SHORT THESIS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY (PHD)
DEVELOPMENT AND CLINICAL TRIALS OF DEVICES FOR THE
POSTOPERATIVE REHABILITATION OF THE KNEE JOINT
by Sándo Manó
Supe iso : Zol án Cse ná ony
UNIVERSITY OF DEBRECEN
Doc o al School o Clinical Medicine
Deb ecen, 2015
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De elopmen and clinical ials o de ices o he pos ope a i e ehabili a ion o
he knee join
By Sándo Manó, MSc
Supe iso : Zol án Cse ná ony, MD, PhD, DSc
Doc o al School o Clinical Medicine, Uni e si y o Deb ecen
Head o he Examina ion Commi ee:
And ás Be a, MD, PhD, DSc
Membe s o he Examina ion Commi ee:
Zsol Bacsó, MD, PhD
Csaba Fa kas, MD, PhD
The Examina ion akes place a Depa men o Oph halmology, Facul y o Medicine, Uni-
e si y o Deb ecen, 04.02.2016, 11:00
Head o he De ense Commi ee:
And ás Be a, MD, PhD, DSc
Re iewe s:
Ri a Kiss, PhD, DSc
Lajos Bo bás, PhD
Membe s o he De ense Commi ee:
Ri a Kiss, PhD, DSc
Lajos Bo bás, PhD
The PhD De ense akes place a he Lec u e Hall o Bldg. A, Depa men o In e nal Medi-
cine, Facul y o Medicine, Uni e si y o Deb ecen, 04.02.2016, 13:00
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1. INTRODUCTION
The numbe o di e en su gical echniques o he ea men o knee join inju ies
is g owing con inuously. In cases o se ious inju ies o wea -and- ea o he join
he only solu ion is he o al join eplacemen , he so called o al endop os hesis.
To al join eplacemen su ge y became a ou ine in e en ion in he 1960s a i s
o he hip join , hen o he knee join a li le mo e han 10 yea s la e . Acco ding
o he cu en ly accep ed p edic ions he numbe o p ima y hip p os hesis im-
plan a ions is said o be inc eased by 30% un il 2030, while he numbe o knee
p os hesis implan a ions may quad uple. In addi ion o he g owing numbe o
join eplacemen su ge ies, pos ope a i e ehabili a ion has inc easing im-
po ance, since he inal ou come o he ope a ion s ongly depends on he success-
ul implemen a ion o he o me . The main goal is o achie e he bes possible
ange o mo ion upon he pa ien ’s discha ge om he hospi al. While he maximal
lexion o he no mal knee (app ox. 150°) is beyond each, apa om a eally ew
excep ions, which is accep ed bo h by he pa ien s and he su geons as well, each-
ing he ull ex ension o he join is essen ial as i s absence – he lexion con ac u e
– may lead o u he p oblems. Despi e he ac ha ull ex ension is eached du -
ing he su ge y, he expe ience shows he de elopmen o lexion con ac u e in an
o e whelming numbe o cases du ing he pos ope a i e pe iod. Based on li e a-
u e da a he incidence o ex ension de ici abo e 10° eaches 24% and 37% o
women and men, espec i ely.
The mos common unde lying cause o he co ec able ull ex ension de ici is he
p o ec i e e lex muscle spasm, igge ed by pain, bu inadequa e coope a ion o
he pa ien may play an addi ional ole in mos o he cases as well. A lexion con-
ac u e o e en a ew deg ees may cause ai ly ad e se biomechanical changes in
he knee join , since wi h ull ex ension only minimal balancing muscle ac i i y is
needed om he muscles su ounding he knee, while in a semi lexion pos u e he
lexo and ex enso muscles a e being o ced o wo k con inuously du ing s anding
posi ion ha leads o he ea ly exhaus ion and consequen pe manen pain o he
a ec ed muscles. Addi ionally, as a esul o he inc eased p essu e be ween he
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su aces o he join , he load on he pa ello emo al join inc eases signi ican ly as
well, while la e , he b oken balance o he so issues may lead o join ins abili y.
