Background: Spastic hemiparesis in children is often combined with hyperlordosis, scoliosis and
reduced leg length.
Aim: Does botulinum toxin injections into psoas muscle have effect on leg length?
Method: 25 patients (mean age 6,9 years; range:3–10 years) with spastic hemiparesis received
39 injections of botulinum toxin A or B as one-side multi-level treatment (psoas,
gastrocnemius, soleus±medial hamstrings). 14 patients received one injection, 6 patients
two and 4 patients three. Injections were performed sonography guided and under analgosedation.
Dosage for psoas muscle were: 0,5–2,5 U/kg (mean 1,1 U/kg) Botox® or 35–50 U/kg Neurobloc®
or 5 U/kg Dysport®. Leg length measurement was performed 4–6 weeks following the injections.
Results: 13 injections (1 injection for 7 patients, 2 injections for 3 patients) improved
leg length by 0,5 (n=11) or 1cm (n=2). Dosage for psoas muscle in responders was 0,5–2,5
U/kg (mean:1,2 U/kg) Botox®.
Discussion: Leg length difference in children with spastic hemiparesis is not only a growth problem
but also caused by psoas spastic. No significant higher dosage were found between
responders and non-resonders. Evidence-based studies are needed to clarify ideal dosage
and progress of leg lengthening after repeated psoas injections in children with spastic
hemiparesis.
