other 

eye was covered. These patients did not complain of any postoperative vertigo or nausea. 

Seven patients had latent, spontaneous horizontal nystagmus that manifested during the 

lateral gaze in the direction of the fast phase only, with a gaze angle of less than 30 º. One 

patient had an upbeating component related to the horizontal nystagmus, and the 

remaining patients had primary horizontal nystagmus with an SPV between 1 and 3 º/s 

accompanied by a minor torsional component. The horizontal direction of nystagmus was 

excitatory in four patients, and inhibitory in three patients. The prevalence of latent, 

54


spontaneous horizontal nystagmus of 33% was significantly higher (p=0.0001) than in 

healthy controls. However, the occurrence of nystagmus did not correlate with vestibular 

symptoms (p=0.30). 

Eleven patients (52%) had vestibular symptoms after the operation. Four patients had 

rotatory vertigo, two vomited, three had a floating sensation, one had a tilting sensation 

and two suffered from unspecific dizziness. The vestibular symptoms were mild in seven, 

moderate in three, and not graded in one patient. Two of these patients stayed overnight in 

hospital. During the night following surgery, no medications were needed, and both 

patients were discharged from hospital the following day and had uneventful recoveries. 

At the time of VOG recordings, only one patient had a mild floating sensation; other 

patients were free of symptoms. 

Postoperative audiograms were performed 2-16 months after the operation. The 

postoperative AB-GAP was 8 dB (range 0-27 dB), and the mean postoperative PTA for 

AC was 30 dB (range 8-70 dB). No significant SNHL greater than 10 dB occurred and the 

average overclosure was 6 dB (range -5-25 dB). The audiological results of patients with 

vestibular symptoms did not differ significantly from those of the whole study group 

(p=0.85). The mean postoperative AB-GAP was 7 dB (range 0-16 dB) and overclosure 

was 8 dB (range 0-25 dB) in patients with vestibular symptoms. 

There were signs of semicircular canal disturbance presented as a latent, spontaneous 

horizontal-torsional nystagmus, but no specific nystagmus pattern was detected in patients 

with vestibular symptoms after the surgery. In conclusion, the origin of vestibular 

symptoms appears to be diverse. 

55

6 Discussion 

Discussion 

The surgical treatment of otosclerosis has evolved greatly since the first successful 

fenestration of the oval window and reconstruction of the ossicular chain with an artificial 

material at 1956 (Shea 1956). During the ensuing decades, less traumatic operative 

techniques have been developed to minimize the risk of inner ear trauma. Prosthesis 

materials that are easier to handle and that have better biocompatibility have been 

introduced, the latest having “memory” enabling the surgeon to crimp the prosthesis 

without touching it (Harris and Gong 2007, Tange and Grolman 2008). Small-opening 

stapedotomy using a laser or micro-drill has become more popular than stapedectomy, in 

which the stapes footplate is removed either partially or totally (Raut et al. 2002). 

Different sealants made of either autologous or artificial material have been introduced. 

Not every new innovation has been successful. For example, the use of gelatin foam as a 

sealing material was later found to be related to an increased risk of postoperative fistula 

(Shea 1988, Hausler 2007). Today, surgery still carries a risk of inner ear trauma, which 

may lead to SNHL or vestibular dysfunction. This is why continuous research into 

surgical treatments is needed. In this thesis, the results of simultaneous bilateral surgery, 

not previously reported in literature, are introduced and discussed. Two other aspects of 

stapes surgery, the use of outpatient surgery and the vestibular effect of surgery, neither of 

which has been widely discussed in the literature, were additional areas of interest. The 

results of applicability of stapedotomy and stapedectomy as an outpatient surgery are 

presented, as is an evaluation of the vestibular side-effects of stapes surgery. 

6.1 Simultaneous bilateral surgery (I) 

Simultaneous bilateral surgical treatment has been introduced successfully in other fields 

of surgery. Cataract surgery in ophthalmology is a good example because it contains a 

similar complication profile as otosurgery. In both situations, bilateral loss of function 

would be catastrophic, except that the loss of vision offers fewer opportunities for 

rehabilitation. However, simultaneous bilateral cataract surgery has been performed 

successfully over the last two decades (Guo et al. 1990, Beatty et al. 1995, Arshinoff et al. 

2003, Sarikkola et al. 2004). Because the prevalence of bilateral otosclerosis is about 70%, 

bilateral surgery in either a single session or two separate sessions is needed to achieve 

binaural hearing in many cases (Guild 1944, Hueb et al. 1991). The benefit of binaural 

hearing includes better speech discrimination in a noisy environment and the ability to 

localize sound. In a report on the quality of life after sequential bilateral stapedectomy, 

both BHI and IWP were significantly improved after the first surgery and after surgery on 

the second ear, showing the importance of binaural hearing for the individual (De Bruijn 

et al. 1998). If surgery could be successfully performed on both ears in a single session, 

the total time spent in the hospital, overall medical leave and the need for follow-up visits 

would be reduced, providing socioeconomic advantages for both the patient and society. 

56

Discussion 

The patient also would achieve the advantage of binaural hearing without a waiting time 

between operations. 

Study (I) with simultaneous bilateral surgery for otosclerosis was initiated after the careful 

exploration of the long-term results of a large patient population in conventional stapes 

surgery. In the past, some authors have discouraged bilateral surgery because of the risk of 

SNHL, which can occur years after surgery (Ludman and Grant 1973, Smyth et al. 1975, 

Hammond 1976). In a study by Ludman and Grant (1973) there was a high rate of dead 

ears (3.4%) during the first postoperative year, with another 2.9% occurring later, half of 

these more than six years postoperatively. However, with modern surgical methods and 

equipment, the risk of inner ear trauma seems to have diminished compared with older 

studies. In a large series of 1800 bilateral partial stapedectomies presented by Daniels et 

al. (2001), there were no dead ears, and in another study of 3050 stapedotomies by 

Vincent et al. (2006) there were only two cases (0.07%) of dead ears. Reports on longterm 

success and safety have also shown stability of these results (House et al. 2002, 

Aarnisalo et al. 2003, Vincent et al. 2006). The proportion of surgeons willing to operate 

on both sides has increased in recent years. However, no consensus exists regarding the 

optimal period between the two surgeries (Raut et al. 2002). 

With the encouraging results of stapes surgery today, this study was undertaken to 

evaluate the outcome of simultaneous bilateral stapes surgery. All patients were fully 

informed about the risks and experimental nature of the operative approach. The risk of 

unilateral severe SNHL or vestibular function, based on prevailing literature and our 

institutions’ 20-year follow-up results of stapes surgery, was estimated to be less than 1%. 

This means a bilateral risk of less than 0.01% if the ears are considered to be independent 

of each other. The patients were informed about the actual risk of 0.01-1% for a bilateral 

complication. Special attention was paid to ensuring that the risk of complications 

remained as low as possible. Patients included in the study were otherwise healthy and had 

not undergone any previous otosurgeries. An experienced surgeon operated on both ears 

with general anaesthesia, all dressings and instruments were changed between sides and 

intravenous antibiotic prophylaxis was administered during the operation. To avoid 

problems due to the prostheses itself, prosthesis from different quality lots or 

manufacturers were selected for the right and left ears of the patient. If any technical 

problems occurred in the first ear, any procedures on the second ear were delayed to a 

future session. The study was executed in two parts; data from the first half of the study 

group were analysed before we proceeded with the remaining patients. 

Hearing results with mean postoperative AB-GAP of 7 dB are comparable with the 8 dB 

result in our institution’s previous study on unilateral stapes surgery and in the literature in 

general (Aarnisalo et al. 2003). The success rate of AB-GAP within 10 dB in at least one 

ear was 100%, and in 81% of the patients this was achieved this bilaterally. Afterwards, 

successful revision surgery was performed on the only patient with an unsatisfactory 

postoperative AB-GAP of over 15 dB. This success rate resembles those of larger studies 

(Daniels et al. 2001, Vincent et al. 2006). 

57

Discussion 

Vestibular symptoms after bilateral surgery were found in half of the patients, which is 

slightly more than that reported in the literature (Birch and Elbrond 1985, Silverstein et al. 

1989). This higher prevalence might be due to bilateral surgery, but accurate data 

collection with both a formal questionnaire and specific oral questions concerning 

dizziness probably had an influence on the greater number of patients reporting vestibular 

symptoms. Actual rotatory vertigo was found in only one patient, and it subsided the same 

day that the surgery was performed. The BI in the VFP was followed, and in five cases 

(28%) there was a minor regression in the results within one week, indicating some 

vestibular disturbance caused by the operation. This is in concordance with the patients’ 

own estimations of symptoms being mild or moderate when rated on a five-point scale. In 

all patients, the BI eventually recovered. 

When patients were asked about performance and quality of life with regard to their health 

after the surgery, they reported significant improvements. This result is analogous with the 

findings of De Bruijn et al. (1998) concerning the effect of bilateral stapedectomy on 

patients' lives. 

In summary, the recovery and hearing results of simultaneous bilateral surgery were 

similar to those of unilateral operations previously reported in the literature. However, the 

patients received the advantage of bilateral hearing improvement in a single session, 

without an extra waiting period and with less time spent in hospital or on sick leave. 

