ASSIST: A randomised feasibility trial to assess the Acceptability of a remouldable Socket System in the Immediate rehabilitation phase of people with a tranSTibial amputation

Research question Is it feasible to conduct a future RCT to evaluate the effectiveness and cost-effectiveness of a remouldable socket for patients with a below-knee amputation fitted for their first prosthesis? Background In the UK, there are ~2,000 new amputations performed below-the-knee annually; the majority of these patients are referred to limb-fitting services. The socket is the device that connects the prosthesis to the residual (remaining) limb. It is traditionally manufactured by taking a plaster-cast mould of the patient s residual limb, before fabricating a polypropylene socket. The patient s residual limb often changes shape during the first year post-amputation, necessitating the fabrication of a new socket. An alternative system exists. It is used in other countries but has not been tested in NHS limb-fitting services. It involves a remouldable socket made from thermoplastic material that is heated and moulded onto the limb directly. It is much quicker than the traditional socket processes and can be remoulded so the patient adapts to the same socket, reducing waiting times and manufacturing costs, and accelerating prosthetic limb-fitting. This will likely improve patient outcomes. Aims and objectives To undertake a multicentre, randomised feasibility trial of a remouldable vs. traditional socket for below-knee amputee patients. We will assess recruitment rates and times; conduct interviews to assess acceptability of study processes and interventions to patients and clinicians; identify important outcomes for a future trial. Methods We will recruit 80 patients with a below-knee amputation who are expected to receive a prosthesis, from five NHS prosthetics centres. They will be randomised to receive the remouldable socket (intervention) or traditional socket (control). They will receive a prosthetic ankle-foot according to their expected mobility level, as per usual care. The only difference between the two groups will be the socket. All patients will receive usual physiotherapy sessions to help them use their prosthesis. We will ask patients to rate their socket comfort and experience of having the socket fitted. We will compare number of clinic visits, manufacturing time and time to receipt of socket/prosthesis. We will ask patients about their experience with the remouldable vs. usual socket, and ask healthcare professionals about their experience of both sockets. Timeline Months(M) Pre-M3: Study set-up, ethics, contracts & approvals M3-6: Site set-up, clinician training M5-16: Patient recruitment and randomisation M6-21: Socket fitting, all assessments M11-15: Patient/clinician interviews M21-24: Data analysis M23-24: Final report and engagement event Anticipated impact and dissemination This will be the first clinical trial investigating a remouldable socket system. We will involve PPI advisors in our project management and dissemination. Our findings will inform the feasibility of a future definitive trial to assess clinical- and cost-effectiveness of the remouldable socket, to aid future decision-making for prosthetics. We will disseminate to stakeholders through academic publications and presentations. Our patient advisory group will share the findings with prosthesis users and charities via an engagement event. If acceptable, the remouldable socket could increase patient satisfaction by reducing waiting times for a socket/prosthesis and number of prosthetics appointments, presenting value-for-money for the NHS.