Du ing he pos ope a i e ehabili a ion ollowing o al knee eplacemen , he so
called Con inuous Passi e Mo ion (CPM) de ices a e used wo ldwide as an addi ion
o physio he apy. Howe e , es o ing he desi ed ange o mo ion a e he ope a-
ion canno be achie ed in many cases due o he because o he muscula de ence.
These de ices p o ide a signi ican aid du ing he ehabili a ion pe iod, bu acco d-
ing o ou e e yday expe ience in ou depa men he cons uc ion o hese de ices
does no allow he ull ex ension o he knee in all o he pa ien s, hus p ese ing
he s a e o lexion con ac u e.
Based on wo indings o ou own, i.e. 1) he CPM de ice does no p o ide o he
ull ex ension o he knee and 2) ha pe iodic ib a ional mo ion loosens he lex-
ion con ac u e, we s a ed he de elopmen o a complemen a y de ice-pai a he
Depa men o O hopaedic Su ge y, Uni e si y o Deb ecen, which was p o en o
signi ican ly dec ease he ex en o he lexion con ac u e. The i s membe o his
pai is he so called Ele a ed Heel Res (EHR), which is ac ually a milled- o-shape
ha d oam o suppo he heel. In addi ion o holding he lowe ex emi y and he
knee in an ele a ed posi ion, i s impo an ea u e is ha i does no allow ou wa d
o a ion so i only a ec s mo emen s and knee join componen s in he sagi al
plane. I s signi icance lies in he ac ha unde physiological condi ions a heal hy
indi iduals hold hei lowe ex emi y in a sligh ly ou wa d o a ed posi ion while
lying supine. Should we no p e en his ou wa d o a ion while ha ing he heel
ele a ed and he knee in he ai , we would c ea e a si ua ion wi h a a isa ion en-
dency a ec ing he knee join .
The o he membe o he de ice-pai , he Heel Vib a ing De ice (HVD) was de el-
oped o p o ide hy hmical ib a ion. As he i s s ep he su geons and physio-
he apis s o ou depa men es ed he de ice on hemsel es and i seemed o be
eally e ec i e. The subjec i e and objec i e esul s o a pilo s udy conduc ed wi h
he sys em a e he addi ion o he EHR we e p omising as well. The clinical ial
ended wi h a ou able esul s, as he pa ien s ound he de ice o be well- ole able
5
and hey we e keen o use i o be e e iciency. Meanwhile, he u he ad ance-
men o he de ice esul ed in a bedside cons uc ion ha does no equi e placing
he pa ien on a sepa a e bed, as i can be olled beside any kind o bed and ea -
men may be s a ed immedia ely.
Du ing he de elopmen p ocess o he EHR and he HVD and while assessing he
e iciency o pos ope a i e knee ea men s, we epea edly aced he essen ial
ques ion ha how he lexion/ex ension angle o he knee can be measu ed wi h
ela i ely high p ecision. In o de o answe his ques ion I ca ied ou an ex ensi e
se ies o measu emen s when I assessed he p ecision and he applicabili y o an
X- ay image-based measu emen me hod.

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2. OBJECTIVES
The objec i es o my wo k we e as ollows:
A. Measu emen s
E alua ion o knee ex ension angles based on con en ional X- ay images ap-
plying a new me hod and he de e mina ion o he accu acy o his new
me hod. De elopmen o he mos sui able me hod o measu emen .
B. De ice de elopmen
De elopmen o new de ices o he p e en ion and ea men o pos ope -
a i e knee lexion con ac u e.
a. De elopmen o a s a ic de ice: he Ele a ed Heel Res (EHR);
b. Cons uc ion o a dynamic de ice: he Heel Vib a ing De ice (HVD);
c. De elopmen o he p o o ype o a combined equipmen : he Knee
Mo ing De ice (KMD)
C. Clinical ials
Conduc ing clinical ials wi h he newly de eloped de ices, summa ising
and s a is ically analysing he expe ience ob ained du ing use.
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3. MATERIALS AND METHODS
Du ing he pos ope a i e ehabili a ion ollowing o al knee eplacemen su ge y
we y o achie e he bes possible lexion, bu ull ex ension is also essen ial. P ac-
ically my esea ch was based on he la e c i e ion and was ealized in wo main
di ec ions.
