Retained foreign bodies are a common and frequently complicated presentation in both the emergency department as well as outpatient medical offices. While retained foreign bodies are usually superficial, they can be missed even when a well-trained clinician performs a thorough history and physical. Therefore, retained foreign bodies are one of the leading causes of malpractice lawsuits in the emergency department. If not found, they can lead to inflammation, delayed healing, and damage to surrounding tissues. Organic objects, such as thorns, splinters, or spines, can cause severe inflammation, hypersensitivity reactions, and even infections. These infections are very resistant to antibiotic treatment and require surgical removal of the foreign body for definitive treatment.
Most foreign bodies are locatable during an extensive wound-probing physical exam. Imaging studies are necessary in cases of suspected but not identified foreign bodies. Imaging is especially necessary following the removal of multiple foreign body pieces or when wound exploration is not possible. Imaging modalities available for detecting foreign bodies include plain film radiographs, computed tomography (CT), magnetic resonance imaging (MRI), and ultrasound. Each modality has its strengths and weaknesses that vary depending on the composition material of the foreign body, as well as the object’s location.