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VOLUME 5, ISSUE 1 

 2022 

 

RESEARCH ARTICLE 

Brüggenjürgen B., Braatz F., Greitemann B., Drewitz H., Ruetz A., Schäfer M., et al. Experts’ perceived patient burden and outcomes of knee-ankle-foot-

orthoses (KAFOs) vs. microprocessor-stance-and-swing-phase-controlled-knee-ankle-foot orthoses (MP-SSCOs). Canadian Prosthetics & Orthotics Journal. 

2022; Volume 5, Issue 1, No.7. https://doi.org/10.33137/cpoj.v5i1.37795 

https://online-publication.com/wp/
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https://doi.org/10.33137/cpoj.v5i1.37795


 

1 

Brüggenjürgen B., Braatz F., Greitemann B., Drewitz H., Ruetz A., Schäfer M., et al. Experts’ perceived patient burden and outcomes of knee-ankle-foot-orthoses 
(KAFOs) vs. microprocessor-stance-and-swing-phase-controlled-knee-ankle-foot orthoses (MP-SSCOs). Canadian Prosthetics & Orthotics Journal. 2022; Volume 
5, Issue 1, No.7. https://doi.org/10.33137/cpoj.v5i1.37795 

 

 

 
RESEARCH ARTICLE 

 

EXPERTS’ PERCEIVED PATIENT BURDEN AND OUTCOMES OF KNEE-ANKLE-FOOT-ORTHOSES 

(KAFOs) VS. MICROPROCESSOR-STANCE-AND-SWING-PHASE-CONTROLLED-KNEE-ANKLE-

FOOT ORTHOSES (MP-SSCOs) 

Brüggenjürgen B.1*, Braatz F.2, Greitemann B.3, Drewitz H.4, Ruetz A.5, Schäfer M.6, Seifert W.7, Steinfeldt F.8, 
Weichold C.9, Yao D.10, Stukenborg-Colsman C.10 
 
1  Institute for Health Services Research and Technical Orthopedics, Orthopedic Department - Medical School Hannover (MHH) at DIAKOVERE Annastift 

Hospital, Hannover, Germany.  
2   Klinik für Unfallchirurgie, Orthopädie und Plastische Chirurgie Universitätsmedizin Göttingen, Georg-August-Universität, Göttingen, Germany. 
3   RehaKlinikum Bad Rothenfelde, Klinik Münsterland, Bad Rothenfelde, Germany. 
4   Abteilung Orthetik, Otto Bock HealthCare Deutschland GmbH,Göttingen, Germany. 
5   Klinik für Konservative Orthopädie, Katholisches Klinikum Koblenz, Montabaur, Germany. 
6   Orthopädie-Technik, Pohlig GmbH, Traunstein, Germany. 
7   Technische Orthopädie, Seifert Technische Orthopädie GmbH, Bad Krozingen, Germany. 
8   Fachklinik und Gesundheitszentrum, Johannesbad Raupennest GmbH & Co. KG, Altenberg, Germany. 
9   Technische Orthopädie, Stiftung Orthopädische Universitätsklinikum, Heidelberg, Germany. 
10 Foot Department and Technical Orthopedics, Orthopedic Department - Medical School Hannover (MHH) at DIAKOVERE Annastift Hospital, Hannover, Germany. 

 

 

 

 

 

  

 

 

 

 

 

 

 

 
 

  

 
OPEN  ACCESS Volume 5, Issue 1, Article No.7. 2022 

 

 

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

 

ABSTRACT 

BACKGROUND: Patients with neuromuscular knee-instability assisted with orthotic devices 

experience problems including pain, falls, mobility issues and limited engagement in daily activities.  

OBJECTIVES: The aim of this study was to analyse current real-life burden, needs and orthotic 

device outcomes in patients in need for advanced orthotic knee-ankle-foot-orthoses (KAFOs). 

METHODOLOGY: An observer-based semi-structured telephone interview with orthotic care experts 

in Germany was applied. Interviews were transcribed and content-analysed. Quantitative questions 

were analysed descriptively. 

FINDINGS: Clinical experts from eight centres which delivered an average of 49.9 KAFOs  

per year and 13.3 microprocessor-stance-and-swing-phase-controlled-knee-ankle-foot orthoses 

(MP-SSCOs) since product availability participated. Reported underlying conditions comprised 

incomplete paraplegia (18%), peripheral nerve lesions (20%), poliomyelitis (41%), post-traumatic 

lesions (8%) and other disorders (13%). The leading observed patient burdens were “restriction of 

mobility” (n=6), followed by “emotional strain” (n=5) and “impaired gait pattern” (n=4). Corresponding 

results for potential patient benefits were seen in “improved quality-of-life” (n=8) as well as “improved 

gait pattern” (n=8) followed by “high reliability of the orthosis” (n=7). In total, experts reported falls 

occurring in 71.5% of patients at a combined annual frequency of 7.0 fall events per year when using 

KAFOs or stance control orthoses (SCOs). In contrast, falls were observed in only 7.2 % of MP-

SSCO users.  

CONCLUSION: Advanced orthotic technology might contribute to better quality of life of patients, 

improved gait pattern and perceived reliability of orthosis. In terms of safety a substantial decrease 

in frequency of falls was observed when comparing KAFO and MP-SSCO users. 