Nevertheless, the number of patients in this study was quite small and the follow-up time 

was only one year. More studies are needed with greater patient numbers and longer 

follow-ups to verify the safety of the simultaneous approach. The small number of patients 

in this study also makes it unsuitable for making any reliable estimations of socioeconomic 

advantages for the patient and/or society. In the future, once the aetiology of 

otosclerosis is revealed, the need for surgical treatment will likely decrease. However, the 

advantages of the individual should be stressed more when bilateral surgery is considered. 

Possible advantages for society should not be the main issue when a new surgical 

approach is planned. These results show that simultaneous bilateral surgery is an 

applicable approach in bilateral otosclerosis. However, at an early stage of introduction of 

a new treatment protocol, one should remain conservative and advocate it only to 

voluntary patients with primary operations and normal anatomical conditions. 

6.2 Outpatient surgery (II) 

Outpatient surgery has generally become more popular with the last few decades. The 

main reason is probably not medical, but an increasing demand for cost-effectiveness, 

forcing hospitals to cut expenses. However, if there is no need for postoperative care from 

health care professionals after surgery, the advantage of an outpatient setting for the 

patient is a more comfortable recovery in familiar surroundings. Nevertheless, not all 

58

Discussion 

surgeries are suitable for an outpatient protocol, and the safety of different treatment 

protocols should be evaluated before they are introduced into common practice. 

The traditional standard for stapes surgery has been a hospital setting with 1-2 days of bed 

rest. Nowadays more and more surgeries are being performed as outpatient procedures. 

Although the number of studies evaluating the outcome of different operative methods of 

otosclerosis is scarce. Dickens and Graham (1989) evaluated differences between inpatient 

and outpatient settings in different otological surgical procedures, including 507 outpatient 

stapes operations and 224 patients that were treated as inpatients. No significant 

differences were observed between the groups. The proportion of large versus smallfenestra 

operations was not reported. Another randomized study from Corvera et al. 

(1996), comparing outpatient stapedotomy and an inpatient protocol, found that the 

outpatient treatment was equally safe and effective. The total patient number was only 20. 

To date, no comparisons between outpatient stapedectomies and stapedotomies exist, and, 

if Dickens and Graham (1989) is excluded, all available reports of stapes surgery consist 

of only small samples. 

In Study II, the hypothesis was that stapedotomy would be more suitable for outpatient 

surgery than stapedectomy. The reasoning for this was that there would be a greater need 

for the manipulation of the footplate in stapedectomy, and thereby, an increased risk of 

temporary irritation of the inner ear. 

Although all of the operations were initially scheduled for an outpatient setting, seven 

patients (7%) had to stay in hospital for one night because of vestibular symptoms and 

nausea. This is a large difference compared with the 0.8% (4/507) of unplanned 

admissions reported by Dickins and Graham (1989). One explanation might be that 357 of 

their 507 outpatients actually stayed in a motel located in the same building, where they 

were transported directly from the recovery room by gurney. There might also be some 

cultural differences associated with the patients and health care professionals. The 

proportion of failures was significantly greater in the stapedectomy group than in the 

stapedotomy group (13% vs. 2%). This is probably due to the greater mechanical 

manipulation of the footplate in stapedectomy, with perilymphatic leakage leading to 

increased irritation of the inner ear. Although not a statistically significant finding, a 

greater number of patients experienced minor SNHL three months after surgery in the 

stapedectomy group (11% vs. 4%). This is in accordance with our results of vestibular 

symptoms presenting a greater risk of inner ear irritation in stapedectomy. But it should be 

noted that no patient suffered significant SNHL (over 10 dB). The higher number of 

patients admitted was not reflected in the postoperative hearing results. As expected from 

previous reports, the hearing results of the groups were similar, with a mean postoperative 

AB-GAP of 8 dB (stapedectomy) and 7 dB (stapedotomy) (House et al. 2002, Aarnisalo et 

al. 2003). Although not significant, slightly more patients in the stapedotomy group (83% 

vs. 70%) achieved a postoperative AB-GAP of less than 10 dB. Overall, the hearing 

results were comparable with those in the general literature. 

59

Discussion 

Both techniques were deemed suitable for outpatient settings. Stapedectomy was related 

significantly more often to outpatient failures due to vestibular symptoms. Generally, the 

prevalence of outpatient failures should be minimized to avoid the extra costs and stress 

associated with unplanned admission. Our findings suggest that stapedotomy should be 

favoured over stapedectomy if an outpatient setting is scheduled. 

6.3 Video-oculography studies (III, IV) 

Although vestibular symptoms are the main reason for prolonged hospital stays, little is 

known about the mechanism causing postoperative vertigo. Many mechanisms have been 

proposed for postoperative vestibular symptoms, including irritation from blood or small 

parts of the footplate entering the vestibulum, the sudden release of proteolytic enzymes 

from foci at the footplate and pressure changes due to surgery (Causse et al. 1988). The 

anatomical closeness of otolith organs has led to the suggestion that mechanical irritation 

of these organs could be one reason for postoperative vestibular symptoms. There are also 

membranous connections found between the stapes footplate and the utricle in one-quarter 

of otherwise normal temporal bones (Backous et al. 1999). These connections and their 

breakage during surgery might be responsible for utricular irritation. Wang et al. (2005) 

discovered that modifying the tip of the prosthesis so that it avoids contact with the 

saccule was effective in reducing postoperative vertigo. Overall, the number of studies 

concentrating on vestibular symptoms is limited, probably because the main interest is in 

postoperative hearing results, and vestibular symptoms are usually mild and transient. 

Otosclerosis is also associated with an increased incidence of vestibular disturbances prior 

to surgery (Aantaa and Virolainen 1978, Birch and Elbrond 1985). The aetiology and the 

end organ causing the preoperative vestibular symptoms have not been unveiled. 

VOG is modern way of measuring eye movements, offering some advantages compared 

with electronystagmography (ENG). With VOG, the problems related to electrodes are 

fully avoided, and it allows exploration of all three components of nystagmus (Bisdorff et 

al. 2000, Geisler et al. 2000). ENG provides only horizontal and vertical components, but 

with VOG the rotatory component can also be evaluated. However, for VOG, the patients’ 

eyes must be constantly open, enabling the software to track eye movements from the 

video recording. This makes it prone to artefacts caused by blinking, drooping eyelids or 

eye lashes. The graphic presentation of the eye movements can, however, be verified 

manually using the recorded video format. 

The aim of Studies III and IV was to determinate reasons for vestibular symptoms after 

stapes surgery. Previous studies has mostly evaluated horizontal nystagmus with ENG, but 

no studies concentrating on the VOG findings of otosclerotic patients have been presented. 

This is why we chose VOG as a method of measurement in these studies. The first study 

(III) included measurements preoperatively and at one week to 3-4 months 

postoperatively. The prevalence of vestibular symptoms after surgery was 27%, which is 

in concordance with previous reports (Birch and Elbrond 1985, Koizuka et al. 1995). 

60

Discussion 

Patients with vestibular symptoms did not present a significant correlation between 

vestibular symptoms and type of nystagmus. Preoperatively, spontaneous horizontal 

nystagmus was found in 18% and postoperatively in 11-19% of patients. These results are 

similar to previous reports (Aantaa and Virolainen 1978, Birch and Elbrond 1985). None 

of the patients had HSN preoperatively. The postoperative prevalence of HSN (11-15%) 

was not significantly different, and there was no correlation with symptoms. A tendency 

was found for vestibular symptoms to be more prevalent after the second ear operation and 

also to be more frequent in stapedectomy than in stapedotomy, but neither difference was 

statistically significant. As had been previously reported in the literature, vestibular 

symptoms were mild and short-lasting. Only one patient (3%) had vestibular symptoms 

one month postoperatively. 

Because Study III was not successful in showing the specific end organ affected, we 

decided to attain VOG measurements immediately after the surgery. Again, no correlation 

was present between type of nystagmus and vestibular symptoms in Study IV. There were 

three cases with pathological nystagmus, all without vestibular symptoms. However, we 

were able to find seven cases of latent, spontaneous horizontal nystagmus prevailing only 

during lateral gaze in the direction of the fast phase, with a gaze angle of less than 30 º. In 

one patient, this was related to the vertical component, and in all other cases a minor 

torsional component was visible. This prevalence of latent, spontaneous horizontal 

nystagmus of 33% was significantly higher (p= 0.0001) than in healthy controls. This type 

of nystagmus displays a weak, peripheral asymmetry between the ears, arising from the 

semicircular canals according to Alexander's law (Robinson et al. 1984). The type of 

horizontal-torsional nystagmus suggests involvement of all semicircular canals analogous 

to that seen after acute unilateral vestibular loss (Fetter and Dichgans 1996). Both 

excitatory and inhibitory types of nystagmus were represented in our study. We could 

identify the torsional component through visual inspection, but as the VOG did not 

quantify the torsional component, its SPV could not be calculated. Patients received 

diazepam preoperatively and short-acting opioids during surgery. Opioids have been 

shown to induce downbeating nystagmus and to suppress the vestibulo-ocular reflex 

(Padoan et al. 1990, Rottach et al. 2002). Sedatives may also cause symmetric gazeevoked 

nystagmus (Baloh and Honrubia 2001). Downbeating nystagmus was not 

encountered in our study, but one patient had symmetric gaze-evoked nystagmus. Taken 

together, opioids may have had a minor suppressive effect on SPV of nystagmus and on 

clinical vestibular symptoms in this study. To avoid this confounder in future, only shortacting 

sedatives should be used if measurements are performed on the same day as the 

operation. 

