Effectiveness and Cost-effectiveness of Lower Limb Prostheses

Comparing the Effectiveness and Cost-effectiveness of Conventional Mechanical Knees and Microprocessor-controlled Knees: a Prospective Cohort Study

The goal of this observational study is to investigate the effectiveness of NMPKs versus MPKs in persons with an LLA in the standard healthcare system in the Netherlands taking all levels of the ICF model into account. Our main aim is to assess the effect of MPK use compared to NMPK use on walking distance, as this is one of the most used outcome variables in literature and thus enables comparison with previous studies. Our secondary aim is to investigate the effect of NMPKs versus MPKs on all ICF-levels: body structures and function, activities and participation.

Participants will be seen four times in a year. During these measurement moments they will:

• Perform two physical tests
• Fill out a set of questionnaires
• Wear an activity tracker for one week

In this prospective cohort study the participants made use of two types of prosthetic knees; the CMK and MKP. A baseline measurement (T0) was performed while the participants were using their own CMK. One week later, they received the MPK to start a six week-trial. During this trial, they received 30 minutes of physical therapy twice a week. In the last week of the trial period, the measurements were performed again (T1). After the trial period, participants switched back to their CMK and after four weeks of getting used to that, the functional performance tests were repeated (T2). Nine months after the last measurement, and if the participant received a MPK, the measurements were repeated again (T3).

The measurements consisted of:

Physical tests:

• 6 minute walking test (6MWT)
• Timed up and Go test (TUGtest)

Questionnaires:

• Cost questionnaire
• Activities-Specific Balance Confidence Scale (ABC-NL)
• Utrecht Scale for Evaluation of Rehabilitation Participation (USER-P)
• Short Questionnaire to Assess Health-enhancing physical activity (SQUASH)
• Prosthesis Evaluation Questionnaire (PEQ)

Activity monitor:

• Activ8 professional. Worn for seven consecutive days.

Inclusion Criteria:

• At least one year post amputation
• Unilateral transfemoral amputation or knee-disarticulation
• Eligible for a trial on an MPK
• Able to read and write in Dutch
• Use a prosthesis with a socket

Exclusion Criteria:

• Bilateral amputation
• Osseointegration
• Previous experience with an MPK