Microprocessor knee versus non-microprocessor knee for backup device in lower limb prostheses: A qualitative study

LAY SUMMARY Current policy in the Canadian Armed Forces (CAF) and Veterans Affairs Canada (VAC) is to provide individuals with an amputation through or above the knee with a prosthesis with a microprocessor knee (MPK) unit for daily use and a backup prosthesis with a non-microprocessor knee (N-MPK) unit. These knee units have significant functional differences. The purpose of this study was to gain an understanding of users’ device preference and the impact of switching between the MPK and N-MPK. To study this, six members participated in semi-structured interviews. Analysis found seven major categories driving prosthetic preference: functionality, physical aspects, mental aspects, activity, maintenance, safety, and health-related quality of life. The MPK was superior in all categories, and immediate switching between devices was problematic. As a result, participants who had an N-MPK backup did not use the device and instead received a loaner MPK from their prosthetist when required. These results suggest that for individuals who do not have ready access to their prosthetist to obtain a loaner knee unit, consideration should be given for a backup prosthesis with the same MPK unit as their daily-use prosthesis. Otherwise, no routine need for a backup N-MPK was identified.