Wounds with a retained foreign body (FB) are a frequent presenting complaint to Emergency Departments. It is important to identify and remove debris and FBs to promote optimal healing. The presence of a FB may not be obvious. Up to 38% of embedded objects are missed on the initial assessment and many of these are frequently missed because imaging was not performed at that time.1 The presence of an unrecognized FB can lead to infection, joint injury, loss of function, osteomyelitis, pain, tendon rupture, tenosynovitis, and vascular injury.2-7 Chronic FBs may lead to the formation of pyogenic granulomas.8 Certain soft tissue FBs have the capacity to migrate great distances months to years after the original injury, leading to increased morbidity and mortality from what originally was a benign FB.9 Assess patients presenting with chronic, recurrent, or delayed skin infections for the presence of an unrecognized FB. Failure to diagnose and treat a FB is a common cause of litigation against Emergency Physicians. A high index of suspicion and careful methodical examination, including appropriate imaging, must be undertaken to identify a FB.
It is important to be familiar with the characteristics of different types of FBs because they may have various pathologic consequences. This information is crucial in determining the urgency or necessity for removal, the imaging techniques required to identify the object, the approach to removal, and determination of whether specialty referral is needed. The successful removal of a FB requires a directed history and physical examination, appropriate imaging, adequate light, anesthesia, exposure, hemostasis, proper equipment, and patient cooperation. The removal of FBs from subcutaneous tissue can be a frustrating and time-consuming endeavor. The Emergency Physician will need to dedicate a reasonable uninterrupted time to attempt removal, provide wound care, and assure appropriate follow-up.
It is important to note that a new type of self-injury known as self-embedding behavior has recently been described in adults and adolescents.10 It involves the self-insertion of a FB into soft tissues. This behavior is relatively rare and is usually not a suicide attempt. Patients who self-embed most often have behavioral health diagnoses. This behavior indicates a much higher risk for this population to commit accidental or intentional suicide.11 It is the responsibility of the Emergency Physician to treat the injury and to provide appropriate referral for prompt psychiatric evaluation.
ANATOMY AND PATHOPHYSIOLOGY
Only a small percentage of wounds contain concealed FBs.12 The mechanism of injury may give some idea of the likelihood of a retained object.1 Crush wounds and puncture wounds, especially those involving the sole of the foot, as well as wounds deeper than 5 mm involving adipose tissue, are associated with a higher incidence of FBs that are often difficult to find.12 Motor vehicle accidents have a higher incidence of retained FBs compared to other injuries.13 Wounds caused by objects ...