ARTICLE INFO 

Received: November 24, 2021 

Accepted: February 10, 2022 

Published: February 25, 2022 

CITATION 

Brüggenjürgen B., Braatz F., 

Greitemann B., Drewitz H., Ruetz A., 

Schäfer M., et al. Experts’ perceived 

patient burden and outcomes of 

knee-ankle-foot-orthoses (KAFOs) 

vs. microprocessor-stance-and-

swing-phase-controlled-knee-ankle-

foot orthoses (MP-SSCOs). 

Canadian Prosthetics & Orthotics 

Journal. 2022; Volume 5, Issue 1, 

No.7.https://doi.org/10.33137/cpoj.v5i

1.37795 

KEYWORDS 

Knee Instability, Ankle Foot 

Orthoses, KAFO, Microprocessor 

Orthoses, MP-SCCOs, Poliomyelitis, 

Patient Burden, Quality of Life, 

Survey  

* CORRESPONDING AUTHOR 

Prof. Dr. med. Bernd Brüggenjürgen 
Head Institute Health Services Research and Technical Orthopedics, Orthopedic Department - Medical School Hannover (MHH) at DIAKOVERE Annastift Hospital, Anna-von-
Borries-Str. 1-7, 30625 Hannover, Germany. 

E-Mail: brueggenjuergen.bernd@mh-hannover.de 
ORCID ID: https://orcid.org/0000-0002-8866-0809  

https://doi.org/10.33137/cpoj.v5i1.37795
https://jps.library.utoronto.ca/index.php/cpoj/index
https://doi.org/10.33137/cpoj.v5i1.37795
https://doi.org/10.33137/cpoj.v5i1.37795
mailto:brueggenjuergen.bernd@mh-hannover.de
https://orcid.org/0000-0002-8866-0809


 

2 

Brüggenjürgen B., Braatz F., Greitemann B., Drewitz H., Ruetz A., Schäfer M., et al. Experts’ perceived patient burden and outcomes of knee-ankle-foot-orthoses 
(KAFOs) vs. microprocessor-stance-and-swing-phase-controlled-knee-ankle-foot orthoses (MP-SSCOs). Canadian Prosthetics & Orthotics Journal. 2022; Volume 
5, Issue 1, No.7. https://doi.org/10.33137/cpoj.v5i1.37795 

ISSN: 2561-987X 
EXPERTS’ PERCEIVED PATIENT BURDEN AND OUTCOMES OF KAFOs VS. MP-SSCOs  

Brüggenjürgen et al., 2022 CPOJ 

 
INTRODUCTION   

Orthotic devices, in particular knee-ankle-foot-orthoses 

(KAFOs) are well accepted for treating knee instability in 

neuromuscular disease and central nervous system 

conditions. However, burden of disease and individual 

demands of patients have been rarely studied. Knee 

instability conditions can cause several problems, including 

pain, falls, range of mobility issues and limited engagement 

in daily activities, which could be alleviated with the use of 

better orthotic devices.1,2   

A KAFO is usually prescribed when other types of bracing 

like ankle-foot-orthoses (AFO) cannot adequately control 

knee instability because of weakness (e.g., quadriceps 

weakness) or ligament laxity.3 Patients suffering from knee 

instability due to neuromuscular disease (e.g., after acute 

poliomyelitis, incomplete spinal cord injury, or femoral nerve 

lesions), benefit from KAFOs with locked or posterior off-set 

orthotic knee joints by preventing the paretic or paralyzed 

leg from collapsing and to aid in safe ambulation.2,4 

However, a locked knee precludes knee flexion during 

swing and, thus, requires compensatory mechanisms to 

achieve sufficient toe clearance.2 

Stance control orthoses (SCO) allow users to flex their knee 

during the swing phase to reduce the compensations of hip 

hiking and circumduction. However, these benefits are 

mostly limited to walking on level surfaces, because the 

difficulty to relock the orthotic knee joint on non-level 

terrains results in limitations in function and safety for 

walking on uneven terrain, stairs, ramps, or with varying 

speed.4-6 In particular, patients’ limited ability to walk and 

maintain conditioning results in a high risk of falling due to 

deconditioned coordination and balance.1  

A microprocessor-swing-and-stance-controlled knee-ankle-

foot-orthosis (MP-SSCO) provide both swing and stance 

phase control for patients suffering from paralysis or paresis 

of the muscles that stabilize the knee. C-Brace (Ottobock, 

Duderstadt, Germany) is the only MP-SSCO currently 

holding a market authorization in the US and the European 

Union. The microprocessor control enables dampening of 

knee flexion during weight-bearing and speed-adapted 

control of knee flexion and extension during the swing 

phase.7 This feature enhances patients’ confidence in knee 

joint function, increased walking speed and energy 

efficiency, and improved safety for walking on uneven 

terrain, stairs, and ramps.8 Limited published data could 

only be obtained for one other microprocessor-controlled 

orthosis type, a microprocessor-controlled-stance-

controlled orthosis (MP-SCO).9 

Independence for individuals with lower limb motor 

disabilities is a key issue in their daily routine and can be 

enhanced with the use of assistive devices to promote their 

participation in social activities and in living a self-sufficient 

life.10 Hence, the key issue in orthotic care is utilizing the 

appropriate orthosis (KAFO or MP-SSCO) to address users’ 

needs and expectations.11-13 Furthermore, real-life settings 

are difficult to scrutinize due to the multitude of underlying 

disease states as well as different settings and patients’ 

behaviors that complicates pragmatic real-life trials. 

