Effects of Microprocessor-controlled Knee Joints on Community Outcomes

Activity, Mobility, Social Functioning, Mental Health and Quality of Life Outcomes in Limited Mobility Transfemoral and Knee Disarticulation Amputees Using Microprocessor-Controlled Knees or Non-Microprocessor Controlled Knees in the United Kingdom: A Cohort Study

About 21% to 35% of people with limb loss are those who lost their limb at trans-femoral level (i.e. above the knee). The increasing number of diabetes-related limb loss (amputation) and the rising proportion of older adult amputees indicates more amputees with limited mobility in the future. Among other factors, prosthesis success highly depends on the function of the knee joints during daily activities.

Presently, there are two categories of prosthetic knee joints; microprocessor-controlled knees (MPKs) and non-microprocessor-controlled knees (n-MPKs). Whilst the n-MPKs are unable to change the knee stiffness, the MPKs alter the joint stiffness and speed of movement according to the users' walking speed.

Although past studies indicate that MPKs could result in reduced risk of falls, improved balance and activity in limited mobility amputees, there is a lack of strong evidence on the effect of MPKs on community outcomes. The aim of this study is to compare activity, mobility, social functioning, depression, anxiety, and health-related quality of life in limited mobility trans-femoral or through-knee (i.e. knee disarticulation) amputees who are users of MPKs prosthesis with users of a prosthesis with n-MPKs.

Inclusion Criteria:

• Unilateral transfemoral amputation or knee disarticulation
• ≤ K2 mobility grade OR SIGAM grade D or below; i.e. able to walk ≤ 50 meters on level ground,
• Users of either MPK or N-MPK for at least 6 months prior to the recruitment date.

Exclusion Criteria:

• Not meeting inclusion criteria