Approach to wooden foreign bodies in the hand using Point of Care Ultrasound.

Medical Student Clinical Pearl

Jefferson Hayre, Med II

Dalhousie Medicine New Brunswick

Detection and removal of a wooden foreign body is often a challenge and time consuming procedure. Failure to detect and remove, and subsequent retention in the soft tissue leads to increased morbidity through infection, pain, multiple clinical visits, and surgery.

Wood is radiolucent and therefore generally goes undetected in plain radiography. One study showed that only 15% of wooden foreign bodies were visible on plain radiography compared to metal (100%) and glass (96%).

Some studies of ultrasound has shown sensitivies of >89% and specificities of >93% in detection of wooden foreign bodies in soft tissue.

We were able to use ultrasound to detect a wooden foreign body (figure 1), as wells as it’s size (figure 2) and orientation. On ultrasound wooden foreign bodies appear as a hyperechoic foci with acoustical shadowing and a hypoechoic halo, usually only seen after 24 hours due to the inflammatory response.

Figure 1 – Wooden foreign body in the hand. Note the hyperechoic line and the acoustic shadow below.

Figure 2 – Measurement of a wooden foreign body in the hand. Using the measuring tools on the ultrasound machine we successfully measured the wooden foreign body to be 85mm.

In addition to removal of the foreign body, the patient’s tetanus immunization status must be reviewed. Immunization should be delivered to those patients who need it.

The wound should be cleaned with an iodophor or other antiseptic solution, and any jagged edges of the wound should be trimmed.

There is currently no solid evidence on the efficacy of prophylactic antibiotics in puncture wounds.

Further Reading on PoCUS for FB – Here

References:

Anderson MA, Newmeyer WL 3rd, Kilgore ES Jr. Diagnosis and treatment of retained foreign bodies in the hand. Am J Surg. 1982 Jul;144(1):63-7.

Baddour LM. Overview of puncture wounds. In: UpToDate, Sexton DJ (Ed), UpToDate, Waltham, MA. (Accessed on May 1, 2015.)