gms | German Medical Science

Objectives: Moderately active amputees (MFCL K2) tend to have limited control over mechanical knee joints (NMPK), and have a significantly increased risk of falling. This can limit both mobility and participation, leading to a progression of vascular disease. Microprocessor controlled knees (MPK) have been shown to decrease the rate of falling and to favor a progression of patients to higher mobility levels, however, this technology has been mainly used for highly active amputees at this time.

The aim of this multicenter, comparative, randomized, cross-over trial was to evaluate if patients with MFCL K1 or K2 could benefit from a new MPK that has been designed for the eldery (Kenevo), particularly in terms of a reduced risk of falling.

Methods: Between March and November 2015, 27 participants (age: 65.6 ± 10.1 years, weight: 76.6 ± 16.0 kg, interval since amputation 61.4 ± 85.5 months, 22 male, 5 female, 26 transfemoral, 1 knee disarticulation, MFCL K2: 24, K1:3), who had used mechanical knee joints before, could be enrolled. After randomization, patients were fitted alternately with Kenevo and NMPK knees over a period of minimum 4 months, and underwent dedicated training sessions. The primary assessment parameter for falling was the timed up and go test (TUG). Additionally, we carried out the SF-36, LCI-5, QUEST 2.0, and documented the number of falls. The statistical analyses were carried out with SPSS using student's t-tests and Mann-Whitney U tests.

Results and conclusion: We found a significant reduction of the TUG test after Kenevo in comparison to NMPK (19.4 ± 5.1s vs. 23.1 ± 5.4s, p = 0.001). Furthermore, the global LCI-5 improved significantly with Kenevo (p=0.02). QUEST 2.0 results showed the level of satisfaction was significantly improved with Kenevo globally (p=0.002), regarding services (p=0.009), and technology (p=0.002).

The SF-36 scale for quality of life was improved with Kenevo with regard to the mental score MH (p=0.009), the limitations related to mental health RE (p=0.04), the physical function PF (p=0.04), limitations related to the physical function RP (p=0.005), and vitality VT (p=0.02). Over the last month of use, 3 falls occured with NMPK, and one with Kenevo. This difference was not significant in terms of the statistical analysis due to the small number of cases, however, this corresponds well to the results in the TUG test.

This study demonstrates that moderately active amputees do profit significantly from Kenevo in terms of improved security, increased mobility, improved quality of life and a reduced number of falls. These data add substantial evidence to prior studies indicating increased security for MFCL K2 amputees, and further substantiate the notion that MPK technology should be used for these patients.