Development of 3D-Printed Orthopedic Insoles for Patients with Diabetes and Evaluation with Electronic Pressure Sensors

Abstract

The correct distribution of loads on foot, known as plantar pressures, is a relevant parameter for evaluating the evolution of some diseases. Anomalies can lead to pain and discomfort in other body parts. Diabetes changes foot tissues and compromises biomechanics, resulting in ulcers and, eventually, amputation. Customized insoles allow the redistribution of plantar pressures and are a complementary strategy to diabetes management. Nowadays, scanning and 3D printing technology can generate faster and more accurate customized insoles opening new opportunities for local medical device development. This study reports the development of 3D-printed insoles using two polymers, thermoplastic polyether-polyurethane and thermoplastic polyurethane polyester-based polymer, and the evaluation of plantar pressure distribution in walk trials using a clinical protocol and low-cost electronic system. The two 3D-printed insoles performed as well as a standard insole. No significant difference was found in average peak pressure distribution. The digital manufacturing workflow of customized insoles can be implemented in middle-income countries. Three-dimensionally printed insoles have the potential for diabetes management, and further material evaluations are needed before using them in health facilities.

3D printing and bioprinting in the battle against diabetes and its chronic complications

“…Foot insoles are used in relieving pains (especially site-specific pains) in persons hailing diabetic foot complications. Plantar pressures (or distribution of loads on foot) in diabetic patients act as one of the important parameters in evaluating the progression of diabetes ( Zuniga et al, 2022 ). Custom insoles, also referred to as “Standard of Care (SoC) insoles” are well-known for its use in dealing with diabetic foot plantar pressures.…”

“…In the past few days, integration of 3D printing, scanning, materials chemistry and software application have been highly beneficial in fine-tuning the procedure of insole fabrication process and in enhancing the performance of insoles as well ( Zuniga et al, 2022 ; Mancuso et al, 2023 ). For instance, Zuniga et al (2022) developed 3D-printed insoles employing the thermoplastic polyether-polyurethane and thermoplastic polyurethane polyester-based polymer for diabetic patients and evaluated its efficiency in plantar pressure distribution with electronic pressure sensors ( Zuniga et al, 2022 ). The insoles were found to perform well and were reported to possess potential in managing diabetes.…”

Biomechanical Evaluation of Plantar Pressure Distribution towards a Customized 3D Orthotic Device: A Methodological Case Study through a Finite Element Analysis Approach

“…The foot silhouette was sketched from the impression taken to generate the insole contour (Figure 6b). The 3D biomodel was placed right above the insole, using Boolean operations and working with surfaces to create a customized insole based on parametric designs set by specialized insole design software [44][45][46][47]. Working with surface modeling for the insole design allowed certain regions to be smoothed and the orthosis to be adjusted to foot morphology (Figure 6c).…”

3D Printed customized diabetic foot insoles with architecture designed lattice structures – a case study

“…Recent studies have investigated the effectiveness of 3D-printed insoles in managing foot ulcers, flat feet, high-arched feet, leg length discrepancies, and diabetic foot conditions. Zuñiga et al [16] demonstrated comparable pressure distribution between 3D-printed and standard insoles. Another research reported improved foot function and comfort with 3D-printed insoles in individuals with flat feet [17].…”