Ultrasonographic evaluation of needle electromyography insertion into the tibialis posterior using a posterior approach.

Abstract

To estimate the safety window for needle insertion in the posterior approach to the tibialis posterior by ultrasonography, particularly in a clinical setting. Cross-sectional study. University hospital. Healthy volunteers (108 legs, from 22 men and 32 women). Not applicable. Distance between the tibia and neurovascular bundles in the posterior aspect of the tibia on a transverse ultrasonographic scan. The safety window at the midpoint was significantly larger than the upper third (0.62-2.16 cm, average 1.47 ± 0.38 cm vs 0.51-1.62 cm, average 1.16 ± 0.31 cm). The depth at the midpoint was significantly more shallow than the upper third (1.57-3.16 cm, average 2.31 ± 0.34 cm vs 1.76-3.66 cm, average 2.52 ± 0.38 cm). Body weight, height, tibial length, and leg circumference showed positive correlation with the safety window at both points. The midpoint may be more favorable than the upper third for needle insertion to the tibialis posterior with a posterior approach.