DoctorA patient re-presents to the Emergency Department with a foreign body sensation in his heel after stepping on a broken window. Despite a negative xray and bedside ultrasound yesterday, the patient still believes that a small foreign body is still in there.  You are unable to find a foreign body despite excising the overlying skin with a scalpel and exploring with forceps.


Trick of the Trade

Use a punch biopsy instrument to excise the soft tissue


For non-cosmetically important and neurovascularly low-risk areas where there is a high suspicion for a small retained foreign body, you can use a small punch biopsy tool (1-2 mm diameter) directly over the maximally tender point to remove the foreign body. Apply LET or inject lidocaine with epinephrine before the biopsy. After excising the core, examine it for the presence of a foreign body.

Watch the YouTube video starting around 00:43 min to see how to use a punch biopsy tool. This example shows one with a 4 mm diameter, which may be too large for your procedure, but it illustrates the technique well.

Thanks to Dr. Matt Silver (Kaiser Permanente, San Diego Medical Center) for the tip. He recently removed a 1 mm x 1 mm glass shard from a patient’s heel using this technique despite a negative XR and US. Way to go!

Michelle Lin, MD
ALiEM Founder and CEO
Professor and Digital Innovation Lab Director
Department of Emergency Medicine
University of California, San Francisco
Michelle Lin, MD


Professor of Emerg Med at UCSF-Zuckerberg SF General. ALiEM Founder @aliemteam #PostitPearls at Bio:
Michelle Lin, MD