110.
Treatment with botulinum toxin-A does not affect ankle joint
biomechanics during gait in children with cerebral palsy
Jesper Bencke, Derek Curtis, Hanne Bloch Lauridsen, Christian Wong, Søren
Anker Pedersen, Stig Sonne-Holm
Gait analysis lab, dept. of Orthopaedic Surgery Hvidovre Hospital; Gait
analysis lab, dept. of Orthopaedic Surgery, Hvidovre Hospital; Gait analysis
lab, dept. of Orthopaedic Surgery, Hvidovre Hospital; Dept. of Orthopaedic
Surgery, Hvidovre Hospital; Dept. of Pediatrics, Hvidovre Hospital; Dept. of
Orthopaedic Surgery, Hvidovre Hospital
Background:
In clinical practice, injections with botulinum toxin-A (BoNT-
A) are used to reduce the spasticity of the calf muscles in children with
cerebral palsy (CP), and thereby reduce equinus and improve function of the
ankle joint.
Purpose / Aim of Study:
The aim of the study was to investigate the effect of
BoNT-A injections in m.triceps surae on the kinematics and kinetics of the
ankle joint during gait in children with CP.
Materials and Methods:
The inclusion criteria were diagnosed unilateral or
bilateral CP, clinically measured spasticity treated with BoNT-A in m.triceps
surae of the affected leg(s) and pre- and post treatment clinical gait analysis.
Twenty-six children (mean age (SD) of 8.0 (2.8) yrs) with a total of 37
affected legs were included. The mean dose was 97.0 (50.7) units of botox
(
Allergan) giving a relative mean of 4.0 (2.0) units per kg bodymass (BM),
administered in 1 ml. dilutions injected in m.triceps surae as recommended by
the manufacturer. The biomechanical parameters A) dorsiflexion angle at
initial contact, B) peak dorsiflexion during stance and C) mean plantarflexor
moment during the initial 50 % of the stance phase were selected, as they
would hypothetically be associated with spasticity during gait.
Findings / Results:
No significant improvements were observed (A: 12.6(7.9)
to 11.4(8.9) degrees plantarflexion (P=0.24); B: 5.6(7.2) to 6.9(6.7) degrees
dorsiflexion (P=0.15); C: 0.52(0.18) to 0.50(0.19) Nm/kg.BM (P=0.30)).
Several factors that influence the clinical effects of BoNT-A have been
suggested. In the present study, the doses were administered in relatively small
dilutions and the injections were given without ultrasound guidance; this may
have influenced the clinical effects.
Conclusions:
No effect on ankle joint biomechanics could be found after
treatment with BoNT-A according to standard procedures.
