To identify the effect of serial casting combined with Botulinum toxin type A (BTX-A) injection on spastic equinus foot.
Twenty-nine children with cerebral palsy who had equinus foot were recruited from the outpatient clinic of Rehabilitation Medicine. The children were divided into 2 groups, one of which received serial casting after BTX-A injection, and the other which only received BTX-A injection. Serial casting started 3 weeks after the BTX-A injection, and was changed weekly for 3 times. Spasticity of the ankle joint was evaluated using the modified Ashworth scale (MAS), and the modified Tardieu scale (MTS). Gait pattern was measured using the physician's rating scale (PRS).
The degree of ankle dorsiflexion and the MAS improved significantly until 12 weeks following the BTX-A injection in the serial casting group (p<0.001), while the BTX-A injection-only group improved until 6 weeks following injection (p<0.05). The combined group showed a significantly greater increase in the degree of dorsiflexion compared to the BTX-A injection-only group at post-injection weeks 6 and 12 (p<0.05). Three children (11.5%) suffered from foot ulcers as a complication caused by the serial casting.
Our study demonstrated that the effect of BTX-A injection with serial casting was superior and lasted longer than the effect of BTX-A injection only in patients with spastic equinus foot. We therefore recommend BTX-A injection with serial casting for the treatment of equinus foot. However, physicians must also consider the possible complications associated with serial casting.
Citations
We present a 50-year-old woman who sustained spastic left hemiplegia secondary to the right thalamic hemorrhage 6 years ago. She complained of persistent severe left calf pain after serial casting for the treatment of shortened plantar flexors of the left ankle. Two months later, magnetic resonance T1-weighted images showed diffuse high signal intensity involving the whole muscle bulk of the soleus and normal signal intensity of thin atrophied gastrocnemius. Needle electromyography of the soleus revealed myopathic patterns. Histologic findings of the soleus showed necrotic muscle fibers with phagocytosis, endomyseal collagen and fat deposition. We concluded that prolonged passive stretch of spastic plantar flexors of the ankle under serial casting induced soleus myopathy with segmental myonecrosis, and which developed left calf pain. Selective induction of soleus myopathy could be explained by the higher stretch tension produced by ankle dorsiflexion in the soleus compared to the gastrocnemius because of different proximal ends.