Aim of this study was to analyse the current real-life burden 

of patients in need for advanced orthotic KAFOs, their 

needs and patient relevant outcomes as well as the 

potential benefit of a MP-SSCO on patient outcomes and 

care processes.   

METHODOLOGY 

System Instrumentation 

An observer-based semi-structured interview survey with 

experts in the field of KAFO/MP-SSCO fitting was used.  

Expert participants were selected based on a) meeting 

orthotic clinical and technical care expertise qualifications 

(both physicians and orthotists) and b) having been involved 

in orthotic care for more than 5 years both with KAFOs as 

well as MP-SSCO in a German orthotic care centre. 

Furthermore, participants were only selected, if willingness 

to devote time and interest to the specific topic was stated, 

as well as informed consent to participate was provided. As 

this survey was neither a notifiable clinical study according 

to §47 par. 3 MDPG nor an epidemiologic study with 

individual patient reference an ethics committee vote did not 

apply. 

Semi-structured interviews are employed in qualitative 

interview research where the order and content of questions 

in an interview can be modified to deepen the exploration of 

a research topic according to the response of the 

interviewee.14 The interviews were conducted by phone and 

survey questions were comprised of the following areas: 

participants’ orthotic experience, challenges in orthotic 

rehabilitation, patient burden and severity of this burden, 

patient needs and benefits, patient relevant outcomes, 

rehabilitation under delivery of new orthotic devices, 

severity and frequency of falls, adverse events other than 

falls. Queries were phrased using MP-SSCO as the product 

group term with C-Brace (Otto Bock, Duderstadt, Germany) 

being presented to the interviewees as an example once or 

on request.  

The information collected in the interviews was transcribed 

and was prepared for a content analysis. Content analysis 

is described as a method to classify written or oral materials 

into identified categories of similar meanings.15 The analytic 

process of the qualitative interview component 

approximated the following steps: determination of category 

and levels of abstraction, the development of inductive 

categories from material, the revision of categories, the final 

https://doi.org/10.33137/cpoj.v5i1.37795
https://www.ottobockus.com/media/local-media/c-brace-may-2020-campaign/c-brace-ifu.pdf
https://www.ottobock.com/en/
https://www.ottobock.com/en/


 

3 

Brüggenjürgen B., Braatz F., Greitemann B., Drewitz H., Ruetz A., Schäfer M., et al. Experts’ perceived patient burden and outcomes of knee-ankle-foot-orthoses 
(KAFOs) vs. microprocessor-stance-and-swing-phase-controlled-knee-ankle-foot orthoses (MP-SSCOs). Canadian Prosthetics & Orthotics Journal. 2022; Volume 
5, Issue 1, No.7. https://doi.org/10.33137/cpoj.v5i1.37795 

ISSN: 2561-987X 
EXPERTS’ PERCEIVED PATIENT BURDEN AND OUTCOMES OF KAFOs VS. MP-SSCOs  

Brüggenjürgen et al., 2022 CPOJ 

 
working through text, and the interpretation of results.16 

Quantitative questions were reported with descriptive 

statistics.  

 

RESULTS 

Eight clinical experts confirmed participation in the semi-

structured telephone interview lasting approximately one 

hour in duration. Interviews were performed from 2020-11-

09 to 2021-02-03. All participants (7 male, 1 female; 4 

physicians and 4 orthotists) had long-term experience in 

prescribing, fitting, and delivering acute as well as subacute 

and chronic rehabilitation care both for KAFOs and MP-

SSCO users. On average, experts’ centres prescribed or 

delivered 49.9 KAFOs per year and 13.3 MP-SSCOs (C-

Brace only) since product availability to patients. The 

treated population is comprised of patients with incomplete 

paraplegia (18%), peripheral nerve lesions (20%), polio-

myelitis (41%), posttraumatic lesions (8%) and other 

disorders, including stroke sequelae (13%). 

Challenges in orthotic rehabilitation  

Half of the experts (n=4) considered a correct indication and 

diagnosis as a key challenge for patient rehabilitation in 

orthotic care, and in particular for MP-SSCO: 38% 

emphasized the need for intensive patient support and 

guidance, especially for understanding and using the 

functionality of the orthosis. A safe stance phase, safe 

handling by the patient and a well-fitting orthosis with proper 

alignment of the components as well as the challenges in 

approaching reimbursement bodies were mentioned by two 

interviewees. Categories reported once only were: 

Standardized assessments for orthosis selection, risk of 

falling due to stiff knee, foot clearance, dressing/undressing 

in daily routine, early integration of orthosis into therapy and 

training, gap between technical feasibility and return to full 

participation in real life as well as a need towards an 

interdisciplinary approach.  

Regarding structure and process of rehabilitation, 7 out of 8 

of the interviewees observed a relevant change when 

switching to MP-SSCO. Changes were mentioned in 

particular with regard to a more intensified initial education 

phase in MP-SSCO patients (57% of those reporting 

change) as the understanding of the orthosis’ potential was 

considered essential (43%). Despite the intensity of early 

rehabilitation activities, a shorter overall process was 

reported (57%). Seven interviewees reported several 

extraordinary case reports, such as a female, middle-aged, 

still active teacher with a lower limb amputation on the 

contralateral side and a substantial paralysis on the 

supplied side being instantly able to return to independent 

ambulation. A further example provided was a young, 

female patient with a complete femoralis paresis after 

polytrauma suffering extremely from abrupt cessation of her 

active life who was able to return to independent ambulation 

with the committed support of the centre’s team. Categories 

of extraordinary cases could be categorized as unexpected 

regain of mobility and ambulation, return to ambulation 

without crutches, possibility of fitting an orthosis in difficult 

posttraumatic situations where orthotic care had been 

unavailable previously, and cases of fully unexpected 

clinical benefit and occupational rehabilitation. 

