Mobility and satisfaction with a microprocessor-controlled knee in moderately active amputees: A multi-centric randomized crossover trial

Objective

Microprocessor-controlled knees are generally prescribed and reimbursed for active amputees. Recent studies suggested that this technology could be useful for amputees with moderate activity level. We compared the efficiency of a microprocessor-controlled knee (MPK, Kenevo, Otto Bock) and non-MPKs (NMPKs) in these indications.

Methods

A multi-centric randomized crossover trial was conducted in 16 hospitals from 3 European countries. Participants were randomized to an MPK-NMPK sequence, testing the MPK for 3 months and the NMPK for 1 month, or to an NMPK-MPK sequence, testing the NMPK for 1 month and the MPK for 3 months. Dynamic balance, the main criteria, was assessed with the Timed-Up and Go test (TUG), functional mobility with the Locomotor Capability Index (LCI-5), quality of life with the Medical Outcomes Study Short Form 36 v2 (SF-36v2) and satisfaction with the Quebec User Evaluation of Satisfaction with Assistive Technology 2.0. The occurrence of falls was monitored during the last month of trial. Analysis was by intent-to-treat and per-protocol (PP).

Results

We recruited 35 individuals with transfemoral amputation or knee disarticulation (27 males; mean age 65.6 years [SD 10.1]). On PP analysis, dynamic balance and functional mobility were improved with the MPK, as shown by a reduced median TUG time (from 21.4 s [Q1–Q3 19.3–26.6] to 17.9 s [15.4–22.7], P = 0.001) and higher mean global LCI-5 (from 40.4 [SD 7.6] to 42.8 [6.2], P = 0.02). Median global satisfaction score increased (from 3.9 [Q1–Q3 3.8–4.4] to 4.7 [4.1–4.9], P = 0.001) and quality of life was improved for the mental component summary of the SF-36v2 (median score from 53.3 [Q1–Q3 47.8–60.7] to 60.2 [51.6–62.6], P = 0.03) and physical component summary but not significantly (mean score from 44.1 [SD 6.3] to 46.3 [7.0], P = 0.08). Monitoring of adverse events including falls revealed no differences between both assessed devices.

Conclusion

This study enhances the level of evidence to argue equal opportunity for all individuals with transfemoral amputation or knee disarticulation, regardless of their mobility grade, to be provided with appropriate prostheses.