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

Summary

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.

Conditions

• Progressive Collapsing Foot Deformity

Interventions

OTHER

Customized foot orthoses

Individually customized bilateral 3D-printed foot orthoses will be designed from each participant's foot morphology and manufactured at UQTR using a Nylon-11 (PA11) shell. Orthoses will incorporate a 6° medially wedged forefoot-rearfoot post and a 6-mm medial heel skive to provide individualized mechanical support. Participants will wear the orthoses during weight-bearing activities for 24 weeks.

OTHER

Exercise

Participants will complete a progressive home-based strengthening program targeting the tibialis posterior, tibialis anterior, and triceps surae muscles. The program will consist of six progressive levels prescribed by a podiatrist according to the participant's baseline clinical presentation. Exercise sessions will last approximately 30 minutes and will be performed at least four times per week for 12 weeks. Progression to the next level will occur after successful completion of four sets of 20 repetitions at the current level.

OTHER

Podiatric Education

All participants will receive the same evidence-based information and clinical guidance at the start of the trial, and will follow a 7-day familiarization protocol with progressive FO wear time, starting at 1 hour per day and increasing by 1 hour daily up to 5 hours per day. Following familiarization, participants will be instructed to wear their assigned FOs during all standing activities, targeting a minimum of 5 hours per day, for the 24-week intervention period. FO-wearing instructions, the exercise program, and study information will be available at any time on the study website : "projetpied.com".

OTHER

Sham foot orthoses

Participants will receive bilateral 3D-printed sham foot orthoses manufactured from low-stiffness FilaForm material. The sham orthoses will have an appearance similar to the customized orthoses but will provide negligible mechanical support, thereby maintaining participant blinding. Participants will wear the orthoses during weight-bearing activities for 24 weeks.

OTHER

Prefabricated foot orthoses

A pair of commercially available PFOs (Powerstep Pinnacle Maxx support, United States of America), in the proper size, will be provided to each participant. The top cover will be made of a polyester fabric. The structural arch support will consist of a polypropylene shell incorporating a 2° medial post. A dual-layer system composed of a black foam top layer and a black ethylene-vinyl acetate (EVA) base layer will also be included (Figure 2). An additional 1 mm black vinyl surface layer will be manually added to the PFOs to keep participants blinded to the condition they are allocated to.

Sponsors & Collaborators

• Canadian Institutes of Health Research (CIHR)

  collaborator OTHER_GOV

• Université du Québec à Trois-Rivières

  lead OTHER

Principal Investigators

• Tessiot Léa · Université du Québec à Trois-Rivières

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

70 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2027-01-01

Primary Completion

2029-01-01

Completion

2030-12-01

Countries

• Canada

Study Locations