Stepping on a piece of glass is a common injury, often occurring when walking barefoot. Even small shards can puncture the skin and lodge in the underlying soft tissues. The consequences of a retained fragment can range from acute localized issues to chronic, long-term medical problems if it is not completely removed.
Acute Symptoms and Infection Risk
The body’s immediate response to a retained piece of glass is to initiate an inflammatory process at the injury site. This reaction is characterized by localized pain, tenderness, and discomfort, especially when pressure is applied. Within the first few days, classic signs of inflammation may appear, including redness, swelling, and warmth around the puncture wound.
The foot is susceptible to contamination because it is constantly exposed to the environment. A retained foreign body, such as glass, can introduce bacteria deep into the tissue, significantly increasing the risk of infection. If an infection develops, acute symptoms intensify, sometimes resulting in the formation of pus or drainage from the wound. Persistent or worsening pain and swelling, often accompanied by a feeling of heat, require medical attention.
Long-Term Foreign Body Reactions
If a glass fragment remains embedded for weeks or months, the body shifts from an acute inflammatory response to a chronic defensive reaction. Since glass is an inorganic material the body cannot break down, the immune system attempts to isolate the foreign object. This isolation often leads to the formation of a foreign body granuloma—a localized mass of immune cells and fibrous tissue.
While the granuloma walls off the glass, this mass can cause chronic pain, tenderness, and a palpable lump under the skin. Retained fragments in the soft tissue are subject to forces from walking, which can cause them to migrate over time. This migration introduces the risk of damage to adjacent anatomical structures, such as nerves or tendons. Nerve damage can result in chronic numbness, tingling, or persistent pain, while tendon injury may impair the normal function and mobility of the foot.
Medical Assessment and Safe Removal
Self-removal is only appropriate for superficial fragments that are clearly visible and easily accessible. Any deep puncture, persistent symptom, or inability to see the object requires professional medical help. A healthcare provider will conduct a thorough examination and review the tetanus vaccination status, as a puncture wound may necessitate a booster.
To locate the fragment, diagnostic imaging is necessary. X-rays are the initial tool of choice because glass is radiopaque, meaning it shows up well, and fragments as small as two millimeters can be detected. If an X-ray is negative but symptoms suggest a retained fragment, an ultrasound is used as a second-line imaging method. Ultrasound is effective for locating smaller, non-radiopaque, or superficially embedded objects, and it provides real-time guidance for precise removal. Professional removal is performed under local anesthesia in a sterile environment. This procedure may involve a minor surgical incision, aided by imaging, to ensure complete extraction and minimize damage to surrounding soft tissues.