Improving Offloading in Diabetic Feet: 3D-Printed Custom Accommodative Insoles Outperform Standard of Care

Abstract Objective 3D-printed custom accommodative insoles may offer improved plantar pressure offloading compared to standard-of-care insoles for individuals with diabetes. We have developed two versions of 3D-printed accommodative insoles that have patient-specific geometries as well as patient-specific stiffnesses and structural behaviors. This study evaluated two 3D-printed custom accommodative insoles against standard-of-care and no insole. Research Design and Methods This in-laboratory clinical trial enrolled 25 adults with diabetes and high plantar pressure. Participants completed over-ground walking trials under the following conditions: no insole, standard-of-care insoles, pressure-based insoles, and finite element insoles. Peak plantar pressure and pressure-time integral were measured in high-risk regions of interest and adjacent regions. Participant comfort and preference were recorded. Results All insoles significantly reduced peak pressure and pressure-time integral in the regions of interest compared to no insole (p<0.001) by greater than 14%. Both pressure-based and finite element insoles further reduced peak pressure (22% and 24% respectively) and pressure-time integral (19% and 35% respectively) beyond standard-of-care (p<0.001). Finite element insoles reduced pressure-time integral and peak pressure in adjacent regions (p<0.01), indicating broader offloading. While finite element insoles demonstrated strong biomechanical performance, participant preferences and feedback indicated improvements in fit and comfort are needed across all insoles before clinical implementation. Conclusions This study demonstrates the potential of personalized, 3D-printed custom accommodative insoles as a patient-centered approach to offloading plantar pressure in individuals with diabetes. These technologies may support more effective and tailored strategies in preventing diabetic foot complications. Further research will assess long-term outcomes and optimize comfort and fit. Highlights Why did we undertake this study? Individuals with diabetes and high plantar pressure are at risk for foot complications, and current insoles may not provide sufficient pressure relief. What is the specific question(s) we wanted to answer? Can two types of 3D-printed custom accommodative insoles—pressure-based and finite element designs—provide superior plantar pressure offloading compared to standard-of-care and no insole conditions? What did we find? Both 3D-printed insole types significantly outperformed standard-of-care insoles in reducing peak plantar pressure and pressure-time integral in the region of interest. Finite element designs also reduced pressure in adjacent regions. What are the implications of our findings? Personalized 3D-printed insoles may improve diabetic foot care by offering targeted offloading. Optimizing fit and comfort is needed before broader clinical use.