Evaluating user satisfaction and feasibility of a remote-digital model for 3D scanning and printing of....

Year Submitted: 2025
Published Date: 08 December 2025

Tags: Care Process ＆ Redesign, Productivity, Technology, Medtech, Workforce Transformation, Upskilling, Job Redesign, Access To Care, Waiting Time, Assistive Technology, Product Development, Product Evaluation

About this Content

Aims

This project aims to address variations in Singapores Prosthetics and Orthotics (P&O) services for access to care, access to digital solutions, and costs through pioneering a remote-digital method of 3D-scanning, 3D-design rendering and 3D-printing of prosthetic sockets for transtibial amputee patients. Through the adoption of digital and additive manufacturing technologies, the project aims to improve productivity and make current prosthetic manufacturing processes leaner in order for amputee patients to receive good quality, well-fitting prostheses earlier as part of the national Hub-and-Spoke model of P&O service delivery.

The project aims to evaluate the user satisfaction and repeatability of clinical outcomes of transtibial prosthetic sockets manufactured through a remote-digital method as compared to conventional production methods, and assess its feasibility and scalability for national care delivery. The secondary aims of the project are the upskilling of support staff to perform patient-fronting roles for remote 3D-scanning and digital measurement of prosthetic sockets.

Background

The demand for Prosthetics & Orthotics (P&O) services in Singapore is projected to grow given global trends of an ageing population and increased incidence of diabetes-related lower limb amputations. Persons with major lower limb amputations rely on a prosthesis for ambulation. The prosthetic socket is the key interface connecting the limb residuum (stump) to the rest of the prosthesis and must transmit forces from the residuum to the ground in a safe and efficient manner. A well-fitting socket is valued by both amputees and clinicians to be the major determinant of comfort and successful rehabilitation outcomes.

The P&O Service at Tan Tock Seng Hospital (TTSH) supports nationwide service provision of customised prostheses under the Hub & Spoke model. In this model, clinical-fronting services are decentralised to Spoke units across other Restructured Hospitals, with a centralised manufacturing Hub at TTSH. Conventional socket manufacturing processes are complex and require a large amount of man hours and highly specialised clinical and technical skill sets. There is no cross-work or job-sharing between P&Os, with Spoke P&Os travelling to the Hub to perform their own plaster cast modifications and bench alignments. The eventual fitting outcome is highly dependent on the skill and experience level of individual clinicians.

3D printed prostheses produced from measurements or digital scans have been proposed as a clinically and cost-effective alternative to address current gaps in practice. However, there is little research on the clinical feasibility and cost effectiveness of such production methods, and of patients perceptions of P&O devices produced using these methods compared to conventionally manufactured ones.

The primary objectives of this research are to evaluate the repeatability of clinical outcomes, user satisfaction and the time and cost-effectiveness of a cross-setting, remote-digital production method for 3D printed transtibial prosthetic

Methods

A 2 period cross-over study was conducted between February 2022 and January 2023 in a multi-centre outpatient setting at the P&O Services of TTSH and KTPH. 16 unilateral transtibial amputee patients of the Services, who are current users of a roll-on silicone liner prosthetic system, and were minimally capable of community ambulation, were recruited through consecutive sampling. Subjects received the laminate and 3D printed prosthetic sockets and used each socket for 4 weeks. The order of socket use was determined through block randomisation using a computerised system.

Subjects attended a session at their respective P&O clinics where they were measured for both socket designs. In the conventional method, a trained P&O plaster casted the subjects residuum. The P&O rectified the plaster cast which was then sent to the Hub for fabrication of a laminate socket. In the remote-digital method, a P&O Technician scanned the subjects residuum through optical imaging using a handheld 3D body scanner (Occipital Structure Scanner PRO). The scan was sent digitally for a different P&O, who had not seen the patient during the measurement session, to rectify using the industry collaborators purpose-built CAD software (Pandofit, ProsFit Technologies JSC). The digital socket design was then exported for 3D printing through Multi Jet Fusion (MJF), and shipped back to the clinic for assembly.

