CLINICAL OUTCOME OF TRANSFEMORAL DIRECT SOCKET INTERFACE (PART 2)

Abstract

BACKGROUND: Amputation at the transfemoral (TF) level reduces the rate of successful prosthetic fitting, functional outcome, and quality of life (QoL) compared with transtibial amputation. The TF socket interface is considered the most critical part of the prosthesis, but socket discomfort is still the most common user complaint.  Direct Socket for transfemoral prosthesis users is a novel interface fabrication process where the socket is shaped and laminated directly on the residual limb and delivered in a single visit.

OBJECTIVE(S): The aim of this study was to investigate if prosthetic users' quality of life (QoL), comfort, and mobility with a Direct Socket TF interface were comparable to their experience with their previous prostheses.

METHODOLOGY: The pre/post design prospective cohort study included 47 subjects. From this cohort, 36 subjects completed the 6-months follow-up (mean age 58 years, 27 males). Outcomes at baseline included EQ-5D-5L^®, PLUS-M™, CLASS, ABC, AMPPRO, and TUG. At 6-weeks and 6-months, subjects repeated all measures. Seven Certified Prosthetist (CP) investigators performed observations and data collection at six different sites (from July 2018 to April 2020). 

FINDINGS: Results showed significant improvement in all outcome measures for the 36 subjects that completed both 6-weeks and 6-months follow-ups. CLASS sub-scales showed significantly improved stability, suspension, comfort, and socket appearance. Improvement in K-Level and less use of assistive devices were observed with the AMPPRO instrument, indicating improved user mobility and performance. QoL was also increased, as measured in Quality-Adjusted-Life-Years (QALY) from the EQ-5D-5L.

CONCLUSION: Evidence from the findings demonstrate that the Direct Socket TF system and procedure can be a good alternative to the traditional method of prosthetic interface delivery.

Layman's Abstract

After lower limb amputation, the goal for most people is to regain mobility and independence and return to normal daily activities. Typically, people with transfemoral amputation are less likely to receive a prosthesis or fully use a prosthesis as compared to people with transtibial amputation. Moreover, their quality of life is also lower. The Direct Socket TF method is a new way of fabricating a prosthetic socket for users with above-knee amputation, enabling fabrication directly onto the residual limb and delivery of the socket in a single visit. In this study, we wanted to understand how the effect of Direct Socket TF on prosthetic 'user's quality of life, health, mobility level, and balance would compare to their previous prosthesis. This new Direct Socket TF procedure was implemented in six different prosthetic clinics across the United States and used by 36 prosthetic users for six months. Our first article on this study describes increased user satisfaction with their new interface and the single visit service model. This second article on the same clinical investigation documents the significant improvement in outcomes compared to their original interface in terms of quality of life, confidence, mobility, comfort, stability, and activity level.