Investigation on a New Power Knee Firmware Update on Gait and Daily Life Activities, a Randomized Controlled Double-blinded Cross-over Investigation
Phase: NA
Conditions: Amputation, Transfemoral Amputation
Sponsor: Össur Iceland ehf



 
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Sponsor
Coordinating/Principal Investigator
Þór Friðriksson 
Medical Officer 
Össur Iceland ehf 
Grjótháls 5 
110 Reykjavík, Iceland 
 
Pete Simpson  
Clinical Specialist - Bionic Solutions 
Bionics Marketing 
Össur Americas 
 
 
 
Sponsor’s Statement: On behalf of the Sponsor, I have reviewed and approved this CIP in its entirety and agree 
to sponsor its implementation. 
Sponsor: 
 
Electronical Approval of Document, front page 
Þór Friðriksson 
Date of Signature: 
 
Electronical Approval of Document, front page 
 
 
Coordinating/Principal Investigator’s Statement: I have reviewed and approved this CIP in its entirety and agree to 
follow carry out its implementation. 
Coordinating/Principal Investigator: 
 
Electronical Approval of Document/ See 
electronic signature page 
Pete Simpson  
Date of Signature: 
 
Electronical Approval of Document/ See 
electronic signature page 
 
 
See List of investigators in [8] for investigational site and list of investigators and monitors.  
 
 

 
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STATEMENT OF INVESTIGATOR COMPLIANCE 
This protocol is a prospectively designed study to investigate the performance of the Power Knee Mainstream after 
a firmware update.  
● Implement and conduct this study diligently and in strict compliance with the protocol, good clinical 
practices (GCP), ISO 14155: 2020 standards, and all applicable laws and regulations.  
● Maintain all information supplied by Össur Iceland ehf in confidence and, when this information is 
submitted to an Ethics Committee (EC), it will be submitted with a designation that the material is confidential.  
● Ensure that all persons assisting with the research are adequately informed about the protocol and their 
research-related duties and functions.  
This document contains confidential information belonging to the Sponsor (Össur Iceland ehf) and therefore, may 
not be disclosed to any other person or entity without the prior written permission of the Sponsor unless such 
disclosure is required by law or regulation.  
Investigator Signature  
I have read and understand the contents of the clinical protocol including this Statement of Investigator 
Compliance. I agree to follow and abide by the guidelines set forth in this document.  
Principal Investigator Name: Pete Simpson 
 
 
 
 
Principal Investigator Signature 
 
Date 
 
 
 

 
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Table of Contents 
1 
How to Refer to This Document ............................................................. 6 
2 
Summary .................................................................................................. 6 
3 
Changes from Previous Revision ........................................................ 10 
3.1 
Changes for Revision 1.00 ....................................................................................... 10 
3.2 
Changes for Revision 2.00 ....................................................................................... 10 
3.3 
Changes for Revision 3.00 ....................................................................................... 10 
4 
Abbreviations ........................................................................................ 12 
5 
Investigational Device ........................................................................... 13 
6 
Justification for the Design of the Clinical Investigation ................... 17 
7 
Objectives and Hypotheses .................................................................. 18 
8 
Design of the Clinical Investigation ..................................................... 22 
8.1 
General .................................................................................................................... 22 
8.2 
Investigational Device(s) and Comparator(s) ........................................................... 23 
8.3 
Subjects ................................................................................................................... 23 
8.4 
Procedures............................................................................................................... 25 
i) 
Recruitment ............................................................................................................................. 25 
ii) 
Test procedure......................................................................................................................... 25 
iii) 
Measurements and data collection .......................................................................................... 27 
8.5 
Compensation .......................................................................................................... 28 
8.5.1 
Subject ..................................................................................................................................... 28 
8.5.2 
Clinic ........................................................................................................................................ 28 
8.6 
Responsibilities ........................................................................................................ 28 
8.7 
Study monitoring and Oversight ............................................................................... 29 
9 
Investigational Device Accountability ................................................. 29 
10 
Statistical Considerations .................................................................... 29 
10.1 
Statistical design and procedures ............................................................................ 29 
10.2 
Sample size calculation ........................................................................................... 30 
10.3 
Additional statistical matters..................................................................................... 30 
11 
Amendments and Deviations from the Protocol (CIP) ........................ 31 
11.1 
Amendments ............................................................................................................ 31 
11.2 
Deviations ................................................................................................................ 31 
12 
Statement of Compliance ..................................................................... 31 
13 
Ethical Considerations ......................................................................... 32 
13.1 
Anticipated clinical benefits ...................................................................................... 32 
13.2 
Device related risk ................................................................................................... 32 
13.3 
Risk of Study (To Patient) ........................................................................................ 34 
13.4 
Risk Mitigation .......................................................................................................... 34 
13.5 
Benefit-Risk Rationale ............................................................................................. 34 
13.6 
IRB Review and Communications ............................................................................ 34 
13.7 
Vulnerable populations ............................................................................................ 34 
13.8 
Informed Consent .................................................................................................... 34 
13.9 
Participant confidentiality – Data management ........................................................ 35 

 
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14 
Evaluation of Adverse Events and Device Deficiencies ..................... 36 
14.1 
Definitions of adverse events, effects and deficiencies ............................................ 36 
14.2 
Reporting procedures .............................................................................................. 36 
14.3 
Suspension or premature termination of the clinical investigation............................ 37 
15 
Publication Policy ................................................................................. 37 
16 
References ............................................................................................. 38 
 
Tables 
Table 1 Summary of procedures and visits for phases I and II ......................................................................... 9 
Table 2 Identification and Description of the Investigational Device .............................................................. 13 
Table 3 Technical and functional features ......................................................................................................... 16 
Table 4 Endpoints, test methods and hypotheses ............................................................................................ 19 
Table 5 Inclusion/Exclusion criteria ................................................................................................................... 23 
Table 6 Visit schedule and procedures .............................................................................................................. 27 
Table 7 2MWT for lower-limb amputees undergoing inpatient rehabilitation ...... Error! Bookmark not defined. 
Table 8 10mWT for lower-limb amputees ................................................................. Error! Bookmark not defined. 
 
 
 

 
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Evaluation phase: 
For each activity block and according to the randomization, Firmware 1 (either the 
current marketed firmware or the updated firmware) will be uploaded to the device. 
Users will then perform the activity block. 
Following this, Firmware 2 will be uploaded to the device. Users will repeat the same 
activities and tests performed with Firmware 1. 
At the conclusion of each activity block, participants will complete a set of questions 
from the in-house questionnaire to evaluate and compare Firmware 1 and Firmware 
2 in relation to the activity block they just performed. 
This evaluation phase will be done by the other group of research engineers (group 
2) who will be blinded. The upload of the firmware will be done by research engineers 
of the Group 1.  
Activity blocks: 
The order of the activity blocks is flexible, they can be applied in different sequences, 
and not all activity blocks need to be complete.  
 