In Study IV, eleven patients (52%) had vestibular symptoms, which is more than generally 

reported in the literature (Aantaa and Virolainen 1978, Birch and Elbrond 1985). The 

reason may simply be the strict protocol inquiring about even the mildest of symptoms. 

Only four patients (19%) had mild rotatory vertigo, which was temporary, and all of these 

patients were treated as outpatients. Three patients had a floating and one patient a tilting 

sensation, which imply symptoms of otolith origin. Two patients spend their first 

61

Discussion 

postoperative night in hospital. They did not need medications during the night following 

surgery and were discharged on the first postoperative day in good health. The vestibular 

symptoms experienced were unrelated to abnormal nystagmus findings, which might be 

due to the subjective sensations mostly occurring immediately after the operation, and our 

recordings being performed later, on average four hours postoperatively, when all but one 

patient was free of symptoms. 

Audiological results were comparable with those in the literature with postoperative AB- 

GAPs of 6 dB (III) and 8 dB (IV). No significant SNHL occurred in either study. Similar 

to a study by Aantaa and Virolainen (1978), no association existed between hearing results 

and vestibular symptoms. 

The eye movements in Studies III and IV were thoroughly evaluated at multiple timepoints, 

but no association with type of nystagmus or vestibular symptoms was found. This 

suggests that vestibular symptoms have a diverse origin. Appearance of vestibular 

symptoms with rotatory and also with floating and tilting sensations immediately after 

surgery are in concordance with this suggestion. In measurements immediately after 

surgery, we saw signs of disturbance of the semicircular canals. However, mechanical or 

other stimulation of the otolith organ might be another cause of dizziness, as suggested by 

the symptoms of floating and tilting in some of our patients, although we observed no 

signs of obvious eye deviation or counter-rolling on the videotapes. Postoperatively, 

increased resting activities of utricular afferents without semicircular canal irritation have 

been suggested. This was explored by evaluating the results of subjective visual horizontal 

and VOG measurements after stapedotomy (Tribukait and Bergenius 1998). Those authors 

found no correlation between vestibular symptoms and objective measurements. This 

could be due to late measurements, a few days after surgery, similarly to our results. In a 

study by Wang et al. (2005), saccular irritation caused by the prosthesis was suggested as 

a reason for vestibular symptoms. In that study, an anatomically modified tip of the 

prosthesis to avoid contact with the saccule was found effective in preventing 

postoperative vestibular symptoms. This is, however, not in concordance with other 

studies concerning changes in saccular function after stapes surgery. VEMPs arising from 

the saccule are not decreased after the surgery, indicating that the function of the saccule 

has been maintained (Singbartl et al. 2006, Stapleton et al. 2008). In our study, VOG was 

found to be an effective method for evaluating vestibular organ irritation. In the future, to 

unveil the pathological process leading to postoperative vertigo, the gap between opening 

the oval window and objective measurements should be as short as possible and 

measurements for otolith organs should be included. 

62

7 Conclusions 

Conclusions 

Audiological results and recovery were comparable between simultaneous bilateral 

surgery and conventional unilateral surgery. Simultaneous bilateral surgery is thus suitable 

for treating bilateral otosclerosis. However, because this treatment is in its early stages of 

introduction, one should remain conservative and advocate this option only to voluntary 

patients with primary operations and normal anatomical conditions. 

Although no statistically significant differences in audiological results were present 

between the two treatmens, stapedotomy was found to be significantly less vulnerable to 

outpatient failures. If an outpatient setting is scheduled, stapedotomy should be preferred. 

However, in experienced hands, both methods are applicable and offer similar hearing 

results. 

Clinically, patients experienced mild to moderate vestibular symptoms likely due to 

irritation of the otolith organ and semicircular canals. Minor irritation of the semicircular 

canals could be detected after the surgery, but this was not connected to vestibular 

symptoms, which have probably a diverse origin. Since vestibular symptoms and signs are 

mild, patients may be safely discharged some hours after stapes surgery. 

63

8 Acknowledgements 

Acknowledgements 

This study was carried out in 2003-2009 at the Department of Otorhinolaryngology, 

Helsinki University Central Hospital, and at the Department of Otorhinolaryngology, 

Seinäjoki Central Hospital. Professors Anne Pitkäranta, Pekka Karma and Jukka Ylikoski, 

Docent Hans Ramsay from Helsinki University Central Hospital and Doctor Panu 

Kuoppala from Seinäjoki Central Hospital are thanked for providing me with the 

opportunity and facilities to carry out this work. 

My deepest gratitude is owed to my supervisor Docent Timo Hirvonen. His vast 

experience in clinical and scientific work could always be relied on when guidance (very 

often) was needed. He also demonstrated admirable patience and understanding when my 

attention was directed more to other aspects of life. His encouragement was instrumental 

to my finishing this thesis. 

I am very grateful to Heikki Aalto, PhD, Docent Juha-Pekka Vasama and Docent Hans 

Ramsay, who were my co-authors in the original publications. Heikki’s contribution to the 

development of equipments for vestibular organ measurements and to the actual 

measurements was irreplaceable. His precise and pedantic attitude toward science and 

everyday work is admirable. Juha-Pekka and Hans were also responsible for the surgical 

interventions in this project together with Timo Hirvonen. 

I am grateful to the reviewers of this thesis, Docent Kyösti Laitakari and Docent Jukka 

Pulkkinen, for their constructive criticism and the comments that greatly improved the 

final product. The language content was reviewed by Carol Ann Pelli of Helsinki 

University Language Services. 

I have warm memories of all of my colleagues during my residency. I especially want to 

thank Tuomas, Samuli, Katriina and Lauri. Tuomas, Samuli and Katriina are thanked for 

the good times in Kotka, where we headed after residency. During the long drives to work, 

all areas of life were covered in conversations, and we became close friends. Lauri is 

another friend I can rely on. His recent experience making a thesis and great advice made 

my work much easier. 

I am indebted to Erkki Hopsu for the many conversations that taught me to defend my 

position and for showing me that one can found new perspectives in almost any issue. It 

was privilege to start as a young specialist under his guidance. He gave me the opportunity 

to try my wings, but when help was needed, I could always rely on him or Juha Tasa. 

Thank you both. 

My colleagues and co-workers in Seinäjoki Central Hospital are warmly thanked for 

sharing the excitement of finishing this thesis. I especially want to thank Pauli Ritvanen at 

the Health library. 

64

Acknowledgements 

Most of my writing in English is not understandable; however, after Carlys’ spell check of 

the original publications and the thesis, I could present my work without shame. I can’t 

find words to express my gratitude so please accept the Finnish chocolate I’ve sent to you 

in Canada as a token of my appreciation. 

My heartfelt thanks go to my family: Sari, Emilia and Johannes. Children make life a bit 

harder, but so much sweeter. Emilia and Johannes have shown me what is truly important 

in life. And my dear wife Sari has selflessly and skilfully taken care of our home when my 

work has kept me away. I love you. 

This study was financially supported by the Instrumentarium Science Foundation, the 

Otologic Research Foundation and the Finnish Medical Foundation. Special government 

subsidies for health sciences research were awarded by Helsinki University Central 

Hospital, Tampere University Central Hospital, Kymenlaakso Central Hospital and 

Seinäjoki Central Hospital. 

Seinäjoki, April 2009 

Juuso Kujala 

65

9 References 

References 

Aantaa E, Virolainen E. The pre- and postoperative ENG findings in clinical otosclerosis 

and the late hearing results. Acta Otolaryngol 85: 313-7, 1978. 

Aarnisalo AA, Vasama J-P, Hopsu E, Ramsay H. Long-term hearing results after stapes 

surgery. A 20-year follow-up. Otol Neurotol 24: 567-71, 2003. 

Abd el-Rahman AG. Cochlear otosclerosis: statistical analysis of relationship of spiral 

ligament hyalinization to hearing loss. J Laryngol Otol 104: 952-5, 1990. 

Althaus SR, House HP. Long term results of perilymph fistula repair. Laryngoscope 83: 

1502-9, 1973. 

Altmann F, Glasgold A, Macduff JP. The incidence of otosclerosis as related to race and 

sex. Ann Otol Rhinol Laryngol 76: 377-92, 1967. 

Arnold W, Busch R, Arnold A, Ritsher B, Neiss A, Niedermeyer HP. The influence of 

measles vaccination on the incidence of otosclerosis in Germany. Eur Arch 

Otorhinolaryngol 264: 741-8, 2007. 

Arnold W, Friedmann I. Detection of measles and rubella-specific antigens in the 

endochondral ossification zone in otosclerosis. Laryngol Rhinol Otol (Stuttg) 66: 167- 

71, 1987. 

Arshinoff SA, Strube YN, Yagev R. Simultaneous bilateral cataract surgery. J Cataract 

Refract Surg 29: 1281-91, 2003. 

Ayache D, Earally F, Elbaz P. Characteristic and postoperative course of tinnitus in 

otosclerosis. Otol Neurotol 24: 48-51, 2003. 

Ayache D, Lejeune D, Williams MT. Imaging of postoperative sensorineural 

complications of stapes surgery. Adv Otorhinolaryngol 65: 308-13, 2007. 

Backous DD, Minor LB, Aboujaoude ES, Nager GT. Relationship of the utriculus and 

sacculus to the stapes footplate: anatomic implications for sound-and/or pressureinduced 

otolith activation. Ann Otol Rhinol Laryngol 108: 548-53, 1999. 

