Differential Diagnosis for Right Ankle Injury
- Single most likely diagnosis
- Undisplaced Salter-Harris 1 fracture of the distal fibular physis with a vertically oriented fracture extending to the physis: This diagnosis is most likely due to the presence of bone marrow edema of 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.
- 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, and the fact that it is undisplaced is consistent with the lack of displaced fragments on the MRI.
- Stress fracture of the distal fibula: The bone marrow edema and linear region of low signal could also be consistent with a stress fracture, although the presence of a physis and the patient's age make a Salter-Harris fracture more likely.
- Do Not Miss diagnoses
- Osteonecrosis of the talus or distal fibula: Although there is no evidence of an osteochondral lesion on the MRI, osteonecrosis could present with similar symptoms and would be a serious complication if missed.
- Infection (e.g. osteomyelitis): Infection could present with bone marrow edema and would be a serious complication if not promptly treated.
- Ligamentous injury (e.g. deltoid ligament or syndesmotic injury): Although the MRI suggests that the ligaments are intact, a ligamentous injury could still be present and would be important to diagnose and treat promptly.
- Rare diagnoses
- Bone cyst or tumor (e.g. unicameral bone cyst, aneurysmal bone cyst): Although unlikely, a bone cyst or tumor could present with similar symptoms and would be an important diagnosis to consider if other diagnoses are ruled out.
- Kohler disease (osteochondritis of the navicular bone): This is a rare condition that could present with similar symptoms, although it is more commonly seen in the foot rather than the ankle.