3.1. Measu emen o knee ex ension angle based on X- ay images
Measu emen o he lexion-ex ension angle o he knee seems o be a simple ask,
bu using he adi ional p o ac o s and goniome e s only app oxima ed esul s
may be ob ained. In o de o achie e app op ia e p ecision we need o know he
exac loca ion and posi ion o he bones, which de e mine he axis o he shin and
he high. An e iden solu ion may be p o ided by he analysis o ou ine la e al X-
ay images, bu we ha e o ace wo p oblems du ing assessmen : (1) he X- ay
images ob ained acco ding o in e na ional s anda ds do no show ei he he en i e
emu o he en i e ibia and (2) he X- ay image ob ained om a di ec ion o he
han he ideal la e al di ec ion may esul in dis o ed measu emen o ex ension
angles on he image.
In o de o clea and elimina e he e ec s o he abo e men ioned ac o s, du ing
he i s pa o my wo k I ca ied ou a se ies o measu emen s ha lead o he
de elopmen o a p ecise me hod o he measu emen o knee ex ension angle on
X- ay images.
To clea and elimina e he e ec o he abo e men ioned ac o s, du ing he i s
pa o my wo k I execu ed a se o measu emen s ha leaded o he de elopmen
o a p ecise me hod o measu e he knee ex ension angle based on X- ay images.
3.1.1. E alua ion o he i ual and he eal la e al axes o he high and he shin
Du ing ou expe imen s we examined he di e ence be ween he eal and he i -
ual X- ay based axes o he high and he shin when he di ec ion o imaging de i-
8
a es om he ideal la e al di ec ion. We ook pho os o 10 cleaned and boiled e-
mu s and 10 ibia- ibula pai s om la e al di ec ion and om a ±30° angle ange
wi h 2° s eps using a s epping mo o o o a e he bone a ound i s longi udinal axis.
Thus, we collec ed 30+1 pho os o each emu and each ibia- ibula pai . Since he e
was no so issue, which would ha e in e e ed wi h he measu emen s we we e
could use a simple digi al came a ins ead o X- ay. Using a ec o g aphics edi ing
so wa e we d ew he ollowing geome ical elemen s on he digi al images:
1. he line be ween he cen e o he g ea e ochan e and he cen e o
he epicondyles ( emo al axis)
2. he hal -line aligned o he an e io dis al con ou o he emu
3. he hal -line aligned o he an e io p oximal con ou o he ibia
4. he hal -line aligned o he pos e io p oximal con ou o he ibia
5. he line segmen be ween he head o he ibula and he la e al malleolus
In o de o e alua e he p ecision a which he lines d awn on a no mal X- ay image
(No. 1, No. 2 and No. 3 hal -lines) de e mine he axis o he emu and he ibia, we
measu ed he angles be ween lines 1-2, 3-5 and 4-5 (angles α, β and γ, espec-
i ely). (The smalle he angle he de e mina ion o he axis o he emu o he
shine is mo e p ecise by he co esponding hal -line).
3.1.2. Measu emen o knee lexion angle in di e en p ojec ions
While ca ying ou ou se ies o measu emen s we sough answe o he ques ion
ha how he known, p e-se lexion angles become dis o ed om di e en poin
o imaging. We applied he same se -up desc ibed p e iously wi h he s epping mo-
o , bu his ime we used a plas ic, ull lowe ex emi y o imaging. A e p e-se -
ing knee lexion angles o 6, 10, 13, 15 and 20° successi ely, we o a ed he mon-
age a ound i s axis wi h s eps o 2° in a ange o ±30° and ook pho os o each s a e.
On he digi al pho os aken om di e en poin s o iew we d ew he axis o he
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emu and he ibia using he landma ks highligh ed on he plas ic bones (based on
sec ion 3.1.1. No. 2 and No. 5 lines), hen we measu ed he i ual lexion angles
wi h an image p ocessing so wa e on all o he images.