Badran K, Gosh S, Farag A, Timms MS. How we do it: Switching from mechanical 

perforation to the CO2 laser; audit results of primary small-fenestra stapedotomy in a 

district general hospital. Clin Otolaryngol 31: 546-9, 2006. 

Bailey HA Jr, Pappas JJ, Graham SS. Small fenestra stapedectomy technique: reducing 

risk and improving hearing. Otolaryngol Head Neck Surg 91: 516-20, 1983. 

Balle V, Linthicum FH. Histologically proven cochlear otosclerosis with pure 

sensoryneural hearing loss. Ann Otol Rhinol Laryngol 93: 105-11, 1984. 

66

References 

Baloh RW, Honrubia. Clinical neurophysiology of the vestibular system third edition. 

Oxford University Press, 2001: 132-51. 

Batman C, Oztürk O, Ramadan SS. Postoperative granuloma after stapedectomy: is it 

destiny or avoidable? Adv Otorhinolaryngol 65: 285-95, 2007. 

Beatty S, Aggarwal RK, David DB, Guarro M, Jones H, Pearce JL. Simultaneous bilateral 

cataract extraction in the UK. Br J Ophthalmol 79: 1111-4, 1995. 

Belden CJ, Weg N, Minor LB, Zinreich SJ. CT evaluation of bone dehiscence of the 

superior semicircular canal as a cause of sound- and/or pressure-induced vertigo. 

Radiology 226: 337-43, 2003. 

Birch L, Elbrond O. Stapedectomy and vertigo. Clin Otolaryngol 10: 217-23, 1985. 

Birch L, Elbrond O, Pedersen U. Hearing improvement after stapedectomy: up to 19 years' 

follow-up period. J Laryngol Otol 100: 1-7, 1986. 

Bisdorff AR, Sancovic S, Debatisse D, Bentley C, Gresty MA, Bronstein AM. Posiotional 

nystagmus in the dark in normal subjects. Neuro-ophthalmology 24: 283-90, 2000. 

Bretlau P, Causse J, Causse JB, Hansen HJ, Johnsen NJ, Salomon G. Otospongiosis and 

sodium fluoride. A blind experimental and clinical evaluation of the effect of sodium 

fluoride treatment in patients with otospongiosis. Ann Otol Rhinol Laryngol 94: 103-7, 

1985. 

Bretlau P, Hansen HJ, Causse J, Causse JB. Otospongiosis: morphologic and 

microchemical investigation after NaF-treatment. Otolaryngol Head Neck Surg 89: 

646-50, 1981. 

Brookler KH, Tanyeri H. Etidronate for the the neurotologic symptoms of otosclerosis: 

preliminary study. Ear Nose Throat J 76: 371-6, 379-81, 1997. 

Browning GG, Gatehouse S, Swan IRC. The Glasgow benefit plot: a new method for 

reporting benefits from middle ear surgery. Laryngoscope 101: 180-5, 1991. 

Bujía J, Alsalameh S, Jerez R, Sittinger M, Wilmes E, Burmester G. Antibodies to the 

minor cartilage collagen type IX in otosclerosis. Am J Otol 15: 222-4, 1994. 

Calmels MN, Viana C, Wanna G, Marx M, James C, Deguine O, Fraysse B. Very faradvanced 

otosclerosis: stapedotomy or cochlear implantation. Acta Otolaryngol 127: 

574-8, 2007. 

Causse JB. Etiology and therapy of cochlear drops following stapedectomy. Am J Otol 1: 

221-4, 1980. 

67

References 

Causse J, Causse JB. Eighteen-year report of on stapedectomy. I: problems of stapedial 

fixation. Clin Otolaryngol 5: 49-59, 1980a. 

Causse J, Causse JB. Eighteen-year report on stapedectomy. III. Postoperative 

complications. Clin Otolaryngol Allied Sci 5: 397-402, 1980b. 

Causse JB, Causse JR, Cezard R, Briand C, Bretlau P, Wiet R, House JW. Vertigo in 

postoperative follow-up of otosclerosis. Am J Otol 9: 246-55, 1988. 

Causse JB, Causse JR, Wiet RJ, Yoo TJ. Complications of stapedectomies. Am J Otol 4: 

275-80, 1983. 

Causse JR, Causse JB, Bretlau P, Uriel J, Berges J, Chevance LG, Shambaugh GE, 

Bastide JM. Etiology of otospongiotic sensoryneural loss. Am J Otol 10: 99-107, 1989. 

Causse JR, Causse JB, Uriel J, Berges J, Shambaugh GE Jr, Bretlau P. Sodium fluoride 

therapy. Am J Otol 14: 482-90, 1993a. 

Causse JR, Chevance LG. Sensoryneural hearing loss due to cochlear otospongiosis 

aetiology. Otolaryngol Clin North Am 11: 125-34, 1978. 

Causse JB, Gherini S, Horn KL. Surgical treatment of stapes fixation by fiberoptic argon 

laser stapedotomy with reconstruction of the annular ligament. Otolaryngol Clin North 

Am 26: 395-416, 1993b. 

Causse JB, Vincent R. Poor vibration of inner ear fluids as a cause of low tone tinnitus. 

Am J Otol 5: 701-2, 1995. 

Causse J, Vincent R, Michat M, Gherini S. Stapedius tendon reconstruction during 

stapedotomy: tehnique and results. Ear Nose Throat J 76: 256-9, 1997. 

Chevance L, Bretlau P, Jorgensen M, Causse J. Otosclerosis: an electron microscopic and 

cytochemical study. Acta Otolaryngol 272: 1-44, 1970. 

Chole RA, McKenna M. Pathophysiology of otosclerosis. Otol Neurotol 22: 249-57, 2001. 

Colletti V, Fiorino FG. Stapedotomy with stapedius tendon preservation:technique and 

long-term results. Otolaryngol Head Neck Surg 111: 181-8, 1994. 

Cody DTR, Baker HL. Otosclerosis: vestibular symptoms and sensorineural hearing loss. 

Ann Otol 87: 778-96, 1978. 

Corvera G, Cespedes B, Ysunza A, Arrieta J. Ambulatory vs. in-patient stapedectomy: A 

randomized twenty-patient pilot study. Head Neck Surg 114: 355-9, 1996. 

Cremers CW, Beusen JM, Huygen PL. Hearing gain after stapedotomy, partial 

platinectomy, or total stapedectomy for otosclerosis. Ann Otol Rhinol Laryngol 100: 

959-61, 1991. 

68

References 

Dahlqvist A, Diamant H, Dahlqvist SR, Cedergren B. HLA antigens in patients with 

otosclerosis. Acta Otolaryngol 100: 33-5, 1985. 

Daniels RL, Krieger LW, Lippy WH. The other ear: findings and results in 1800 bilateral 

stapedectomies. Otol Neurotol 22: 603-7, 2001. 

De Bruijn AJC, Tange RA, Dreschler WA. Evaluation of second-ear stapedotomy with the 

Glasgow benefit plot. ORL 61: 92-7, 1999. 

De Bruijn AJC, Tange RA, Dreschler WA, Grolman W, Shouwenburg PF. Bilateral 

stapedotomy in patients with otosclerosis: a disability-oriented evaluation of the 

benefit of second ear surgery. Clin Otolaryngol 23: 123-7, 1998. 

Declau F, van Spaendonck M, Timermans JP, Michaels L, Liang J, Qiu JP, van de 

Heyning P. Prevalence of otosclerosis in an unselected series of temporal bones. Otol 

Neurotol 22: 596-602, 2001. 

De La Cruz A, Fayad JN. Revision stapedectomy. Otolaryngol Head Neck Surg 123: 728- 

32, 2000. 

Del Bo M, Zaghis A, Ambrosetti U. Some observations concerning 200 stapedectomies: 

fifteen eyars postoperatively. Laryngoscope 97: 1211-3, 1987. 

Derks W, De Groot JA, Raymakers JA, Veldman JE. Fluoride therapy for cochlear 

otosclerosis? An audiometric and computerized tomography evaluation. Acta 

Otolaryngol 121: 174-7, 2001. 

Dickins JRE, Graham SS. Otologic surgery in the outpatient versus the hospital setting. 

Am J Otol 10: 252-5, 1989. 

Doherty JK, Linthicum FH Jr. Spiral ligament and stria vascularis changes in cochlear 

otosclerosis: effect on hearing level. Otol Neurotol 25: 457-64, 2004. 

Ealy M, Chen W, Ryu GY, Yoon JG, Welling DB, Hansen M, Madan A, Smith RJ. Gene 

expression analysis of human otosclerotic stapedial footplates. Hear Res 240: 80-6, 

2008. 

Elonka DR, Applebaum EL. Otosclerotic involvement of the cochlea: a histologic and 

audiologic study. Otolaryngol Head Neck Surg 89: 343-51, 1981. 

Esquivel CR, Mamikoglu B, Wiet RJ. Long-term results of small fenestra stapedectomy 

compared with large fenestra technique. Laryngoscope 112: 1338-41, 2002. 

Falcone MT, Gajewski BJ, Antonelli PJ. Hearing loss with stapedotomy in otitis media. 

Otolaryngol Head Neck Surg 129: 666-73, 2003. 

