TECHNICAL NOTE Design and Construction of a New Partial Foot Prosthesis Based on High-Pressure Points in a Patient with Diabetes with Transmetatarsal Amputation: A Technical Note Fatemeh Zarezadeh, PhD, Mokhtar Arazpour, PhD, Mahmood Bahramizadeh, PhD, Mohammad Ali Mardani, PhD, John Head, PhD ABSTRACT INTRODUCTION: Diabetic foot ulcers are significant complications of diabetes that can lead to amputation. Partial foot pros- theses can be used to redistribute the plantar pressure on the residual limb to alleviate local pressures. The aim of this study was to describe the fabrication of an original silicone foot prosthesis that provided an improved functional outcome for a patient with a transmetatarsal amputation due to diabetes. METHODS: High-pressure areas on the foot were identified using Force-Sensing Resistor sensors. During prosthetic fabrica- tion, silicone with low shore was injected in these areas. Different silicone stiffness was used to reduce pressure accordingly. The silicone injection was achieved in two stages, using cast formers and wax. DISCUSSION: The bespoke method of fabrication used in this study and the use of various levels of silicone stiffness provided a highly cosmetic prosthesis that offered improved pressure distribution. (J Prosthet Orthot. 2018;30:00–00) KEY INDEXING TERMS: diabetic foot, partial foot amputation, silicone foot prosthesis C hronic foot ulcers are one of the most serious complica- tions for people with diabetes. 1,2 A history of a previous lower-limb amputation increases the risk for further ulcer- ation, infection, and subsequent amputation because of abnormal distribution of plantar pressures and altered bone structure. 3,4 Effective distribution of pressure, with reduced peak plantar pressure during walking, can help to prevent injury. 5–7 The ideal partial foot prosthesis for individuals with diabetes should there- fore be able to distribute the loads generated during ambulation over the largest possible area of the residual limb, thereby preventing the creation of localized pressure points. 8 Partial foot amputa- tion prostheses can be divided into two categories: high-profile designs that extend onto the tibia up and low-profile devices that terminate inferior to the malleolus. 9 It seems that many individuals with partial foot amputations prefer to use the low- profile prostheses, specifically, flexible and semiflexible designs. Silicone prostheses that are flexible devices have a full-contact fitting on the residual limb. Silicone is an elastic material that can be used effectively within flexible foot prosthetic devices. Sili- cone gel has many positive properties, including proper distri- bution of stress with nonstress concentration, and it maintains original structure during the continued usage. A review of relevant literature has suggested that, up to this point, silicone partial foot prostheses have predominantly used a consistent and equal level of material stiffness throughout their design and structure. 10–12 Studies also suggest that there is a significant increase in acute levels of plantar pressure in the residual limb after partial foot amputations during ambula- tion. 7,13,14 Changing the levels of pressure and redistributing them more effectively to reduce high concentrations of pressure would therefore seem to be beneficial to prosthesis users and could help to prevent repeat amputation. Given the current state of knowledge, the aim of this study was to manufacture an original prosthetic design for partial foot amputation using a silicone- based material with various levels of stiffness matched accordingly to each respective area of the residual limb. This could help to reduce pressures in potentially high-pressure areas and help to provide more pressure in appropriate tolerant areas that could maintain and enhance safe, normal usage, and function. METHODS SUBJECT The patient was a 56-year-old woman who had diabetic transmetatarsal amputation 4 years ago. She was referred to FATEMEH ZAREZADEH, PhD, MOKHTAR ARAZPOUR, PhD, MAHMOOD BAHRAMIZADEH, PhD, AND MOHAMMAD ALI MARDANI, PhD, are affil- iated with the Orthotics and Prosthetics Department, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran. MOKHTAR ARAZPOUR, PhD, is affiliated with the Pediatric Neurorehabilitation Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran. JOHN HEAD, PhD, is affiliated with the Prosthetics and Orthotics School of Health Sciences PO47, Brian University of Salford, United Kingdom. Disclosure: The authors declare no conflict of interest. Copyright © 2018 American Academy of Orthotists and Prosthetists. Correspondence to: Mohammad Ali Mardani, PhD, Department of Orthotics and Prosthetics, University of Social Welfare and Rehabilitation Sciences, Kodakyar Street, Daneshjo Boulevard, Evin, Tehran 1985713834, Iran; email: natelnoory@yahoo.com Volume 30 • Number 2 • 2018 1 Copyright © 2018 by the American Academy of Orthotists and Prosthetists. Unauthorized reproduction of this article is prohibited.