MiracleFeet Foot Abduction Brace Sensor Trial (mFAB)

Efficacy of a New Design of Foot Abduction Brace (FAB) Compared to Standard FAB During Ponseti Treatment of Idiopathic Clubfoot by Measuring Rate of Recurrence and Compliance Using Novel Touch Sensors

Bai Jerbai Wadia Hospital for Children, Mumbai, India, Metwiz Materials, CURE, Biomedical Engineering and Technology (Incubation) Center, Bombay

The aim of this study is to determine the effect of a new design of FAB type on compliance and treatment outcomes of idiopathic clubfeet treated by the Ponseti method. Very little literature exists on the effect of brace type or the difference between reported and actual at-home compliance, which is integral to the success of treatment with the Ponseti method. Eighty children less than 1 year of age will be enrolled in the study into two arms, using block randomization. These two groups will use two different designs of foot abduction brace (FAB). Outcomes will be measured by number of recurrences per group (using recasting and/or surgical procedures and Pirani score as indicators), time of recurrences (in months), compliance with brace wear using sensors and comparing the data with brace wear reported by parents, and parent satisfaction with FAB (measured on a modified Orthotics and Prosthetics User Sur vey). Enrollment will be on a rolling basis; subjects will be enrolled at their last cast application and followed for approximately 6 months. Recurrences, time of recurrence, parent satisfaction, and reported vs. actual compliance will be analyzed.

Clubfoot is the most common birth defect affecting 1 in every 750 live births, that is about 200,000 babies each year globally (80% mainly in developing countries). An estimated average 1 million children are currently living with untreated clubfoot. In India every 10 minutes a child is born with clubfoot i.e. over 50,000 children are born with this deformity every year (1 per 500 birth). The Ponseti Method is now recognized as the accepted standard for the medical treatment of clubfoot. The Ponseti Method is ideally suited for the developing world in that it is inexpensive, non-surgical and the casting component can be completed by trained medical and paramedical personnel. Clubfoot causes the feet of the affected individual to point downward and inward. Left untreated, clubfoot causes a permanent physical disability, preventing the individual from walking normally and limiting his or her mobility. Decreased ambulation can lead to the inability to perform daily tasks, such as going to school, leading to increased dependency and a negative economic impact on the family. Furthermore, deformity caused by neglected clubfoot can lead to limited social integration and stigma for both the individual and the family. The gold standard of clubfoot treatment is the Ponseti method, which consists of 6-8 weeks of serial castings followed by a percutaneous Tendo Achilles tenotomy in the majority of cases. The casting is followed by the use of a foot abduction brace (FAB) for approximately 4 years. The goal of the treatment is to correct the deformity so that the patient has a functional, painless, plantigrade foot with full mobility without the need for orthotics. The 6-8 weeks of serial casting corrects the clubfoot deformity while the use of the FAB after casting prevents the deformity from reoccurring and is required for successful treatment. Noncompliance of FAB use increases the risk of relapse 17-fold. Currently, the Steenbeek Foot Abduction Brace (SFAB), a version of the Denis Browne splint, is the only low-cost FAB available. The SFAB is made by hand by artisans, limiting its large-scale production. Furthermore, it can be challenging to put on a child due to the shoes being attached to the bar and lacking a strap in addition to laces, potentially leading to noncompliance. The more recently developed MiracleFeet Foot Abduction Brace (mFAB) is made of injection molded plastic, making it easy to mass produce, and includes removable shoes with a strap to hold the heel in place, claiming to be more comfortable and easier to use, leading to improved compliance. The MiracleFeet Foot Abduction Brace (mFAB) is a Denis Browne Splint used for the treatment of clubfoot. Use of the Denis Browne Split is standard in clubfoot treatment and the mFAB complies with the standards for foot abduction braces for clubfoot: Adjustable to 65 and 45 degrees to accommodate unilateral and bilateral clubfoot 10 degrees dorsiflexion The mFAB was designed with the following additional features, based on requests from parents and providers: Large window to view the heel, ensuring it lays flat in the shoe Dorsal strap to secure the heel, allowing the shoe to be tied with two hands Removable shoes so that the shoes may be applied and then clipped into the bar A flat bottom The bar is made of strong injection-modeled plastic, in order to be reused The shoes are meant to be worn only by 1 child and then discarded The mFAB shoes are made of canvas and polyester and the bar and shoe plates are made of ortholite and T90 and are manufactured using the injected-molded plastic process in Batavia, Illinois, USA. The mFAB has been tested in Nicaragua, Brazil, South Africa and the Philippines and is currently in use in 10 countries. Both braces meet the specifications as detailed by the Ponseti method and the same bracing protocol is used for both. This study will compare treatment outcomes and compliance using the two brace designs, SFAB and mFAB. We will compare the number and time of recurrences, as well as the reported compliance and actual compliance, which will be measured by novel sensors. Few studies exist that compare brace types or actual versus reported compliance and FABs with sensors are a novel technology. Of the literature that exists, FAB use was show to decline significantly during the first 3 months and actual wear is less than reported wear.

