Feasibility Study on Using Smart Templates, That Link Rectification Approaches to Particular Patient Characteristics, for Socket Fitting

A well-fitting, comfortable prosthetic socket is an urgent priority for the 170 million people worldwide with amputation as it stops people being able to achieve their goals and participate in society. For clinics providing sockets, there is an increasing demand for prosthetic limbs, increasing costs and a shortage of prosthetists (the people who fit the limbs to the patients). The prosthetic socket connects a person's remaining limb with the rest of the prosthetic limb. When a prosthetic socket does not fit properly, it causes skin irritation, blistering and in the worst cases, ulcers. It will also lead to patients avoiding prosthetic use altogether or repeat clinic visits. These sockets are complicated to design due to differences in patient limb shape, skin properties and ability to tolerate pressure. Therefore, there is a need to support prosthetists to achieve the best socket fit they can for the patient, quicker, and with fewer complications that can lead to patients not wanting to wear their prosthetic limb.

Socket design involves a process called rectification which aims to optimise comfort, stability and mobility for the prosthesis user. To achieve this, the prosthetist will remove material or add material to shape the final socket design. Rectification is a very complicated problem; yet there is currently little guidance or evidence to support the process. This leaves the socket dependent upon the skill and experience of the individual prosthetist, who require years of training and experience. Even then getting an optimal socket fit can take up to 9 clinic visits.

The development of evidence-based socket design to improve socket fit is a primary objective of the International Society for Prosthetics & Orthotics. Critical to this is the ability to use information about past socket designs to learn from and increase understanding of the socket design process. This need goes back many decades, with Klasson asking the following questions in 1982 which are still unsolved today:

• What is a good fit?
• What information is necessary to achieve a good fit?
• Which processing of the information is necessary to arrive at a good fit?

Since 2014, University of Southampton researchers have developed technology to meet the patient and clinic need, guided by input from prosthetics providers including Opcare, and patients. This work has so far resulted in world-leading research on analysing shape and optimising socket design and the spin out of a company (Radii Devices). As part of a collaboration with Opcare, in November 2019, a study was carried out to assess the current socket design software, understand current practice and how socket design could be supported. Five prosthetists of varying experience were recruited and key areas in which computer software can be improved were identified, including: