Keywords
clubfoot - gait - congenital lower limb deformities - orthopedic manipulation - treatment
outcome
Introduction
Congenital clubfoot (PTC) is a complex malformation distal to the knee and associated
with hindfoot equinus deformity, forefoot cavus, subtalar varus and midfoot and forefoot
adduction deformities. The incidence of PTC is 1 in 1,000 live births, with a male
predominance at a 2:1 rate; bilateral involvement occurs in 50% of cases. Congenital
clubfoot is one of the most frequent birth defects in the lower limbs.[1]
[2]
[3]
[4]
The current gold standard treatment for PTC is the Ponseti method. It involves a series
of specific manipulations and plaster applications to correct deformity components.
Percutaneous calcaneus tenotomy is performed in up to 90% of cases to improve the
remaining equinus deformity and reach the final correction. After the foot is corrected,
an abduction orthosis is used to prevent deformity recurrence. This device is used
full time for 4 months and then part time (14 hours/day) until the child is at least
4 years old.[5]
[6]
[7]
[8]
Despite being a low morbidity method, during initial visits, it is common for parents
to express concern if the treatment or condition will affect the motor development
their child, more specifically independent gait. Recent studies have suggested that
walking may be delayed in children with PTC treated with the Ponseti method.[9]
[10]
[11] Zionts et al.[11] observed 94 patients with idiopathic clubfoot treated with the Ponseti method and
noted an average delay of 2.4 months in achieving independent walking compared to
healthy children from a multicenter study.[12] However, the reality of this population may be different from ours and we did not
find any paper in the Brazilian literature addressing this issue.
The present study aimed to determine the age at which children with idiopathic PTC
treated with the Ponseti method start walking, comparing it to a control group, and
to determine other factors related to the gait start in these patients.
Methods
This was a case-control study carried out through active search in the electronic
system of outpatient visits for patients with a clubfoot diagnosis (International
Classification of Diseases [ICD]-10 Q660 - Congenital talipes equinovarus) and in
the surgical system for procedures registered as “surgical treatment of congenital
clubfoot”, from July 2012 to July 2016, in a pediatric orthopedics reference hospital.
The research project was approved by the institutional Medical Ethics Committee.
Medical records were evaluated according to gender, laterality, age at the beginning
of treatment, number of plaster cast changes, tenotomy requirement and age in which
it was performed, history of recurrence (reappearance of one or more of the characteristic
deformities requiring treatment), age at gait start, supplementary surgical procedures
and follow-up time at the institution. Patients with PTC born with < 37 weeks of gestation,
starting treatment after 6 months of age, previously treated at another facility and
presenting other orthopedic problems that might interfere with motor development were
excluded. Patients followed-up for < 24 months were also excluded. Parents and/or
caregivers were contacted by phone for data confirmation and were specifically asked
about the exact moment of gait start. If accurate information was lacking or if the
parents/caregivers did not know the answer, the subject was excluded. The sample size
of the study group was defined by convenience and was formed by the total number of
eligible patients during the research period.
The control group consisted of 100 walking children, with an average age of 3.5 years
old, with no musculoskeletal conditions or other factors that could delay gait start,
who were with their parents waiting for being seen at the pediatric emergency room
of this hospital during the study period. The lack of accurate information or not
knowing how to answer was also an exclusion criterion for the control group.
Data were collected and stored in a Microsoft Excel (Microsoft Corporation, Redmond,
WA, USA) spreadsheet. Statistical analysis was performed using IBM SPSS Statistics
for Windows, Version 22.0 (IBM Corp. Armonk, NY, USA). For data presentation, descriptive
analysis was used; categorical variables were presented as frequency and percentage
mean values, whereas quantitative variables were described as mean and standard deviation
values. Quantitative variables, including number of plaster cast changes and age at
gait start from the study and control groups were compared with the Kolmogorov-Smirnov
normality test; parametric variables were analyzed by the Student t test. A 95% confidence
interval (CI) (p-value ≤ 0.05) was adopted.
Results
In total, 234 subjects were diagnosed with equinus varus deformity and treated during
the study period; 128 were excluded (60 due to other diagnoses, 40 due to lack of
information in the medical record and failure to contact, 16 who began treatment at
another facility, 5 who began treatment after 6 months old and 7 born prematurely).