Patient Burden 

In terms of expert-observed burden on patients due to 

impairment, “restriction of mobility” ranked highest among 

the queried three most serious items (n=6), followed by 

“emotional strain” (n=5) as these patients often suffer from 

severe progressive and/or continuously deteriorating 

conditions with multiple comorbidities. The third item was 

“impaired gait pattern” (n=4), including “lack of symmetry” 

and “negative impact on full social participation”, 

exemplified by one interviewee as issues with the aesthetic 

appearance (both n=4). Further impairments observed were 

“extension contractures or flexion restrictions”, “painful 

conditions”, “impaired climbing of stairs” and “lack of 

postural control”, as those patients may have impaired 

stability and/or not have the ability to stand (n=2). (Figure 1)  

 For those serious impairment items reported at least by two 

experts, “impaired climbing of stairs” obtained the highest 

observed frequency followed by “restriction of mobility”, 

“lack of postural control”, “restricted participation”, impaired 

gait”, and “emotional strain”. “Pain” and “contracture” were 

reported sometimes or rarely with regard to frequency. 

(Figure 2) 

Potential Patient Benefits 

Experts judged “quality of life” of patients (n=8) as well as 

“improved gait pattern” (n=8), followed by “high reliability of 

the orthosis” (n=7) as the most relevant domains of potential 

patients’ benefits from optimal delivery of orthotic care. 

“Patient satisfaction”, “personal autonomy” and “reduction in 

compensatory mechanisms” were reported as relevant by 

six experts. The items “ability to perform daily routine”, 

“wearing comfort” and “higher velocity” obtained a 

frequency of five reports. (Figure 3)  

When valuing each benefit’s importance to patients and 

selecting the three most relevant aspects, “perception of 

safety and high stability while walking” ranked highest (n=5), 

followed by “physiologic gait” (n=4) and the ability for 

“participation in daily life” (n=3). “Not having to think about 

the orthosis”, i.e., no need for conscious orthotic control, 

“prevention of falls”, “mobility” and “ability to swing” were 

seen by two experts amongst the three top-ranking domains 

of patient need. (Figure 3) 

 

https://doi.org/10.33137/cpoj.v5i1.37795


 

4 

Brüggenjürgen B., Braatz F., Greitemann B., Drewitz H., Ruetz A., Schäfer M., et al. Experts’ perceived patient burden and outcomes of knee-ankle-foot-orthoses 
(KAFOs) vs. microprocessor-stance-and-swing-phase-controlled-knee-ankle-foot orthoses (MP-SSCOs). Canadian Prosthetics & Orthotics Journal. 2022; Volume 
5, Issue 1, No.7. https://doi.org/10.33137/cpoj.v5i1.37795 

ISSN: 2561-987X 
EXPERTS’ PERCEIVED PATIENT BURDEN AND OUTCOMES OF KAFOs VS. MP-SSCOs  

Brüggenjürgen et al., 2022 CPOJ 

 

 

Figure 1: Patient impairments and burden as perceived by experts 

 

 

 

 

 

 

0 1 2 3 4 5 6

Restriction of Mobility

Emotional Strain

Impaired Gait

Restricted Participation

Contracture

Pain

Impaired Climbing of Stairs

Missing Postural Control

Cosmetic Appearance

Lumbar Impairment

Strain Contralateral Side

Muscle Weakness

Length Difference

Lymphatic Drain

Incontinence

Job Loss

Changing Clothes

Imminent Fall

Frequency of Responses (n)

Patient Impairments and Burden as Perceived by Experts

0

10

20

30

40

50

60

70

80

90

100

Impaired Climbing
of Stairs

Restriction of
Mobility

Missing Postural
Control

Restricted
Participation

Impaired Gait Emotional Strain Pain Contracture

Expert-Observed Frequency of Impairments’

Figure 2: Expert-observed frequency of impairments (reported more than one time). Categories (always, often, sometimes, seldom, never) 

were transferred to 0-100-scale with 100 representing the highest frequency “always”.   

https://doi.org/10.33137/cpoj.v5i1.37795


 

5 

Brüggenjürgen B., Braatz F., Greitemann B., Drewitz H., Ruetz A., Schäfer M., et al. Experts’ perceived patient burden and outcomes of knee-ankle-foot-orthoses 
(KAFOs) vs. microprocessor-stance-and-swing-phase-controlled-knee-ankle-foot orthoses (MP-SSCOs). Canadian Prosthetics & Orthotics Journal. 2022; Volume 
5, Issue 1, No.7. https://doi.org/10.33137/cpoj.v5i1.37795 

ISSN: 2561-987X 
EXPERTS’ PERCEIVED PATIENT BURDEN AND OUTCOMES OF KAFOs VS. MP-SSCOs  

Brüggenjürgen et al., 2022 CPOJ 

 

 

Figure 3: Reported expert-perceived patient benefits. 

