Feasibility study of an orthosis for treatment of a Clubfoot

An idiopathic clubfoot - or congenital talipes equinovarus - is a congenital
deformation of the foot. Approximately 1 per 1000 children are born with a
unilateral or bilateral clubfoot, which makes it one of the most common
congenital deformities. In the Netherlands every year approximately 190
children are born with a clubfoot (Besselaar et al. 2018). Its incidence is
higher in boys than in girls and in about half of the cases it is bilateral
(both feet are affected). Sex and laterality do not influence the severity of
the deformity (Zionts et al., 2017). Clubfeet are commonly treated with serial
casting, named the Ponseti method (Ponseti, 2008; Ponseti et al., 1963). The
Ponseti method is worldwide accepted as the golden standard for the treatment
of a clubfoot (Hennessey, 2012). In this method, the clubfoot is weekly
manipulated and fixated in a slightly more corrected position using a plaster
cast. The cast is typically changed every week for approximately 4 to 6 weeks.
In many cases a percutaneous Achilles tenotomy is done after casting for the
final clubfoot correction. An abduction brace is worn for several years to
prevent any relapse (Dobbs et al., 2004).

Although the Ponseti method is highly effective in the treatment of clubfoot,
there are many clues indicating that the Ponseti method is in need of a
correction. The plaster cast of the Ponseti method prevents bathing, gets in
the way with diaper changes, interferes with cuddling. Additionally, the cast
appears to cool the child*s feet (Giesberts et al., 2018) and to provoke
judgement from people suggesting physical abuse. Its position-controlled
approach is likely to be inefficient. Experiments, in which the cast is changed
more frequently in an attempt to minimize the treatment duration (e.g. Harnett,
Freeman, Harrison, Brown, & Beckles, 2011) showed the same positive result
without any negative consequence. In our experience these issues are unknown to
most treating physicians and easily dismissed. Several studies have indicated
the need for medical professionals to acknowledge that the Ponseti method
causes increased stress for the families (Malagelada et al., 2016; Nogueira et
al., 2013). For some caregivers these issues are real and require a solution.

Our hypothesis is that the clubfoot treatment can be improved by the use of a
dynamic clubfoot brace that is based on a force-controlled approach instead of
a position-controlled approach, because it will accelerate the correction
process, making it a more efficient treatment option and making the treatment
more user-friendly. Moreover, the number of hospital visits will be reduced
from at least 7 to 2.

Primary Objective
The primary objective of this study is to examine the feasibility of using the
clubfoot brace. This will be done by recording the effect of the brace on the
clubfoot deformity by determining the improvement of the Dimeglio and Pirani
score progress during three stages:
• First stage: at the start and after two hours
• Second stage: at the start and after one week
• Third stage: at the start and end of the treatment (before an Achilles
Tenotomy is performed)
The time for full correction is also part of the feasibility, because we aim at
an accelerated correction process.
In addition, the caregivers will fill out a log to record when they remove the
clubfoot brace, and which problems they experience with the brace during use
and while taking it on and off. Other experiences with the clubfoot brace such
as malfunction or a part breaking while using the brace are documented in the
log during the study period as well.

Secondary Objective
The secondary objective of this study is to evaluate physical complications the
baby and the caregivers experience using the brace. The caregivers will fill
out a log to record, which physical problems the clubfoot brace cause such as
skin problems or pain.

Observational pilot study.

Duration:
From 19 September 2022 to 19 April 2024

A brace was realized that can treat a clubfoot and can be removed temporarily
for diaper change or a bath. The force applied on the foot by the brace should
be enough to correct the deformations of the foot, targeting all four aspects
of deformity similarly to how it is done with the Ponseti method.
The brace will be fixed to the leg via two adaptable straps (to account for
different sizes and growth), one around the thigh and one below the knee.
The brace is in contact with the foot and apply force only in two locations:
the Talar Neck (TN) and the First Metatarsal (FM), the same locations used in
the Ponseti method. Two polymer spiral structures with spring-like behaviour
will generate the force on the TN and FM and the lower leg. Each spiral spring
initial position matches the foot in the normal, corrected position. Therefore,
when a spiral spring is stretched to fit the deformed foot, it will generate
forces to return to the initial position. The correction will be done in two
stages, again according to the Ponseti protocol. The first stage will use
spiral spring 1 to correct the cavus deformity. The second stage will use
spiral spring 2 that corrects the adductus and varus deformity.

The burden for patients involves wearing the brace. Furthermore patients have
to visit the hospital twice a week for check-up. During a three week
intervention period a log should be kept daily to monitor the use of the brace.
The major risk while using the brace is that the clubfoot is not corrected due
to the change in position of the brace on the foot. The major benefit may be
the improvement of the clubfoot treatment compared with the Ponseti method in
terms of duration of the treatment, limited number of visits to the hospital,
increased comfort for the baby and the parents and the absence of the parents
being accused of child abuse.