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VOLUME 4, ISSUE 1 

 2021 

 

RESEARCH ARTICLE 

Yazgan A, Kutlutürk S, Lechler K. Clinical outcomes comparing two prosthetic knee designs in individuals with unilateral transfemoral amputation in Turkey. 

Canadian Prosthetics & Orthotics Journal. 2021;Volume 4, Issue 1, No.8. https://doi.org/10.33137/cpoj.v4i1.35297 

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1 

Yazgan A, Kutlutürk S, Lechler K. Clinical outcomes comparing two prosthetic knee designs in individuals with unilateral transfemoral amputation in Turkey. 
Canadian Prosthetics & Orthotics Journal. 2021;Volume 4, Issue 1, No.8. https://doi.org/10.33137/cpoj.v4i1.35297 

 

 

 
RESEARCH ARTICLE 

 

CLINICAL OUTCOMES COMPARING TWO PROSTHETIC KNEE DESIGNS IN INDIVIDUALS WITH 

UNILATERAL TRANSFEMORAL AMPUTATION IN TURKEY 

Yazgan A1,2*, Kutlutürk S3, Lechler K4
 

 

1 Orthotics - Prosthetics Master of Science Program, Graduate School of Healthy Sciences, Istanbul Medipol University, Istanbul, Turkey. 
2 Össur Turkey Academy, Istanbul, Turkey. 
3 Department of Physical Therapy and Rehabilitation, School of Healthy Sciences, Istanbul Medipol University, Istanbul, Turkey. 
4 Össur Medical Office, R&D Össur ehf, Reykjavik, Iceland. 

 

 

 

 

  

 

 

 

 

 

 

 

 
 

INTRODUCTION   

Lower extremity amputation causes impairment in 

functional mobility, sensation, body image and quality of life. 

As the functional mobility decreases, quality of life (QoL) 

decreases and the risk for joint degradation increases.1,2 

Typical challenges encountered in rehabilitation of 

individuals with transfemoral amputation (ITF) are reduced 

walking distances,3 balance impairment4 and increased 

metabolic cost.5 Adequate prosthetic component selection 

for ITF is a critical factor to assist in prevention of additional 

burden and the restoration of functional mobility.6 A large 

variety of prosthetic knee designs are available for 

individuals with transfemoral amputation.7  

The appropriate prescription requires comprehensive 

consideration to provide safety, satisfaction and function,8 

and therefore relies on qualified professionals to select the 

adequate solution. In line with theses objectives, the 

development of prosthetic knees aims to create a device 

that provides balance confidence, balance ability and to 

support walking performance in ITF.9 Historically, 

transfemoral prostheses use a passive, mechanical 

mechanism to control the swing and stance phases of the 

prosthetic gait. Today, microprocessor controlled knees 

(MPK) are becoming more common.10 Even though Non-

MPK and MPK are functionally similar in range of motion 

 
OPEN  ACCESS Volume 4, Issue 1, Article No.8. 2021 

 

 

Journal Homepage: https://jps.library.utoronto.ca/index.php/cpoj/index 

 

ABSTRACT 

BACKGROUND: Clinical outcome assessments provide important input for the rehabilitation of 

individuals with transfemoral amputation. Differences in prosthetic knee designs may influence clinical 

outcomes. 

OBJECTIVE(S): The aim of this study was to compare functional mobility, balance, prosthetic 

satisfaction and quality of life in individuals with unilateral transfemoral amputation with microprocessor-

controlled (MPK) and non-microprocessor knee designs (Non-MPK). 

METHODOLOGY: The study included ten experienced MPK (Rheo Knee) users (Group 1) and ten 

experienced Non-MPK (Total Knee® 2000) users (Group 2). For mobility; the 6 Minute Walk Test 

(6MWT), for balance; the Berg Balance Scale (BBS), Single Leg Stand Test (SLST) and Four Square 

Step Test (FSST), for quality of life; the Nottingham Health Profile (NHP) and for prosthetic satisfaction; 

the Satisfaction with Prosthesis Questionnaire (SATPRO) were administered. 

FINDINGS: 6MWT results of the MPK group were significantly higher than Non-MPK group (p <0.05). 