 

 

Figure 4: Relevance of suggested patient assessment criteria. 

 

 

 

 

 

 

 

 

 

0

2

4

6

8

10

12

14

Reported Expert-Perceived Patient Benefits

Response Importance

Response Frequency

0 1 2 3 4 5 6

Gait Analysis

Number of Falls

Participation

Walking distance

Time up and Go

Quality of Life

Wearing comfort

Gait feeling in daily routine

Need for additional medical aid

Frequency of Responses

Patient Relevant Outcomes Criteria

F
re

q
u
e
n
c
y
 o

f 
R

e
s
p
o
n
s
e
s
 (

n
) 

https://doi.org/10.33137/cpoj.v5i1.37795


 

6 

Brüggenjürgen B., Braatz F., Greitemann B., Drewitz H., Ruetz A., Schäfer M., et al. Experts’ perceived patient burden and outcomes of knee-ankle-foot-orthoses 
(KAFOs) vs. microprocessor-stance-and-swing-phase-controlled-knee-ankle-foot orthoses (MP-SSCOs). Canadian Prosthetics & Orthotics Journal. 2022; Volume 
5, Issue 1, No.7. https://doi.org/10.33137/cpoj.v5i1.37795 

ISSN: 2561-987X 
EXPERTS’ PERCEIVED PATIENT BURDEN AND OUTCOMES OF KAFOs VS. MP-SSCOs  

Brüggenjürgen et al., 2022 CPOJ 

 

Outcomes Assessment in Orthotic Device Alignment 

Furthermore, experts provided suggestions to implement 

specific tools for patients’ assessment in clinical routine 

covering both patient-relevant orthotic-device related 

outcomes as well as quality assurance aspects. In this 

context, “gait analysis”, e.g. via video, was reported most 

often with high relevance (n=5), followed by “number of falls 

in patient history” (n=4), “participation” and “walking 

distance” (n=3). (Figure 4) 

Orthosis-specific safety and long-term outcomes 

Frequency of Falls and Resource Use - KAFO 

When using KAFOs or stance control orthoses without 

microprocessor control (SCOs), falls were estimated to 

occur once weekly (standard deviation (SD) 0.0) in 4.0 % 

(SD=9.9) of patients. Monthly falls were seen in 23.8% (SD= 

28.3) and annual falls in 43.8% (SD=30.0) of patients with a 

frequency of 1.25 (SD=0.9) and 3.19 (SD=1.5), 

respectively. In total, falls were reported to occur in 71.5% 

of patients at a combined annual frequency of 7.0 fall events 

per year when using KAFOs or SCOs. 

Serious falls may result in the need for medical care. 

Healthcare resource use related to falls with non-

microprocessor-controlled knees (non-MPKs) was 

estimated to require hospital care in 4.0% (SD=3.7) and 

non-hospital medical care in the out-patient setting in 19.3% 

of fall cases (SD=17.5). 76.7% (SD=20.1) of total falls were 

considered not to require any health professional care. 

Long-term Consequences 

Wearing KAFOs and SCOs is associated with both adverse 

effects and long-term consequences. Adverse effects 

include “excessive lumbar loading with lack of trunk 

stability” (n=3), “impairment of gait” (n=2) and “stiff limb”, 

“rollator dependency”, “fitting problems”, “risk of luxation in 

hip replacement patients” and “noise” which were each 

reported only once. Regarding long-term consequences, 

most experts considered “lumbar disorders with a locked 

knee joint” (n=4) as the most relevant item, followed by 

 

Figure 5: Observed long-term consequences (primary axis: number of experts reporting, secondary axis: Transposed frequency of 

consequences in percent of time occurring - Categories (always, often, sometimes, seldom, never) were transferred to 0- 100-scale with 100 

representing the highest frequency “always”.) 

0

10

20

30

40

50

60

70

80

90

100

0

1

2

3

4

Observed Long-Term Consequences

Number of experts' entries Frequency of long-term consequences

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7 

Brüggenjürgen B., Braatz F., Greitemann B., Drewitz H., Ruetz A., Schäfer M., et al. Experts’ perceived patient burden and outcomes of knee-ankle-foot-orthoses 
(KAFOs) vs. microprocessor-stance-and-swing-phase-controlled-knee-ankle-foot orthoses (MP-SSCOs). Canadian Prosthetics & Orthotics Journal. 2022; Volume 
5, Issue 1, No.7. https://doi.org/10.33137/cpoj.v5i1.37795 

ISSN: 2561-987X 
EXPERTS’ PERCEIVED PATIENT BURDEN AND OUTCOMES OF KAFOs VS. MP-SSCOs  

Brüggenjürgen et al., 2022 CPOJ 

 
“muscular atrophy” (n=3). “Orthosis cut-out oedema”, “scrub 

marks” and “degenerative impact” were reported being 

relevant by two experts. “Pelvic adverse effects”, “mental 

burden”, “physical discomfort due to forearm crutches”, 

“contractures”, “pain” and “hyperlordosis / scoliosis” were 

reported as relevant by one expert each. “Scrub marks” 

were reported both as adverse effect and long-term 

consequence. All long-term consequences were considered 

to occur “always” to “sometimes” in frequency (Figure 5). 