69

References 

Faye-Lund H, Stanngeland N, Rohrt T. Long-term results of bilateral stapedectomy. J 

Laryngol Otol 98: 247-54, 1984. 

Feldman AS. An investigation of secondary nerve degeneration in clinical otosclerosis. 

Arch Otolaryngol 72: 425-30, 1960. 

Fenton JE, Turner J, Shirazi A, Fagan PA. Post-stapedectomy reparative granuloma: a 

misnomer. J Laryngol Otol 110: 185-8, 1996. 

Fetter M, Dichgans J. Vestibular neuritis spares the inferior division of the vestibular 

nerve. Brain 119: 755-63 1996. 

Fish U. Vestibular symptoms before and after stapedectomy. Acta Otolaryngol 60: 513- 

30, 1965. 

Fisch U. Stapedectomy versus stapedectomy. Am J Otol 4: 112-7, 1982. 

Fowler EP. Anterior crurotomy and mobilization of the ankylosed stapes foot-plate; 

introduction to a motion picture demonstration. Acta Otolaryngol 46: 319-22, 1956. 

Fowler EP. Otosclerosis in identical twins. A study of 40 pairs. Arch Otolaryngol 83: 324- 

8, 1966. 

Franklin DJ, Pollack A, Fisch U. Meniere’s symptoms resulting from bilateral otosclerotic 

occlusion of the endolymphatic duct: an analysis of a causal relationship between 

otosclerosis and menieres disease. Am J Otol 11: 135-40, 1990. 

Frenz M. Physical characteristics of various lasers used in stapes surgery. Adv 


Gacek RR. The diagnosis and treatment of poststapedectomy granuloma. Ann Otol Rhinol 

Laryngol 79: 970-5, 1970. 

Gantz BJ, Tyler RS, Rubinstein JT, Wolawer A, Lowder M, Abbas P, Brown C, Hughes 

M, Preece JP. Binaural cochlear implants placed during the same operation. Otol 

Neurotol 23: 169-80, 2002. 

Gapany-Gapanavicius B. The incidence of otosclerosis in the general population. Isr J 

Med Sci 11: 465-8, 1975. 

Goh JP, Chan LL, Tan TY. MRI of cochlear otosclerosis. Br J Radiol 75: 502-5, 2002. 

Govaerts PJ, Raemaekers J, Verlinden A, Kalai M, Somers T, Offeciers FE. Use of 

antibiotic prophylaxis in ear surgery. Laryngoscope 108: 107-10, 1998. 

Geisler C, Bergenius J and Brantberg K. Nystagmus findings in healthy subjects 

examined with infrared videonystagmoscopy. ORL 62: 266-9, 2000. 

70

References 

Gersdorff M, Nouwen J, Gilain C, Decat M, Betsch C. Tinnitus and otsclerosis. Eur Arch 


Glasscock ME, Storper IS, Haynes DS, Bohrer PS. Stapedectomy in profound cochlear 

loss. Laryngoscope 106: 831-3, 1996. 

Grayeli AB, Sterkers O, Roulleau P, Elbaz P, Ferrary E, Silve C. Parathyroid hormoneparathyroid 

hormone-related peptide receptor expression and function in otosclerosis. 

Am J Physiol 277: 1005- 12, 1999. 

Gristwood RE, Venables WN. Pregnancy and otosclerosis. Clin Otolaryngol Allied Sci 8: 

205-10, 1983. 

Gristwood RE, Venables WN. Otosclerosis and chronic tinnitus. Ann Otol Rhinol 

Laryngol 112: 398-403, 2003. 

Grolman W, Tange RA, de Bruijn AJ, Hart AA, Schouwenburg PF. A retrospective study 

of the hearing results obtained after stapedotomy by the implantation of two Teflon 

pistons with a different diameter. Eur Arch Otorhinolaryngol 254: 422-4, 1997. 

Gros A, Zargi M, Vatovec J. Does it make sense to preserve the stapesial muscle during 

surgical treatment for otosclerosis. J Laryngol Otol 114: 930-4, 2000. 

Guil SR. Histologic Otosclerosis. Ann Otol Rhinol Laryngol 53: 246-267, 1944. 

Guo S, Nelson LB, Calhoun J, Levin A. Simultaneous surgery for bilateral congenital 

cataracts. J Pediatr Ophthalmol Strabismus 27: 23-5; discussion 26-7, 1990. 

Hall JG. Otosclerosis in Norway, a geographical and genetical study. Acta Otolaryngol 

Suppl 324: 1-20, 1974. 

Hammond V. The indications for stapedectomy. J Laryngol Otol 90: 23-9, 1976. 

Hannley MT. Audiological characteristics of the patients with otosclerosis. 

Otolaryngologic Clinics of North America 26: 373-87, 1993. 

Harris JP, Gong S. Comparison of hearing results of nitinol SMART stapes piston 

prosthesis with conventional piston prostheses: postoperative results of nitinol stapes 

prosthesis. Otol Neurotol 28: 692-5, 2007. 

Hausler R. General history of stapedectomy. Adv Otorhinolaryngol 65: 1-5, 2007. 

Hinojosa R, Marion M. Otosclerosis and sensuryneural hearing loss: a histopathologic 

study. Am J Otolaryngol 8: 296-307, 1987. 

Hirvonen TP, Hirvonen M, Aalto H. Postural control measured by visual feedback 

posturography. ORL 3: 186-90, 2002. 

71

References 

Hough JV, Dyer RK Jr. Stapedectomy. Causes of failure and revision surgery in 

otosclerosis. Otolaryngol Clin North Am 26: 453-70, 1993. 

House JW, Cunniningham CD. Cummings Otolaryngology, Head & Neck Surgery 4th 

edition. Edited by Cummings CW et al. Mosby Inc., Philadelphia 2005: 3562-73. 

House HP, Hansen MR, Al Dakhail AAA, House JW. Stapedectomy versus stapedotomy: 

Comparison of results with long-term follow-up. Laryngoscope 112: 2046-50, 2002. 

House WF, Sheehy JL. Stapes surgery: selection of the patient. Ann Otol Rhinol Laryngol 

70: 1062-8, 1961. 

Huber AM, Ma F, Felix H, Linder T. Stapes prosthesis attachment: the effect of crimping 

on sound transfer in otosclerosis surgery. Laryngoscope 113: 853-8, 2003. 

Huber A, Linder T, Fisch U. Is the Er:YAG laser damaging to inner ear function. Otol 

Neurotol 22: 311-5, 2001a. 

Huber AM, Schwab C, Linder T, Stoeckli SJ, Ferrazzini M, Dillier N, Fisch U. Evaluation 

of eardrum laser Doppler interferometry as a diagnostic tool. Laryngoscope 111: 501- 

7, 2001b. 

Hueb MM, Goycoolea MV, Paparella MM, Oliveira JA. Otosclerosis: The University of 

Minnesota temporal bone collection. Otolaryngol Head Neck Surg 105: 396-405, 

1991. 

Huovinen P, Vaara M. Mikrobiologia ja infektiosairaudet. Kustannus Oy Duodecim, 

Helsinki 2005; (2): 81-109. 

Huotari K, Lyytikäinen O, Seitsalo S. Patient outcomes after simultaneous bilateral total 

hip and knee joint replacements. J Hosp Infect 65: 219-25, 2007. 

Huttenbrink KB. Biomechanics on stapedoplasty: a reviev. Otol Neurotol 24: 548-59, 

2003. 

Häusler R. Schär PJ, Pratisto H, Weber HP, Frenz M. Advantages and dangers of erbium 

laser application in stapedotomy. Acta Otolaryngol 119: 207-13, 1999. 

Imauchi Y, Lombès M, Lainé P, Sterkers O, Ferrary E, Grayeli AB. Glucocorticoids 

inhibit diastrophic dysplasia sulfate transporter activity in otosclerosis by interleukin-6. 

Laryngoscope 116: 1647-50, 2006. 

Imauchi Y, Jeunemaître X, Boussion M, Ferrary E, Sterkers O, Grayeli AB. Relation 

between renin-angiotensin-aldosterone system and otosclerosis: a genetic association 

and in vitro study. Otol Neurotol 29: 295-301, 2008. 

72

References 

Jablokow VR, Kathuria S. Fatal meningitis due to Serratia marcescens after stapedectomy. 

Arch Otolaryngol 108: 34-5, 1982. 

Jastreboff PJ. Phantom auditory perception (Tinnitus): mechanisms of generation and 

perception. Neurosci Res 8: 221-254, 1990. 

Jerger J. Clinical experience with impedance audiometry. Arch Otolaryngol 92: 311, 1970. 

Johnson EW. Hearing aids and otosclerosis. Otolaryngol Clin North Am 26: 491-502, 

1993. 

Johnsson LG, Pyykkö I, Pollak A, Gleeson M, Felix H. Cochlear vascular pathology and 

hydrops in otosclerosis. Acta Otolaryngol 115: 255-9, 1995. 

Karhuketo TS, Lundmark J, Vanhatalo J, Rautiainen M, Sipilä M. Stapes surgery: A 32year 

follow-up. ORL 69: 322-6, 2007. 

Karosi T, Jókay I, Kónya J, Petkó M, Szabó LZ, Sziklai I. Expression of measles virus 

receptors in otosclerotic, non-otosclerotic and in normal stapes footplates. Eur Arch 


Kaufman RS, Schuknecht HF. Reparative granuloma following stapedectomy: a clinical 

entity. Ann Otol Rhinol Laryngol 76: 1008-17, 1967. 

