A Multicenter, Superiority Randomized Controlled Trial of Three Interventions for Patients With a Progressive Collapsing Foot Deformity

Background Progressive collapsing foot deformity (PCFD) is a painful musculoskeletal disorder leading to a progressively developing flat foot, which affects mobility and function and negatively impairs quality of life. Foot orthoses (FOs) are often prescribed to attenuate pain and improve function in patients with PCFD. However, no study has yet investigated the impact of adding FOs, whether custom (CFOs) or prefabricated (PFOs), to the usual treatment for PCFD. Thus, the primary objective of this trial will be to compare three different non-surgical interventions combining foot exercises and education with either CFOs, PFOs or sham FOs (SFOs).

Methods/Design This participant-blinded multicentric superiority randomized controlled trial with three parallel groups will be conducted at the Université du Québec à Trois Rivières (UQTR) and the Center for Interdisciplinary Research in Rehabilitation and Social Integration (Cirris) in Canada. One hundred and ninety-eight participants with PCFD will be recruited via referral from physiotherapy and podiatry clinics and targeted advertising on social media. Participants will be randomized to receive CFOs, PFOs or SFOs. All groups will also receive a foot and ankle exercises program and education about their condition. They will be evaluated at four time points: baseline, 12 weeks, 24 weeks and 52 weeks. The primary outcome will be the subcategories of pain from the Foot Function Index (FFI) questionnaire. The secondary outcomes will be: foot pain and limitations (other categories of FFI, mean and maximal pain during walking for the most painful foot during the past week), self-assessed clinical progress (Global Rating Of Change), health-related quality of life (5-Level EQ-5D), gait biomechanics, fear avoidance (Fear avoidance Scale), supination resistance and ankle and hip endurance and force.

Discussion This trial first aims to determine whether FOs treatment is effective, and second, whether one of the three FO interventions is more effective than the others. This trial will help guide FOs prescription recommendations for managing foot pain, function, and biomechanical outcomes in individuals with PCFD in the future.