Level-ground walking  
 
10mWT 
 
Sit-to-stand  
 
5XSTS 
 
Ramps 
 
Stairs 
 
Squatting 
 
2-Minute Walk Test 
 
Pro-Flex Terra (For the phase I, they will perform the activity block using the 
last Firmware of the evaluation part (Firmware 2). For the phase II, they will 
perform these tasks with the updated firmware.) 
The activities are video recorded to visually compare the performance of the two 
firmware. Biomechanical data may be collected. 
Debriefing session: 
After the testing session, a debriefing session will be organized, and all the research 
engineers will take part. The blindness will be removed for the users and the research 
engineers. 
End of the visit: 
At the end they will be fitted back to their prescribed device. If the user has a Power 
Knee and if the user agrees, the current marketed version of the firmware will be 
uploaded to their devices if it was not already. 
See Table 1 below for summary of procedures and visits. 
* Question on pain affecting their functional ability (yes/no) 
** Socket fit: socket comfort score (SCS) over 7 
*** Self-reported 
 
 
 

 
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End of the study 
 
X 
3 Changes from Previous Revision 
3.1 Changes for Revision 1.00 
Initial release. 
September 2024 
 
3.2 Changes for Revision 2.00 
September 2024 
Statement of investigator compliance added 
 
3.3 Changes for Revision 3.00 
November 2024 
Chapter 2: 
- 
Inclusion/exclusion changed to include complex presentations and users with MPKs who tried Power Knee 
within the last 3 years 
- 
Number of users for phase II increased from 15 to 30 
- 
Precision of the use of an Össur foot (Pro-Flex LP) if the prescribed foot is not an Össur foot 
- 
Precision of the option of updating the Power Knee firmware for the users’ device if the users have a Power 
Knee 
- 
Equipment: LASAR Posture, Xsens, Moticon Insoles, Optogait, Microgate Witty Timing Gate added 
- 
Table 1: test procedures changed to gather activities in blocks 
Chapter 4: MPK added 
Chapter 5: Change in the firmware name from PKK3.MMT.03.02.xxx to PKK3.MMV.03.02.xxx. 
Chapter 6: Study design updated  
Chapter 7: Addition of the phrase concerning the fact that the phase I can be repeated as many times as needed. 
Addition of few hypotheses concerning biomechanical data as exploratory. 
Chapter 8: 
- 
Equipment added: LASAR Posture, Xsens, Moticon Insoles, Optogait, Microgate Witty Timing Gate 
- 
For Phase II, number of users increased from 15 to 30  
- 
For phase II: number of investigational devices increased from 5 to 10 
- 
Inclusion/exclusion changed to include complex presentations (hip disarticulation, knee disarticulation and 
bilateral amputees)  
- 
Inclusion/exclusion changed to include users with passive microprocessor-controlled knees who tried 
Power Knee within the last 3 years 

 
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- 
Total duration of phase I is therefore one week for every repetition and total duration of phase II is therefore 
up to three weeks. 
- 
Test procedure updated with the number of users, the possible repetition of phase I and the use of Össur 
foot for the investigation. 
- 
Data collection updated with the use of LASAR Posture, Xsens, Moticon Insoles, Optogait, Microgate Witty 
Timing Gate. 
- 
Recruitment strategy updated with the use of investigation sites’ database, Össur’s customer database, 
external clinics and customers, word of mouth or customer representative meetings to maximize the reach 
and efficiency of participant enrollment.  
- 
Table 6 updated according to the new test procedures 
Chapter 13: 
- 
Risk of study updated to include users who tried Power Knee. 
Annex 17.1: 
- 
Screening form updated to match the inclusion/exclusion criteria 
Annex 17.2: questions added and reorganized in activity blocks  
Annex 17.5: description of biomechanical data added 
 
 
 

 
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4 Abbreviations 
ADE 
Adverse Device Effect 
ADL 
Activities of Daily Living 
AE 
Adverse Event 
AR 
Adverse Reaction 
BL 
Baseline 
CA 
Competent Authority 
CEP 
Clinical Evaluation Plan 
CER 
Clinical Evaluation Report 
CI 
Co-Investigator 
CIB 
Clinical Investigator´s Brochure 
CIP 
 
Clinical Investigation Plan 
CIR 
 
Clinical Investigation Report 
CRF 
Case Report Form 
EDS 
Electronic Data capture Service 
FU 
Follow-Up 
ICF 
Informed Consent Form 
IDMF 
Investigational Device Management Form 
IFU 
Instructions For Use 
IRB 
Independent/Institutional Review Board 
KD 
Knee Disarticulation 
LCI 
Local Co-Investigator 
LPI 
Local Principal Investigator 
LRA 
Local Research Assistant 
MPK 
Microprocessor-controlled Knee 
PI 
Principle Investigator 
SAE 
Serious Adverse Event 
SADE 
Serious Adverse Device Event 
TF 
Transfemoral 
USADE 
Unanticipated Serious Adverse Device Effect 
10mWT 
10-meter walk test 
2MWT 
2-minute walk test 
STS 
Sit To Stand 
5XSST 
5 Times Sit To Stand 
 
 

 
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5 Investigational Device 
Exoskeletal prosthetic devices are by their nature non-invasive. They are non-sterile, reusable, single user 
devices that are part of a prosthetic system consisting of e.g. a liner, socket, lock, adapter, pylon, foot module, foot 
cover and aesthetic finish. The prosthetic medical device will neither provide any benefits nor has any intended 
purpose unless being used as a part of such a system. 
The device under investigation (the Investigational Device) is a modification of a CE-marked medical device 
currently marketed (Power Knee Mainstream). From now on in this document, the investigational device will be 
referred to as POWER KNEE Mainstream Firmware Update. The core component of the system is a motorized 
knee prosthesis along with other important parts which, are necessary for the device’s operation, functionality and 
safety. More specifically, POWER KNEE Mainstream Firmware Update is composed of four parts. Besides the 
motorized knee itself one of these is a detachable battery pack providing the system with power and thereby 
making it operational as a motorized knee prosthesis. Another part is the prosthesis configuration device that 
allows adjustment of the knee parameters to optimize its performance with respect to the user physiological 
characteristics, activity level, gait style and personal preferences. Furthermore, with the battery pack comes an off-
the-shelf power supply allowing recharging of the battery when not installed in the knee prosthesis. 
POWER KNEE Mainstream Firmware Update is based on the concept and technology of the existing POWER 
KNEE MAINSTREAM which is commercially available, but the firmware has been updated to enhance functions 
of ADLs such sit to stand, level walking, and stair ascent. Hence some changes in the algorithm have been made: 
The description of the modifications for the sit to stand, swing phase, and stair ascent are: 
 
Sit-to-stand: The change concerns the power delivery from the motor during standing up. The triggering 
will remain the same, but the motor motion will change. 
 
Swing phase: During the swing phase, the gains of the motor control changes based on the knee angle 
relative to the target flexion angle. 
 
Stair ascent: The stair ascent activity should be more fluid and in synchronization with the user. 
See Table 2 for details on the investigational device. 
Table 2 Identification and Description of the Investigational Device 
Summary description of 
the investigational 
device and its intended 
purpose: 
POWER KNEE Mainstream Firmware Update is composed of a motorized knee 
prosthesis, which forms the core of the system, as well as other devices used to 
sustain operation on a daily basis. More specifically, POWER KNEE Mainstream 
Firmware Update is composed of five devices. Operation of the motorized knee 
prosthesis relies on a detachable battery pack, which provides system power, and a 
Prosthesis Configuration Device that allow adjustment of the knee parameters to 
optimize its performance with respect to the user physiological characteristics, 
activity level, gait style and personal preferences. Furthermore, the battery pack is 
provided and a charger and an off-the-shelf power supply, allowing conveniently 
recharging the battery pack when not used in the knee prosthesis.  
POWER KNEE Mainstream Firmware Update is intended as Power Knee 
Mainstream, for moderate to high-active users of low to moderate impact levels, 
building on established powered knee technology and utilizing the clinical benefits 
associated with powered prosthetics.  
 
