Differential Diagnosis for Right Ankle Injury
Single Most Likely Diagnosis
- Undisplaced Salter-Harris 1 fracture with a vertical component: This diagnosis is most likely due to the presence of bone marrow edema in the distal fibula, a linear region of low signal extending from the physis distally, and minimal bone marrow edema superior to the physis, all of which are consistent with a Salter-Harris 1 fracture. The fact that the physeal plate is not widened but has similar signal to other physes, and the absence of ligamentous injury, further supports this diagnosis.
Other Likely Diagnoses
- Undisplaced fracture of the lateral malleolus: The presence of bone marrow edema and a linear region of low signal in the lateral malleolus suggests a fracture, which is consistent with the patient's tenderness over the lateral malleolus.
- Stress fracture: Although less likely, the presence of bone marrow edema could also suggest a stress fracture, particularly if the patient has a history of repetitive stress or overuse.
Do Not Miss Diagnoses
- Osteonecrosis: Although the MRI does not show evidence of osteonecrosis, it is a potential complication of fractures and could have serious consequences if missed. The presence of bone marrow edema could potentially mask early signs of osteonecrosis.
- Infection: Infection is a rare but serious complication of fractures, and could be masked by the presence of bone marrow edema. Although there is no evidence of infection on the MRI, it is essential to consider this possibility, particularly if the patient has a fever or other signs of infection.
Rare Diagnoses
- Osteochondritis dissecans: Although the MRI does not show evidence of an osteochondral lesion, osteochondritis dissecans is a rare condition that could potentially cause similar symptoms. It is characterized by a fragment of cartilage and bone becoming detached from the surrounding bone.
- Bone cyst or tumor: Although rare, bone cysts or tumors could potentially cause similar symptoms and findings on MRI. However, the presence of a fracture and the patient's age make this diagnosis less likely.