3.2. De elopmen o ehabili a ion de ices o he ea men o lexion con-
ac u e
3.2.1. The Ele a ed Heel Res (EHR)
As he i s s ep o ou de ice de elopmen sub-p ojec we de eloped he de ails o
he EHR ha assis s he s a ic elaxa ion and ex ension. The EHR is a cube om
ha d oam ha con ains a e ical g oo e ha suppo s and ixes he heel and he
o eleg up o he la e al malleolus and assu es ha he lowe limb ele a es om
he plane o he bed. As he axis o he leg is ixed in e ical posi ion, i p e en s
he la e al o a ion o he hip and assu es he ho izon al posi on o he c oss axis
o he knee join , so he e ec o he o ce o g a i y clea ly y o ex end he knee.
The eal e iciency o he EHR could be expe ienced du ing long- ime use o pa allel
applica ion o he de ice desc ibed in he nex sub-chap e .
3.2.2. The bed-dependen e sion o he Heel Vib a ing De ice (HVD)
This de ice is basically a mechanical cons uc ion connec ed o an ex a-low ol -
age con ol uni ha was de eloped based on he ollowing equi emen s:
- he ampli ude and he equency o he ib a ion mus be con inuously
adjus able (be ween 10-30 mm and 1-3 Hz, espec i ely)
- he de ice mus be p og ammable
- he dimensions o he de ice mus allow i o be posi ioned a he end o
he pa ien bed
In o de o demons a e he e iciency o hese newly de eloped EHR and HVD we
conduc ed a andomized clinical ial in ol ing 144 pa ien s, who unde wen p i-
ma y o al knee eplacemen su ge y. Du ing he ial we basically examined ha
wha kind o ex ension esul s may be achie ed wi h ou new de ices compa ed o
16
he p e-se knee lexion angle, hus de e mining he di e ence be ween he known
p e-se angle and he i ual angle econs uc ed by he cons uc ion lines d awn
on he X- ay images. The impo ance o his expe imen lies in he ac ha i is
essen ial o know he objec i i y and p ecision o he X- ay image-based measu e-
men alues in pa ien s wi h signi ican lexion con ac u e occu ing di ec ly e en
in he pos ope a i e pe iod o la e (which is some imes a ue issue in he clinical
p ac ice, wha e e he unde lying cause migh be).
A e p ocessing he da a we may d aw simila conclusion as in he p e iously de-
sc ibed expe imen , i.e. i we conside he knee as a sys em and we examine he ull
lowe ex emi y, he signi icance o de ia ion om he ideal la e al di ec ion du -
ing X- ay imaging – while s aying wi hin a ela i ely no mal ange - is less han we
an icipa ed. The e o in angle es ima ion in ela i ely ex eme condi ions ( lexion
con ac u e o 20° wi h a de ia ion o 30° om he la e al di ec ion du ing imag-
ing) was only 2.5°, which is negligible in he clinical p ac ice. Ne e heless, acco d-
ing o ou expe ience, he inc ease in he lexion angle o he knee causes an expo-
nen ial ele a ion o he e o in axis de e mina ion, e en wi h la e al de ia ions o
10-20° du ing imaging.
Based on ou expe imen s we may conclude ha using la e al X- ay images o he
measu emen o knee ex ension angles, mo e accu a e alues may be achie ed du -
ing imaging wi h knee being ex ended and wi h a heel suppo in use, which also
ensu es ha he opposi e knee will be ou side o he image. In hese ins ances he
X- ay casse es may be posi ioned di ec ly nex o he ex emi y o be assessed,
on o he bed, o on a console placed beside he bed.
Using his se -up we sugges aking la e al X- ay images in o de no o miss any
impo an de ails, bu a he same ime o ge he images om a ai ly impo an
posi ion sui able o measu ing he ull ex ension angle.
Based on ou measu emen s we concluded ha while he accu acy o o he knee
angle measu emen me hods a e ques ionable ega ding he measu emen aken

17
in ull ex ension, la e al X- ay images aken in ully ex ended posi ion p o ide ac-
cu a e and eliable measu emen esul s.
I should be no ed ha ou measu emen me hod can be applied o knees wi h
no mal ana omy only, hus his p ocedu e may no be sui able in ce ain cases
(nea knee ac u es, os eo omies, exos oses).