In the MPK group a strong negative correlation was found between the FSST and the 6MWT (r= -0.661, 

p=0.038). No statistically significant differences were found between the groups (p>0.05) comparing 

balance, prosthesis satisfaction and quality of life values. 

CONCLUSION: The findings will inform about the patient’s prognosis and the expected clinical 

outcomes when prescribing an MPK or an Non-MPK. Individuals with unilateral transfemoral amputation 

covered longer distances using an MPK compared to Non-MPK. 

ARTICLE INFO 

Received: December 22, 2020 

Accepted: June 22, 2021 

Published: June 29, 2021 

CITATION 

Yazgan A, Kutlutürk S, Lechler 

K. Clinical outcomes comparing 

two prosthetic knee designs in 

individuals with unilateral 

transfemoral amputation in 

Turkey. Canadian Prosthetics & 

Orthotics Journal. 2021;Volume 

4, Issue 1, No.8.  

https://doi.org/10.33137/cpoj.v4i

1.35297 

KEYWORDS 

Balance, Functional Mobility, 

Prosthetic Satisfaction, 

Transfemoral Amputation, 

Quality of Life, Prosthesis 

 

 

* CORRESPONDING AUTHOR 

Ayse Yazgan, 

Össur Turkey Academy, Istanbul, Turkey; İstanbul Medipol University 
Orthotics - Prosthetics Master of Science Program, Istanbul, Turkey. 

E-Mail: ayazgan@ossur.com 

ORCID ID: https://orcid.org/0000-0003-0744-503X 

https://doi.org/10.33137/cpoj.v4i1.35297
https://jps.library.utoronto.ca/index.php/cpoj/index
https://doi.org/10.33137/cpoj.v4i1.35297
https://doi.org/10.33137/cpoj.v4i1.35297
mailto:ayazgan@ossur.com
https://orcid.org/0000-0003-0744-503X


 

2 

Yazgan A, Kutlutürk S, Lechler K. Clinical outcomes comparing two prosthetic knee designs in individuals with unilateral transfemoral amputation in Turkey. 
Canadian Prosthetics & Orthotics Journal. 2021;Volume 4, Issue 1, No.8. https://doi.org/10.33137/cpoj.v4i1.35297 

ISSN: 2561-987X 
CLINICAL OUTCOMES COMPARING TWO PROSTHETIC KNEE DESIGNS  

Yazgan et al. 2021 CPOJ 

 
acting, within one degree of freedom, MPK designs allow 

dynamic management of the motion behavior throughout 

the gait cycle.8 The sensor technology allows for quicker 

adaptation to varying walking speeds by making decisions 

on the application of resistance and appropriate 

transitions.11   

Walking with an MPK has been reported to improve gait 

symmetry,12 assist in more physiological mobility and 

loading pattern on the prosthetic side,13 and reduce loading 

on the contralateral side.14  Some clinical studies are 

inconclusive,14,15 others report clear differences between 

the MPK and Non-MPK in functional performance, balance 

and psychology parameters.16  

The majority of literature comparing functional outcomes 

have been conducted in Western societies and rarely 

among Turkish ITF. Differences in culture or rehabilitation 

practices may affect these outcomes. 

The aim of the study was to compare balance, functional 

mobility, prosthetic satisfaction and QoL in individuals with 

unilateral transfemoral amputation using Non-MPK versus 

MPK after long term adaptation in Turkey. We hypothesized 

that there is a difference between individuals using MKP 

and Non-MPK in balance, functional mobility, prosthetic 

satisfaction and quality of life. 

METHODOLOGY 

A two group design was chosen to compare objective 

performances, observer-reported and patient-reported 

outcomes after longterm adaptation on the prescribed MPK; 

(Group 1) Rheo Knee (Össur, Reykjavik, Iceland) and 

(Group 2) Non-MPK; Total Knee® 2000 (Össur, Reykjavik, 

Iceland). For consistency and to reduce confounding factors 

all participants were recruited from one clinic. All twenty 

subjects used the energy storing and-return (ESAR) Vari-

flex (Össur, Reykjavik, Iceland) foot design.  