Subjects were fitted with and asked to rate the initial comfort of each socket using the Socket Comfort Score (SCS). At 2 and 4 weeks post-fitting, subjects returned to the centres for follow-up and adjustments of the sockets. All fittings and adjustments to the prosthesis were carried out by the P&O who casted the patient. After 4 weeks, the prosthesis-specific question set of the Prosthesis Evaluation Questionnaire (PEQ) and the SCS were administered. The other socket design was fitted and the process repeated. On completion of the study, subjects were asked to choose which socket des

Results

15 of 16 subjects completed study procedures. 9 subjects indicated a final preference for the 3D printed socket. Reasons cited that influenced final socket preference included socket appearance, preference for an intimate socket fit, and novelty of the technology used. There were no significant differences in the types and incidence of adverse events for either socket design. There were no significant differences in mean scores for the 3D printed vs laminate sockets for all PEQ subscales of Appearance (p=0.70), Residual Limb Health (p=0.37), Sounds (p=0.78), Utility (p=0.30), and Satisfaction (p=0.18). Nil statistically significant differences were noted in initial SCS for 3D printed (Mean = 7.22) vs laminate sockets (Mean = 7.53). There was a non-significant decrease of 0.77 points (p=0.3) in SCS after 4 weeks of socket use for both socket types.

There was a 2.9-fold reduction in total man hours required to produce and fit a standard transtibial prosthesis with the remote-digital method as compared to the conventional method. Reductions in both P&O (p=0.17) and Technician time (p0.01) were obtained. Significant savings in Technician time were obtained through outsourcing the physical manufacturing processes of plaster cast processing, lamination and finishing for 3D printing. The remote-digital method resulted in cost savings on manpower and equipment as compared to the conventional method.

Conclusion

3D printed transtibial sockets produced through the remote-digital method were perceived by amputees in Singapore to be comparable in clinical outcomes to laminate sockets produced through conventional methods. The concept of a remote-digital prosthetic production method to support the Hub & Spoke model of P&O service delivery in Singapore appears to be a feasible one. More work needs to be done to keep operating costs of using digital technologies low to ensure that these digital production methods remain cost-effective for both the healthcare system and the patients, in order to increase scalability and long-term sustainability.

Lessons Learnt

Overall user satisfaction with a prosthesis is a composite score that is influenced by factors such as effects on Residual Limb Health, function (Utility), form (Appearance, Sounds), and comfort. No significant differences were noted in overall user satisfaction between both socket types and across all PEQ subscales, and in self-reported comfort scores between both socket types. 3D printed transtibial sockets produced through the remote-digital method appear to be as repeatable and effective as sockets produced through conventional methods.

User perceptions influencing the acceptance of prosthetic interventions may be better measured through qualitative rather than quantitative means. In addition to physical or medical eligibility criteria, gathering patient feedback on prosthetic intervention should form a key part of clinicians assessment and treatment process. Qualitative feedback obtained from participants in this study indicate that non-clinical factors such as cultural differences and personality have some influence on user perceptions and patient acceptance of clinical interventions. Such factors should be taken into account when administering clinical interventions.

This study underscores the importance of evaluating the time and cost-effectiveness of novel clinical interventions in addition to the clinical efficacy of the proposed intervention. Although the 3D printed sockets produced via the remote digital method were comparable in terms of clinical effectiveness to laminate sockets produced through conventional means, and statistically significant time savings were obtained for both P&Os and Technicians, more research needs to be done to look at the operating costs, such as licence fees and freight, of such services to ensure scalability and sustainability beyond the departmental or institutional level. Clinicians and administrators involved in the evaluation and roll out of new clinical services should take into account all stages in the end-to-end

Additional Information

This project is funded by the Centre for Allied Health & Pharmacy Excellence (CAPE).

Keywords

Amputation, 3D Printing, Prosthetic Socket, Prosthetics and Orthotics, User Satisfaction

Innovators' Details

Connect with this contributor!

Tabitha Quake Zhi Hui - tabitha.zh.quake@nhghealth.com.sg

Project Attachment

939_TTSH, KTPH_CAPE FY21_Evaluating user satisafaction & feasibility of a remote-digital model for 3D scanning.pdf