It is a Class II product and is a further development of a well-established technology. 
The device is classified as an “External assembled lower limb prosthesis” according 
to 
Title 
21 
§890.3500, 
bearing 
the 
product 
code 
ISW 
(Assembly, 
Knee/Shank/Ankle/Foot, External). 
 
It is 510(k) exempt, except for general requirements. The system is not used in direct 
contact with the body. It should be noted that the aspect of the prosthesis that is in 

 
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For further details on the Investigational device, please refer to Power Knee PKA01 Instructions for Use [4]. 
Table 3 Technical and functional features 
# 
Feature 
Description (if not 
obvious) 
Covered by this 
investigation: 
1 
Powered knee flexion/extension 
Sit to stand support 
Yes 
2 
Controlled yielding 
Sit to stand support, safety 
in ramp and stair ascent
Yes 
3 
Compliance stance 
Support in stance phase in 
level ground walking 
No 
4 
Actuator torque level 
Safety in ramp and stair 
descent 
No 
5 
Motorized swing phase 
Active flexion and 
extension during walking, 
enables users to walk 
further with less exertion. 
Yes 
6 
Natural speed adaptation 
No perceived speed limit 
Yes 
7 
Ascent and descent in ramps/stairs 
 
Yes 
8 
Secure stance phase with locked motor 
Perceived safe and stable 
stance phase 
No 
9 
Flexion hold at different angles 
Comfort in standing 
No 
10
Gait controls 
Ease of use of gait 
functions 
No 
11
Device setup 
For CPO 
No 
12
Noise level 
Acceptable noise level 
No 
 
 
 

 
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6 Justification for the Design of the Clinical Investigation  
The introduction of microprocessor controlled prosthetic knee in 1997 was a major leap in prosthetics in restoring 
function and increase safety of individuals with a lower limb amputation. Countless studies should the benefits of 
such devices, e.g. Hafner et al.1 and Bellmann et al.2. However, such devices are still passive with a major 
shortcoming, which is that they cannot provide positive power to support the user. In other words, they are unable 
to generate concentric moments to support the user in situations in which such moments are needed. Standing up 
and step over step stair climbing are two examples where concentric moments are in principal needed, in order to 
fulfil these tasks. Although recent passive microprocessor controlled prosthetic knees have been introduced that 
offer modes which facilitate step over step stair climbing, the power needed still has to be generated by the proximal 
hip joint of the user. Especially in individuals with a transfemoral amputation, who may have reduced all over 
physical capabilities, such modes cannot be used, due to the physical limitations of the user. This fact is for 
example substantiated by the inclusion criteria in Bellmann et al., who investigated step by step stair climbing in 
K-Level 3-4 subjects with a passive microprocessor controlled prosthetic knee. Beside in these rather complex 
movement patterns, knee power is an also needed for knee flexion in the swing phase while walking. Although the 
magnitude of the power needed in this state is rather small, providing power has a pronounced clinical impact, 
since a reduced clearance in swing is associated with a higher risk of falls.  
Several studies have provided evidence for the clinical performance of previous versions of the Power knee (PK), 
which has the same function and intended use, those are detailed in the Literature review device report [7].  
Results of studies on previous versions of the Power knee indicate that the Power knee provides support in the sit 
to stand and stand to sit activity, provides stance phase flexion in level ground walking, support in ascending and 
descending ramps and stairs and that it does provide active flexion and extension during walking which leads to 
users being able to walk further and feel less tired. In addition, Pasquina et al.10 tested the Power Knee as an initial 
knee prosthesis after combat-related TF amputation or knee disarticulation and found indications that the Power 
Knee can be helpful as initial prosthesis after TF/KD amputation, participants reached mobility milestones faster 
than norms identified by expert panel. Shortening the rehabilitation time after amputation has the potential for great 
savings in healthcare expenditure and large benefits for the patients, e.g. with earlier mobilization and 
independence. Creylman et al.11 compared the Power knee and the Rheo knee (passive MPK), their results 
indicated more symmetric gait with the PK compared to passive MPK. As the literature shows, a powered prosthetic 
knee which is able to generate concentric moments is of high interest, to better counterbalance the disability of 
individuals with a lower limb amputation.  
Study design for phases I and II  
 

 
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7 Objectives and Hypotheses 
The purpose of the investigation is to generate clinical data on the updated device for understanding its full benefits 
and for collecting performance data.  
In phase I, the primary objective of this study is to evaluate the efficacy of the investigation device with the firmware 
update compared to the previous one regarding level walking, sit-to-stand, and stair ascent activities for moderate 
to high actives prosthetics users within the intended population for the investigational device. 
All the activities will be documented via video documentation and comments will be noted.  
A noticeable support of the swing phase in flexion and extension should be visible, plus a similar or an improved 
capacity at keeping up with the user in comparison to the current firmware. The dynamic of the swing phase while 
walking will be investigated via the 2MWT and 10mWT and potentially lead to similar or improved performance in 
comparison to the current firmware. 
Concerning the sit-to-stand activities, time to perform the 5 times sit to stand test (5XSST) will be evaluated.  
Similar as the previous tasks, stair ascent will be noticeable in the video documentation. In particular the subject 
will walk upstairs, stop and fully load the prosthetic knee. The time to perform the stair ascent will be documented 
and the performance will be evaluated with the Stair Assessment Index.  
For each activity, the users will be asked to compare both firmware and rate on a worse, equal, better scale, if 
these tasks felt similar or different with the second firmware (without knowing which firmware is the updated one). 
Additionally, feedback on the performance of the Pro-Flex Terra Foot and the POWER KNEE (phase I: with 
firmware 2, phase II: with updated firmware) will be collected. 
The first phase can be repeated as many times as needed. 
In phase II, the primary objective is to validate the firmware update. 
The investigational device will be assessed with regards to its capability to be used with the indicated patient group, 
providing benefits to the subjects. No risks or anticipated adverse device effects (ADE) are to be assessed. The 
hypothesis and endpoints are specified in Table 2. 
No claims are to be evaluated. 
The following performance aspects are to be verified (relating to features in table 3 above): 
 
The investigational device provides perceived support to the user in sit to stand activities (Powered flexion 
and extension). 
 
The investigational device provides perceived support to the user in stand to sit activities (Controlled 
yielding). 
 
The investigational device provides natural speed adaptation within typical walking cadence, no perceived 
speed limit (Natural speed adaptation).  
 
The investigational device provides natural ambulation in stair ascent. 
 