Kennedy DW, Hoffer ME, Holliday M. The effects of etidronate disodium on progressive 

hearing loss from otosclerosis. Otolaryngol Head Neck Surg 109: 461-7, 1993. 

Khalifa A, el-Guindy A, Erfan F. Stapedectomy for far-advanced otosclerosis. J Laryngol 

Otol 112: 158-60, 1998. 

Klemens JJ, Mhoon E, Redleaf M. Is simultaneous bilateral mastoidectomy ever 

advisable? J Laryngol Otol 121: 1041-7, 2007. 

Klockars T, Kentala E. Case report: Meniere’s disease and otosclerosis – different 

outcome of the same disease? Auris Nasus Larynx 34: 101-4, 2007. 

Kos MI, Montandon PB, Guyot JP. Short- and long-term results of stapedotomy and 

stapedectomy with a Teflon-wire piston prosthesis. Ann Otol Rhinol Laryngol 110: 

907-11, 2001. 

Koizuka I, Sakagami M, Doi K, Takeda N, Matsunaga T. Nystagmus measured by ENG 

after stapes surgery. Acta Otolaryngol Suppl 520: 258-9, 1995. 

Kougias P, Kappa JR, Sewell DH, Feit RA, Michalik RE, Imam M, Greenfield TD. 

Simultaneous carotid endarterectomy and coronary artery bypass grafting: results in 

specific patient groups. Ann Vasc Surg 21: 408-14, 2007. 

73

References 

Laitakari K, Löppönen H, Luotonen J. Huonokuuloisuuden kiireetön leikkaushoito. 

Yhtenäiset kiireettömän hoidon perusteet. Sosiaali- ja terveysministeriön oppaita 

2005(5): 163. 

Lesinski GS. Causes of conductive hearing loss after stapedectomy or stapedotomy: a 

prospective study of 279 consecutive surgical revision. Otol Neurotol 23: 281-8, 2002. 

Lesinski GS, Newrock R. Carbon dioxide lasers for otosclerosis. Otolaryngol Clin North 

Am 26: 417-41, 1993. 

Levo H, Aalto H, Hirvonen TP. Nystagmus measured with video-oculography: 

methodological aspects and normative data. ORL 3: 101-4, 2001. 

Lippy WH, Battista RA, Berenholz L, Schuring AG, Burkey JM. Twenty-year review of 

revision stapedectomy. Otol Neurotol 24: 560-6, 2003. 

Lippy WH, Berenholz LP, Schuring AG, Burkey JM. Does pregnancy affect otosclerosis? 

Laryngoscope 115: 1833-6, 2005. 

Linthicum FH. Histopathology of otosclerosis. Otolaryngologic Clinics of North America 

26: 335-52, 1993. 

Linthicum FH Jr. Histological evidence of the causes of failure in stapes surgery. Ann 

Otol Rhinol Laryngol 80: 67-77, 1971. 

Lolov SR, Edrev GE, Kyurkchiev SD, Kehayov IR. Elevated autoantibodies in sera from 

otosclerotic patients are related to the disease duration. Acta Otolaryngol 118: 375-80, 

1998. 

Lolov SR, Encheva VI, Kyurkchiev SD, Edrev GE, Kehayov IR. Antimeasles 

immunoglobulin G in sera of patients with otosclerosis is lower than that in healthy 

people. Otol Neurotol 22: 766-70, 2001. 

Ludman H, Grant H. The case against bilateral stapedectomy, and problems of postoperative 

follow-up from the King's College Hospital series. J Laryngol Otol 87: 833- 

43, 1973. 

Mafee MF, Henrikson GC, Deitch RL, Norouzi P, Kumar A, Kris R, Valvassori GE. Use 

of CT in stapedial otosclerosis. Radiology 156: 707-14, 1985. 

Mahendran S, Hogg R, Robinson JM. To divide or manipulate the chorda tympani in 

stapedotomy. Eur Arch Otorhinolaryngol 262: 482-7, 2005. 

Mann WJ, Amedee RG, Fuerst G, Tabb HG. Hearing loss as a complication of stapes 

surgery. Otolaryngol Head Neck Surg 115: 324-8, 1996. 

Marchese MR, Cianfrone F, Passali GC, Paludetti G. Hearing results after stapedotomy: 

role of the prosthesis diameter. Audiol Neurootol 12: 221-5, 2007. 

74

References 

Markou K, Goudakos J. An overview of the etiology of otosclerosis. Eur Arch 


Maureen TH. Audiological characteristics of the patients with otosclerosis. 

Otolaryngologic Clinics of North America 26: 373-87, 1993. 

McGee TM. The loose wire syndrome. Laryngoscope 91: 1478-83, 1981. 

McKenna MJ, Kristiansen AG, Tropitzsch AS. Similar COLA1 expression in fibroblasts 

from some patients with clinical otosclerosis and those with type I osteogenesis 

imperfecta. Ann Otol Rhinol Laryngol 111: 184-9, 2002. 

McKenna MJ, Mills BG. Immunohistochemical evidence of measles virus antigens in 

active otosclerosis. Otolaryngol Head Neck Surg 101: 415-21, 1989. 

McKenna MJ, Mills BG. Ultrastructural and immunohistochemical evidence of measles 

virus in active otosclerosis. Acta Otolaryngol Suppl 470: 130-40, 1990. 

McKenna MJ, Mills BG, Galey FR, Linthicum FH Jr. Filamentous structures 

morphologically similar to viral nucleocapsids in otosclerotic lesions in two patients. 

Am J Otol 7: 25-8, 1986. 

Menger DJ, Tange RA. The aetiology of otosclerosis: a review of the literature. Clin 

Otolaryngol 28: 112-20, 2003. 

Miani C, Bergamin AM, Barotti A, Isola M. Multifrequency multicomponent 

tympanometry in normal and otosclerotic ears. Scand Audiol 29: 225-37, 2000. 

Mills BG, Singer FR. Nuclear inclusions in Paget's disease of bone. Science 194: 201-2, 

1976. 

Moon CN Jr. Perilymph fistulas complicating the stapedectomy operation. A review of 

forty-nine cases. Laryngoscope 80: 515-31, 1970. 

Mosnier I, Bouccara D, Ambert-Dahan E, Ferrary E, Sterkers O. Cochlear implantation 

and far-advanced otosclerosis. Adv Otorhinolaryngol 65: 323-7, 2007. 

Motta G, Moscillo L. Functional results in stapedotomy with and without CO(2) laser. 

ORL J Otorhinolaryngol Relat Spec 64: 307-10, 2002. 

Moumoulidis I, Axon P, Baguley D, Reid E. A review on the genetics of otosclerosis. Clin 

Otolaryngol 32: 239-47, 2007. 

Naumann IC, Porcellini B, Fisch U. Otosclerosis: incidence of positive findings on highresolution 

computed tomography and their correlation to audiological test data. Ann 

Otol Rhinol Laryngol 114: 709-16, 2005. 

75

References 

Nelson EG, Hinojosa R. Questioning the relationship between cochlear otosclerosis and 

sensorineural hearing loss: a quantitative evaluation of cochlear structures in cases of 

otosclerosis and review of the literature. Laryngoscope 114: 1214-30, 2004. 

Niedermeyer HP, Arnold W. Otosclerosis: a measles virus associated inflammatory 

disease. Acta Otolaryngol 115: 300-3, 1995. 

Niedermeyer HP, Arnold W, Schwub D, Busch R, Wiest I, Sedlmeier R. Shift of the 

distribution of age in patients with otosclerosis. Acta Otolaryngol 121: 197-9, 2001. 

Niedermeyer HP, Becker ET, Arnold W. Expression of collagens in the otosclerotic bone. 

Adv Otorhinollaryngol 65: 45-9, 2007. 

Nielsen TR, Thomsen J. Meningitis following stapedotomy: a rare and early complication. 

J Laryngol Otol 114: 781-3, 2000. 

Nylen B. Histopathological investigations on the localization, number, activity and extent 

of otosclerotic foci. J Laryng 63: 321-27, 1949. 

Oliveira CA. How does stapes surgery influence severe disabling tinnitus in otosclerosis 

patients? Adv Otorhinolaryngol 65: 343-7, 2007. 

Padoan S, Korttila K, Magnusson M, Pyykkö I, Shalen L. Reduction of gain and time 

constant of vestibulo-ocular reflex in man induced by diazepam and thiopental. J 

Vestib Res 1: 97-104, 1990-1991. 

Palva T. Argon laser in otosclerosis surgery. Acta Otolaryngol 104: 153-7, 1987. 

Paparella MM, Cureoglu S, Shao W, Schachern PA. Otosclerosis and associated 

otopathologic conditions. Adv Otorhinolaryngol 65: 31-44, 2007. 

Papsin BC, Gordon KA. Bilateral cochlear implants should be the standard for children 

with bilateral sensorineural deafness. Curr Opin Otolaryngol head Neck Surg 16: 69- 

74, 2008. 

Parahy C, Linthicum FH Jr. Otosclerosis: relationship of spiral ligament hyalinization to 

sensorineural hearing loss. Laryngoscope 93: 717-20, 1983. 

Pauw BK, Pollak AM, Fisch U. Utricle, saccule, and cochlear duct in relation to 

stapedotomy. A histologic human temporal bone study. Ann Otol Rhinol Laryngol 

100: 966-70, 1991. 

