Objective: To investigate the accuracy of manual needle placement into gastrocnemius muscle (GCM) for botulinum toxin type A (BTX-A) injection in children with spastic cerebral palsy (CP).
Design: Prospective clinical study.
Setting: University-affiliated hospital.
Participants: A total of 272 injections in GCMs of 39 children with spastic CP who were scheduled to receive BTX-A injections in GCMs.
Intervention: Not applicable.
Main outcome measures: The accuracy of manual needle placement was checked against ultrasonography.
Results: The needle was accurately inserted into GCM muscles in 78.7% of cases. Accuracy was 92.6% into gastrocnemius medialis (GM) and 64.7% into gastrocnemuis lateralis (GL). Muscle thickness at the needle insertion site was significantly thinner in GL than GM. Accuracy of GL in the younger age group (<4y, 57.6%) was lower than in the older age group (> or =4y, 78.1%). For GM, accuracy in both younger and older age groups was good (>90%).
Conclusions: Injection of the toxin into GCMs through the use of anatomic landmark was acceptable in GM, but not acceptable in GL, especially in young children.