Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT05048355 |
| Other study ID # |
CII2021050747 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
May 26, 2021 |
| Est. completion date |
August 25, 2021 |
Study information
| Verified date |
September 2021 |
| Source |
Össur Ehf |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
This study is conducted to evaluate the efficacy of the Power Knee Mainstream Dynamic
compared to passive microprocessor-controlled knees (MPKs) regarding metabolic cost for high
active transfemoral amputees.The test is of a single group repeated measures crossover
design. The primary endpoint is the difference in MET/HRI-VO2 index between conditions.
Subjects are measured on their prescribed device at visit 1, be fitted to the PKM which they
wear as their primary prosthesis for one week before coming for visit 2 and being measured
again on the PKM.
Description:
The metabolic cost of ambulation for individuals living with a lower limb amputation is
significantly increased compared to able-bodied individuals. Individuals living with
transfemoral amputation have shown up to 65% more exertion to generate half the ambulation
speed of able-bodied individuals.
The Power Knee Mainstream - Dynamic, was designed to provide powered swing dynamics to
restore muscle activity and thereby attempting to mitigate this increase in metabolic cost
that individuals living with TF amputation face. This study aims to evaluate this indirectly
by measuring the heart rate during level ground walking on the Power Knee Mainstream -
Dynamic compared to a passive MPK.
Previous studies reported in the literature on previous versions of the Power Knee have shown
that it provides active flexion and extension during walking2, 3, 4 and more symmetric gait5
compared to passive microprocessor-controlled knees (MPKs). By providing increased symmetry
and active swing during level ground walking the knee is meant to lower the effort needed by
the transfemoral prosthesis user to swing the leg forward and thereby lower the metabolic
cost of level ground walking.
This underpins the hypothesis being tested in this investigation, that the Power Knee
Mainstream - Dynamic enables the user to walk with less metabolic cost compared to passive
MPKs.
A pilot investigation that was conducted with 5 subjects indicated that the Power Knee
Mainstream - Dynamic enabled users to walk on level ground with less metabolic cost compared
to passive MPKs, however the difference did not reach statistical significance. The same
study procedure will be used in this study with sufficient sample size to achieve the
statistical power needed, which was determined in a power analysis using data form the pilot
study mentioned above.
The primary objective of this study is to evaluate the efficacy of the investigational device
compared to passive microprocessor-controlled knees (MPKs) regarding metabolic cost for high
active transfemoral amputees.
The test is of a single group repeated measures crossover design. Amputees are a small
proportion of the general population. The primary endpoint is the difference in MET/HRI-VO2
index between conditions.
Testing takes place in Össur HQ in Iceland as well as in Össur facility in Germany, the
collective sample size in both sites is 20 subjects.
Subjects are measured on their prescribed device at visit 1, be fitted to the PKM which they
wear as their primary prosthesis for one week before coming for visit 2 and being measured
again on the PKM.
If a subject in the study is a current PKM user the procedure will apply in reverse and they
will be provided with a Rheo knee to act as a comparator.
Prior to the first visit subjects will be contacted via telephone and asked screening
questions, if they fit the inclusion criteria they will be booked for study visit 1. They
will receive instructions to consume no alcohol and perform no exercise for 24 hours before
study visit 1, the same applies to visit 2. In addition, they will be instructed to consume
no caffeine prior to the visits (same day) or drink the same amount before both visits and
keep the same routine the 24 hours prior to visit 1 and 2 (breakfast, water/drink consumption
etc.).
During the one week follow up, subjects will be called via telephone to check the status of
the device and the alignment and if there are issues identified they will be asked to come in
to correct those.