Out of the 106 patients who met the inclusion criteria, 9 were excluded because their
parents were unable to answer or had doubts about gait start; as such, the study group
consisted of 97 patients ([Fig. 1]). The mean follow-up time was 48.9 ± 13.3 months (ranging from 26 to 73 months).
Fig. 1 Inclusion and exclusion criteria for the study.
In the study group, 64 patients (66%) were male and 51 patients (53%) had bilateral
involvement. Among those with unilateral deformity, the right foot was affected in
27 cases (59%). The mean age at treatment start was 4.0 ± 3.3 weeks (ranging from
1 to 22 weeks). The average number of plaster casts applied before tenotomy was 8.1
(ranging from 3 to 26 plasters). A total of 84 patients (87%) underwent an Achilles
tenotomy and the mean age at the procedure was 3.5 ± 2.1 months old. In 18 patients
(19%), the deformity recurred before gait start; all of these subjects had undergone
percutaneous tenotomy and at least 1 new series of manipulations and plasters (1 to
4 changes) followed by resuming the usage of the orthosis. Of these, three required
a new Achilles tenotomy and four required surgical releases before gait start (including
two posterior releases, one posteromedial release and one posteromediolateral release).
The average age at which study group patients started walking was 14.7 ± 3.2 months
(ranging from 9 to 26 months). The control group, consisting of 100 children (58 females
and 42 males), started walking at an average age of 12.6 ± 1.5 months old (ranging
from 10 to 16 months old). The difference in mean values from each group, of 2.1 months,
was significant (p < 0.05). Although the exclusion of patients with recurrence (n = 18) reduced the difference between mean values (1.7 months), it remained significant
(p < 0.05).
[Table 1] shows the influence of patient- and treatment-related variables on gait age in the
study group. Age at the start of treatment was significantly related to late gait,
with patients aged > 3 weeks at the beginning of treatment starting walking on average
1.5 months after those who started therapy earlier (mean, 15.7 versus. 14.2 months;
p < 0.05); subjects with > 7 plaster cast changes began to walk on average 2.3 months
later than those with a lower number of cast changes (mean, 15.8 versus 13.5 months;
p < 0.05); patients who relapsed walked 2.4 months later compared to those who did
not relapse (mean, 16.7 versus 14.3 months; p < 0.05); finally, subjects who did not undergo an Achilles tenotomy walked 1.2 months
later than those who required the procedure (mean, 14.9 versus. 13.7 months; p < 0.05). Patients starting treatment at 3 weeks old or more required, on average,
2.2 more plaster changes than those who started earlier (8.9 versus. 6.7 plaster changes;
p < 0.05).
Table 1
|
Number of patients (%)
|
Age at gait start (months)[*]
|
P Value[**]
|
|
Total number of patients
|
97 (100%)
|
14.7 ± 3.2
|
N/A
|
|
Gender
|
|
|
|
|
Male
|
64 (66%)
|
14.7 ± 3.1
|
0.13
|
|
Female
|
33 (34%)
|
14.8 ± 3.3
|
|
|
Laterality
|
|
|
|
|
Unilateral
|
46 (47%)
|
14.0 ± 2.8
|
0.94
|
|
Bilateral
|
51 (53%)
|
15.4 ± 3.3
|
|
|
Age at treatment start (weeks)
|
|
|
|
|
≤ 3
|
63 (65%)
|
14.2 ± 2.2
|
< 0.05
|
|
> 3
|
34 (35%)
|
15.7 ± 3.7
|
|
|
Number of plaster changes
|
|
|
|
|
≤ 7
|
45 (46%)
|
13.5 ± 2.6
|
< 0.05
|
|
> 7
|
52 (54%)
|
15.8 ± 3.2
|
|
|
Recurrence
|
|
|
|
|
Yes
|
18 (19%)
|
16.7 ± 4.0
|
< 0.05
|
|
No
|
79 (81%)
|
14.3 ± 2.8
|
|
|
Achilles Tenotomy
|
|
|
|
|
Yes
|
84 (87%)
|
13.7 ± 2.1
|
< 0.05
|
|
No
|
13 (13%)
|
14.9 ± 3.3
|
|
Patients with bilateral involvement walked an average of 1.4 months later than patients
with unilateral involvement (nonsignificant difference, p = 0.94). Male subjects started walking 0.1 month before females (p = 0.13).