The study was approved by Istanbul Medipol University 

ethics institutional review board, and informed written 

consent was obtained. The criteria for enrollment included 

unilateral transfemoral amputation, age between 18-59 

years and a minimum of one year experience with the same 

prosthesis, Medicare functional classification level K3 or 

K4,17 and the ability to walk at least 10 m without using any 

assistive device. Criteria for exclusion were chronic residual 

limb skin breakdown. Subjects were also excluded if they 

had an acute illness, chronic illness, dependency on 

walking aids, neuromuscular problems or any secondary 

medical condition that preclude performance of the test 

protocol. The subject profile data is presented in Table 1. 

Balance was evaluated using the BBS,18 FSST19 and 

SLST.20 The measures were administered in the same 

order for all the subjects starting with the BBS. The 14 items 

of the BBS were answered by the participants with the 

supervision of researchers only assisting when the 

participant asked for clarification. Following this the 

observational section of the BBS test with its 5 point ordinal 

scale (0-4) was administered. The maximum score that can 

be achieved is 56, with higher scores reflecting better 

balance. A score of 45 is required for independent safe 

ambulation.18 Following the BBS, static balance was 

assessed by the SLST. With a 5 minute break between each 

task single leg standing was timed on the amputated and 

non-amputated side. Participants started on the non-

amputated side inside a parallel bar. The time the 

participants stood on one leg was measured with a 

stopwatch and recorded in "seconds". The stopwatch was 

started as the participants raised the contralateral leg and 

removed the hands or any support from the side bars. Time 

was stopped when the participants reached out for support 

or contacted the ground with the contralateral side or by 

reaching the maximum standing time of 30 seconds.20   

For the FSST individuals were asked to step across four 

squares, as quickly as possible following the instructions 

provided by Gouelle et. al. 2020.19 Participants had to step 

forward, backward, right, and left and the time of completion 

was noted. The FSST was repeated two times and the 

second result was reported.  

The 6MWT was administered according to the instructions 

of the American Thoracic Society21 in order to capture the 

walking distance covered by the participants within the 6 

minutes given. The 30 meters walkway was solid and 

leveled and marked every 3 meters. Pylons marked the end 

points. Participants were instructed to start walking when 

ready and follow the researcher's instructions and reminded 

not to run or jog. As soon as the participants started to walk 

the timer was started. With the sound of the timer the 

subject stopped walking and sat down on a chair. The 

distance covered within 6 minutes was recorded. 

The Nottingham Health Profile (NHP) and the Satisfaction 

with Prosthesis Questionnaire (SATPRO) were 

administered in a paper based format in Turkish.22,23 All 

measures were conducted within half a day and paper-

based results were scanned and transferred to a digital 

format. 

Statistical analysis 

Using an effect size of 1.629 based on previously reported 

data for BBS, 6MWT, NHP and SATPRO,23 a sample size 

of 18 (9 per group) was deemed necessary to ensure a type-

1 error rate of 0.05 and power of 0.95. To account for drop 

outs, the study was conducted with the participation of 20 

transfemoral individuals with amputation. All analyses were 

performed using SPSS version 21.00 (IBM, USA). The p 

value was set to 0.05 in all statistics. The Mann Whitney U 

test was used to detect group differences. The relationship 

https://doi.org/10.33137/cpoj.v4i1.35297
https://www.ossur.com/en-ca/prosthetics/knees/rheo-knee
https://www.ossur.com/en-ca/prosthetics/knees/total-knee-2000
https://www.ossur.com/en-ca/prosthetics/feet/vari-flex
https://www.ossur.com/en-ca/prosthetics/feet/vari-flex


 

3 

Yazgan A, Kutlutürk S, Lechler K. Clinical outcomes comparing two prosthetic knee designs in individuals with unilateral transfemoral amputation in Turkey. 
Canadian Prosthetics & Orthotics Journal. 2021;Volume 4, Issue 1, No.8. https://doi.org/10.33137/cpoj.v4i1.35297 

ISSN: 2561-987X 
CLINICAL OUTCOMES COMPARING TWO PROSTHETIC KNEE DESIGNS  

Yazgan et al. 2021 CPOJ 

 
between FSST and 6MWT was evaluated using Pearson 

Correlation. 