Frequency of Falls and Experiences with MPK fitting 

Experts termed orthotic care with an MP-SCCO as 

outstanding only when patients benefitted considerably in 

real life settings (following a sound trial fitting), despite 

ambiguous diagnostic results during the initial assessment 

(n=4). Further outstanding experts’ experiences were 

successful fitting of orthosis in complex post-traumatic and 

postoperative situations (n=3) and the regain of mobility in 

the patients´ daily routine (n=2). 

The frequency of falls in MP-SCCO users was estimated on 

an annual basis. Falls were observed to occur in 7.2 % 

(SD=10.3) of all patients with an annual frequency of 2.2 

(SD=3.0) fall events per year. 

DISCUSSION  

Burden of patients in need of KAFOs was analysed with an 

experts’-based interview survey. Restriction of mobility, 

emotional strain and impaired gait were reported as major 

impairment aspects. Potential for improving care in patients 

who use non-microprocessor-controlled KAFOs is seen in 

particular with regard to quality of life (QoL), gait, and 

reliability of the orthosis. The experts underscored the 

importance of appropriate outcomes assessment criteria, 

such as gait analysis, orthosis safety (prevention of falls), 

and participation in activities of daily living.  In terms of 

frequency of falls, a substantial difference between non-

microprocessor-controlled KAFOs and MP-SSCOs was 

reported. 

In our study improved gait pattern, QoL and high reliability 

of the orthosis were most often reported as important 

outcomes to patients. This is largely in line with health care 

professional (HCP) estimates reported by O’Connor et al., 

where comfort, confidence in mobility and increased 

stability were most often reported as being very or extremely 

important to patients.1 Though QoL in our study was most 

frequently stated as a relevant patient benefit of optimal 

orthotic care, no expert valued QoL or patient satisfaction 

amongst the three most important domains. This lack of 

perceived high importance might be due to the fact that QoL 

comprises different physical and psychological domains of 

health-related QoL and, hence, results in an improvement, 

if a majority of other aspects of benefit have been achieved. 

Adding to this line of reasoning is the fact that retraining of 

compensatory gait patterns, such as circumduction, 

requires time and, hence, may delay an early, 

straightforward improvement in QoL.17 Furthermore, the 

reported experts’ perception might be influenced by the 

German healthcare reimbursement decision making 

process, where QoL has just recently gained more 

importance.  

Unlike Yang et al., we conducted interviews with experts 

caring for patients in need for lower limb orthoses.10 

However, despite not directly involving patients’ responses, 

research of health-related QoL did show that the results 

obtained from attending HCPs considerably overlap with 

patients’ individual feedback, resulting in reasonable 

agreement that make the HCPs’ perception a valuable 

source of assessment.18 However, when assessing 

individual patients, there was some discordance between 

scores obtained from HCPs compared to patients, with 

physicians systematically underestimating overall QoL, 

social functioning, and role functioning. Interestingly, 

patients in the UK expected the orthotic device to foremost 

enable them to engage in ‘normal’ daily activities and taking 

part in social events and gatherings which represent 

relevant QoL domains.1 Hence, demands and potential 

benefits of MP-SSCOs in domains such as participation, 

mental well-being and QoL reported by HCPs in our study 

might be underestimated. 

Yang et al. reported that patients with neurologic conditions 

are mostly interested in restoring both walking and standing, 

whereas patients with musculoskeletal injuries had a single 

focus on normal walking.10 Problems of orthosis use related 

to normal walking in patients with damage to the nervous 

system were mentioned mostly with regard to restricted 

mobility, skin injury due to excessive rubbing, orthosis 

durability and material-related issues. For those focusing on 

standing, material-related issues dominated. Problems in 

orthosis use by patients with musculoskeletal injuries were 

restricted mobility and material-related issues.10 

The post-fall syndrome (depression, fear of falling and other 

psychological problems) is a common consequence of 

repeated falls, with up to 40% of patients not reporting 

recent falls and up to 70% of recent fallers reporting fear of 

falling.19 Loss of self-confidence as well as social 

withdrawal, confusion and loneliness can occur, even if 

there has been no injury. Reduced physical and functional 

activity is associated with fear and anxiety of falling - strong 

correlations have been found between fear and poor 

postural performance.20 Hence, the reported reduction in 

fall rate in our study indicates the potential for improved self-

confidence and better QoL with a MP-SSCO. 

Our results underline the need for proper alignment of 

orthosis components to reflect the individual patients’ 

anatomy. This is in line with Yang et al. as their results show 

that users with the same symptoms may use different 

https://doi.org/10.33137/cpoj.v5i1.37795


 

8 

Brüggenjürgen B., Braatz F., Greitemann B., Drewitz H., Ruetz A., Schäfer M., et al. Experts’ perceived patient burden and outcomes of knee-ankle-foot-orthoses 
(KAFOs) vs. microprocessor-stance-and-swing-phase-controlled-knee-ankle-foot orthoses (MP-SSCOs). Canadian Prosthetics & Orthotics Journal. 2022; Volume 
5, Issue 1, No.7. https://doi.org/10.33137/cpoj.v5i1.37795 

ISSN: 2561-987X 
EXPERTS’ PERCEIVED PATIENT BURDEN AND OUTCOMES OF KAFOs VS. MP-SSCOs  

Brüggenjürgen et al., 2022 CPOJ 

 
orthoses.10 Our results confirm the need for incorporating 

patient relevant outcomes in real-life settings into high-

quality research of orthotic devices for knee instability 

related to neuromuscular and central nervous system 

conditions.3 

Study limitations:  

Despite having interviewed experts with different expertise 

and professional backgrounds, the low number of 

interviewees might contribute to potential bias. However, in 

Germany, there are only a few expert centres experienced 

both in treating and fitting patients with muscular knee 

instability and MP-SSCO fitting, resulting in an appropriate 

representation of centres’ experience.  