Discussion
During the last 30 years, the Ponseti method became the treatment of choice for clubfoot.
It is considered a highly effective, fast method, with low morbidity compared to previous
treatments; in addition, it has been shown to provide high satisfaction, with almost
normal mobility and aspect. Parents have easy access to information about this method
through the internet and social media, and they frequently ask about the impact of
the treatment or of the deformity on motor development, specifically gait development.
Population studies with healthy children have shown that they begin to walk at an
average age ranging from 11.7 to 12.8 months old. In 2006, the World Health Organization
(WHO) carried out a study with healthy children and found out that 50% walked at 12
months old and 90% at 14.4 months old. Recently, studies have evaluated the age at
gait start in patients with clubfoot: Sala et al.[10] (with 51 patients) observed an average age of 13.9 months old; Zionts et al.[11] (94 patients), 14.5 months old; and Aulie et al.[13] (93 patients), 14.1 months old; these authors, however, did not present a control
group for comparison.
As far as we know, no other Brazilian study has addressed this issue, and the aforementioned
papers might not be applied to our population. To better understand our patients with
PTC, we compared them to a control group of children with no neuromuscular conditions
who were treated for nonmusculoskeletal reasons at the same institution. We found
out that patients with PTC walked, on average, 2 months later than the control group
(14.7 versus 12.6 months). In the study group, 50% of the patients walked at 14 months
old and 90% at 18 months old.
We also studied factors that could influence age at gait start. As expected, delayed
treatment start resulted in delayed gait beginning (mean, 14.2 months ≤ 3 weeks old
versus 15.7 months > 3 weeks old); in addition, higher numbers of plaster cast changes
were reflected in later gait (average, 13.5 months old ≤ 7 changes versus 15.8 months
old > 7 changes). Relapsing patients also started walking later (mean, 16.7 months
old versus 14.3 months old). This finding could be attributed to the requirement of
additional plasters and extend time under full orthosis use.
Children that did not require an Achilles tenotomy tended to start walking later compared
to those who required it (mean, 14.9 months old versus. 13.7 months old). This result
may not be representative due to the small number of patients who did not require
tenotomy (n = 18/97). On the contrary, another study found a tendency of delayed gait in the
group submitted to tenotomy; however, the number of patients who did not required
a tenotomy was limited (n = 5/94).[11] There was also a relationship with younger age at the beginning of treatment and
a lower number of cast changes (6.7 casts, ≤ 3 weeks old versus 8.9 casts > 3 weeks
old).
No significant gender influence or clubfoot laterality was found. These findings agree
with previous studies.[10]
[11] Lööf et al.[14] also found no difference between clubfoot laterality when analyzing motor development
until the age of 5 years old.
One patient from the study group started walking at an extreme age, at 26 months old.
This patient, in addition to starting treatment after 5 months old, had recurrences
and underwent a posteromediolateral release at 22 months old. Even excluding patients
who needed supplementary procedures from the analysis, the significance of variables
did not change.
The reasons why children with idiopathic clubfoot walk later than other children are
open for speculation. Garcia et al.[9] suggested that early restrictions on lower extremities movement imposed by plasters
and orthoses can change the balance or strength of certain muscle groups. They also
hypothesized that PTC may be a marker for an underlying mild motor development dysfunction.
The present study was limited by its retrospective aspect, unmatching of groups according
to age, nonadoption of a classification of deformity severity and possible correlation
with treatment variables and outcomes, as well as the dependence on parents' report
on the age at gait start, which may have influenced data accuracy. The presence of
a control group was intended to minimize such influence. Despite this, the data found
are consistent with the few other studies in the literature and may be used by orthopedists
to guide parents on factors impacting gait development and age.
Conclusion
Patients with idiopathic clubfoot treated with the Ponseti method started to walk
independently approximately 2 months later than the control group. This delay was
related to later treatment start, greater number of plaster cast changes, recurrence
and failure to perform an Achilles tenotomy.
