Clinical Investigation (Beta) of Power Knee Mainstream - Dynamic

Össur Iceland ehf

Status: Completed

Conditions: Amputation; Prosthesis User

Treatments: Device: Power Knee

Study type: Interventional

Funder types: Industry; Other

Identifiers

NCT04787627

CIP2019050213

Details and patient eligibility

About

Prospective two group cross over investigation, comparing the investigational device (Power Knee, a powered microprocessor controlled prosthetic knee) and subjects prescribed microprocessor prosthetic knee (MPK).

The primary objective was to evaluate the efficacy of the investigational device in reducing exertion during walking compared to passive MPKs. Additionally to evaluate the efficacy of the investigational device in the short and long term compared to passive MPKs and previous versions of the Power Knee, during daily living activities i.e. walking on level ground, in stairs and inclines, rising from and sitting down to a chair as well as performance of gait functions and ease of set up for average to highly active transfemoral/knee disarticulation amputees and Certified Prosthetists/Orthotists (CPOs).

Full description

This is a prospective two group cross-over study, within subject comparison. 3 study visits are planned for amputee subjects, with approximately 2-3 weeks between visits, and an optional fourth visit 8-12 weeks after the third visit. During the first visit subjects will be check for inclusion/exclusion, consented and randomly assigned into two groups and Group 1 (transitioning to the investigational device) will perform functional tests and answer questionnaires on the performance of their current prosthesis to provide baseline information. The Group 1 subjects will be fitted and trained on the investigational device and a recommended prosthetic foot which they will use as their prescribed prosthesis for 2-3 weeks until the second visit, the other half will stay on their prescribed prosthesis until the second visit.

During the second visit the subjects of Group 1 will perform the same functional tests as in the first visit on the investigational device and answer questionnaires on the performance of the investigational device, and then return to their prescribed prosthesis. The Group 2 will perform the same tests/questionnaires on their prescribed prosthesis and then be fitted and trained on the investigational device and use it as their usual prosthesis for 2-3 weeks.

During the third visit all subject will repeat the tests and questionnaires on the prosthesis they are fitted with (Group1 on the prescribed and Group 2 on the investigational device). Subjects will have the option to use the investigational device for an additional 8-12 weeks, those who choose that will be fitted with the investigational device or will stay on it, depending in which they are in at this point. They will be booked for the fourth visit; they will be contacted via telephone 4-5 weeks later and asked to provide feedback on their experience with the device so far. Those that choose not to keep using the investigational device will be returned to their prescribed prosthesis.

During the fourth visit subjects will answer the same questionnaires and perform the same functional tests as the other visits. Data will be collected from the knee on activity. They will then be fitted back to their prescribed prosthesis.

End of study. CPO (Certified Prosthetist Orthotist) subjects will answer a questionnaire on the ease of setup of the investigational device and provide feedback on the ease of setup of gait functions.

Statistical considerations:

Outcomes at each timepoint were visually inspected for normality using histograms and qq-plots, as well as a Shapiro-Wilk Normality Test. If the data were deemed to be normal the hypotheses were tested using a two-tailed, paired, student's t-test. Non-normal data was tested using the Wilcoxon signed-rank test.

Enrollment: 17 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• 50Kg< body weight < 116Kg
• K3-K4 amputees with unilateral transfemoral amputation or Knee disarticulation
• Allows for 37mm knee center height to dome of pyramid alignment
• Currently using a MPK or Power Knee
• Older than 18 years old
• No socket issues/changes in the last 6 weeks and no socket changes expected during the duration of the study period.
• Comfortable and stable socket fit
• Willing and able to participate in the study and follow the protocol

Exclusion criteria

• 50Kg> body weight > 116Kg
• Bilateral amputees
• Users with socket problems
• Users with co-morbidities in the contra-lateral limb, which affect their functional mobility
• Younger than 18 years old
• Users with stump pain
• Users with cognitive impairment
• Users not involved in other clinical tests and/or receiving treatment that the testing might affect.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: None (Open label)

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17 participants in 2 patient groups

Power Knee before prescribed prosthesis

Experimental group

Description:

Power Knee, the investigational device is fitted on subjects and they use it as their primary prosthesis for 2 weeks before coming in for data collection on the device. After being on the investigational device for 2 weeks subjects go back on their prescribed prosthesis for 2 weeks and comparator data is collected.

Treatment:

Device: Power Knee

Power Knee after Prescribed prosthesis

Experimental group

Description:

Subjects start the study by using their prescribed prosthesis for 2 weeks, then they come in for data collection of comparator data, in that same visit they are fitted with the investigational device and wear that for 2 weeks before coming in for data collection on that device.

Treatment:

Device: Power Knee