Northwestern University Flexible Subischial Vacuum Socket for persons with transfemoral amputation-Part 1: Description of technique

BACKGROUND Current transfemoral prosthetic sockets restrict function, lack comfort, and cause residual limb problems. Lower proximal trim lines are an appealing way to address this problem. Development of a more comfortable and possibly functional subischial socket may contribute to improving quality of life of persons with transfemoral amputation. OBJECTIVES The purpose of this study was to (1) describe the design and fabrication of a new subischial socket and (2) describe efforts to teach this technique. STUDY DESIGN Development project. METHODS Socket development involved defining the following: subject and liner selection, residual limb evaluation, casting, positive mold rectification, check socket fitting, definitive socket fabrication, and troubleshooting of socket fit. Three hands-on workshops to teach the socket were piloted and attended by 30 certified prosthetists and their patient models. RESULTS Patient models responded positively to the comfort, range of motion, and stability of the new socket while prosthetists described the technique as "straight forward, reproducible." CONCLUSION To our knowledge, this is the first attempt to create a teachable subischial socket, and while it appears promising, more definitive evaluation is needed. Clinical relevance We developed the Northwestern University Flexible Subischial Vacuum (NU-FlexSIV) Socket as a more comfortable alternative to current transfemoral sockets and demonstrated that it could be taught successfully to prosthetists.