Furthermore, the fact that results were obtained from a 

health care professionals’ point of view might have led to 

different perceptions compared to direct patient interviews 

or surveys. While formerly HCP-derived patient information 

was perceived to be superior to those collected from studied 

subjects,21 more recently patient self-reported outcomes 

are considered as an equally valuable contribution in the 

health sciences, where interviewer and physician 

assessments are understood to be complementary to self-

assessed health measures.22,23 Furthermore, studies 

showed that results obtained from HCPs consistently 

underrate the positive impact on mental well-being and 

hence experts’ estimates might serve as conservative 

estimate of patients’ outcomes and needs.18  

CONCLUSION 

Patients with muscular knee instability following 

neuromuscular or central nervous system injuries or 

conditions who use KAFOs/SCOs are suffering from 

restricted mobility, emotional strain and impaired gait 

patterns. Advanced orthotic technology might contribute to 

better QoL of patients, improved gait patterns with 

subsequent reduction of long-term consequences and 

perceived reliability of the orthosis. In terms of safety, a 

substantial decrease in the frequency of falls with MP-

SSCO compared to non-microprocessor-controlled KAFOs 

was reported. Advanced orthotic devices may enhance 

physical and psychological health and well-being by 

enabling patients to pursue their daily routines. In selected 

patients who are unable to be fitted with non-

microprocessor-controlled KAFO/SCO, mobility might be 

regained through MP-SSCOs with the additional benefit of 

spending less time in a wheelchair or even discontinuing its 

use. Advanced orthoses require even more interdisciplinary 

rehabilitation with a standardized outcomes assessment 

comprising instruments for gait analysis and assessing the 

number of falls as well as individual participation in activities 

of daily living.  

 

ACKNOWLEDGEMENTS 

No assistance in the preparation of this article is to be declared. 

DECLARATION OF CONFLICTING 

INTERESTS 

Bernd Brüggenjürgen, Frank Braatz, Bernhard Greitemann, Axel 

Ruetz, Friedemann Steinfeldt, Daiwei Yao, and Christina 

Stukenborg-Colsman received lecture fees; Heiko Drewitz is an 

employee of Otto Bock; Michael Schäfer, Wolfgang Seifert have 

collaborations with the sponsor. Claudia Weichold none to be 

declared.   

AUTHOR CONTRIBUTION 

Bernd Brüggenjürgen: 

Conception and design, analysis and drafting of the paper, 

interpretation of the data; revising it critically for intellectual content 

and final approval of the version to be published. 

Frank Braatz, Bernhard Greitemann, Heiko Drewitz, Axel 

Ruetz, Michael Schäfer, Wolfgang Seifert, Friedemann 

Steinfeldt, Claudia Weichold, Daiwei Yao, Christina 

Stukenborg-Colsman: 

Interpretation of the data; revising it critically for intellectual content 

and final approval of the version to be published. 

SOURCES OF SUPPORT 

This work was supported by a grant of Otto Bock Healthcare 

Products GmbH, Wien. 

ETHICAL APPROVAL 

Expert participants were only selected, if willingness to devote time 

and interest to the specific topic was stated, as well as informed 

consent to participate was provided. As this survey was neither a 

notifiable clinical study according to §47 par. 3 MDPG nor an 

epidemiologic study with individual patient reference, an ethics 

committee vote did not apply. 

REFERENCES 

1.O'Connor J, McCaughan D, McDaid C, Booth A, Fayter D, 

Rodriguez-Lopez R, et al. Orthotic management of instability of the 

knee related to neuromuscular and central nervous system 

disorders: systematic review, qualitative study, survey and costing 

analysis. Health technology assessment. 2016;20(55):1-262. DOI: 

10.3310/hta20550 

2.Fox JR, Lovegreen W. 22 - Lower Limb Orthoses. In: Webster JB, 

Murphy DP, editors. Atlas of Orthoses and Assistive Devices (Fifth 

Edition). Philadelphia: Elsevier; 2019; 239-46.e1. 

3.McDaid C, Fayter D, Booth A, O'Connor J, Rodriguez-Lopez R, 

McCaughan D, et al. Systematic review of the evidence on orthotic 

devices for the management of knee instability related to 

neuromuscular and central nervous system disorders. BMJ Open. 

2017;7(9):e015927. DOI: 10.1136/bmjopen-2017-015927 

4.Probsting E, Kannenberg A, Zacharias B. Safety and walking 

ability of KAFO users with the C-Brace((R)) Orthotronic Mobility 

https://doi.org/10.33137/cpoj.v5i1.37795


 

9 

Brüggenjürgen B., Braatz F., Greitemann B., Drewitz H., Ruetz A., Schäfer M., et al. Experts’ perceived patient burden and outcomes of knee-ankle-foot-orthoses 
(KAFOs) vs. microprocessor-stance-and-swing-phase-controlled-knee-ankle-foot orthoses (MP-SSCOs). Canadian Prosthetics & Orthotics Journal. 2022; Volume 
5, Issue 1, No.7. https://doi.org/10.33137/cpoj.v5i1.37795 

ISSN: 2561-987X 
EXPERTS’ PERCEIVED PATIENT BURDEN AND OUTCOMES OF KAFOs VS. MP-SSCOs  

Brüggenjürgen et al., 2022 CPOJ 

 
System, a new microprocessor stance and swing control orthosis. 