5.2. De elopmen o ehabili a ion de ices o he ea men o lexion con-
ac u e
The ‘gold-s anda d’ in he pos ope a i e ehabili a ion o o al knee eplacemen
has been he CPM ea men o decades. The a ou able e ec o he sys em on
knee lexion was examined and demons a ed in se e al publica ions, bu i s e ec
on ex ension is ques ionable a leas , p edominan ly because – acco ding o ou
own expe ience as well – he ex ension angle se on he de ice is a o om he
eal ex ension angle.
Ou p ima y objec i e was o de elop a de ice ha can be applied in he ea ly pos -
ope a i e ehabili a ion pe iod a e p ima y o al knee eplacemen su ge y. Ap-
plying a ib a ing mo ion o he heel ( ela i ely apid and hy hmic upwa ds and
downwa ds mo ing i.e. ib a ion), he ine ial o ces in addi ion o he mass o he
ull lowe ex emi y help he ex ension o he knee and he elaxa ion/ex ension o
he pos e io so issues, he eby p e en ing he de elopmen o an ex ension de -
ici . Applying his de ice concomi an ly wi h a CMP machine p o ides he neces-
sa y e ec o knee lexion as well.
The i s phase o he de elopmen p ocess esul ed in he cons uc ion o he i s ,
bed-dependen e sion o he Heel Vib a ion De ice. The wo king p inciple o he
de ice is ha he machine o ce he heel o he a ec ed lowe ex emi y o ib a e
wi h an adjus able ampli ude and equency, while he pa ella and he ans e se
axis o he knee emain ho izon al. This way, he ine ia and he mass o he lowe
ex emi y exe a passi e ex ension e ec a he bo om end-poin o he mo emen
on he pos e io s uc u es o he knee join , which in u n helps i o each he
ulles ex ension possible.
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A e elimina ing he p oblems and he ‘unease-o -use’ o he i s e sion, we de-
eloped a new, bedside, olling, hus much mo e mobile design o he HVD ha can
be easily posi ioned. In his cons uc ion he heel o he pa ien is placed in a bel
ha p o ides a ce ain le el o sel -adjus men o he ope a ed lowe ex emi y
du ing he apy, since i se s he ma gins o he oo in e ical posi ion. The de ice
can be con olled e y easily, e en by he pa ien , u he mo e, he ea men does
no ha e any special equi emen s, as i can be ca ied ou on any egula hospi al
bed. A e s a ing he de ice, he ea men does no equi e supe ision by he
physio he apis , he e o e, in addi ion o i s ou s anding e iciency he de ice sa es
signi ican human esou ces as well. Conside ing he ac ha we achie ed ai ly
eliable esul s wi h e y sho -du a ion ea men s, la e on we plan o ex end he
du a ion o he ea men s and exploi he e iciency o he de ice e en mo e. Ac-
co ding o ou expe ience, pa ien s ole a e he ea men o a du a ion o 10
minu es, bu as soon as we ha e mo e o hese de ices, we s ongly ecommend o
epea he ea men mo e imes pe day.
Randomized p ospec i e clinical ials we e conduc ed o he e alua ion o he e -
iciency o bo h de ices.
The ial esul s wi h he o iginal HVD demons a ed ha he numbe o pa ien s
in he sa is ac o y ex ension ca ego y o 0°± 5° was highe by 25% in he g oup
ea ed wi h HVD compa ed o he con ol g oup ea ed wi h CPM only.
The cu en ly on-going clinical ial wi h he imp o ed, bedside e sion o he HVD
has a sligh ly e ised p o ocol o he be e de ec ion o he e ec o he de ice on
he lexion con ac u e. Acco dingly, he analysis ocused on he da a o pa ien s
wi h p e-exis ing lexion con ac u e. The esul s demons a ed ha he ex en o
lexion con ac u e imp o emen was much highe among pa ien s using he HVD
compa ed o he g oup o pa ien s, who we e ea ed wi h CPM only (imp o emen
o 2.4° s -0.9°).
