Improvement in Functional Outcomes with the Infinite Socket

Abstract

ABSTRACT Introduction The prosthetic socket, which provides an important patient interface for weight bearing and mobility, cannot adequately account for the dynamics of the residual limb, and problems with pain, skin breakdown, verrucous hyperplasia, and bursitis are frequent. To address these issues, LIM Innovations, a prosthetics manufacturer, has developed the Infinite Socket, an adjustable, custom-molded modular socket made of a carbon fiber frame and a two-part tensioning system that can be adjusted by the user. Materials and Methods Patients with transtibial or transfemoral amputations were asked to participate in this study between the period of June 30, 2015, and January 1, 2017, if they had a standard-of-care thermoplastic socket and were dissatisfied. Patients were fit with an Infinite Socket, and functional outcome tests were performed at the time of the Infinite Socket fitting. It was hypothesized that the Infinite Socket would improve functional outcomes compared with the subjects' legacy prosthetic sockets. Results One hundred twenty-seven patients with limb loss (18 transtibial and 109 transfemoral) participated in this study. The mean age of participants was 48 years (range, 19–82) and 82% were male. Data indicate that the Infinite Socket had superior outcomes compared with legacy standard-of-care prosthetic sockets for socket comfort scores (7.64 ± 2.00 vs. 4.52 ± 2.22, P < 0.0001), 2-minute walk test (108.80 ± 31.28 vs. 101.53 ± 33.96, P = 0.007), and the Four-Step Square Test (17.01 ± 12.14 vs. 21.57 ± 18.52, P = 0.005). There was no statistically significant difference in the L Test (30.98 ± 27.51, 36.31 ± 45.64, P = 0.246). Conclusions A new modular, patient-adjustable prosthetic socket demonstrated improved functional outcomes compared with the legacy standard-of-care prosthetic socket. Participants reported higher socket comfort scores and mobility scores were improved for the two-minute walk test and Four-Step Square Test for those using the Infinite Socket.