Expected Results

Definition & Overview

Any type of puncture that affects not only the skin but also the muscles and/or tendon sheath is a potentially dangerous condition, especially if the object that created the puncture is left inside the body. The human body does not respond well to foreign objects. In fact, the immune system does everything it can to fight the object, but it can only do so much. If the object resides in the body for even a few hours, an infection can occur and wreak havoc on the surrounding tissue. If the infection enters the blood stream, it can result in a condition called sepsis, which can lead to septic shock and eventually, death. Due to the possibility of serious complications, doctors are very particular when diagnosing and treating puncture wounds. They need to ensure that no foreign bodies are left inside the body. The majority of these foreign objects are made of metal, glass, wood, or plastic. These can be divided into two categories: radiopaque and radiolucent. Radiopaque objects are materials that are visible or detectable using an x-ray imaging device. Radiolucent materials are more difficult to detect using x-ray because they allow radiation to pass through making them virtually undetectable. It is because of this that doctors seldom rely on radioactive imaging devices alone. Many hospitals are now relying on ultrasound devices, as these can detect both radiopaque and radiolucent materials.
Using ultrasound to detect foreign bodies is a skill that must be developed. Many emergency doctors are not only trained in foreign body removal but also in point of care ultrasound (PoCUS) as well. As a result, there have been significant improvements in the successful detection and removal of foreign bodies in muscle and tendon sheath at hospitals that use PoCUS as a primary modality in the removal of foreign objects in the body. Aside from ultrasound, other imaging devices, such as a computed tomography (CT) scan and magnetic resonance imaging (MRI), can also be used to detect a foreign object. However, such procedures are costly when compared to an ultrasound.

Who Should Undergo & Expected Results

Every patient who has suffered a puncture wound must be carefully assessed for the presence of foreign objects to avoid infection. This may happen after the provision of emergency care to treat the wound. If the patient does not notice any significant improvement of the wound after a few days of treatment, he or she should have the condition re-evaluated. In the past, the only way to find a foreign object was to look for it physically, which means that an exploratory surgical procedure would need to be performed. In such procedure, the surgeon would create a longer incision to extend the wound and probe the area for any foreign objects. This often results in additional trauma, blood loss, and longer healing time. With the use of an ultrasound device, doctors are able to avoid performing exploratory surgery as much as possible. The majority of foreign objects can be detected as well as the degree of penetration and exact location.

How Does the Procedure Work?

When a patient is brought into the emergency department with a puncture wound as a complaint, doctors typically perform a physical examination of the area to look for foreign objects and order an ultrasound evaluation of the puncture wound. Most, if not all, foreign objects are visible on an ultrasound. This is because they emit a different texture when compared to soft tissue. Moreover, doctors would also be able to detect the presence of an infection. Infections usually occur within 24 hours of a foreign body’s presence in the puncture wound. On an ultrasound image, an infection would appear like a halo surrounding the foreign object. To increase the accuracy of the procedure, the doctor will also obtain ultrasound images from both longtitudinal and transverse planes. Doing so would not only determine the presence of a foreign body, but also its dimensions and precise location. Once the object has been identified, the doctor will remove the object and close the wound. Such a procedure would require the use of an anaesthetic to numb the area. The procedure is performed using a needle localisation technique. The technique involves using an ultrasound to guide a needle through the skin and directly onto the foreign object. Anaesthesia will then be introduced. The doctor will then use a scalpel to create an incision in the skin and tissue large enough for the foreign object to pass through. The object is removed using forceps. After removing the object, the doctor will check the ultrasound once again to ensure that all the objects have been removed. If so, the doctor will clean the wound and close it using sutures.

Possible Risks and Complications

While ultrasound is one of the best ways to detect foreign bodies, it is important to understand that it may also detect natural occurrences as well. For instance, if the ultrasound indicates the presence of a halo, this could mean the presence of a foreign object with an infection at the surrounding area, or simply an infection without the presence of a foreign object. The situation is called a false-positive result. It is also important to understand that although ultrasound scans increase the possibility of detecting a foreign object, a doctor’s skill must not be discounted. This means that false-negative results are also possible. Should the condition fail to improve after some time, further diagnostic imaging procedures will be needed to detect such objects.


  • David Lewis, Aman Jivraj, Paul Atkinson, Robert Jarman;”My Patient is Injured: Identifying foreign bodies with ultrasound”; http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4760591/
  • Mohamed Ragab Nouh, Ahmed Mohamed Sabry Nasr, Mohamed Osama El-Shebeny; “Wooden splinter-induced extremity injuries: Accuracy of MRI evaluation”; http://www.sciencedirect.com/science/article/pii/S0378603X13000740
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