Quality of Life Assessment in Transtibial Amputees using K2 vs K3 Prosthetic Feet


The functional level of transtibial amputees is used to determine the K-level classification of prosthetic feet that can be reimbursed. A lower K-level prosthesis lacks the technology of higher K-level prosthesis and thus may diminish the patient’s ability to perform daily tasks such as balance and gait while increases chances of expensive injuries due to trips and falls. Our hypothesis is that a K3 prosthesis will not only show improvements in daily tasks such as balance and gait but will also improve the patient’s quality of life. Ten subjects with transtibial amputations secondary to diabetes and vascular disease were recruited. Subjects were asked to participate in two visits. A V-gait CAREN (Computer Assisted Rehabilitation Environment Network, Motek Medical, The Netherlands) system and a 12-camera Motional Analysis System were used to create virtual environments where subjects were assessed performing balance and gait task. These two visits were separated by a two week trial period in which subjects were randomized to wear a K2 or K3 prosthetic foot above, below or at their specific level of function. Data collected at both visits were evaluated alongside quality of life information gathered from the Physiological Cost Index, the Reintegration to Normal Living Index, and the SF-36 questionnaires. Results were analyzed with pared t-tests. Subjects switching from a K2 to K3 level prosthesis showed a significant increase in SF 36 scores (p=0.0005). Those switching from a K3 to K2 level prosthesis expressed significant decrease in SF 36 scores (p=0.01). The quality of life domains most impacted in subjects switching from a K2 to K3 level were physical functioning, limitations due to physical health, as well as energy and fatigue. The only domain that was not impacted was social functioning. Subjects switching from a K3 to K2 level prosthetic expressed the greatest difference in limitations due to physical health, energy and fatigue, physical functioning and pain. The results to this point confirm that K3 prosthetic feet lead to a greater quality of life. Providing higher functioning prosthetics to lower functional level amputees may not only lead to improved balance and coordination, but it may also lead to increased cost effectiveness due to an elevated level of function with less injuries and falls. Therefore, it is vital that the proper prosthetic is prescribed to transtibial amputees.

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