Co esponding o he gene al p ac ice in Hunga y we did no employ any knee
sco e sys ems du ing he e alua ion o ou esul s. De ailed case his o ies we e
19
aken and ho ough physical examina ions we e ca ied ou be o e su ge y, u -
he mo e we used isual analogue scale o he be e assessmen o he subjec i e
aspec s o ou esul s.
The e we e no complica ions a all du ing he clinical applica ion o he de ice and
he pa ien s ole a ed he ea men excep ionally well and he e was no single
case whe e he discon inua ion o he 7-day long ea men became necessa y on
he pa ien ’s eques . Some imes he pa ien s did no wan o use he de ice o he
ull 10 minu es du ing he i s he apeu ic session, bu he necessa y ole ance
was eached a he nex o a he hi d session a he la es .
The applica ion o he HVD is on-going wi hin he amewo k o he clinical ial
and in he clinical p ac ice as well, bu no acco ding o he assignmen de e mined
du ing andomiza ion. We use i p ima ily in di icul cases a e o al knee eplace-
men and o pa ien s who a e suscep ible o he de elopmen o lexion con ac-
u e due o hei p eope a i e de o mi y o ex ension de ici o e en due o an ab-
no mal gai o pos u e.
In summa y, we may conclude ha we success ully de eloped and in oduced a
de ice o clinical p ac ice, which can be applied o he p e en ion and ea men
o pos ope a i e lexion con ac u es du ing he ea ly pos ope a i e pe iod wi h
p omising esul s, p ima ily in cases o o al knee eplacemen , bu i can be used
in condi ions wi h simila ly dec eased anges o mo ion bu wi h a iable unde ly-
ing cause.
The applica ion o ou HVD and EHR du ing he pos ope a i e ehabili a ion pe iod
was p o en o signi ican ly dec ease he occu ence o lexion con ac u es, so he
con inuous applica ion o hese de ices is easonable and s ongly ecommended.
The esul s o ou de elopmen we e published in pee - e iewed jou nals in o de
o main ain ou ole as he p op ie o s o his in en ion.
A e he de elopmen o he bedside HVD a easonable need was conside ed,
namely o me ge he ad an ages o he CPM and he HVD in a single de ice. In o de
o accomplish his challenge we s a ed o cons uc a new de ice (Knee Mo ing
20
De ice, KMD), which cu en ly is in he inal s age o de elopmen . The compu e -
con olled KMD is able o mo e he knee in i s ull ange o mo ion acco ding o he
ins alled ea men p og ams and is capable o applying he ib a ing unc ion o
he HVD a angled posi ions and in ull ex ension as well. Acco ding o ou plans
he inal e sion would include a o ce measu emen sys em buil in o he heel sup-
po , which would p o ide eedback o he sys em and he e o e would allow a
new, o ce-based con ol mode as well, so he a ge alue o he mo ing could be
a o ce ins ead o an angle o e en he combina ion o hese. Thus, o example we
may se a o ce limi o he ex ension mo ing, bu he angle posi ion o he ex en-
sion would be di e en ea men -by- ea men o e en in each mo ing cycle.
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6. SUMMARY
The issue o knee lexion con ac u e a e o al knee eplacemen su ge y appea s
o occu ela i ely o en. I may cause p oblems in one- hi d o qua e o he pa-
ien s, and may ei he mani es as a limi a ion o he ROM o as an inc eased load
o he su ounding muscles and he join su aces.
In he i s pa o my wo k I ocused on he measu emen o lexion con ac u e. I
ied o ind a eliable measu emen me hod ha can be used o p ecisely de e -
mine he angle o he con ac u e and he ex ension. The esul s demons a ed ha
an X- ay image-based angle measu emen p o ides high accu acy e en wi h sho
ilms and e en when he di ec ion o he X- ay imaging is no exac ly la e al.
A e analysing he measu emen me hod o he knee lexion-ex ension angle, a
new de ice has been de eloped du ing second pa o my wo k – he Heel Vib a ing
De ice – o he ea men o lexion con ac u e. This de ice signi ican ly and e -
ec i ely dec eases he angle and he incidence o lexion con ac u es as an addi-
ion o he CPM compa ed o he CPM used alone.