𝑭𝒐𝒓 𝒂𝒍𝒍 𝒉𝒚𝒑𝒐𝒕𝒉𝒆𝒔𝒊𝒔:  
 𝜇଴𝑖𝑠 𝑎𝑣𝑒𝑟𝑎𝑔𝑒 𝑜𝑓 𝑚𝑒𝑎𝑠𝑢𝑟𝑒𝑚𝑒𝑛𝑡𝑠 𝑎𝑡 𝑏𝑎𝑠𝑒𝑙𝑖𝑛𝑒 𝑤𝑖𝑡ℎ 𝑡ℎ𝑒 𝑐𝑜𝑚𝑝𝑎𝑟𝑎𝑡𝑜𝑟 (𝑃𝑜𝑤𝑒𝑟 𝐾𝑛𝑒𝑒 𝑤𝑖𝑡ℎ 𝑐𝑢𝑟𝑟𝑒𝑛𝑡 𝑚𝑎𝑟𝑘𝑒𝑡𝑒𝑑 𝑓𝑖𝑟𝑚𝑤𝑎𝑟𝑒);  
𝜇ଵ 𝑖𝑠 𝑡ℎ𝑒 𝑎𝑣𝑒𝑟𝑎𝑔𝑒 𝑜𝑓 𝑚𝑒𝑎𝑠𝑢𝑟𝑒𝑚𝑒𝑛𝑡𝑠 𝑤𝑖𝑡ℎ 𝑡ℎ𝑒  𝑖𝑛𝑣𝑒𝑠𝑡𝑖𝑔𝑎𝑡𝑖𝑜𝑛𝑎𝑙 𝑑𝑒𝑣𝑖𝑐𝑒  (𝑃𝑜𝑤𝑒𝑟 𝐾𝑛𝑒𝑒 𝑤𝑖𝑡ℎ 𝑓𝑖𝑟𝑚𝑤𝑎𝑟𝑒 𝑢𝑝𝑑𝑎𝑡𝑒);  
𝑎𝑛𝑑 |𝑀ேூ|  𝑖𝑠 𝑡ℎ𝑒 𝑚𝑎𝑟𝑔𝑖𝑛 𝑜𝑓 𝑛𝑜𝑛−𝑖𝑛𝑓𝑒𝑟𝑖𝑜𝑟𝑖𝑡𝑦  
𝑎𝑛𝑑 |𝑀ா|  𝑖𝑠 𝑡ℎ𝑒 𝑚𝑎𝑟𝑔𝑖𝑛 𝑜𝑓 𝑒𝑞𝑢𝑖𝑣𝑎𝑙𝑒𝑛𝑐𝑒  
𝑎𝑛𝑑 𝑃𝑟  𝑖𝑠 𝑡ℎ𝑒 𝑝𝑟𝑜𝑏𝑎𝑏𝑖𝑙𝑖𝑡𝑦 𝑜𝑓 𝑎 𝑟𝑎𝑡𝑖𝑛𝑔 
Clarification: Phase I will include up to 10 subjects and will be conducted before the firmware is going 
through formal validation. Phase II will include up to 30 subjects and will be conducted to validate the 
firmware. 

 
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Table 4 Endpoints, test methods and hypotheses 
 
Hypothesis 
Test 
Method 
Endpoint 
Acceptance 
Criteria 
for 
phase I 
Acceptance 
Criteria for phase II 
Limitations, 
comments 
A1 
Sit to stand activity 
is 
perceived 
as 
better 
and 
not 
worse 
with 
the 
firmware 
update 
compared 
to 
previous. 
Rating: 
worse, 
same, 
better (1-
3) 
 
Rating 
score 1-3 
 
In 
average 
no 
more than 22.5% 
of 
the 
subjects 
should rate the 
firmware 
update 
no worse. 
𝐻଴: 𝑃௪௢௥௦௘= 0,333 
𝐻ଵ: 𝑃௪௢௥௦௘< 0,333 
∧ 
𝐻଴: 𝑃௕௘௧௧௘௥= 0,333 
𝐻ଵ: 𝑃௕௘௧௧௘௥> 0,333 
∀𝑝< 0,05 
 
A2 
Stand to sit activity 
is 
perceived 
as 
better 
and 
not 
worse 
with 
the 
firmware 
update 
compared 
to 
previous. 
Rating: 
worse, 
same, 
better (1-
3) 
 
Rating 
score 1-3 
 
In 
average 
no 
more than 22.5% 
subjects 
should 
rate the firmware 
update no worse. 
𝐻଴: 𝑃௪௢௥௦௘= 0,333 
𝐻ଵ: 𝑃௪௢௥௦௘< 0,333 
∧ 
𝐻଴: 𝑃௕௘௧௧௘௥= 0,333 
𝐻ଵ: 𝑃௕௘௧௧௘௥> 0,333 
∀𝑝< 0,05 
 
B 
Mobility 
is 
no 
worse 
with 
the 
firmware 
update 
compared 
to 
previous. 
10mWT 
 
Time in 
seconds 
 
Exploratory 
No significant increase in 
time needed to perform 
the 10mWT with the 
firmware upgrade. 
𝐻଴: 𝜇଴−𝜇ଵ ≥|𝑀ேூ|   
𝐻ଵ: 𝜇଴−𝜇ଵ < |𝑀ேூ|   
𝑀ேூ= 𝑀𝐷𝐶 
𝑀𝐷𝐶=  0,13 𝑚/𝑠13 
𝑝< 0,05 
To be able to 
check if the 
knee keeps up 
with the user 
in 
a 
better 
way. 
Sensors 
logging  
C 
Mobility 
is 
no 
worse 
with 
the 
firmware 
update 
compared 
to 
previous. 
2MWT 
Distance in 
meters 
Exploratory 
No significant reduction 
in distance walked on 
2MWT with the firmware 
upgrade. 
𝐻଴: 𝜇଴−𝜇ଵ ≥|𝑀ேூ|   
𝐻ଵ: 𝜇଴−𝜇ଵ < |𝑀ேூ|   
𝑀ேூ= 𝑀𝐷𝐶 
𝑀𝐷𝐶=  34 𝑚14 
𝑝< 0,05 
Sensors 
logging  
 
D 
Users perception of 
level-ground 
walking is no worse 
with the firmware 
update compared 
to previous. 
Rating: 
worse, 
same, 
better (1-
3) 
 
Rating 
score 1-3 
 
In 
average 
no 
more than 22.5% 
of 
the 
subjects 
should rate the 
firmware 
update 
no worse. 
𝐻଴: 𝑃௪௢௥௦௘= 0,333 
𝐻ଵ: 𝑃௪௢௥௦௘< 0,333 
∧ 
𝐻଴: 𝑃௕௘௧௧௘௥= 0,333 
𝐻ଵ: 𝑃௕௘௧௧௘௥> 0,333 
 

 
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∀𝑝< 0,05 
E 
The PK firmware 
update shows no 
worse results in 
stair 
ascent 
activities compared 
to previous. 
Stair 
assessmen
t index 
 
 
Rating 
score 1-13 
 
Exploratory 
𝐻଴: 𝜇଴−𝜇ଵ≥|𝑀ேூ|  
𝐻ଵ: 𝜇ଵ−𝜇଴< |𝑀ேூ| 
  𝑀ேூ = 1 point 
𝑝< 0,05 
Sensors 
logging  
ICCs of rs = 
1.00 
(p 
< 
0.001) 12                       
F 
Users perception of 
stair ascent is no 
worse 
with 
the 
firmware 
update 
compared 
to 
previous. 
Rating: 
worse, 
same, 
better (1-
3) 
 
Rating 
score 1-3 
 
Exploratory 
𝐻଴: 𝑃௪௢௥௦௘= 0,333 
𝐻ଵ: 𝑃௪௢௥௦௘< 0,333 
∧ 
𝐻଴: 𝑃௕௘௧௧௘௥= 0,333 
𝐻ଵ: 𝑃௕௘௧௧௘௥> 0,333 
∀𝑝< 0,05 
 
G 
Users perception of 
exiting from stair 
ascent mode is no 
worse 
with 
the 
firmware 
update 
compared 
to 
previous. 
Rating: 
worse, 
same, 
better (1-
3) 
 
Rating 
score 1-3 
 
Exploratory 
𝐻଴: 𝑃௪௢௥௦௘= 0,333 
𝐻ଵ: 𝑃௪௢௥௦௘< 0,333 
∧ 
𝐻଴: 𝑃௕௘௧௧௘௥= 0,333 
𝐻ଵ: 𝑃௕௘௧௧௘௥> 0,333 
∀𝑝< 0,05 
 