RESULTS 

Twenty ITF were recruited at a single study site. No 

differences in age, height, weight, body mass index, time 

since amputation, prosthetic experience, experience with 

MPK/Non-MPK, patient-reported daily standing and daily 

exercise time between groups (p> 0.05) could be identified 

(Table 1, Table 2).  

There were no differences between two groups for the BBS, 

SLST and FSST (p> 0.05) (Table 3). All participants 

achieved the maximum of 30 seconds for the SLST on the 

sound side. 

There were no differences between the two groups for the 

SATPRO and NHP scores (p> 0.05) (Table 4). NHP sub-

parameters range from 0 to 100. Higher NHP scores relate 

to more pain, more social isolation, more emotional reaction 

but less physical abilities, energy level and sleep. 

 

   Table 1: Participant details 

 Group 1 (MPK) (n=10) Group 2 (Non-MPK) (n=10) Mann Whitney U Test 

 Min-Max Mean±SD Min-Max Mean±SD u z p 

Age 23.0-50.0 38.0±8.4 18.0-59.0 39.3±13.0 49.00 -0.07 0.97 

BMI (kg/m2) 19.0-26.9 23.7±2.6 16.9-29.7 24.3±4.1 46.00 -0.30 0.79 

Height (cm) 170.0-183.0 177.6±4.4 150.0-191.0 170.1±13.2 32.00 -1.36 0.19 

Weight (kg) 55.0-90.0 75.0±10.6 46.0-88.0 70.1±13.7 39.50 -0.79 0.43 

Time of amputation (years) 3.0-37.0 22.5±11.1 1.5-31.0 14.1±12.7 31.00 -1.43 0.16 

Prosthetics use experience (years) 2.0-35.0 18.9±9.7 1.0-31.0 13.1±12.3 34.50 -1.17 0.24 

Experience with Non-MPK/MPK 
(years) 1.0-8.0 5.7±2.9 1.0-10.0 3.7±3.2 31.00 -1.46 0.16 

Daily standing time (hour) 1.0-16.0 8.8±4.7 2.0-15.0 7.4±5.0 40.50 -0.72 0.48 

Daily exercise time (hour) 1.0-4.0 2.1±1.4 1.0-4.0 2.1±1.2 43.00 -0.55 0.63 

 

    Min: Minimum, Max: Maximum, SD: Standard Deviation, p value is significant when p< 0.05. 

      Table 2: Participant gender, side of amputation, cause of amputation and residual limb length. 

  Group 1 (MPK)  Group 2 (Non-MPK)  

Gender 
Female 1 (10%) 3 (30%) 

Male 9 (90%) 7 (70%) 

Amputation Side  
Right 5 (50%) 7 (70%) 

Left 5 (50%) 3 (30%) 

Cause of amputation 

Trauma 8 (80%) 4 (40%) 

Congenital Abnormalities 1 (10%) 3 (30%) 

Peripheral Vascular Disorder 1 (10%) 1 (10%) 

Cancer 0 (0%) 1 (10%) 

Infections 0 (0%) 1 (10%) 

Residual Limb Length* 

Short 1 (10%) 2 (20%) 

Medium 7 (70%) 4 (40%) 

Long 2 (20%) 4 (40%) 

         *as defined in the standard ISO/WD 8548-2:2018(E): amputation level= short (proximal third)/medium (middle third)/long (distal third)  

      Table 3: Comparison of the balance parameters of two groups. 

 
 

Group 1 (MPK)  Group 2 (Non-MPK)  Mann Whitney U Test 

Min-Max Mean±SD Min-Max Mean±SD u p z 

SLST(sec) 0.0-5.0 1.7±2.0 0.0-7.0 0.8±2.2 35.00 0.28 -1.33 

FSST(sec) 2.6-6.3 4.9±1.2 4.0-7.8 5.4±1.3 44.00 0.68 -0.45 

BBS 50.0-54.0 52.5±1.7 46.0-55.0 51.4±2.8 -1.01 0.35 37.00 

 
       SLST: Single Leg Stand Test prosthetic side, FSST: Four Step Square Test, BBS: Berg Balance Scale, Min: Minimum, Max: Maximum, sec.: second, SD: Standard Deviation, p  value is   nnn  

n n  significant when p<0.05. 