This will be a hospital-based study with single blinding of the investigator. Subjects will be randomized in order to prevent systematic differences between the groups to prevent bias. Our groups will be parallel, there will be no crossover. The two parallel groups will use two different versions of FABs; the Steenbeek Foot Abduction Brace (SFAB) and the MiracleFeet Foot Abduction Brace (mFAB). Both types of FAB will be equipped with discretely hidden sensors; subjects and their families will not be aware of the actual function of the sensor to avoid increased compliance due to the sensor. Due to practical constraints (the brace being visibly identifiable), the study will not be blind. This study will use number of recurrences in the two groups as the primary outcome of interest. Recurrence will be checked for at each scheduled follow-up visit (see schedule below) and recorded in event of occurrence. A process of rolling recruitment will be used until our groups are complete.

The study will follow the subject for 6 months after their enrollment, beginning at first FAB use. The Steenbeek Foot Abduction Brace (SFAB) is a fixed metal bar attached to two leather shoes with laces. The shoes have laces and a strap. The FABs provide 10 degrees of dorsiflexion and 45 or 65 degrees of abduction, and will be equipped with sensors to measure at-home FAB compliance. After the last cast is removed, a brace will be worn for 23 hours/day for the first 3 months and the time will be gradually decreased thereafter to a 'nights and naps' protocol for a total of 12 hours/day. At follow-up appointments the brace will be checked for fit and Pirani score recorded.

The study will follow the subject for 6 months after their enrollment, beginning at first FAB use. The MiracleFeet Foot Abduction Brace (mFAB) is an injected plastic molded bar with fabric shoes that clip off and on. The shoes have laces and a strap. Both FABs provide 10 degrees of dorsiflexion and 45 or 65 degrees of abduction, and will be equipped with sensors to measure at-home FAB compliance. After the last cast is removed, a brace will be worn for 23 hours/day for the first 3 months and the time will be gradually decreased thereafter to a 'nights and naps' protocol for a total of 12 hours/day. At follow-up appointments the brace will be checked for fit and Pirani score recorded.

The FAB will be equipped with discretely hidden sensors; subjects and their families will not be aware of the actual function of the sensor in order to avoid increased compliance due to the sensor. Sensors work on the principle of force-sensing resistor material whose resistance changes when a force or pressure is applied. Force-sensing resistors consist of a conductive polymer, which changes resistance in a predictable manner following application of force to its surface. On the top of braces sole we have fixed force resistive sensor (FSR), which changes resistance whenever force is applied. Threshold of detection is 30-40 gram. The changes of resistance is detected by using micro-controller.

Sensors in the mFAB will measure whether the shoe is on, the foot is in contact with the sole of the shoe and the shoes are clipped into the bar. Sensors work on the principle of force-sensing resistor material whose resistance changes when a force or pressure is applied. Force-sensing resistors consist of a conductive polymer, which changes resistance in a predictable manner following application of force to its surface. On the top of braces sole we have fixed force resistive sensor (FSR), which changes resistance whenever force is applied. Threshold of detection is 30-40 gram. The changes of resistance is detected by using micro-controller.

The Pirani score is a standardized tool measuring that severity of clubfoot deformity. It will be assessed at all visits - baseline, during treatment and follow-up - to evaluate gradual recurrence of clubfoot deformity.

Parent satisfaction with the FABs will be determined by administering an OPUS to them at each follow-up visit.

To measure at-home brace use compliance, the sensor data will be collected and compared to parent-reported brace usage. This will be tabulated in number of minutes the brace is used per day, collected at each follow-up visit.

Inclusion Criteria: Unilateral or bilateral cases of idiopathic clubfoot in children who have not yet started walking at first presentation, receiving a brace for the first time after successful correction with the Ponseti method of treatment, at the Bai Jerbai Wadia Hospital for Children over a period of 6 months. Exclusion Criteria: All children who are already walking at presentation; All children with previous treatment; All children who have used FAB previously; All children treated with surgery other than tenotomy; All children with syndromic or neuropathic cases of clubfoot; All children with atypical clubfoot.

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