Is the outcome of diagnostic nerve block related to spastic muscle echo intensity? A retrospective observational study on patients with spastic equinovarus foot

Objective: To investigate the relationship between spastic calf muscles echo intensity and outcome of tibial nerve motor branches selective block in patients with spastic equinovarus foot. Design: Retrospective observational study. Patients: Forty-eight patients with spastic equinovarus foot. Methods: Each patient was given selective, diagnostic nerve block (lidocaine 2% perineural injection) of the tibial nerve motor branches. All patients were evaluated before and after block. Outcomes: spastic calf muscles echo intensity measured with the Heckmatt scale; affected ankle dorsiflexion passive range of motion; calf muscles spasticity measured with the modified Ashworth scale and the Tardieu scale (grade and angle). Results:  As to the outcome of tibial nerve selective diagnostic block (difference between pre- and post-block condition), the Spearman correlation showed a significant inverse association of the spastic calf muscles echo intensity with the affected ankle dorsiflexion passive range of motion (P=0.045.