H 
Users perception of 
entering 
stair 
ascent mode is no 
worse 
with 
the 
firmware 
update 
compared 
to 
previous. 
Rating: 
worse, 
same, 
better (1-
3) 
 
Rating 
score 1-3 
 
Exploratory 
𝐻଴: 𝑃௪௢௥௦௘= 0,333 
𝐻ଵ: 𝑃௪௢௥௦௘< 0,333 
∧ 
𝐻଴: 𝑃௕௘௧௧௘௥= 0,333 
𝐻ଵ: 𝑃௕௘௧௧௘௥> 0,333 
∀𝑝< 0,05 
 
Secondary 
I 
Exiting stair ascent 
mode  with the 
firmware 
update 
reduces 
unexpected 
movements 
compared 
to 
previous. 
2 
repetition
s of Stair 
ascent  
Count 
of 
unexpecte
d 
movement
s  
Exploratory 
Significant reduction in 
unexpected movements 
when 
exiting 
stair 
ascent: 
𝐻଴: 𝜇଴−𝜇ଵ ≤0 
𝐻ଵ: 𝜇଴−𝜇ଵ > 0 
𝑝< 0,05 
 
J 
Users 
perception 
with Power Knee 
and Pro-Flex Terra 
is 
no 
worse 
Rating: 
worse, 
same, 
Rating 
score 1-3 
 
Firmware 2 will be 
tested: 
In 
average 
no 
more than 22.5% 
Updated firmware will be 
tested : 
𝐻଴: 𝑃௪௢௥௦௘= 0,333 
Sensors 
logging  
Activities :  

 
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compared to the 
combination of the 
Power Knee and 
the 
prescribed 
foot. 
better (1-
3) 
 
of 
the 
subjects 
should rate the 
combination 
no 
worse. 
𝐻ଵ: 𝑃௪௢௥௦௘< 0,333 
∧ 
𝐻଴: 𝑃௕௘௧௧௘௥= 0,333 
𝐻ଵ: 𝑃௕௘௧௧௘௥> 0,333 
∀ 𝑝< 0,05 
Walking 
on 
level 
ground 
(SSWS, 
slow 
and fast) 
Sit 
to stand 
and stand to sit 
Stair 
ascent 
and descent 
Ramp 
ascent 
and descent 
Squatting 
Exploratory 
K 
Amount of time 
needed to perform 
5XSST 
5 times sit 
to 
stand 
test 
Time 
in 
seconds 
 
 
 
L 
Temporal 
spatial 
parameters during 
5XSST 
Moticon 
Insoles 
Xsens 
Optogait 
Temporal 
spatial 
parameter
s 
 
 
 
M 
Temporal 
spatial 
parameters during 
2MWT 
Moticon  
Insoles 
Xsens 
Optogait 
Temporal 
spatial 
parameter
s 
 
 
 
N 
Temporal 
spatial 
parameters during 
10mWT 
Moticon  
Insoles 
Xsens 
Optogait 
Temporal 
spatial 
parameter
s 
 
 
 
 
 
 

 
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8 Design of the Clinical Investigation 
8.1 General 
The test will be a randomized, controlled, double-blinded, cross-over investigation for both phases I and II. 
Amputees are a small proportion of the general population. The population group specified in the 
inclusion/exclusion criteria is a further subsample of amputees. For practical reasons, i.e. to achieve statistical 
power, it is therefore more feasible to use within-subject comparison rather than creating study arms to compare. 
The results of the phase I data collection will be used subsequent to first testing, to further improve the tested 
device, i.e. PKM. Furthermore, as mobile amputees generally have and use a prosthetic device for their daily 
activities, within-comparison is feasible comparing to the subjects previous device. 
All investigational activities will be conducted at prosthetic out-patient clinics. 
As stated above the primary endpoint is the general usability of the Power Knee Firmware Update in ADLs, which 
are specifically explained in the secondary endpoints are (see Table 4) in that respective order of significance. 
See previous chapter on objectives and hypothesis and Table 4 for rationale. 
Drop-outs and withdrawals may be replaced if deemed necessary to fulfil the methodological standards of the 
study. 
Instruments for data collection will include the following: 
2MWT: 2-minute walk test 
10mWT: 10-meter walk test 
5XSST: 5 times sit-to-stand test 
Specific questionnaire: In-house generated questionnaire on specific features in the investigation device. 
Video 
Data logging by Ossur Logic/ Ossur Toolbox 
See chapter 10.2 Sample size calculation. 
 
Equipment required for each subject: 
 
Detailed protocol 
 
Chair with Armrests for 5XSST 
 
Measuring tape 
 
Markers and a measure corridor/course of known distance for 2MWT and 10mWT 
 
Video camera for video documentation 
 
PC to read out Ossur Logic and Ossur Toolbox results 
 
Case report forms (CRFs) – Tablet/computer OR printed out case report forms 
 
Investigational device: POWER KNEE with the Firmware Update  
 
POWER KNEE with the current marketed firmware 
 
Pro-Flex Terra feet 
 
Other components as applicable (pylons and adapters for fitting) 
 
Tools for fitting 
 
LASAR Posture equipment for alignment 
 
Xsens (Annex 17.5.1) 
 
Moticon Insoles (Annex 17.5.2) 

 
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 
 Optogait (Annex 17.5.3) 
 
Microgate Witty Timing Gate (Annex 17.5.4) 
The equipment used does not require specific monitoring, or maintenance. 
8.2 Investigational Device(s) and Comparator(s) 
The subjects will be asked to use the investigational device with the updated firmware as they usually do with their 
primary prosthesis. The comparator device will be the Power Knee Mainstream with the latest firmware version 
released. It has the same intended use as the investigational device. Furthermore, they are indicated for the same 
condition and population group. 
The subjects will be using the remaining part of their current prosthetic system with the investigational device, as 
it was used with the comparator device. 
For Phase I, up to 10 subjects are to be enrolled, two per days and up to 3 investigational devices will be used. 
For Phase II, up to 30 subjects are to be enrolled, two per days and up to 10 investigational devices will be used. 
8.3 Subjects  
All subjects will be dispositioned as follows: 
Screen Failure: Subject did not pass screening procedures, not called in for clinical visit; 
Candidate for enrollment: Passed screening procedures, accepts to come in for clinical visit; 
Enrolled: Subject signs informed consent; 
Fitted: Subject leaves the clinic on the investigational device; 
Discontinued: Candidate for enrollment or Enrolled subject whose participation ended because they withdrew 
consent, were withdrawn by the Investigator, were lost to follow up, or died; 
Table 5 Inclusion/Exclusion criteria 

 
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Inclusion: 
Only patients with the following characteristics 
are eligible for study entry: 
Exclusion: 
Patients with the following characteristics are not 
eligible for study entry: 
50Kg< body weight < 116Kg 
Users with pain* 
Lower limb loss, amputation or deficiency 
Users with co-morbidities in the contralateral 
limb, which significantly affect their functional 
mobility (except bilateral amputees) 
Cognitive ability to understand all instructions 
and questionnaires in the study 
Users with cognitive impairments 
Transfemoral amputees 
Pregnant users*** 
MPK users who use Power Knee or who tried 
Power Knee within the last 3 years 
 
