Evaluation of Additive Manufacture in the Production of Orthotic Insoles
Condition: Diabetes
Study type: Interventional

Summary: 
      This study will assess the ability of different orthotic insole treatments to reduce pressure
      under the ball of the foot. This is important for people who have diabetes because their feet
      are at higher risk of foot problems in this area. This study will involve the participants
      wearing a a range of insoles produced by milling, handmade processes and additive manufacture
      along with normal orthotic footwear. A researcher will measure the pressures under the feet
      while the participants walk wearing the orthotic insoles.
    

Detailed description: 
      The study is divided into multiple appointments over which the investigators assess the
      performance of the orthotic insoles the participants are using.

      Screening Appointment (1 hour): The participants will be asked to come to the orthotics
      department at the Royal Blackburn Hospital. A clinician will perform a routine clinical foot
      assessment, which will include taking photographs of the feet, to ensure it is safe for the
      participants to participate in the study. If the participants are not eligible they will not
      be able to participate in the study, this will not affect the participants normal orthotic
      care. If the participants are eligible, information on the shape of their feet will be taken
      using a 3D foot scanner to allow the investigators to produce suitable insoles.

      Supply Appointment (1 hour): When the insole is ready the participants will come in for a
      supply appointment the investigators will check that the insoles and shoes the participants
      will receive are the correct shape, design and are suitable to wear. At this appointment the
      investigators will measure the pressure under the feet whilst walking wearing the insoles to
      check the insole is working correctly. This is done using a thin layer of flexible sensors
      which go into the participants shoes. The participants will then receive insoles to take home
      and wear as normal.

      After the participants have been supplied with orthotic insoles, a member of the National
      Health Service (NHS) clinical team will contact them by telephone. This will be each week for
      the first 4 weeks and then once a month until six months. The call will last no more than 15
      minutes and the participants will be asked about their general health, the NHS foot care
      services they may have used and about the orthotic insoles. In addition at 3 and 6 months
      after the participants received their orthotic insoles they will be asked to come back into
      the clinic for a review appointment which will take approximately 1 hour. At these
      appointments the investigators will measure the pressure under their feet again, using a thin
      layer of flexible sensors that go into the participants shoes on top of the orthotic insole.

      The investigators will also be asking some participants if they would be willing to take part
      in focus group discussions which will allow more detailed questions to be asked about the
      participants experiences wearing the orthotic insoles. The participants can decide whether to
      be involved in these independent of the primary trial. These will be held at the Royal
      Blackburn Hospital.
    

Intervention name(s): Additive Manufactured Orthotic Device; Moulded orthotic; Milled orthotic
Intervention type(s): Device; Device; Device
Intervention description(s): The 3D foot scan data will be used to generate a 3D model of the foot orthotic which will then be adapted to be suitable for solid printing. The final model will be saved in .stl format for use in the printing software. The additive manufactured orthotic insoles and all features or additions will be produced in a single build from additive materials matched for hardness to medium density EVA. Post production the orthotic will be cleaned to remove support material and a top cover will be attached to the final additive manufactured orthotic insole.; The foam impression box and prescription will be sent to an external company for production of the handmade moulded orthotics. Handmade moulded orthotics will be produced by heating and wrapping medium density Ethylene-vinyl acetate (EVA) around plaster casts of the impression boxes. The orthotic insoles may be manually adapted to meet the requirements of the prescription, this could include cut out sections designed to offload regions of the foot or the addition of features such as metatarsal bars which provide varied support. Features and additions will be added in post manually by cutting and gluing onto the moulded orthotic insole. A top cover will be attached to the final moulded orthotic insole.; The 3D foot scan data will be used to generate a 3D model of the foot orthotic. This will then be saved in .pan format for use in a CNC milling software. Orthotics and all features will be milled in a single mill from a block of medium density EVA. Post milling the orthotics will be cleaned. The orthotic insoles may be manually adapted to meet the requirements of the prescription, this could include cut out sections designed to offload regions of the foot or the addition of features such as metatarsal bars which provide varied support. Features and additions will be added in post manually by cutting and gluing onto the milled orthotic insole. A top cover will be attached to the final milled orthotic insole.
Allocation: Non-Randomized
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Additive Manufacture; Orthotic Insole