The esul s o he clinical ial wi h he i s e sion o he de ice in ol ing 144
pa ien s we e a ou able and he u he ad anced design p o ed o be e en mo e
p omising. The pa ial esul s om he cu en ly on-going clinical ial show ha
he applica ion o he de ice leads o signi ican imp o emen s in he p e en ion
and he ea men o lexion con ac u e (p=0.0033) compa ed o a con en ional
CPM de ice.
The esul s o he o e all wo k consis o an angle measu emen me hod based on
X- ay images, de eloped o he accu a e de e mina ion o knee ex ension angle
and suppo ed by se e al hund ed measu emen s, u he mo e, a ehabili a ion
de ice ha can be applied e ec i ely o he p e en ion and ea men o lexion
con ac u e as i was demons a ed in clinical ials.

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7. NEW RESULTS
A. Measu emen s
a. Using a new me hod de eloped by me and using con en ional la e al X- ay
images I de e mined
i. he axis o he emu is p ac ically pa allel wi h he an e io co ical;
ii. he pos e io co ical o ibia is he mos sui able line o he de e -
mina ion o he axis o he shin.
b. I p o ed ha du ing he e alua ion o he lexion-ex ension angle o he
knee, he dis o ion e ec o he la e al de ia ion o imaging is minimal:
wi hin he ealis ic ±30° ange i is bellow 2.5°.
B. De ice de elopmen
a) We de eloped a ela i ely simple s a ic aid o he suppo o he heel, called
he Ele a ed Heel Res , which was applied as a eally use ul accesso y bo h
du ing he pos ope a i e ehabili a ion and du ing ob aining he la e al X-
ay images as well.
b) We de eloped an o iginal hen an ad anced e sion o a de ice, called he
Heel Vib a ing De ice o he p e en ion and ea men o pos ope a i e
knee lexion con ac u es.
c) We cons uc ed he p o o ype o an ins umen ( he Knee Mo ing De ice)
ha combines he mo ing unc ions o he cu en CPM de ices and he new
ib a ing unc ion o he HVD as well. We an icipa e u he e iciency im-
p o emen om his de ice compa ed o he HVD bu i s clinical in oduc-
ion will ake place in 2016.
C. Clinical ials
We conduc ed clinical ials wi h he newly de eloped HVD and EHR p o o ypes
ha demons a ed he e iciency o he de ices. Based on he esul s we demon-
s a ed ha he applica ion o bo h e sion o he HVD in addi ion o he EHR leads
o signi ican ly mo e a ou able esul s compa ed o he CPM in dec easing knee
ex ension de ici s.
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ACKNOWLEDGEMENTS
In he i s place, I hea ily hank my supe iso , P o esso Zol án Cse ná ony o
his highly p o essional and humane suppo . Wi h his ex ended p o essional expe-
ience, use ul pieces o ad ice and con inuous encou agemen he signi ican ly con-
ibu ed he o ganiza ion and he execu ion o he measu emen s and he conduc-
ion o he clinical ials, u he mo e, he p o ided in aluable help du ing he p o-
cessing and he analysis o he esul s. He was my main suppo in my o ien a ion
as an enginee in a clinical en i onmen .
I would like o hank o he suppo and he use ul pieces o ad ice I go om Judi
Pálinkás and János Szabó a he beginning o he clinical ials.
Special hanks o he physio he apis o ou depa men Ka alin Bakó, Ve onika
Kósa, Lí ia Ta and Ágnes Bagi and u he mo e o Zol án Fehé .
I would like o hank Gyula Győ i, who con ibu ed o he compila ion o he he-
ses, u he mo e, hanks o he ollowing pe sons o hei help du ing he de el-
opmen p ocess o he de ices and in he edi ing o he publica ions: Is án Szabó,
Ka alin Deu sch, Tibo Juhász, Judi T. Nagy, Pé e Zsoldos, László Kiss.
And in he end, and mos impo an ly, I would like o hank my wi e Mónika and
my child en Sanci and Majácska o hei suppo and long-las ing pa ience.
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