Differential Diagnosis for Midfoot Injury
Single most likely diagnosis
- Lisfranc injury or fracture not visible on initial X-ray: This is a common injury in the midfoot area, especially with a normal initial X-ray. The increase in pain and swelling over time, particularly forming a "goose egg," suggests a possible fracture or severe ligamentous injury that may not have been immediately apparent on the X-ray.
Other Likely diagnoses
- Contusion or bruising of the midfoot: The description of a "goose egg" suggests significant soft tissue injury, which could be a contusion or bruising of the midfoot area. This would explain the swelling and pain.
- Midfoot sprain: A sprain in the midfoot area could also lead to increased pain and swelling over time, especially if the patient continues to bear weight on the injured foot.
Do Not Miss (ddxs that may not be likely, but would be deadly if missed)
- Compartment syndrome: Although less common, compartment syndrome is a serious condition that can occur after any significant injury, including those to the midfoot. It is characterized by increased pressure within a muscle compartment, leading to nerve and muscle damage. The symptoms can include severe pain, swelling, and pallor, which might initially seem similar to other less severe conditions.
- Infection (e.g., cellulitis or abscess): If the skin was broken during the injury, there's a risk of infection. While less likely if the skin is intact, any sign of increasing redness, warmth, or swelling, especially with fever, should prompt consideration of an infectious process.
Rare diagnoses
- Tarsal coalition or stress fracture: These are less common conditions that could potentially cause midfoot pain and swelling. A tarsal coalition is an abnormal connection between two or more of the tarsal bones in the foot, which can cause pain and stiffness. A stress fracture, a small crack in a bone, could also occur in the midfoot, especially in athletes or individuals with repetitive stress on the foot.
- Neoplastic processes (e.g., bone tumor): Although extremely rare as a cause of acute trauma symptoms, a bone tumor could potentially weaken the bone structure, leading to a pathologic fracture or significant pain and swelling after a relatively minor injury.