Pearson RD, Kurland LT, Cody DT. Incidence of diagnosed clinical otosclerosis. Arch 

Otolaryngol 99: 288-91, 1974. 

Pedersen U, Madsen M, Lamm LU, Elbrønd O. HLA-A, -B, -C antigens in otosclerosis. J 

Laryngol Otol 97: 1095-7, 1983. 

76

References 

Perkings RC. Laser stapedotomy for otosclerosis. Laryngoscope 90: 228-42, 1980. 

Perkins R, Curto FS Jr. Laser stapedotomy: a comparative study of prostheses and seals. 

Laryngoscope 102: 1321-7, 1992. 

Persson P, Harder H, Magnuson B. Hearing results in otosclerosis surgery after partial 

stapedectomy, total stapedectomy and stapedotomy. Acta Otolaryngol 117: 94-9, 1997. 

Politzer A. History of otology. Columella Press, Virginia, 1981: 136-43. 

Porter MJ, Zeitoun H, Brookes GB. The Glasgow benefit plot used assess the effect of 

bilateral stapedectomy. Clin Otolaryngol 20: 68-71, 1995. 

Precechtel A. Determination of the effect of pregnancy on the activation of otosclerosis. 

Acta Otolaryngol 63: 121-7, 1967. 

Probst R. Audiological evaluation of patients with otosclerosis. Adv Otorhinolaryngol 65: 

119-26, 2007. 

Ramsay H, Kärkkäinen J, Palva T. Success in surgery for otosclerosis: hearing 

improvement and other indicators. Am J Otol 18: 23-8, 1997. 

Raut VV, Toner JG, Kerr AG, Stevenson M . Management of otosclerosis in the UK. Clin 

Otolaryngol 27: 113-9, 2002. 

Reshetnikov NN, Popova TI. IgA, IgM and IgG levels and antibodies to native DNA and 

collagen type II in the perilymph of patients with otosclerosis. Vestn Otorinolaringol 3: 

14-6, 1992. 

Rizer FM, Lippy WH. Evolution of techniques of stapedectomy from the total 

stapedectomy to the small fenestra stapedectomy. Otolaryngol Clin North Am 26: 443- 

51, 1993. 

Robinson DA, Zee DS, Hain TC, Holmes A, Rosenberg LF. Alexander's law: its behavior 

and origin in the human vestibulo-ocular reflex. Ann Neurol 16: 714-22, 1984. 

Rosowski JJ, Mehta RP, Merchant SN. Diagnostic utility of laser-Doppler vibrometry in 

conductive hearing loss with normal tympanic membrane. Otol Neurotol 24: 165-75, 

2003. 

Rosowski JJ, Merchant SN. Mechanical and acoustic analysis of middle ear 

reconstruction. Am J Otol 16: 486-97, 1995. 

Rottach KG, Wohlgemuth WA, Dzaja AE, Eggert T, Straube A. Effect of intravenous 

opioids on eye movements in humans: possible mechanisms. J Neurol 249: 1200-5, 

2002. 

77

References 

Rotteveel LJ, Proops DW, Ramsden RT, Saeed SR, van Olphen AF, Mylanus EA. 

Cochlear implantation in 53 patients with otosclerosis: demographics, computed 

tomographic scanning, surgery, and complications. Otol Neurotol 25: 943-52, 2004. 

Ruckenstein MJ, Rafter KO, Montes M, Bigelow DC. Management of far advanced 

otosclerosis in the era of cochlear implantation. Otol Neurotol 22: 471-4, 2001. 

Ruedi L. Otosclerotic lesion and cochlear degeneration. Arch Otolaryngol 89: 364-71, 

1969. 

Sabitha R, Ramalingam R, Ramalingam KK, Sivakumaran TA, Ramesh A. Genetics of 

otosclerosis. J Laryngol Otol 111: 109-12, 1997. 

Salvinelli F, Casale M, Vitaliana L, Greco F, Dianzani C, D'Ascanio L. Delayed 

peripheral facial palsy in the stapes surgery: can it be prevented? Am J Otolaryngol 25: 

105-8, 2004. 

Sarikkola AU, Kontkanen M, Kivela T, Laatikainen L. Simultaneous bilateral cataract 

surgery: a retrospective survey. J Cataract Refract Surg 30: 1335-41, 2004. 

Schmerber S, Karkas A, Righini CA, Chahine KA. The quartile benefit plot: a middle ear 

surgery benefit assessment scheme. Laryngoscope 118: 843-8, 2008. 

Schmerber S, Cuisnier O, Charachon R, Lavieille JP. Vein versus tragal perichondrium in 

stapedotomy. Otol Neurotol 25: 694-8, 2004. 

Schuknecht HF. Stapedectomy and Graft-Prosthesis Operation. Acta otolaryngol 51: 241- 

3, 1960. 

Schuknecht HF Sensorineural hearing loss following stapedectomy. Acta Otolaryngol 54: 

336-48, 1962. 

Schuknecht HF. Pathology of the ear. Harvard University Press, Cambridge, 

Massachusetts and London, 1974: 351-73. 

Schuknecht HF, Barber W. Histologic variants in otosclerosis. Laryngoscope 95: 130-17, 

1985. 

Schuknecht HF, Kirchner JC. Cochlear otosclerosis: fact or fantasy. Laryngoscope 84: 

766-82, 1974. 

Seicshnaydre MA, Sismanis A, Hughes GB. Update of reparative granuloma: survey of 

the American Otological Society and the American Neurotology Society. Am J Otol 

15: 155-60, 1994. 

Sennaroğlu L, Unal OF, Sennaroğlu G, Gürsel B, Belgin E. Effect of Teflon piston 

diameter on hearing result after stapedotomy. Otolaryngol Head Neck Surg 124: 279- 

81, 2001. 

78

References 

Shabana YK, Ghonim MR, Pedersen CB. Stapedotomy: does prosthesis diameter affect 

outcome? Clin Otolaryngol 24: 91-4, 1999. 

Shambaugh GE, Glasscock ME. Surgery of the ear. W.B. Saunders Company, 

Philadelphia, London, Toronto, 1980: 476-516. 

Shambaugh GE, Scott A. Sodium fluoride for arrest of otosclerosis; theoretical 

considerations. Arch Otolaryngol 80: 263-70, 1964. 

Shea JJ. Symposium on the operation for mobilization of the stapes in otosclerotic 

deafness. Laryngoscope 66: 729-84, 1956. 

Shea JJ. Fenestration of the oval window. Ann Otol Rhinol Laryngol 67: 932-51, 1958. 

Shea JJ. Stapedectomy - long-term report. Ann Otol Rhinol Laryngol 91: 516-20, 1982. 

Shea JJ. Thirty years of stapes surgery. J Laryngol Otol 102: 14-9, 1988. 

Shea JJ Jr. Forty years of stapes surgery. Am J Otol 19: 52-5, 1998. 

Shea JJ Jr, Ge X. Delayed facial palsy after stapedectomy. Otol Neurotol 22: 465-70, 

2001. 

Sheehy JL, Nelson RA, House HP. Revision stapedectomy: a review of 258 cases. 

Laryngoscope 91: 43-51, 1981. 

Shin YJ, Fraysse B, Deguine O, Cognard C, Charlet JP, Sevely A. Sensorineural Hearing 

Loss and Otosclerosis: A Clinical and Radiologic Survey of 437 Cases. Acta 

Otolaryngol 121: 200-4, 2001. 

Shulman A, Strashun AM, Afriyie M, Aronson F, Abel W, Goldstein B. SPECT Imaging 

of Brain and Tinnitus-Neurotologic/Neurologic Implications. Int Tinnitus J 1: 13-29, 

1995. 

Silverstein H. Laser stapedotomy minus prosthesis (laser STAMP): a minimally invasive 

procedure. Am J Otol 19: 277-82, 1998. 

Silverstein H, Hester TO, Deems D, Rosenberg S, Grosby N, Kwiatkowski T. Outcome 

after laser stapedotomy with and without preservation of the stapedius tendon. Ear 

Nose Throat J 78: 923-8, 1999. 

Silverstein H, Hoffmann KK, Thompson JH Jr, Rosenberg SI, Sleeper JP. Hearing 

outcome of laser stapedotomy minus prosthesis (STAMP) versus conventional laser 

stapedotomy. Otol Neurotol 25: 106-11, 2004. 

Silverstein H, Rosenberg S, Jones R. Small fenestra stapedotomies with and without KTP 

laser: A comparison. Laryngoscope 99: 485-8, 1989. 

79

References 

Singbartl F, Basta D, Seidl RO, Ernst A, Todt I. Perioperative recordings of vestibularevoked 

myogenic potentials in otosclerosis. Otol Neurotol 27: 1070-3, 2006. 

Singhal SK, Mann SB, Datta U, Panda NK, Gupta AK. Genetic correlation in otosclerosis. 

Am J Otolaryngol 20: 102-5, 1999. 

Smith MC, Simon P, Ramalingam KK. Delayed facial palsy following uncomplicated 

stapedectomy. J Laryngol Otol 104: 611-2, 1990. 

Smyth GDL, Kerr AG, Singh KP. Second ear stapedectomy-a continued controversy. J 

Laryngol Otol 89: 1047-56, 1975. 

Smyth GDL, Patterson CC. Results of middle ear reconstruction: do patients and surgeons 

agree? Am J Otolaryngol 6: 276-9, 1985. 