https://doi.org/10.33137/cpoj.v4i1.35297


 

4 

Yazgan A, Kutlutürk S, Lechler K. Clinical outcomes comparing two prosthetic knee designs in individuals with unilateral transfemoral amputation in Turkey. 
Canadian Prosthetics & Orthotics Journal. 2021;Volume 4, Issue 1, No.8. https://doi.org/10.33137/cpoj.v4i1.35297 

ISSN: 2561-987X 
CLINICAL OUTCOMES COMPARING TWO PROSTHETIC KNEE DESIGNS  

Yazgan et al. 2021 CPOJ 

 

A statistically significant difference was found between two 

groups for the 6MWT distance (p< 0.05). 6MWT results of 

Group 1 were statistically significantly higher than Group 2 

(p< 0.05) (Table 5).  

For Group 1, a high negative correlation was found between 

the FSST and 6MWT (p< 0.05) (Table 6). 

DISCUSSION 

Our study compared two groups of ITF (MPK and non-MPK) 

who had been using their prosthesis between 1 and 10 

years. The results indicate that subjects in the MPK group 

walked further compared to subjects using a Non-MPK. No 

difference between the groups was found for patient 

reported balance, prosthesis satisfaction and QoL. In 

addition, a high correlation was found between the dynamic 

balance and functional activity of ITF using MPK.  

The parallel group design allowed us to avoid order affects 

that have been reported in previous studies.24,25 In addition, 

previous studies using a randomized cross over design 

have had shorter adaptation and as a result failed to 

demonstrate that subjects reached a plateau in their 

performance measures.17 By contrast a minimum usage 

time of one year makes it highly likely that performance 

plateau was reached for the subjects in this study.  

Balance is beneficial for daily functioning of patients with a 

lower limb amputation and often assessed by the SLST20 to 

reliably test the balance performance. It is known that SLST 

is less on the amputated side than on the unaffected side. 

Comparing the two groups by SLST, no statistically 

significant difference between the Non-MPK and the MPK 

could be detected on the prosthetic side.  

     Table 4: Comparison of quality of life (NHP) and patient satisfaction (SATPRO). 

 
 

Group 1 (MKP)  Group 2 (Non-MPK)  Mann Whitney U Test 

Mean±SD Mean ±SD u z p 

Patient satisfaction (SATPRO)  33.3±5.2 35.7±2.7 39.50 -0.80 0.43 

Quality of life 
(NHP 
subtests) 

Pain  6.5±7.8 11.7±15.8 41.50 -0.67 0.52 

Social Isolation  0.0±0.0 3.5±11.2 45.00 -1.00 0.73 

Emotional Reaction  1.0±3.3 1.8±5.5 49.50 -0.07 0.97 

Physical Abilities  4.4±7.7 9.7±11.9 39.00 -0.94 0.43 

Energy Level  11.0±17.8 11.0±17.8 50.00 0.00 1.00 

Sleep  1.3±4.0 0.0±0.0 45.00 -1.00 0.73 

 Total  Score  24.2±27.8 37.8±36.0 44.50 -0.88 0.39 

 
      Min: Minimum, Max: Maximum, SD: Standard Deviation, p value is significant when p< 0.05. 

     Table 5: Comparison of 6MWT distance of two groups. 

 
Group 1 MKP  Group 1 Non-MPK  Mann Whitney U Test 

 Mean±SD Min-Max Mean±SD Min-Max u z p 

6 MWT (m) 474.8±56.1 386.0-552.0 346.6±60.5 276.0-445.0 7.00 -3.25 0.00* 

 
       6MWT: 6 Minute Walk Test, SD: Standard Deviation m: meter, p value is significant when p< 0.05.  

     Table 6: Correlation between 6MWT, FSST, BBS, SLST and residual limb length within the two groups. 

