Toward personalizing prosthesis prescription: A take-home study of three microprocessor-controlled prosthetic knees: A randomized crossover study

BACKGROUND: Previous studies on microprocessor-controlled prosthetic knees (MPKs) often investigate benefits of MPKs as a class of knees rather than clinically relevant differences between specific knees, despite their distinct features. OBJECTIVES: To systematically evaluate and report outcomes associated with three commercially available MPKs following a standardized real-world use period. DESIGN: Randomized crossover study. SETTING: Research laboratory and community environment. PARTICIPANTS: Ten patients with transfemoral amputation. INTERVENTIONS: Three MPKs were fitted, trained, and worn for a 1-week period including C-Leg 4.0 (Ottobock, Duderstadt, Germany), Rheo Knee-Model RM7 (Össur, Reykjavik, Iceland), and Power Knee-PKA01 (Össur, Reykjavik, Iceland). MAIN OUTCOME MEASURES: Primary outcomes were the 10-meter walk test (10-mwt), the 2-minute walk test (2-mwt), and the Prosthesis Evaluation Questionnaire (PEQ). Secondary outcomes were stance time asymmetry, physiological cost index, stair and ramp speeds, the narrowing beam walking test, and community ambulation monitoring. RESULTS: Participants walked 11% faster in Rheo than Power Knee during the 10-mwt (95% confidence interval [CI]: 0.046-0.184, p = .015). In the 2-mwt, participants walked 12% faster in C-Leg (95% CI: 0.034-0.241, p = .003) and 9% faster in Rheo (95% CI: 0.031, 0.163, p = .027) than in Power Knee. On the PEQ, participants reported greater satisfaction with C-Leg compared to Power Knee (p = .006). Ramp ascent speed was 8% faster in Rheo than Power Knee (95% CI: 0.026-0.130, p = .024). No significant differences were found for other secondary outcomes. Notably, 10 of 12 outcomes showed individuals performing their best by a defined difference on an MPK different from the cohort's best-performing MPK. CONCLUSIONS: Participants walked faster in C-Leg and Rheo than Power Knee and reported greater satisfaction with C-Leg. Consideration of patient needs and characteristics may allow more individualized MPK prescription and thereby improve rehabilitation outcomes. DATABASE REGISTRATION: NCT06399471.