Efficacy of arch contouring foot orthoses for midfoot osteoarthritis: Protocol for a randomised controlled trial

Introduction Midfoot osteoarthritis (OA) is a painful and disabling condition. Arch contouring foot orthoses have been recommended for midfoot OA, yet there is no high‐quality evidence from randomised controlled trials to support their use. This clinical trial aims to evaluate the efficacy of arch contouring foot orthoses for midfoot OA. Methods This will be a parallel‐group randomised controlled superiority trial. One‐hundred and forty community‐dwelling people with painful midfoot OA will be randomised to receive either arch contouring foot orthoses or flat sham inserts. Outcome measures will be obtained at baseline, 4, 8 and 12 weeks; the primary endpoint for assessing efficacy being 12 weeks. The primary outcome measure will be average midfoot pain whilst walking over the last 7 days on an 11‐point numerical rating scale. Secondary outcome measures include function (walking/standing subscale of the Manchester–Oxford Foot Questionnaire), participants' perception of overall treatment effect (self‐reported global rating of change on a 15‐point Likert scale), physical activity (Incidental and Planned Exercise Questionnaire), general health‐related quality of life (Short Form‐12 Version® 2.0), use of co‐interventions and adverse events. Discussion This trial will evaluate the efficacy of arch contouring foot orthoses for relieving pain and improving function, physical activity and health‐related quality of life in people with midfoot OA. The findings will provide high‐quality evidence as to whether arch contouring foot orthoses are efficacious and will help to inform clinical guidelines about the use of foot orthoses for midfoot OA. Trial registration Australian and New Zealand Clinical Trial Registry (ACTRN12623000953639).