Needle Insertion Into the Tibialis Posterior: Ultrasonographic Evaluation of an Anterior Approach

Rha D-W, Im SH, Lee SC, Kim S-K. Needle insertion into the tibialis posterior: ultrasonographic evaluation of an anterior approach.ObjectiveTo investigate the ultrasonographic anatomy of the lower leg for safe and accurate needle placement into the tibialis posterior using the anterior approach.DesignCross-sectional study.SettingUniversity rehabilitation hospital.ParticipantsHealthy volunteers (N=62; 30 men, 32 women).InterventionsNot applicable.Main Outcome MeasuresThe safety window (the tibia to the neurovascular bundle) and the depth to the midpoint of the safety window (skin to the tibialis posterior) at the upper third and the midpoint of the tibia were measured with a transverse ultrasonographic scan.ResultsThe safety window at the upper third of the tibia was significantly larger than that at the midpoint (P<.01). The safety window ranged from .64cm to 2.13cm at the upper third tibialis point and from .32cm to 1.30cm at the midpoint. The depth to the tibialis posterior at the upper third of the tibia was significantly deeper than that in the midpoint (P<.01). The depth ranged from 2.47cm to 4.66cm at the upper third tibias point and from 2.35cm to 4.28cm at the midpoint.ConclusionsUltrasonography is a useful tool in measuring the safety window and the depth to the tibialis posterior using the anterior approach. Considering the safety window, we suggest the needle placement at the upper third point of tibia rather than that at the midpoint.