Differential Diagnosis for High-Grade but Likely Full-Thickness Tear of the ATFL and Partial-Thickness Tear of the Calcaneofibular Ligament
- Single Most Likely Diagnosis
- Ankle Sprain: This is the most likely diagnosis given the description of the injury, which involves tears to the anterior talofibular ligament (ATFL) and calcaneofibular ligament, both of which are commonly injured in ankle sprains. The severity of the tears (high-grade and full-thickness for the ATFL, partial-thickness for the calcaneofibular ligament) is consistent with a severe ankle sprain.
- Other Likely Diagnoses
- Ankle Instability: Chronic or acute ankle instability could be a consideration, especially if the patient has a history of repeated ankle sprains or feels like their ankle is "giving way." The high-grade tear of the ATFL and involvement of the calcaneofibular ligament could contribute to this instability.
- Syndesmotic Injury: Although less common, a syndesmotic injury (involving the ligaments connecting the tibia and fibula above the ankle) could be considered, especially if there's suspicion of a more complex ankle injury. However, the primary focus on the ATFL and calcaneofibular ligament tears makes this less likely.
- Do Not Miss Diagnoses
- Fracture: It's crucial not to miss a potential fracture, especially an occult fracture that might not be immediately apparent on initial X-rays. A fracture could significantly alter the treatment plan and prognosis.
- Osteochondral Lesion: An osteochondral lesion of the talus or other bones in the ankle could be a serious condition that might not be immediately diagnosed with a focus on ligamentous injuries. These lesions involve both bone and cartilage and can be painful and debilitating.
- Rare Diagnoses
- Peroneal Tendon Injury: While less common than ligamentous injuries in the context provided, peroneal tendon injuries (tears or ruptures) could occur, especially with severe ankle sprains. These would typically present with pain and weakness on the outside of the ankle.
- Ankle Dislocation: Although rare and typically associated with more significant trauma, an ankle dislocation could be a consideration, especially if there's a suspicion of a more severe injury mechanism. The presence of ligamentous tears as described could be part of the dislocation injury pattern.