Adjustable prosthetic sockets for children and adolescents with lower limb loss to accommodate growth

Pediatric limb loss, although relatively infrequent compared to adults, results in substantial hardship for children and their families. The principal business interest? iFIT Prosthetics, LLC®? successfully developed and manufactured innovative, fully adjustable, transtibial and transfemoral prosthetic devices, and demonstrated their safety, comfort, and functionality in adults. Made of injection-molded, advanced-polymer materials, the iFIT prostheses can be mass-produced at a significant cost advantage relative to conventional devices. Our overarching goal in this project is to bring such technology to the pediatric market, where evidence suggests an acute unmet need for comfortable, affordable prosthetic devices that can accommodate limb growth and prevent skin breakdown as the child develops. Specifically, our Phase I, Specific Aim 1 is to develop adjustable prosthetic sockets for children with limb loss and limb deficiency. Prototypes using patented mechanical concepts with pediatric componentry will be tested by five subjects under age 12, at least two with transfemoral and two with transtibial limb loss. Through a feedback-and-refinement process, we will improve the prototypes until the optimal design is reached. Evaluation of Phase I success will be based on objective metrics demonstrating whether: i) the five subjects use the iFIT prostheses and ambulate comfortably, ii) they ambulate within 10% of their walking speed with their conventional devices, and iii) there are lower intrasocket pressures with the adjustable prototype devices compared to their conventional sockets. Phase II, Specific Aim 1 will determine the comfort, ease-of-use, and patient satisfaction with the transtibial and transfemoral iFIT pediatric prostheses and assess how well growth is accommodated by the adjustable device. To that end, we will conduct a longitudinal, prospective, 8-week trial of children and adolescents aged 3 to 18 years old with transfemoral (20 subjects) and transtibial (20 subjects) limb loss. Subjects will return at six and 12 months to assess how well growth has been accommodated. Key outcomes include: i) age-specific, validated, self-reported measures of patient’s use of and satisfaction with the device as compared to their conventional prosthesis, ii) a qualitative assessment of prosthetists’ impressions regarding ease-of-fitting, and iii) objective, quantitative measures of function and use (step monitoring, activity monitoring, gait biomechanics, and intra-socket pressures). Phase II, Specific Aim 2 will estimate the market potential of iFIT among children and adolescents, quantify associated prosthetic utilization and costs, and model cost- effectiveness from payer and societal perspectives of iFIT prostheses relative to conventional devices. With its adjustable design, the iFIT device holds great promise in addressing the well-documented limitations of current pediatric prosthetic technology— frequent skin breakdown and limb pain due to ill-fitting prostheses, high out- of-pocket costs, and high time costs for children and their families in securing new prostheses to accommodate growing limbs—for the large number of children and adolescents living with limb loss worldwide.