 Group 1 (MKP)  Group 2 (Non-MPK)  

 6MWT (m) 6MWT (m) 

 r* p* r* p* 

BBS 0.20 0.66 0.39 0.71 

SLST (sec) 0.37 0.37 0.54 0.06 

FSST (sec) -0.66* 0.02* -0.40 0.22 

Residual Limb Length (short/medium/long)** 0.17 0.62 0.42 0.22 

 
      6MWT: 6 Minute Walk Test, BBS: Berg Balance Scale, FSST: Four Square Step Test, SLST: Single Leg Stand Test, m: meter, sec: second,  

      * Spearman Correlation Test, Statistical significance limit is 0.05, r: Spearman’s rank correlation coefficient. 

      **according to ISO/WD 8548-2:2018(E): amputation level= short (proximal third)/medium (middle third)/long (distal third).  

https://doi.org/10.33137/cpoj.v4i1.35297


 

5 

Yazgan A, Kutlutürk S, Lechler K. Clinical outcomes comparing two prosthetic knee designs in individuals with unilateral transfemoral amputation in Turkey. 
Canadian Prosthetics & Orthotics Journal. 2021;Volume 4, Issue 1, No.8. https://doi.org/10.33137/cpoj.v4i1.35297 

ISSN: 2561-987X 
CLINICAL OUTCOMES COMPARING TWO PROSTHETIC KNEE DESIGNS  

Yazgan et al. 2021 CPOJ 

 
Major et. al.18 reported a BBS median score of 52 (49-54) 

for ITF and showed high reliability and validity of BBS in 

community-dwelling persons with lower extremity 

amputation. Despite not being specific to prosthetic knees, 

differences in BBS score of 49.0± 9.9 were found26 between 

mechanical and hydraulic (non-MPK) stance controlled 

knees. Also, BBS showed sensitivity when transitioning 

from the Non-MPK to MPK (Rheo Knee) with an increase 

for MPK users scoring between 54 and 56.15  Both studies 

reported on BBS shortly after transitioning. In our study, no 

statistically significant difference in BBS scores was found 

after a long adaptation period. The BBS scores (52.50 ± 

1.26) being generally high may indicate that users have 

adapted well and the BBS scores were not sensitive to 

differences in knee component designs for individuals 

having used them for a long time.  

Lythgo et. al.,27 examined the function, gait and dynamic 

balance of ITF using two different Non-MPK designs. There 

was no difference in FSST (13.6±3.0 / 13.2±2.2 seconds) 

for the two Non-MPK. Our findings showed 4.85 seconds in 

FSST for MKP and 5.44 seconds for Non-MPK. Unlike the 

literature19,27,28 both groups in our study performed almost 

1sec faster than Kahle et. al. 201629 indicating a generally 

higher dynamic balance level. Kahle et. al. compared two 

socket technologies and their volume adaptation on one 

single user. Our cohort included high active users, e.g. 

playing soccer, dancing, etc. which likely explains their 

improved performances. The small difference in favor of the 

Non-MPK may be explained by the higher ratio of congenital 

amputation cause and longer residual limb length in the 

Non-MPK group. Kamali et. al.30 indicated that a longer 

residual limb may improve standing stability and dynamic 

balance. 

Hafner et. al.8 showed that the transition from Non-MPK to 

MPK significantly increases function and performance. In 

our study there was a significant difference between the two 

groups in walking distance covered during the 6MWT. In 

contrast to the aforementioned studies that showed 

performance difference after only a couple of weeks 

adaptation time, our study included two different groups and 

showed these effects after a long adaptation period of 

several years. 

Using the NHP, Demet et. al. assessed the importance of 

different factors associated with health related QoL in 

LLAs.31 They found physical disability, pain and energy 

level32 to be the most important factors and mobility to be 

the only independent factor for health related QoL 

measured by NHP. Ülger et. al.26 found a total NHP score 

of 91.1±28.6 and 51.9±12.5 for two different Non-MPK in 

contrast to higher scores in our study for both Non-MPK and 

MPK of 37.77±35.97 and 24.21±27.82, respectively. Burçak 

et. al.33 reported on increased quality of life, improved 

functional performance, increased prothesis satisfaction 

and decreased perception of body image disturbance when 

using an MPK prosthesis versus a Non-MPK. They used the 

SATPRO questionnaire for prosthetic satisfaction and 

observed an increase in the use of MKP. We found no 

difference in Qol and prosthesis satisfaction between the 

two groups. 

