How can I differentiate between a sprain and a fracture in a patient with an ankle injury?

Differentiating between an ankle sprain and a fracture in a patient presenting with an ankle injury primarily relies on a thorough clinical assessment, although definitive diagnosis often requires imaging ¹ (Wedmore and Charette, 2000).

Key indicators that may suggest a fracture over a sprain include:

• Inability to bear weight: If the patient cannot bear weight immediately after the injury and in the emergency department, this raises suspicion for a fracture (Wedmore and Charette, 2000).
• Localized bony tenderness: Significant tenderness upon palpation over specific bony prominences, such as the posterior edge or tip of either malleolus, the navicular bone, or the base of the fifth metatarsal, is a strong indicator for a potential fracture (Wedmore and Charette, 2000). Foot fractures are frequently misdiagnosed as ankle sprains, emphasizing the need for careful palpation (Judd and Kim, 2002).
• Gross deformity: Any visible deformity of the ankle or foot is highly suggestive of a fracture or dislocation (Wedmore and Charette, 2000).

Both sprains and fractures can present with pain, swelling, and bruising, making initial differentiation challenging based solely on these symptoms (Wedmore and Charette, 2000).

For a definitive diagnosis, especially when clinical suspicion for a fracture is high based on these criteria, X-rays are typically required (Wedmore and Charette, 2000). In children, ankle injuries can involve growth plates, and careful evaluation is necessary (Solove and Turcotte Benedict, 2020).

If a fracture is confirmed, management will follow specific guidelines for non-complex or complex fractures ¹,³. Rehabilitation is a crucial part of recovery for both sprains and fractures ².