RESUMO
Objective: To assess the feasibility of an adjustable, subischial transfemoral prosthesis by comparing self-reported outcome measures regarding socket comfort, fit and utility relative to a persons' conventionally made socket. Assessing limb compressibility was another aim of this study. Design: A single-group pre-post intervention design. Setting: Physical medicine and rehabilitation biomechanics laboratory. Participants: All 18 enrolled participants (N = 18) completed the feasibility trial. There were 16 men and 2 women with an average age of 59.4 (±7) years. Most of the participants (61.1%) had worn a socket for 1 to 10 years before the trial, 22.2% of the participants had worn one for less than a year, and 16.7% of the participants had worn a prosthesis for more than 10 years. Intervention: Participants were fit with the study prosthesis and used it for a 2-week home trial. Main Outcome Measures: A Prosthetic Comfort and Utility Questionnaire was completed on the participant's conventional prosthetic device and the subischial socket system after the trial. Results: The adjustable subischial prostheses were rated superior overall to the participant's conventional sockets (40.9 ± 7.2 vs 32.8 ± 10.8; P=.004). Six of the 10 parameters measured (adjustability, overall fit, prosthesis weight, sitting comfort, standing comfort, and standing stability) were rated higher for the adjustable prostheses compared to the conventional sockets. Compression of the soft tissues of the thigh ranged from 5.6 ± 4.2 cm at the distal end to 7.3 ± 3.6 cm at the proximal site. There were no falls, skin breakdown, or limb ischemia. At the 2-month telephone follow-up, 61% of subjects had transitioned to using the adjustable subischial socket most of the time. Conclusions: The adjustable, immediate fit, subischial prosthesis provided safe, comfortable, and functional ambulation for persons with transfemoral limb loss in this short-term feasibility study. This study supports the consideration of a new paradigm in transfemoral prosthetics-adjustable subischial sockets. These devices should be tested in a larger multi-center study.
RESUMO
BACKGROUND: There exists a need for an adjustable socket to accommodate residual limb volume and shape changes. Further, limb loss rates globally are rising and there is a large unmet need for affordable and accessible prosthetic systems. OBJECTIVE: To assess the utility of an immediate fit modular prosthetic system (iFIT Prosthetics, LLC). DESIGN: Prospective feasibility study involving a 2-week single-group pre-post intervention study. SETTING: Physical Medicine and Rehabilitation gait laboratory. PARTICIPANTS: Participants were at least 6 months post amputation and walking with a conventional prosthesis. They were free of skin wounds, other neurological disorders, and severe pain conditions. METHODS: Participants were fit with an immediate fit prosthesis and instructed to wear it for a 2-week evaluation period. They were given a progressive wearing schedule and they completed outcome measurements at the 2-week follow-up. MAIN OUTCOME MEASUREMENTS: Self-reported satisfaction, gait biomechanics, and intrasocket peak pressures. RESULTS: Twenty-six participants entered the study, with 22 completing the single group pre-post study. They averaged 50 years (SD ±10.2) of age; four were female. Sixteen were dysvascular and 10 were traumatic in etiology. Significant differences (P = .03) in self-reported satisfaction were found in favor of the iFIT device 29.33 (SD ± 4.51) versus the conventional device 25.52 (SD ± 6.8). No falls or limb ischemia were reported. Gait biomechanics revealed no differences across any temporal characteristics. Intrasocket peak pressures were significantly lower for the iFIT prostheses overall (P = .0014), at the anterior tibia (P = .0002), and the lateral side of the residual limb (P = .013). CONCLUSIONS: The iFIT transtibial prosthetic system appears to be safe in this short-term single-group pre-post study. This study provided preliminary evidence to support the feasibility of the iFIT system. It compared favorably to participants' conventional prostheses across all outcome measures. With its cost, adjustability, and accessibility advantages, this device may prove useful for persons with transtibial amputations. A larger multicenter study is needed to confirm these results. LEVEL OF EVIDENCE: III.