The Influence of Botulinum Toxin A Injections into the Calf Muscles on Genu Recurvatum in Children With Cerebral Palsy

Abstract

Background With cerebral palsy (CP), an equinus deformity may lead to genu recurvatum. Botulinum toxin A (BtA) injection into the calf muscles is a well-accepted treatment for dynamic equinus deformity. Questions/purposes The purpose of this study was to determine whether BtA injections into the calf muscles to decrease equinus would decrease coexisting genu recurvatum in children with diplegic CP. Methods In a retrospective study, 13 children (mean age, 5 years) with spastic diplegic CP showing equinus and coexisting primary genu recurvatum, who were treated with BtA injections into the calf muscles, were included.Evaluations were done before and 6 and 18 weeks after intervention using three-dimensional gait analysis and clinical examinations according to a standardized protocol. Basic statistical analyses (power analysis, ANOVA) were performed to compare genu recurvatum before treatment and at 6 and 18 weeks after injection with BtA.

Botulinum Toxin Type A Injection for Spastic Equinovarus Foot in Children with Spastic Cerebral Palsy: Effects on Gait and Foot Pressure Distribution

“…A number of studies have demonstrated the benefits of BoNT-A injection for dynamic equinus foot in patients with CP. 1 2 13 14 15 19 34 35 However, previous studies on the effects of such an injection for dynamic equinovarus foot have rarely addressed children with CP. For dynamic equinovarus foot, TP and calf muscles are the target muscles for BoNT-A injection.…”

“…In children with CP with dynamic equinus foot, a number of studies have previously demonstrated significant improvements in ankle kinematic parameters 10 11 12 13 15 39 and kinetic data 10 12 using computerized gait analysis after BoNT-A injection into the calf muscles. The significant improvements in ankle kinematic data shown in our study were due to the reduction of ankle plantarflexor tone after injection, which contributed to significant improvement in ankle dorsiflexion during gait.…”

“…On the other hand, the secondary effects of BoNT-A injection for equinus foot on the proximal joints are inconsistent in the literature. After injection into the calf muscles for equinus foot, several studies have demonstrated significant changes in knee kinematic data, 12 13 while others have not shown significant effects on the knee joint. 13 39 In addition, the secondary effects of BoNT-A injection on the hip joint have been rarely investigated in children with CP.…”

“…After injection into the calf muscles for equinus foot, several studies have demonstrated significant changes in knee kinematic data, 12 13 while others have not shown significant effects on the knee joint. 13 39 In addition, the secondary effects of BoNT-A injection on the hip joint have been rarely investigated in children with CP. Only one study has demonstrated a significant secondary effect on the hip joint, specifically an increase in hip flexion at initial contact and hip excursion after injection into the calf muscles, characterized by a more flexed hip during the entire gait cycle.…”

“…Previous studies using computerized gait analysis after BoNT-A injection for equinus foot in children with CP revealed several significant changes in ankle kinematic data and kinetic data. 8 10 11 12 13 14 15 Although used as a gold standard for planning and assessing the outcome of corrective musculoskeletal surgery in CP patients, the computerized gait analysis system has limited ability to reveal significant changes in foot deformities in the frontal plane such as valgus and varus deformities after therapeutic intervention. 16 17 …”