Bilateral amputees 
 
Hip 
disarticulation 
/ 
Knee 
disarticulation 
amputees 
 
Age ≥ 18 years  
 
Moderate to high-active users 
 
Willing and able to participate in the study and 
follow the protocol 
 
Comfortable and stable socket fit** 
 
No socket issues/changes in the last 6 weeks 
 
 * Question on pain affecting their functional ability (yes/no) 
** Socket fit: socket comfort score (SCS) over 7 
*** Self-reported 
 A subject can withdraw from participation at any time, at his/her discretion, and this will not have any 
consequences for the participant’s treatment. In such cases a report stating reasons for discontinuation of the 
participant shall be prepared by the LPI. No further investigational procedures concerning the subject will be 
conducted, except for a statement explaining the reason for withdrawal, including but not limited to: interacting or 
interviewing the subject in order to obtain data on him/her; obtaining additional private information on the subject 
by either observing the subject or collecting or receiving such information from any source. 
The LPI can withdraw the participant from the trial at any time. The reasons shall be documented. There are no 
pre-specified criteria for discontinuation of participants from the trial. The discontinuation of participants in the trial 

 
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will not result in replacement with new participants. If withdrawal is due to problems related to the investigational 
device the participant will be asked for permission to follow the status/condition outside the clinical investigation. 
The follow-up will be individualized. 
The LPI will initiate the recruitment process by screening potential participants from their customer database. This 
database includes individuals who have previously engaged with their services and fit the criteria for the study. In 
addition to the local database, participants may be recruited from Össur’s customer dabase, external clinics and 
customers, word of mouth and/or customer representative meetings. The PI or LPI will establish communication 
with interested participants and will provide detailed information about the study.  
For both phases, the visits to the clinic are expected to take 3-4 hours/subject. Total duration of phase I is therefore 
one week for every repetition and total duration of phase II is therefore up to three weeks. 
The total time period required to implement the clinical investigation is expected to be up to 12 months. Each 
individual subject is expected to participate in the clinical investigation for the time mentioned above. The estimated 
time needed to include this number (enrolment period) is 1 month for phase I and 3 months for phase II. 
At least 15 subjects are required to finish the protocol for statistical data analysis for phase II, see chapter 10.2 
Sample size calculation. 
8.4 Procedures  
i) Recruitment 
Potential subjects will be identified by using the investigation sites’ existing database of patients, or from Össur’s 
customer database. Participants may be also recruited from external clinics and customers, through word of mouth, 
or during customer representative meetings where Össur representatives engage with users and clinicians. 
Customer representatives, who have prior experience interacting with and servicing patients, will evaluate if a 
potential participant is cognitively capable of participating in the study. Based on their assessment, the customer 
representative will inform the LPI of the potential subject and provide their contact information.  
The LPI or PI will establish communication with potential participants and provide information about the 
investigation. 
If a potential participant meets the inclusion and exclusion criteria, the LPI or the PI will contact them via telephone. 
During this call, the LPI or PI will: 
 
Verify the participant's interest in the study. 
 
Provide detailed information about the study and potential risk of participating in the investigation  
 
Answer questions related to the study. 
 
Conduct a preliminary screening to assess eligibility. 
The LPI or PI will communicate to the study monitor the number of users he has identified that meet the inclusion 
criteria and are willing to participate. 
ii) Test procedure 
For both phases, at the beginning of the visit, a researcher qualified to obtain informed consent will explain the 
study to the subject and proceed as described in chapter 13.8 Informed consent.  
The users will be fitted with the Power Knee device in a combination with an Össur foot. If the prescribed foot is 
an Össur foot, it will be used for the test. If the prescribed foot is not an Össur foot, then Pro-Flex LP will be 
provided for the test. 
 
Configuration phase: 
Both the current marketed firmware and the updated firmware will be optimally configured for each user. 
This configuration will be carried out by the research engineers (Group 1), who will not participate in the evaluation 
phase to ensure blinding. 
 

 
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Randomization: 
Once optimal configuration is achieved for both firmware versions, users will be randomized into two groups: 
 
Group A will start activity blocks with the current marketed firmware. 
 
Group B will start activity blocks with the Power Knee Firmware Update. 
 
Evaluation phase: 
For each activity block and according to the randomization, Firmware 1 (either the current marketed firmware or 
the updated firmware) will be uploaded to the device. Users will then perform the activity block. 
Following this, Firmware 2 will be uploaded to the device. Users will repeat the same activities and tests performed 
with Firmware 1. 
At the conclusion of each activity block, participants will complete a set of questions from the in-house 
questionnaire to evaluate and compare Firmware 1 and Firmware 2 in relation to the activity block they just 
performed. 
This evaluation phase will be done by the other group of research engineers (group 2) who will be blinded. The 
upload of the firmware will be done by research engineers of the Group 1. 
 
Activity blocks: 
The order of the activity blocks is flexible, they can be applied in different sequences, and not all activity blocks 
need to be complete.  
 
Level-ground walking  
 
10mWT 
 
Sit-to-stand  
 
5XSTS 
 
Ramps 
 
Stairs 
 
Squatting 
 
2-Minute Walk Test 
 
Pro-Flex Terra (For the phase I, they will perform the activity block using the last Firmware of the evaluation 
part (Firmware 2). For the phase II, they will perform these tasks with the updated firmware.) 
 
Debriefing session: 
After the testing session, a debriefing session will be organized, and all the research engineers will take part. The 
blindness will be removed for the users and the research engineers. 
The activities are video recorded to visually compare the performance of the two firmware. Biomechanical data 
may be collected. 
At the end they will be fitted back to their prescribed device. If the user has a Power Knee and if the user agrees, 
the current marketed version of the firmware will be uploaded to their devices if it was not already. 
Phase I  
The first phase will be used to assess the parameters defined in Table 4. Tasks performed include ADLs; Level 
ground, inclined, decline walking stair ascent and descent, squatting, standing up and sitting down to a regular 
chair. Subjects will perform the 5XSST, 10mWT and 2MWT, see full description of functional tests in Annex 17.4. 
Subjects will be asked to provide feedback on the tasks tested with in-house questionnaires (see Annex 17.2 and 
17.3) and open comments. 
Phase II 

 
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 
Screen subjects 
 
Explain trial to participants 
 
Responsible for obtaining informed consent from test subjects 
 
Conduct all trial procedures at investigators’ site 
 
Collect data 
 
Fit users with trial device and back to their current prosthesis 
 
Manage study documentation 
8.7 Study monitoring and Oversight 
The study monitor will ensure that all procedures are followed correctly and according to the study protocol. The 
study monitor will gather and review all study data and inform the LPI of missing data or nonconformities to the 
study protocol. 
The study monitor and LPI will maintain communication on a minimum biweekly basis, via telephone and email. 
The LPI will provide the study monitor with information of all scheduled study visits. The study monitor will visit 
each investigational site at least once while a study visit takes place. 
 
9 Investigational Device Accountability 
The investigational devices will be provided as needed for the study population. Devices will not be packaged but 
will be labeled according to FDA regulatory requirements.  
The LPI will keep records documenting the receipt, use and return of the investigational device in the 
Investigational Device Management Form, including: 
 
Date of receipt 
 
ID of each investigational device 
 
Date of use 
 
Subject ID 
 
Date of device return 
 
Date of return of unused, expired or malfunctioning investigational devices, as applicable 
 
10 Statistical Considerations 
10.1 Statistical design and procedures 
Phase I  
The dataset will be assessed with descriptive statistics only, comparing the means and variance for the two data 
points: prior-evaluation (current device with current firmware) and post-evaluation (investigational device with 
investigational firmware). Acceptance criteria for the data, as applicable, is defined in Table 4 Endpoints, test 
methods and hypotheses.  
 