Azuma et. al.34 found a correlation between dynamic 

balance and walking ability in ITF using the BBS and 6MWT. 

Similarly, our study supports the relationship between 

balance parameters and functional activity. Comparing both 

groups the MPK showed a high negative correlation 

between 6MWT and FSST. ITF using an MPK 

demonstrated good dynamic balance and increased 

functional activity.  

Limitations 

The limitations in this study include the recruitment 

constraints, resulting in a small sample size and therefore 

the results cannot be generalized. Although small samples 

limit generalizability of the results, small samples are 

common in rehabilitation research35 and they relate to 

identification, recruitment, and enrollment of subjects. The 

two group design is lacking the statistical strength of a 

paired design. In our study, balance, functional mobility, 

prosthesis satisfaction and QoL of ITF using MPK and Non-

MPK were compared in two similarly profiled groups with 

long-term accommodation to their prescribed prosthesis. A 

cross over design with such a long adaptation time would 

be unfeasible. In future studies we would like to include 

more subjects to show differences in balance and mobility 

with MKP and Non-MPK after long-term adaptation. We 

propose that in future studies, more ITF using different types 

of prosthetic knee design should be included to provide 

more information for practitioners. 

Outcomes were only measured at one time point, and thus 

might only reflect the specific situation at the time of 

measurement. Longitudinal designs allow statement on 

reliability not possible herein. No objective balance 

measures were used to add strength and sensitivity to the 

findings for the patient and observer-reported measures. 

The inclusion of only one type of MPK (Rheo Knee) and 

Non-MPK (Total Knee® 2000) does not allow to generalize 

these results to other prosthetic knee designs. However 

limiting the number of knee designs allowed for the 

identification of the specific outcomes related to the 

designs.  

CONCLUSION 

While this study did not highlight differences in most of the 

clinical outcomes administered, subjects using an MPK 

were able to walk longer distances in comparison to those 

using a Non-MPK. These findings will provide decision 

makers with a more accurate prognosis when selecting 

between the two knee designs.  

https://doi.org/10.33137/cpoj.v4i1.35297


 

6 

Yazgan A, Kutlutürk S, Lechler K. Clinical outcomes comparing two prosthetic knee designs in individuals with unilateral transfemoral amputation in Turkey. 
Canadian Prosthetics & Orthotics Journal. 2021;Volume 4, Issue 1, No.8. https://doi.org/10.33137/cpoj.v4i1.35297 

ISSN: 2561-987X 
CLINICAL OUTCOMES COMPARING TWO PROSTHETIC KNEE DESIGNS  

Yazgan et al. 2021 CPOJ 

 
ACKNOWLEDGEMENTS 

We thank Össur Research and Development Department 

for providing technical advice and support. Thanks to Micah 

Nicholls, scientific director at Össur for proofreading context 

and the English. 

DECLARATION OF CONFLICTING 

INTERESTS 

The authors had no interests which might be perceived as 

posing a conflict or bias. 

AUTHOR CONTRIBUTION 

• Ayse Yazgan: Contributed  to  the  study  concept  and 

design, participated  in  data  gathering, analyzed  and  

interpreted  data, contributed to the drafting of the 

manuscript, read and approved the final manuscript. 

 

• Seval Kutlutürk: Contributed  to  the  study  concept  and 

design, analyzed  and  interpreted  data, contributed to the 

drafting of the manuscript, read and approved the final 

manuscript. 

 

• Knut Lechler: Analyzed  and  interpreted  data, contributed 

to the drafting of the manuscript, read and approved the final 

manuscript. 

SOURCES OF SUPPORT 

Össur Medical Office, R&D Össur ehf, Reykjavik, Iceland. 

ETHICAL APPROVAL 

The study was approved by Istanbul Medipol University 

ethics institutional review board, and informed written 

consent was obtained. 

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Canadian Prosthetics & Orthotics Journal. 2021;Volume 4, Issue 1, No.8. https://doi.org/10.33137/cpoj.v4i1.35297 

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