Snyder BD, Boies LR Jr, Ulvestad RF, McGuiness PA. Delayed meningitis following 

stapes surgery. Arch Neurol 36: 174-5, 1979. 

Somers T, Govaerts P, Marquet T, Offeciers E. Statistical analysis of otosclerosis surgery 

performed by Jean Marquet. Ann Otol Rhinol Laryngol 103: 945-51, 1994. 

Sørensen MS, Nielsen LP, Bretlau P, Jørgensen MB. The role of type II collagen 

autoimmunity in otosclerosis revisited. Acta Otolaryngol 105: 242-7, 1988. 

Spandow O, Soderberg O, Bohlin L. Long-term results in otosclerotic patients operated by 

stapedectomy and stapedotomy. Scand Audiol 29: 186-90, 2000. 

Stapleton E, Mills R, Tham C. Sacculo-collic response in otosclerosis and following 

successful stapes surgery. J Laryngol Otol 122: 347-50, 2008. 

STAKES. National Research and Development Centre for Welfare and Health. 

www.stakes.fi/FI/tilastot/aiheittain/Terveyspalvelut/laitoshoito/benchmarking.htm 

Sugiura M, Naganawa S, Sone M, Yoshida T, Nakashima T. Three-dimensional fluidattenuated 

inversion recovery magnetic resonance imaging findings in a patient with 

cochlear otosclerosis. Auris Nasus Larynx 35: 269-72, 2008. 

Tange RA, de Bruijn AJG, Grolman W. Experience with a new pure gold piston in 

stapedotomy for cases of otosclerosis. Auris Nasus Larynx 25: 249-53, 1998. 

Tange RA, Grolman W. An analysis of the air-bone gap closure obtained by a crimping 

and a non-crimping titanium stapes prosthesis in otosclerosis. Auris Nasus Larynx 35: 

181-4, 2008. 

Tange RA, Grolman W, Dreschler WA. Gold and titanium in the oval window: a 

comparison of two metal stapes prostheses. Otol Neurotol 25: 102-5, 2004. 

80

References 

Toner JG, Smyth GDL. Comparison of methods of evaluating hearing benefit of middle 

ear surgery. J Laryngol Otol 107: 4-5, 1993. 

Topsakal V, Fransen E, Schmerber S, Declau F, Yung M, Gordts F, Van Camp G, Van de 

Heyning P. Audiometric analyses confirm a cochlear component, disproportional to 

age, in stapedial otosclerosis. Otol Neurotol 27: 781-7, 2006. 

Tribukait A, Bergenius J. The subjective visual horizontal after stapedotomy: evidence for 

an increased resting activity in otolithic affrents. Acta Otolaryngol 118: 299-306, 1998. 

Tshifularo MI, Joseph CA. Otosclerosis among South African indigenous blacks. East Afr 

Med J 85: 223-5, 2005. 

Uzicanin A, Eggers R, Webb E, Harris B, Durrheim D, Ogunbanjo G, Isaacs V, 

Hawkridge A, Biellik R, Strebel P. Impact of the 1996-1997 supplementary measles 

vaccination campaigns in South Africa. Int J Epidemiol 31: 968-76, 2002. 

Vartiainen E. Sex differences in patients with hearing impairments caused by otosclerosis. 

Eur Arch Otorhinolaryngol 256: 431-3, 1999. 

Vartiainen E, Vartiainen J. The effect of drinking water fluoridation on the natural course 

of hearing in patients with otosclerosis.Acta Otolaryngol 116: 747-50, 1996. 

Vartiainen E, Vartiainen J. The influence of fluoridation of drinking water on the longterm 

hearing results of stapedectomy. Clin Otolaryngol Allied Sci 22: 34-6, 1997a. 

Vartiainen E, Vartiainen T. Effect of drinking water fluoridation on the prevalence of 

otosclerosis. J Laryngol Otol 111: 20-2, 1997b. 

Verschuur HP, de Wever WW, van Benthem PP. Antibiotic prophylaxis in clean and 

clean-contaminated ear surgery. Cochrane Database Syst Rev. 2004;(3):CD003996. 

Vincent R, Sperling NM, Oates J, Jindal M. Surgical findings and long-term hearing 

results in 3050 Stapedotomies for primary otosclerosis: a prospective study with the 

otology-neurotology database. Otol Neurotol 27: S25-S47, 2006. 

Vrabec JT, Coker NJ. Stapes surgery in the United States. Otol Neurotol 25: 465-9, 2004. 

Wang PC, Merchant SN, McKenna MJ, Glynn RJ, Nadol JB Jr. Does otosclerosis occur 

only in the temporal bone? Am J Otol 20: 162-5, 1999. 

Wang ZM, Chi FL, Dai CF. Modified stapes prosthesis to limit postoperative vertigo. 

Otolaryngol Head Neck Surg 132: 50-4, 2005. 

Welling DB, Glasscock ME 3rd, Gantz BJ. Avulsion of the anomalous facial nerve at 

stapedectomy. Laryngoscope 102: 729-33, 1992. 

81

References 

Wengen DF. A new self-retaining titanium clip stapes prosthesis. Adv. Otorhinolaryngol 

65: 184-9, 2007. 

Wiet RJ, Harvey SA, Bauer GP. Complications in stapes surgery. Options for prevention 

and management. Otolaryngol Clin North Am 26: 471-90, 1993. 

Wiet RJ, Kubek DC, Lemberg P, Byskosh AT. A meta-analysis review of revision stapes 

surgery with argon laser: effectiveness and safety. Am J Otol 18: 166-71, 1997. 

Williams MD, Antonelli PJ, Williams LS, Moorhead JE. Middle ear prosthesis 

displacements in high-strength magnetic fields. Otol Neurotol 22: 158-61, 2001. 

Zarroug AE, Hamner CE, Pham TH, Houghton SG, Stavlo P, Moir CR, Rodeberg DA. 

Bilateral staged versus bilateral simultaneous thoracotomy in the pediatric population. 

J Pediatr Surg 41: 647-51, 2006. 

Zhao F, Wada H, Koike T, Ohyama K, Kawase T, Stephens D. Transient evoked 

otoacoustic emissions in patients with middle ear disorders. Int J Audiol 42: 117-31, 

2003. 

Ziyeh S, Berlis A, Ross UH, Reinhardt MJ, Schumacher M. MRI of active otosclerosis. 

Neuroradiology 39: 453-7, 1997. 

Yoo TJ. Etiopathogenesis of otosclerosis: a hypothesis. Ann Otol Rhinol Laryngol 93: 28- 

33, 1984. 

82

Appendix 

Questionnaire used to assess patients’ personal estimation of hearing gain, vestibular symptoms and 

quality of life. Data were collected preoperatively and at one, 3 and 12 months postoperatively. 

Numerical scores (1-5) were given to the corresponding subjective symptoms during data analysis. 

Nimi:__________________________________ Pvm:______________________________ 

Kyselykaavake Otoskleroosipotilaan Kuulosta Ja Huimauksesta 

Olkaa hyvä ja vastatkaa kaikkiin kysymyksiin. Vastatkaa numeroin tai ympyröikää vaihtoehto, joka parhaiten 

kuvaa vointianne. Valitkaa vain yksi vaihtoehto joka kysymyksestä. 

1. Monta vähintään 20 minuutin kiertohuimauskohtausta teillä on ollut viimeisen 6 kuukauden aikana ? 

____ kpl 

2. Kuuloni on 

1. ============== 2. ============== 3. ============= 4. ============= 5. 

Erinomainen Hyvä Kohtalainen Huono Erittäin huono 

3. Minua huimaa: 

1. ============== 2. ============== 3. ============= 4. ============= 5. 

Harvoin Silloin tällöin Puolet ajasta Enimmäkseen Aina 

4. Kun minua huimaa, oireeni on useimmiten: 

1. ============== 2. ============= 3. ============== 4. ============= 5. 

Erittäin lievä Lievä Kohtalainen Kohtalaisen vaikea Vaikea 

5. Minkälainen on huimaukseni vaikutus päivittäisiin toimintoihin kuten työntekoon, autolla ajoon, 

ostoksilla käyntiin, perheestä ja itsestä huolehtimiseen? 

1. ============= 2. ============== 3. ============= 4. ============= 5. 

Ei vaikutusta Lievä Kohtalainen Suuri Erityisen suuri 

6. Mikä on vointini vaikutus yleiseen elämänlaatuuni? Esimerkiksi sosiaalisiin aktiviteetteihin, läheisiin suhteisiin, tulevai 

suunnitelmiin, työn saantiin tai työssä käyntiin ja vapaa-aikaan: 

1. ============= 2. ============== 3. ============= 4. ============ 5. 

Ei vaikutusta Lievä Kohtalainen Suuri Erityisen suuri 

7. Pelkään saavani huimausta: 

1. ============= 2. ============== 3. ============= 4. ============ 5. 

En koskaan Harvoin Silloin tällöin Usein Aina 

8. Onko vointini verrattuna viime kertaiseen käyntiini? 

1. ============= 2. ============== 3. ============= 4. ============ 5. 

Huomattavasti Jonkin verran Samanlainen Jonkin verran Huomattavasti 

huonompi huonompi parempi parempi 

83

Original publications 

84

Modern surgical treatment of otosclerosis - Helda - Helsinki.fi

Create successful ePaper yourself

Delete template?

Save as template?