Phase II 
The hypotheses (A1, A2, D, F, G, H, J) will be assessed with one sample binomial test. Other hypotheses will be 
tested using a two-tailed, paired, student’s t-test (if the data are deemed to be normal) or using the Wilcoxon 
signed-rank test (if the data are deemed to be non-normal). 

 
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Subgroup analysis will not be performed as no subgroups are defined. 
Repeated measures analysis has the advantage of increased power vis-à-vis group allocations and reduction in 
error variance associated with individual difference, as each subject acts as its own control. This is important for 
studying amputees as the group is a small proportion of the total population, and with specific inclusion/exclusion 
criteria the total eligible population becomes very small, making it difficult to find and recruit subjects to attain an 
acceptable level of power. This limited population pool often results in slightly heterogeneous sample, as the 
amputees available are few and far between, in every sense. Furthermore, no single amputation procedure and 
therefore amputated stump is exactly the same, making the experience of each amputee a bit unique. The within-
subject design significantly reduces the individual differences when comparing the two conditions. 
The drawback of the design is the potential of “carryover effects”, i.e. experience from one condition can affect 
outcome or performance in the other condition, creating a confounding extraneous variable that varies with the 
independent variable. Such effects are: practice, positive carryover effect to the latter condition; and fatigue, 
negative carryover effect to the latter condition 
10.2 Sample size calculation 
Phase I: 
Phase I is of exploratory nature, a convenience sample of 10 subjects are unexpected to complete the procedures. 
Phase II: 
Power analysis for the estimated required sample size was conducted using G*Power.  See protocol below: 
Exact - Proportion:  
Difference from constant (binomial test, one sample case)  
Analysis: 
 
A priori: Compute required sample size  
Input: 
 
 
Tail(s)  
 
= 
One 
 
 
 
Effect size g 
 
= 
0.2834003 
 
 
 
α err prob 
 
= 
0.025 
 
 
 
Power (1-β err prob) 
= 
0.80 
 
 
 
Constant proportion       =        0.6666 
Output:  
 
Lower critical N         
=        14.0000000 
 
 
 
Upper critical N         
=        14.0000000 
Total sample size         =        15 
Actual power         
=        0.8290491 
Actual α         
 
=        0.0193871 
It is therefore expected that at least 15 subjects are required to complete the protocol with a power of 0.80 and 
significance at 0.025.  
For pass/fail criteria, see Table 4 Endpoints, test methods and hypotheses. 
10.3 Additional statistical matters 
Any deviations from the statistical plan provided in this protocol will have to be approved by the sponsor and the 
reasons for the deviation reported in the clinical investigational report. Drop-outs and withdrawn participants will 
be included in the data analysis for the procedures that they completed. They will be grouped together and 
compared to the group that finished the protocol. Any statistical differences of the two groups will be reported. If 
the participants have not provided any data, they will not be included in the data analysis. No particular information 
will be excluded from the statistical analysis and tests, as described above. 
 

 
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13.3 Risk of Study (To Patient) 
During each visit, the local principal investigator, a certified prosthetist and orthotist, and the study monitor will be 
present to ensure the safety. Potential risks with using the Power Knee Mainstream Firmware Update, are the 
same as using Power Knee and only Power Knee users or users who tried Power Knee, that have been fully 
trained on the device and its controls, will be recruited.  
 
The study adds no additional risk. Subjects will use the investigational device as their primary prosthesis in the 
same manner as they would normally do on their current prosthesis. Thus, they are not required to do anything 
different from their routine clinical visit for acquiring a new MPK prosthesis and their daily living activities. 
13.4 Risk Mitigation 
For each device designed by Össur risk mitigation is part of the design process according to ISO 14971 [1] [3]. 
Furthermore,  for each fitting with the Power Knee Mainstream with the updated firmware, a fully qualified 
professional will ensure the safety of the user. Only Power Knee Mainstream users, that have been fully trained 
on the device and its controls, will be recruited. 
13.5 Benefit-Risk Rationale 
The development of a MPK prosthesis is controlled by a multi-level verification and validation processes before 
being authorized for field testing and subsequent release. The Design & Verification process execution, coupled 
with the risk management and control strategy deployed for POWER KNEE Mainstream Firmware Update ensure 
that the risks associated with use of the device in typical daily living conditions does not exceed risks level 
associated with the operation of any such device under similar conditions. 
The residual risks of the investigation and the investigational device are minimal and are significantly out weighted 
by the benefits of participating in the investigation. 
13.6 IRB Review and Communications 
The study protocol (CIP), informed consent form, and other study documentation forms require IRB review and 
approval. Communication to and from the IRB shall be directed from or to the primary Össur contact, the Sponsor 
Co-Investigator/Monitor. Continuous communication will be maintained between Össur and the IRB, as required. 
Moreover, communication will be maintained between the LPIs and PI and the IRB, as required. 
13.7 Vulnerable populations 
No vulnerable populations will be enrolled.  
13.8 Informed Consent 
The Local Principal Investigator (LPI) at each site, or any researcher qualified, will obtain from the subject, written 
signed informed consent form to his/her inclusion in the study, after explaining the rationale for and the details of 
the study, the risks and benefits of alternative treatments, and the extent of the subject's involvement. The subject 
will receive a copy of the informed consent. 
The protocol consists of different phases, subjects will consent only for the phase they participate in. Signing the 
ICF only applies to the current phase. If a subject participates in one phase it does not mean they have to participate 
in the other phases. Enrollment for each phase is separate. 
The subjects will be informed that their participation is voluntary and that they can withdraw from participation at 
any time, at his/her discretion and this will not have any consequences for the participant’s treatment. 
In case the information on the ICF changes, and subjects need to be provided with new information, the LPI will 
contact each subject by phone and explain the new information as required. 
Subjects that for any reason are unable to provide informed consent will not be enrolled in the study. 