Prosthet Orthot Int. 2017;41(1):65-77. DOI: 10.1177/ 

0309364616637954 

5.Arazpour M, Ahmadi F, Bani MA, Hutchins SW, Bahramizadeh 

M, Ghomshe FT, et al. Gait evaluation of new powered knee-ankle-

foot orthosis in able-bodied persons: a pilot study. Prosthet Orthot 

Int. 2014;38(1):39-45. DOI: 10.1177/0309364613486917 

6.Tian F, Hefzy MS, Elahinia M. State of the art review of knee–

ankle–foot orthoses. Ann Biomed Eng. 2015;43(2):427-41. DOI: 

10.1007/s10439-014-1217-z 

7.Deems-Dluhy S, Hoppe-Ludwig S, Mummidisetty CK, Semik P, 

Heinemann AW, Jayaraman A. Microprocessor controlled knee 

ankle foot orthosis (KAFO) vs stance control vs locked KAFO: A 

randomized controlled trial. Arch Phys Med Rehabil. 

2021;102(2):233-44. DOI: 10.1016/j.apmr.2020.08.013 

8.Schmalz T, Pröbsting E, Auberger R, Siewert G. A functional 

comparison of conventional knee–ankle–foot orthoses and a 

microprocessor-controlled leg orthosis system based on 

biomechanical parameters. Prosthet Orthot Int. 2016;40(2):277-86. 
DOI: 10.1177/0309364614546524 

9.Daines KJF, Farah J, Baddour N, Duke C, Bhatti J, Lemaire ED. 

Preliminary kinematic and kinetic evaluation of a modular 

microprocessor-controlled stance-control knee-ankle-foot orthosis. 

CMBES Proceedings. 2019;42(0). 

10.Yang BS, Chen YW, Tong JR. User experience of lower-limb 

orthosis. Assist Technol. 2018;30(5):267-73. DOI: 10.1080/ 

10400435.2017.1322157 

11.Borsci S, Londei A, Federici S. The Bootstrap Discovery 

Behaviour (BDB): a new outlook on usability evaluation. Cogn 

Process. 2011;12(1):23-31.  

12.Ravneberg B. Usability and abandonment of assistive 

technology. J Assist Technol. 2012;6(4):259-69. DOI:10.1108/ 

17549451211285753 

13.Söderström S, Ytterhus B. The use and non‐use of assistive 

technologies from the world of information and communication 

technology by visually impaired young people: a walk on the 

tightrope of peer inclusion. Disabil Soc. 2010;25(3):303-15. 
DOI:10.1080/09687591003701215 

14.Klandermans B, Staggenborg S. Methods of Social Movement 

Research. Boston: University of Minnesota Press; 2002. 

15.Moretti F, van Vliet L, Bensing J, Deledda G, Mazzi M, Rimondini 

M, et al. A standardized approach to qualitative content analysis of 

focus group discussions from different countries. Patient Educ 

Couns. 2011;82(3):420-8. DOI: 10.1016/j.pec.2011.01.005 

16.Cho JY, Lee E-H. Reducing Confusion about Grounded Theory 

and Qualitative Content Analysis: Similarities and Differences. Qual 

Rep. 2014; 19. DOI:10.46743/2160-3715/2014.1028 

17.Santer J, MacDonald S, Rizzone K, Biehler S, Beiswenger T. 

Strategies for gait retraining in a collegiate runner with transfemoral 

amputation: A case report. Int J Sports Phys Ther. 2021;16(3):862-

9. DOI: 10.26603/001c.23671 

18.Wilson KA, Dowling AJ, Abdolell M, Tannock IF. Perception of 

quality of life by patients, partners and treating physicians. Qual Life 

Res. 2000;9(9):1041-52. DOI: 10.1023/a:1016647407161 

19.Tinetti ME, Mendes de Leon CF, Doucette JT, Baker DI. Fear of 

falling and fall-related efficacy in relationship to functioning among 

community-living elders. J Gerontol. 1994;49(3):M140-7. DOI: 

10.1093/geronj/49.3.m140 

20.Maki BE, Holliday PJ, Topper AK. Fear of falling and postural 

performance in the elderly. J Gerontol. 1991;46(4):M123-31. DOI: 

10.1093/geronj/46.4.m123 

21.Kriegsman DM, Penninx BW, van Eijk JT, Boeke AJ, Deeg DJ. 

Self-reports and general practitioner information on the presence of 

chronic diseases in community dwelling elderly. A study on the 

accuracy of patients' self-reports and on determinants of 

inaccuracy. J Clin Epidemiol. 1996;49(12):1407-17. DOI: 

10.1016/s0895-4356(96)00274-0 

22.Ferraro KF, Su YP. Physician-evaluated and self-reported 

morbidity for predicting disability. Am J Public Health. 2000; 

90(1):103-8. DOI: 10.2105/ajph.90.1.103 

23.Smith KV, Goldman N. Measuring health status: self-, 

interviewer, and physician reports of overall health. J Aging Health. 

2011;23(2):242-66. DOI: 10.1177/0898264310383421 

 

https://doi.org/10.33137/cpoj.v5i1.37795

