Effectiveness of modified ankle foot orthosis of low-temperature thermoplastics in idiopathic congenital talipes equino varus

Abstract

The aim of this study was to study the effectiveness of modified ankle foot orthosis fabricated from low-temperature thermoplastics, as an alternative orthosis for the maintenance of correction in idiopathic congenital talipes equino varus (CTEV) deformity. The study was conducted in infants after the completion of the Ponseti serial manipulation and cast treatment, with or without, percutaneous Achilles tenotomy. Both male and female infants with unilateral or bilateral CTEV deformity were included in our study. A custom-made modified ankle foot orthosis was fabricated on the day of the removal of the last plaster of Paris cast. Initial clinical assessment, including medical history, Pirani score, modified Dimeglio score, clinical method of evaluating tibial torsion, ankle and foot range of motion were carried out on the day of the fabrication of the orthosis. Follow-up assessments were carried out at regular intervals for a duration of 6 months. All infants were provided with a set of exercises in the outpatient department three to five times per week, and other sessions were carried out by the caregivers in the form of home exercise programmes, daily every 2 h. In our study, we had 40 infants. Of these, 12 were lost to follow-up. The remaining 28 infants (22 males and six females) were included in the study. Of the 28 infants, six were left sided, seven were right sided and 15 were bilateral cases. The age at which cast treatment was initiated ranged from 1 week to 8 months, and the age at which modified ankle foot orthosis was given ranged from 1 month 1 week to 15 months. The average number of plaster of Paris casts given was six. Sixteen infants required tenotomy. We found that there was a significant reduction in the Pirani and modified Dimeglio scores from baseline to the third and to the sixth months, that is, improvement and/or maintenance of the baseline scores of Pirani and modified Dimeglio was observed (P<0.05). The difference in the Pirani and modified Dimeglio scores was not significant in the posttreatment results in cases with and without Achilles tenotomy (P>0.05). The difference was independent of the side (left or right) (P>0.05). The mean tibial internal torsion in left foot cases was 14 degrees and in right foot cases was 15.13 degrees . Improvement was observed in the range of motion of both the left and right ankle and foot movements, specifically ankle dorsiflexion. In conclusion, a modified ankle foot orthosis of low-temperature thermoplastics, designed at our centre, is an effective alternative orthosis to maintain the correction of both unilateral and bilateral idiopathic CTEV deformity after the Ponseti cast treatment.