 
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13.9 Participant confidentiality – Data management 
a) Subjects will be assigned a random study identification (ID) number. This ID will be used in all relevant 
documentation. Confidentiality of all relevant subject feedback and information will be maintained through use of 
the identifying number only, in all documentation. The study sponsor, Össur, will remain the sole owner of the 
study data.  
Data will be collected and stored either through the Electronic Data Capture (EDS) system Smart-Trial, or via paper 
based CRFs. 
A list connecting the ID to the subject ́s name will be stored either in the Electronic Data Capture (EDS) system 
Smart-Trial or in a locked file with the LPI at each site. Only appropriately qualified individuals designated by the 
Investigator will have access to this information. Access is controlled by password protected accounts. Accounts 
are enabled with designated permissions only. 
b) Physical source data (e.g. signed Informed Consent forms and paper based forms as applicable) will reside in 
the Local Principal Investigator Site File. This will be physically locked and accessible to the Investigator only. 
c) Case report forms in Smart-Trial are developed in accordance with this protocol and are quality checked against 
the protocol by the study team before use, the same is true in case of paper-based CRFs. In Smart-Trial, validated 
fields and reference rules are used to control quality of data on entry and where required the order of data 
collection. In case of paper based CRFs they are reviewed by the investigator and a study monitor to ensure 
completeness of data. 
Data that are missing or collected out of timeframe will be flagged. Smart-Trial contains audit history and data 
query functionality, in case of paper based CRFs, data queries are raised by the investigator or study monitor. 
Data queries may be raised ad hoc or at scheduled monitoring visits. Data queries may be reconciled by designated 
individuals (by account permissions in Smart-Trial) only. Where physical records are used these will be stored as 
source data in the investigator site file and attached to Smart Trial forms as scans if applicable. 
d) The Smart-Trial system is validated as per the Össur QMS Software Validation process PR-00037 [5] reported 
in VAL1825 [6]. The validation of the software system consists of review of Smart Trial company validation records. 
The validation of individual case report forms against the study protocol is performed by the study team and 
recorded. 
e) In case of electronic data collection; SMART-TRIAL (www.smart-trial.com) will be used as the primary Electronic 
Data Capture tool in this study. SMART-TRIAL is designed and developed in compliance with the PIC/S Guidance, 
PI-011-3 Good Practices for Computerized Systems in Regulated “GxP” Environments, with software validation 
based on IEC 62304. SMART-TRIAL is designed to enable the user to comply with Good Clinical Practice (ISO 
14155:2020), ICH GCP and other industry requirements, such as FDA 21 CFR Part 11 and HIPAA. All data in 
SMART-TRIAL is collected, transferred, and stored encrypted in databases, which are hosted on Microsoft Azure 
ISO certified servers that are managed by SMART-TRIAL within the European Union (Dublin, Ireland). Backups 
are performed continuously throughout the day and stored within the same server. Given that Smart-Trial does 
send messaging to patients in research studies, as part of the informed consent process, (as reviewed by the IRB), 
patients will be asked to consent to communications through these channels. Smart-Trial is adherent to CAN-
SPAM and international equivalents. Frames in video recordings will only contain the lower extremities of subjects 
and any ambulatory assistance provided with their hands. Frames containing the face or other identifiable features 
of subjects will be deleted immediately, if accidentally captured. 
The data of subjects that withdrawn from participation will be deleted unless a specific agreement with these 
subjects to evaluate their data can be obtained. 
g) Photographs and frames in video recordings will only contain as far as possible the lower extremities of subjects 
and any ambulatory assistance provided with their hands only. Frames containing the face or other identifiable 
features of subjects will be blurred, cropped or deleted if accidentally captured. The data of subjects that are 
withdrawn from participation will be retained. Subjects may request that their research data is delinked from their 
personally identifiable data during the course of the study. 
h) In case of EDS, database entry is locked after final patient data is entered. Database is closed and deidentified 
data exported by the sponsor Co-investigator/Monitor on completion of close-out monitoring activities including 
resolution of all data queries. Smart Trial audit history is extracted for records of monitoring activities. Exported de-
identified data is stored on password protected PC intranet for analysis. In case of paper based data collection, 
de-identified data is scanned and shared with the sponsor Co-investigator/Monitor after data collection is complete. 

 
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Representatives of the sponsor, sponsor co-investigators and monitors, will be present at the study sites. A 
declaration of confidentiality to be signed by the representatives, ensures necessary data protection. Sponsor 
representatives will only observe and not interact with subject during the investigational procedures. 
i) The data retention period for unlinked clinical data will be a minimum of 5 years in accordance with ISO 
14155:2020. Clinical investigation documents, including but not limited to CIP, CIB, CRFs and clinical investigation 
report(s) should be incorporated into the device technical documentation under the quality management system of 
the manufacturer. 
k) A Clinical Investigation Report (CIR) will be generated by Össur Medical Office. The report will be stored with 
the device technical file within Össur Quality Management System, along with the unlinked data and all 
accompanying investigational documents, according to the R&D and Quality documentation procedures. Subjects 
participating in the study can have access to the results, on demand, when the CIR is internally published. 
Study results, data, and documentation will be stored for a minimum of 5 years.  
 
14 Evaluation of Adverse Events and Device Deficiencies 
For a list of foreseeable adverse events and anticipated adverse device effects, together with their likely incidence, 
mitigation or treatment see chapter 13.2 above and in the Power Knee PKA01 Instructions for use [4]. 
14.1 Definitions of adverse events, effects and deficiencies 
An adverse event (AE) is any untoward medical occurrence, unintended disease or injury, or untoward clinical 
signs (including abnormal laboratory findings) in subjects, users or other persons, whether or not related to the 
investigational medical device. 
An adverse device effect (ADE) is any adverse event related to the use of an investigational medical device, 
including events resulting from insufficient or inadequate instructions for use, operation, malfunction, etc. 
A serious/severe adverse event (SAE) is an AE that: 
 
Is life-threatening or fatal 
 
requires or prolongs hospitalization 
 
results in permanent impairment of a body function 
 
or results in permanent damage to a body structure. 
A serious/severe adverse device effect (SADE) is an adverse device effect that has resulted in any of the 
consequences characteristic of a SAE. 
An anticipated serious adverse device effect (ASADE) is an effect which by its nature, incidence, severity or 
outcome has been identified in the risk management for the device.  
An unanticipated adverse device effect (UADE) is a serious adverse effect on health or safety of participants 
caused by the device if not previously identified in nature, severity, or degree of incidence in the protocol (CIP) or 
the risk analysis for the device.  
A device deficiency (DD) is the inadequacy of a medical device with respect to its identity, quality, durability, 
reliability, safety or performance. Device deficiencies include malfunctions, use errors, and inadequate labelling. 
A use error (UE) is an act or omission of an act that results in a different medical device response than intended 
by the manufacturer or expected by the user. 
See ISO 14155 [2] for details. 
14.2 Reporting procedures 
All device related adverse events will be investigated. Adverse events that are serious, unanticipated and (possibly) 
device related shall be reported to the sponsor by telephone as soon as possible.  The complete adverse event 
investigation form shall be faxed to the sponsor within 24 hrs. Within ten days the Sponsor will report to the IRB 

 
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and FDA. Any serious device related adverse event will lead to the immediate termination of the trial. In this case 
all participants will be contacted immediately. 
As the investigational device will only be used on site under supervision of investigators adverse events will be 
reported immediately. 
Participants will be provided the contact information of the investigator and told to call them in the event of an 
adverse event that may be connected to previous use of the device.  
The investigator shall supply a copy of the complete adverse event investigation form, together with a cover letter 
to the IRB when events are judged to be serious, unanticipated and (possibly) device related.   
Contact in case of serious adverse events and serious adverse device effects:  
Pete Simpson mobile: (208)-915-6338; email : psimpson@ossur.com 
Any device deficiencies that did not lead to an adverse event but could have led to a medical occurrence 
 
if either suitable action had not been taken, 
 
if intervention had not been made, or 
 
if circumstances had been less fortunate, 
shall be reported according to the same procedure as if an ADE had taken place, specified above. 
14.3 Suspension or premature termination of the clinical 
investigation 
The sponsor/principal investigator, the IRBs, and the regulatory authorities can decide about investigation 
continuation. The clinical investigation can be suspended or prematurely terminated if the serious adverse device 
effects are considered disproportionately large compared to the possible benefits of the intervention. If the 
investigation is terminated or suspended all participants will be informed and appropriate follow-up will be assured. 
If sponsor/principal investigator terminates or suspends the investigation the relevant IRBs and regulatory 
authorities will be provided with a detailed written explanation of the termination or suspension. 
The sponsor/principal investigator can upon completion of the analysis of the reason(s) for a suspension decide to 
lift the suspension, when the necessary corrective actions have been implemented. The investigators, IRBs, and 
relevant regulatory authorities will be notified and provided with the relevant data supporting the decision. 
Breaking of blinding will not be relevant in this trial, since group allocation is visible. 
 
15 Publication Policy 
These results are for internal consumption by Össur employees involved with the project, marketing and for 
regulatory documentation purposes. 
Publication will be pursued as agreed by the Sponsor and Investigator. 
 
 
 
 
 
 

 
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