Arm flexion during ultrasound assists localization of an intramuscular etonogestrel contraceptive implant.

A nonpalpable etonogestrel implant was identified by high-frequency ultrasound in the biceps muscle 4-6mm below the skin. Active elbow flexion resulted in proximal movement of the implant relative to the ultrasound probe, suggesting localization in the muscle. This maneuver may assist in verifying intramuscular placement prior to surgical excision.